Re: [time-nuts] Source for DC-blocking 50-ohm terminators? (Spectracom 8140)
Julien, I have a Spectracom 8140 also, and have the same problem. I found a couple of the 10 MHz Line Taps on Ebay at reasonable price, however, I would like to eliminate them. The +12C at the 10MHz outputs is the power for the line taps, which are meant to drive long distribution lines in a plant. If you don't have a copy of the manual for the 8140, you can download it from Spectracom's web site (https://spectracom.com/sites/default/files/document-files/8140_manual.pdf). Look at the schematic, you can see that you can remove the inductors associated with the outputs (L9, L10, L11 and L12), and the DC will be gone from the outputs. Much easier and cheaper than DC blocks, and safer for your equipment in case you forget to install a DC block.. Dave M [time-nuts] Source for DC-blocking 50-ohm terminators? (Spectracom 8140) Julien Goodwin Sun, 03 Jun 2018 21:10:45 -0700 I'm looking at using a Spectracom 8140 for 10Mhz distribution, and they specify using a DC-blocking 50-ohm terminator on each run.These seem to be odd enough that none of my usual sources have them (75-ohm DC-blocking terminators yes, 50-ohm, no). While it's easy enough to chain a DC block and a terminator, I'd prefer a single module I can more obviously label as the line termination. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Phase Noise Measurement Fundamentals Webcast from Keysight
I just got this email from Keysight announcing a web seminar on phasse noise testing. Thought it might be of interest to the group. Phase Noise Measurement Fundamentals Webcast Wednesday, May 16 . 10 a.m. PT/1 p.m. ETLearn More Register This 60-minute webcast will cover the fundamentals of phase noise measurements and its impact on the performance of receivers and systems being designed. Join Keysight's Bob Nelson, Senior Applications Engineer with over 20 years of experience in test and measurement, to learn more about: a.. Phase noise and how it affects your signals b.. Making accurate phase noise measurements c.. Comparing and understanding the trade-offs of the various phase noise measurement techniques We look forward to your participation. Sincerely, Eileen Meenan Market Initiative Manager Keysight Technologies Unable to attend? Register anyway and we'll send you the link to the recorded event. Contact US 1 800 829- Canada +1 877 894-4414 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] accurate 60 hz reference chips/ckts
National Semi used to make a chip (MM5369) that was designed specifically for that task, but it's long out of production. I don't know of any off-the -shelf 60Hz generators, but it's pretty easy to build one. Here are a couple of web pages that will generate a 60Hz crystal controlled signal. http://electronicsmaker.com/em/admin/pdf/circuit_idea/60Hz%20CRYSTAL%20CONTROLLED%20TIME%20BASE.pdf http://www.electronicecircuits.com/electronic-circuits/50hz-60hz-frequency-generator-circuit-using-crystal-oscillator Accuracy of the generated 60Hz will depend, of course, upon the tempco of the crystal, the complete oscillator circuit itself, and on the accuracy to which you adjust the oscillator's frequency. Cheers, Dave M Patrick Barthelow wrote: PIcked up a couple of large size Radio Shack 63-960 LED clocks with Settable alarm, at local Goodwill store. $3.00 ea work great see across room, loud Alarm, etc... Barely missed, by seconds, getting a classic Hallicrafters General coverage receiver (not like say, S-38) but a larger light green metal box. nearly perfect condx. $25.00 with the famous h logo speaker probably late 50s Vintage. :-( Dang... Checked LED clocks by ear and eye with WWV, They drift a few seconds in the course of a few days, and wander back and forth. Thought AC mains frequency was tighter than that. They use an LM 8560 Clock chip. Uses a switchable AC mains frequency reference pin 50/60 hz. Want to provide an accurate (relatively accurate) 60 hz reference to the chip. Some room inside for custom modifications. Does a TCXO or similar exist in a small package that provides 60 hz ticks? Best, 73, Pat Barthelow AA6EG apol <apollo...@gmail.com>lo...@gmail.com *"The most exciting phrase to hear in Science, the one that heraldsnew discoveries, is not "Eureka, I have found it!"but:* "That's funny..." Isaac Asimov ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Vectron Labs 100MHz OCXO datasheet?
Neil Smith G4DBN wrote: Does anyone have any technical info on a Vectron Laboratories 100MHz OCXO, model 724Y3067 (part number A61583-1) please? Can’t find a datasheet on the current Vectron Inc website and my Google-fu is weak today. Neil The 724Y is a model in Vectron's CO-724 series. I've sent a copy of the datasheet directly to Neil Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Looking for info on Austron 1100-1 OXCO
Thanks for the info, Roger Dave M Roger Tilsley wrote: Greetings Dave, While I do not know the Austron 1100 oscillators, I have experience of Austron 1120 oscillators. I suspect the 1100 and 1120 are very similar. I am sending a data sheet for the 1120 and an operating spec for the 1120 L. Note that the 1120Ls does not have varicap fine frequency trimming. Austron were consistent with the pin-out for IO plug-in oscillators. The 1120s have soldered base to can joints and I have successfully take them apart for repair (extra capacitance!). The 1120s are very good. Regards, Roger T. On Fri, 30 Jun 2017 12:14:14 -0500, "Dave M" <dgmin...@mediacombb.net> wrote: Does anyone have any data on the Austron 1100-1 5MHz OXCO? Pinout & specs would be great. Thanks! Dave M ___ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Looking for info on Austron 1100-1 OXCO
Does anyone have any data on the Austron 1100-1 5MHz OXCO? Pinout & specs would be great. Thanks! Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] ebay posting
Bert Kehren via time-nuts wrote: Since I have a Tracor 527E I am not going to bid on the following link. I have bought two items with very good results and have nothing to do with the seller. I suspect based on his location that this is NASA material. The unit has a FRK Rb in it. Bert Kehren _http://www.ebay.com/itm/Argosystems-AS210-RM-Rubidium-Time-Frequency-Calibr ation-System/332265338742?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m14 38.l2649_ (http://www.ebay.com/itm/Argosystems-AS210-RM-Rubidium-Time-Frequency-Calibration-System/332265338742?ssPageName=STRK:MEBIDX:IT&_trksid=p20603 53.m1438.l2649) A friend has a number of the AS210-04 Digital Delay Generators. We've been unable to find any info on the unit. Does anyone have a link for a downloadable copy of the manual, or at least the schematic, for these items? Would love to get a PDF of the complete AS210 system manuals Thanks!! Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Fw: HP 1820-0313 4.2V Logic (Flip-flop)
Dave M wrote: Poul-Henning Kamp wrote: In message <1580810140.741428.1494966823...@mail.yahoo.com>, Ulf Kylenfall via time-nut s writes: That the 1820-0313 is unobtanium I can understand.Has anyone created an equvalent based on discretesor is there a suitable SMD "single" flip-flop like single gatesthat could be suitable? I did a divider board for the LED clock: http://phk.freebsd.dk/hacks/HP5065A/20160112_working_clock/index.html The 1820-0313 is a Fairchild 931HC or Motorola MC931G DTL clocked flipflop. I think if you toy with a TTL or CMOS JK-flipflop; it should work with no issues. The only caveat would be the 4.2V Vcc. The DTL logic was spec'ed to run at 5V, same as TTL, but don't know how TTL logic would work at 4.2V. . You might find a 3.3V flipflop and zener the 4.2V Vcc down to 3.3V and build it all onto a small piece of perfboard. I've attached a copy of the pertinent pages from my old Motorola databook (1966 Motorola Semiconductor Handbook) directly to Poul. Dave M Oops... I meant to say that I sent a copy of the datasheet to the OP Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 1820-0313 4.2V Logic (Flip-flop)
Poul-Henning Kamp wrote: In message <1580810140.741428.1494966823...@mail.yahoo.com>, Ulf Kylenfall via time-nut s writes: That the 1820-0313 is unobtanium I can understand.Has anyone created an equvalent based on discretesor is there a suitable SMD "single" flip-flop like single gatesthat could be suitable? I did a divider board for the LED clock: http://phk.freebsd.dk/hacks/HP5065A/20160112_working_clock/index.html The 1820-0313 is a Fairchild 931HC or Motorola MC931G DTL clocked flipflop. I think if you toy with a TTL or CMOS JK-flipflop; it should work with no issues. The only caveat would be the 4.2V Vcc. The DTL logic was spec'ed to run at 5V, same as TTL, but don't know how TTL logic would work at 4.2V. . You might find a 3.3V flipflop and zener the 4.2V Vcc down to 3.3V and build it all onto a small piece of perfboard. I've attached a copy of the pertinent pages from my old Motorola databook (1966 Motorola Semiconductor Handbook) directly to Poul. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Berkeley Nucleonics Phase Noise Testing system webinar
Thought this might be of interest --- I own couple BNC (Berkeley Nucleonics Corp) instruments, and get ads from them occasionally. Perhaps someone in the group might be interested, since we all are interested in measuring and limiting phase noise in our sources. Obviously, they are promoting their technology, but they might have something new and interesting to offer. Take advantage of this opportunity to register for BNC's Evolution Series webinar focusing on our highest performance Phase Noise Testing system yet, the model 7330. This webinar being held on Wednesday, May 17th at 10am PST offers a glimpse into the future of phase noise testing technology and its direction. Be ahead of the curve with RF Instrumentation for the modern engineer. A complete turnkey PC-Driven solution providing measurements from 5MHz to 33GHz with offsets from .01 Hz to 100 MHz Users enjoy the portability, durability, and reliability of an "interface-less" PC-driven package designed with the user in mind. Unrivaled and powerful performance that is extremely easy to use, with measurements performed with a simple click of a button. Advanced measurement tools provided are: Pulsed measurements, Amplitude Measurements, Ultra-low noise internal references or external references with a -185dBc/Hz noise floor, Absolute and additive measurements together. Register using this Link Come see the best solution for VCO characterization, ATE requirements, Amplitude measurements, and Pulsed capabilities! ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SR620 Failure Code.
Complete manuals, including service info, are available on the net. Google for SR620 manual Dave M W2GPS wrote: Time-nuts, My SR620 has started reporting "test error 34" on power-up and will do nothing after that. Does anyone know what that message means? I have a reasonable lab and I would try to repair the unit myself but I have no documentation. Is service documentation available or should I just ship it back to Stanford Research to get fixed? Rick W2GPS ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Prologix USB-GPIB Controller
That's interesting... My memory chips must be experiencing bit failures lately. This isn't the first time it's happened over the past few weeks. I sit (more comfortable than standing) corrected. Thanks for the admonition. Dave M Bob Camp wrote: Hi That’s been my experience as well over the last few decades, based on using a variety of adapters. Bob On Oct 7, 2016, at 5:36 PM, John Miles <j...@miles.io> wrote: thanks for the offer, Geo We've already found a new Prologix unit at much less than retail. I'm not familiar with the NI units, and have seen postings that they are tempermental with some instruments. I've mentioned before that NI adapters are the _least_ temperamental of all of them. -- john, KE5FX Miles Design LLC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Prologix USB-GPIB Controller
thanks for the offer, Geo We've already found a new Prologix unit at much less than retail. I'm not familiar with the NI units, and have seen postings that they are tempermental with some instruments. I know the Prologix units work with the friend's equipment; that's why we specifically went shopping for a Prologix. Dave M George Dubovsky wrote: I have a real NI GPIB-USB-HS if he'd be interested in that. Prolly cheaper than a new Prologix. geo On Fri, Oct 7, 2016 at 3:15 PM, Dave M <dgmin...@mediacombb.net> wrote: Does anyone happen to have a Prologix USB-GPIB Controller available for sale? One of my friends needs one for his bench. He is retired and on a limited budget, and would like to find one cheaper than MSRP from Prologix. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Prologix USB-GPIB Controller
Does anyone happen to have a Prologix USB-GPIB Controller available for sale? One of my friends needs one for his bench. He is retired and on a limited budget, and would like to find one cheaper than MSRP from Prologix. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Rare HP clock
It's Ebay item 351861979923 Dave M KA2WEU--- via time-nuts wrote: I can not find the item on EBAY , Ulrich In a message dated 10/3/2016 11:51:24 A.M. Eastern Daylight Time, jn6...@gmail.com writes: According to my -hp- catalogs it was available only in rack-mount form, not in a cabinet. That suggests it was being marketed to a specific small group so it may indeed have been manufactured in small quantities. Jeremy On Monday, October 3, 2016, Magnus Danielson <mag...@rubidium.dyndns.org> wrote: Since you force-feed it 100 KC at the back, no crystal would be needed. Cheers, Magnus On 10/03/2016 04:57 PM, paul swed wrote: Also notice the missing something on the far right that may have been some xtal or something. I went to look for a manual to see what it was. No luck though the manual may be out there. I would say its rare, but the price is going to most likely go up because it is a bid. Great winter project but not worth a lot of $ to me at least. Good luck to whoever gets it. Regards Paul WB8TSL On Mon, Oct 3, 2016 at 10:42 AM, Bob Camp <kb...@n1k.org> wrote: Hi Rare is indeed a relative term. I would certainly call it rare, but others might not. You likely would be the only person on your block who has one :) In the picture of the innards you can see a number of fine old wet slug tantalum capacitors. One even appears to have goo leaking out of it. I’d plan on having a lot of fun tracking down this or that part to get it working reliably. On Oct 3, 2016, at 10:27 AM, Jeremy Nichols <jn6...@gmail.com> wrote: I saw that. Is it really rare or just hype by the luster? Jeremy On Monday, October 3, 2016, Bert Kehren via time-nuts < time-nuts@febo.com> wrote: There is a rare HP clock on ebay for the collectors among us. I am to old. RARE HP H20 115BR FREQUENCY DIVIDER & DIGITAL CLOCK STANDARD VINTAGE TEST Bert Kehren ___ time-nuts mailing list -- time-nuts@febo.com <javascript:;> To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. -- Sent from Gmail Mobile ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow the instructions there. When the people fear the government, there is tyranny. When the government fears the people, there is liberty -- Thomas Jefferson Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Normal operating specs of a Morion MV89?
From my experience, your best and cheapest approach is to contact the seller and see if they will just send you a replacement. If the seller won't cooperate, and insists that you return the item, just close the issue and try to repair it, or buy another one. If you bought the MV89 from an Ebay seller, Ebay will require that you return the item by a traceable shipment, which will probably cost you more than the MV89 cost. Sorry to say that, but that's just the dimmer side of buying unknown items from across the big pond. Dave M Tim Lister wrote: On Wed, Sep 28, 2016 at 4:14 AM, Bob Camp <kb...@n1k.org> wrote: Hi You have one of the many MV89A’s with an output problem. To be absolutely sure of the output, you need to have the scope set to 50 ohm input. If it was set to Hi-Z, the output is likely even lower….. It seems that the scope is 1 MOhm input impedance and is not changeable. I will have to see if we have any 50 Ohm in-line terminators around that I can also borrow. Does anyone think that there is any value in trying to pursue a return and replacement with the ebay seller (being China, it's likely to be a long round-trip time for both messages and parcels) or just live with it and move on (potentially replacing the capacitor later if I get some way of getting the casing open safely). From what Bob and others have said, it seems that most of the MV89's have this problem so it seems unlikely I would get a better one without a lot of trials. Tim Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Adjusting nominal frequency of FTS 1200-100 OCXO?
Adrian, Your connector has probably experienced a problem common to gold plated contacts and component leads. Years ago, I worked in the avionics repair and calibration facility at the Navy base in Jacksonville, FL. I saw this quite frequently in HP and Tektronix instruments that had been in service for a number of years. The issue is that the gold plating peels away from the base metal of the contact or component lead, exposing the base metal to contaminants. Our microminiature soldering lab began instructing all technicians to completely remove the affected components and tin the leads with solder. Then, wick away the solder to completely rid the amalgam of the gold, then resolder the component in place. This was the only permanent solution to the problem; it might occur on a different component, but not on the one that was properly repaired. More often than not, the problem was exhibited as an intermittent failure, consistant with board flexure or pressure. Some of the problems were very hard to find, but we had to keep investigating until we had isolated the real point of failure. Cheers, Dave M Adrian wrote: Christopher, my 4060 has been locking exactly 0.5 Hz off of the correct frequency. The 1000B has had a contact problem on the edge connector. Over the years, an insulating black layer had built up between the solder and the gold plating of the contacts. I had to re-solder each of them carefully twice to get it working reliably. Regards, Adrian Christopher Hoover schrieb: I've been debugging a FTS 4050 with the 5000M module. It looks like the problem is the FTS 1200-100 OCXO. It seems to have aged to the point that it is very low in frequency. (Chuck Harris reported a similar situation a long time ago.) I have it out of the 5000M and determined that I need to give it +8.8V on the control to get it within 50uHz of 5 MHz. The power draw after a short warm up is < 2.5W (on this hot day); it looks like the oven is behaving. Has anyone figured out how to adjust the nominal frequency of an FTS 1200 -100 to recover the EFC range? Also, anyone have a schematic for any model of the FTS 1200? Thanks, -christopher 73 de AI6KG ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Efratom M-100 Rubidium
A friend gave me an Efratom M-100 Rubidium standard to check out and calibrate. I found a couple manuals to download, and they appear to be pretty complete. Even have schematics!! The unit belonging to my friend is p/n 70502-7. The manuals appear to be for p/n 70502-1. Close to the front of the manual is a statement: "A model M-100 with a part number other than 70502-1 is a modified unit". My question is thus: Is there a document anywhere that has a comprehensive list of modifications for the M-100? Or, at least a description of the modification on the -7 unit? It may well be just mechanical or cosmetic in nature, and have no bearing on the operation (I haven't fired it up yet). It appears to be physically identical to the illustrations of the 70502-1 in the manual. Any help or comments are welcome. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucent boxes
It's under the MANUALS tab.
Dave M
Richard W. Solomon wrote:
This Home Page ??
http://www.ko4bb.com/getsimple/index.php?id=index-1
Don't see any search box there ???
73, Dick, w1KSZ
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
Artek Manuals Sent: Tuesday, July 19, 2016 10:19 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lucent boxes
Dick
Not rocket science ...go to KO4BB main page and enter "RFTGm"
In the search box
Dave
NR1DX
On 7/19/2016 12:42 PM, Richard W. Solomon wrote:
KO4BB's site is massive, can you pin down the cable drawing ?
Tnx, Dick, W1KSZ
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
Douglas Baker
Sent: Monday, July 18, 2016 2:39 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lucent boxes
Chris,
The RFTGm ("m" for miniature even though still a large box) is a
later version of the RFTG line. The XO unit houses the GPS receiver
which is essential for disciplining. Both boxes operate at 24 VDC
and there is an interface cable drawing on line at KO4BB's web site.
Never tried to hook them up together, but it might work. Maybe
others here may know. Good luck with it. 73's Doug
On Jul 18, 2016 12:52 PM, "Chris Waldrup" <kd4...@gmail.com> wrote:
Hi Everyone,
I have two Lucent RFTG boxes in my workshop. The XO is a loaner.
I'm curious if they will interface with each other or (most likely)
they are a different series as the interface connectors on each have
a different number of pins.
One is marked RFTG-u REF 0
The other is RFTGm-II-XO
Thanks in advance.
Chris
KD4PBJ
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When the people fear the government, there is tyranny. When the
government fears the people, there is liberty -- Thomas Jefferson
Dave M
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Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping
Take a look at the oven at http://whizoo.com/buy . They sell several kits as well as a complete kit to modify a toaster oven, and a ready-to-go oven for $699, shipping included. According to the web site, it uses a B model T01303SB toaster oven, capable of handling an 8"x10.5" board. The oven and controller, as shipped, is calibrated for lead-free solder, but if requested, he can recalibrate for any solder paste, so long as you provide the manufacturer's reflow requirements. The controller firmware is open source. ControLeo2 specifications and features a.. ATmega32u4 microcontroller with Arduino Leonardo boot loader a.. 32Kb Flash memory b.. 2.5Kb SRAM c.. 1Kb EEPROM b.. LCD display - 2 lines x 16 characters. c.. 4 relay outputs - relays are connected using screw terminals or the 6-pin relay header (4 outputs, +5V, GND). The outputs provide up to 220mA at 5V. The outputs support connections to solid-state relays (SSRs) or mechanical relays d.. Buzzer - 80db at 10cm e.. 2 momentary switches - for user input. f.. ABS plastic case - custom fit, flame-retardant (UL94-5VA) g.. MAX31855KASA thermocouple - capable of reading temperatures from -200°C to 1350°C using a k-type thermocouple. h.. Input voltage: 5V (USB or screw terminals) - For reliability and longevity, the screw terminals should be used to power ControLeo2. For solid-state relays, the 500mA provided by USB is sufficient to power ControLeo2 and the relays. For mechanical relays please use a 1000mA 5V power supply connected to the screw terminals. i.. Pre-loaded software - Reflow Wizard Looks like a pretty decent project. I've no connection with the seller... I found this project after getting intrested in this thread. Cheers, Dave M Chris Albertson wrote: Am I missing some obvious cheapie oven without these types of problems? A lot of people are building them from Black and Decker (and the like) toaster ovens. Use Arduino for controller or just eyeballs. oven thermometer and wrist watch.It is not rocket science the Arduino controller software reads a thermocouple and controls an on/off relay. Lots of instructions around if you google for reflow toaster oven. As for pick and place, the old method still works. Work by hand under a low power stereo microscope. You buy a syringe of solder past and place little dabs on each pad then place the part with twitters. Many years ago I worked at a place that had a few dozen women who did this all day long. You can get a very good used microscope (5x to 20x zoom works well) for under $250 and a workable one for under $100. But many people today are using cameras and a big computer monitor in place of the microscope. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TU60-D120-131 Specs....?
Datasheet: http://www.rabel.org/archives/Navman_Jupiter_11_12/LA010050B_JupiterT_DataSheet.pdf Example projects: http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm http://www.vhfcomm.co.uk/GPS%20control.pdf More info by searching Google for NAVMAN TU60-D120 Cheers, Dave M Bud Patten wrote: Does anyone know anything about the TU60-D120-131 being offered on ebay (voltage? 10Khz? 1 pps?, etc.) . The seller tells me that he doesn't know anything about the item he is selling.. ;-) Any input would be appreciated. Regards, Bud ARS W0LCP ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Phase meter for synchronizing osc's to GPSDO
I looked through the complete index of the magazine for any further articles by the authors but no joy. It's fairly certain that they didn't do a followup in VHF Communications magazine (it ceased publication in 2013). The authors were A Daretti, and G Canale. You might search the web for those names and see if you can contact them for more info. Cheers, Dave M Bud Patten wrote: > Back in the spring of 2012 an article was published in VHF > Communications entitled "A Phase Meter: a help to synchronize > oscillator's to GPSDO". In it the authors indicated that they hoped > to add a "rotation counter" perhaps using Arduino.Does anyone > know whether further work was done on this? > > > > Regards, > > Bud > > W0LCP ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Looking for Z3801 Power Supply Board
Dan, If you haven't already found the Z3801A page at http://www.realhamradio.com/GPS_Frequency_Standard.htm, you should read it thoroughly (in your case, especialy the section on the power supply). there is a good pictorial that shows locations of all the power supply test points. Using that pictorial, you should be able to determine which power supply is causing the problem (there are several). Otherwise, (I'm sure you're well aware) if you're set on getting a replacement PSU assembly, you're probably looking at buying a parts unit and salvaging the PSU board from it. However, you might find that the parts unit also has a bad PSU. It's a chance you take. Cheers, Dave M Dan Rae wrote: My Z3801 power supply board has given up the ghost. It had been working well apart from an occasional Error 230 causing it to go into Holdover for no good reason from time to time which may well be related of course. Does anyone have a good power supply from an otherwise dead unit which might enable me to get it going again? I've had the darn thing for fifteen years and miss it :^) Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Temperature controlled TCVCXO
David wrote: I was thinking of holding the temperature right at 25C or maybe a little higher at an inflection point to minimize the possibility of condensation. The difficulty is that the ambient temperature could vary above or below that so the TEC has to both heat and cool but that is a solved problem. On Fri, 13 May 2016 10:05:02 -0400, you wrote: A problem I had with TE heater coolers was condensation when the ambient temperature was higher than the TE temperature. I was trying to operate the crystals on the lower temperature inflection point. After a while, corrosion became a major issue. John WA4WDL The HP 3450A & B model digital multimeters used a Peltier device to control the temperature of the voltage reference zener diode. You can download the manual for the "B" model from Keysight's web site to get an idea of the control circuitry (http://www.keysight.com/main/techSupport.jspx?searchT=3450B=3450B:epsg:pro=3450B:epsg:pro=US=eng). There's also a sales bulletin for that model that gives a bit more information about the Peltier device and chamber (http://www.ko4bb.com/getsimple/index.php?id=manuals). Search for 3450A on that site. The chamber is controlled to 43C by the Peltier device, allowing quite fast warmup times for the instrument, and operation above normal environmental temperatures. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Prescaler
Good catch on that board, Ignacio. I didn't read the complete description before posting. Given that it seems to be a 1-board solution, I might buy one and see how it turns out. My frequency counting capabilities are limited to 1.3 GHz right now, as is my signal generation capabilities, so I really haven't had a need to go higher. I need to investigate the input and output conditions and limitations of these Hittite chips. Might have to add an amp and/or attenuator pad to make it work with my instruments. Cheers, Dave M EB4APL wrote: The first reference is a board for a two stage divider. They mention that a /2 and a /5 chips can be combined, so you can make a /10 prescaler. Regards, Ignacio, EB4APL El 27/03/2016 a las 23:24, Dave M escribió: Bob Albert via time-nuts wrote: Does anyone know of an inexpensive prescaler for a counter that goes beyond 2 GHz? I would actually like to find a kit but everything seems a bit pricy. I currently have capability of 500 MHz and that will stretch to about 700 with care. So a divide by 10 would be ideal. If you're good at kit-building, you might take a look at the Ebay items 160703629055, 181982380658, 400265187641, and 60703624281. These are PCBs made to specifically fit a number of frequency divider chips. Each board holds a single divider chip and associated components, such as the decoupling caps, bias resistors, and pads for interconnections. A series of these boards that add up to a divide-by-100 can get you to 2 - 5GHz easily. I've never used any of these boards or dividers, but I have used a few of the seller's amplifier boards, with great success. There's also a construction article from Silicon Chip magazine (Oct, 2006) dedicated to constructing a 2.8 GHz 1000:1 prescaler for counters. The PCB layout and all the active parts are available. Send me an email for a copy of the article. I don't know of any prescaler chips that get you a divide-by-10 prescaler at your target frequency range. There might be (probably is) one available... I just haven't run across it. BTW, which frequency counter do you have? There might be a better solution for you than an external prescaler. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. When the people fear the government, there is tyranny. When the government fears the people, there is liberty -- Thomas Jefferson Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Prescaler
Bob Albert via time-nuts wrote: Does anyone know of an inexpensive prescaler for a counter that goes beyond 2 GHz? I would actually like to find a kit but everything seems a bit pricy. I currently have capability of 500 MHz and that will stretch to about 700 with care. So a divide by 10 would be ideal. If you're good at kit-building, you might take a look at the Ebay items 160703629055, 181982380658, 400265187641, and 60703624281. These are PCBs made to specifically fit a number of frequency divider chips. Each board holds a single divider chip and associated components, such as the decoupling caps, bias resistors, and pads for interconnections. A series of these boards that add up to a divide-by-100 can get you to 2 - 5GHz easily. I've never used any of these boards or dividers, but I have used a few of the seller's amplifier boards, with great success. There's also a construction article from Silicon Chip magazine (Oct, 2006) dedicated to constructing a 2.8 GHz 1000:1 prescaler for counters. The PCB layout and all the active parts are available. Send me an email for a copy of the article. I don't know of any prescaler chips that get you a divide-by-10 prescaler at your target frequency range. There might be (probably is) one available... I just haven't run across it. BTW, which frequency counter do you have? There might be a better solution for you than an external prescaler. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Austron 2010B
There's a CDROM available from http://www.prc68.com/P/Prod.html#Austron that contains a manual for the 2010B, as well as several other Austron models. Don't know if it's just a user guide or a full Op/Svc manual. Email the seller (Brooke Clark) for details. Cheers, Dave M paul swed wrote: James Funny I thought that manual would be around also and its not. So it is a disciplined oscillator and thats nice. The question is what does it want to control it. It may be quite a useful unit if as an example it took a 1pps in. But I will speculate it wanted something from the loran c timing receivers. Regards Paul WB8TSL On Wed, Mar 23, 2016 at 12:49 PM, James Fournier <ja...@jfits.ca> wrote: Hello All, I just picked one of these up at a local ham fest. I'm not sure exactly what it was used for. I bought it mainly for the ovenized quartz inside of it. Before I part it out I was hoping to find a copy of the manual so I could determine if it is worth keeping intact. Usually they aren't that hard to find via google but I have had no luck so far. Does anyone have a pdf copy they would be willing to send me? Many thanks! - James ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DC-DC Converters
Goldmine has been around for a bunch of years. I've bought lots of stuff from them. Most of the time, their prices are significantly below MSRP. They sell first class stuff, usually discontinued items and retailers' clearance items. Great folks to buy from. My only heartburn with them is their shipping charges. They don't seem to have any cut-rate deals with any of the major shippers, but it's not like a bunch of Ebay sellers, that make their money with exhorbitant shipping charges. $50 to ship a 1/2 lb. item to the next state is a bit rediculous. Overall, a good source of good stuff at good prices. Cheers, Dave M paul swed wrote: Dave never heard of these guys before. It looks like they have lots of stuff that can be useful at reasonable prices. Thanks for sharing. Paul WB8TSL On Sat, Mar 19, 2016 at 1:59 PM, Dave M <dgmin...@mediacombb.net> wrote: Alert for anyone repairing or toying with telcom equipment. Goldmine Electronics has a number of DC-DC converters having approx. 35 - 75 VDC inputs with various output voltage and current ratings listed in their web catalog (http://www.goldmine-elec-products.com/products.asp?dept=1492). Pretty good prices on most. If you're interested in any of them, be sure to inspect the datasheets before ordering to help avoid big surprises. Some have minimum output current levels, making them less desirable to use as general purpose power supplies, but might work nicely inside a box such as the Z3801A or similar. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] DC-DC Converters
Alert for anyone repairing or toying with telcom equipment. Goldmine Electronics has a number of DC-DC converters having approx. 35 - 75 VDC inputs with various output voltage and current ratings listed in their web catalog (http://www.goldmine-elec-products.com/products.asp?dept=1492). Pretty good prices on most. If you're interested in any of them, be sure to inspect the datasheets before ordering to help avoid big surprises. Some have minimum output current levels, making them less desirable to use as general purpose power supplies, but might work nicely inside a box such as the Z3801A or similar. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Inside a CTS 1960017 OCXO
Pete Lancashire wrote: ... I was using an HP lab supply>>> Model ? Age ? My bench has some pretty old HP's even Harrison Lab branded supplies. I have had to re-cap a few of them. In a way it is almost a curse how reliable their supplies were. You always got the V and I you wanted so one never thought about the filtering getting worse over the years. Also HP had two variations of their bench supplies. The basic ones and the low noise versions. When I need to make measurement like this, I make sure I'm using one of the low noise/ripple models. Adding my few cents' worth to the power supply ripple/noise thoughts, I've found that the old linear supplies by Power Designs Inc were among the best, at considerably lower cost than the HP/Harrison Labs units. Ripple/Noise in the low millivolts and high microvolts, 0.01 - 0.005% regulation and temperature stability in the neighborhood of 0.01%/degC were common. I have a couple on my bench, and they just keep on working. They still pop up at auction frequently. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SMD TADD-1 distribution amplifier
Amp (now Tyco) did introduce them. Called "Decoupled Connectors'' Info at http://www.te.com/usa-en/search.html?q=Decoupled%2BConnectors=header Tyco parts 413476-2 and 5413476-2 are available from Mouser, maybe Digikey as well Cheers, Dave M Chris Caudle wrote: On Fri, December 18, 2015 4:50 pm, Bruce Griffiths wrote: On Friday, December 18, 2015 12:27:33 PM Charles Steinmetz wrote: It is perfectly possible to ground coax connector bodies at RF without grounding them at power-line frequencies Something like an annular ring capacitor that insulates the BNC body from the chassis whilst capacitively shorting it to the Chassis at RF ??. Yes, exactly what I was referring to previously when I mentioned the telecom solution to this problem. I have an Amp connector in my parts bin with this style of connection, but it doesn't have a full part number printed so I can't find the drawing. I believe this Amp patent from 1990 may refer to the method of assembling such a connector: http://www.google.com/patents/US5062811 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX
I found all ICs except the VCXO here in the US, from only two sources; Mouser and Unicorn Electronics. A couple substitutions can be made without affecting the circuit. The 78L06 is the only change i made... substituting an LM317L adjustable regulator for the fixed 6-volt reegulator. I've attached a PDF of the IC list, sources and price. Hope this helps, Dave M Nick Sayer via time-nuts wrote: On Nov 22, 2015, at 7:47 AM, paul swed <paulsw...@gmail.com> wrote: As mentioned a nice answer to the wwvb modulation change. I looked up the parts and it seems that they have gone into the NOS state. Though you can get some from digikey and such especially in the SOIC package. Also the VCO isn't available. It appears that the Chinese sight has the lmc6484 and LM387n at reasonable prices for small quantities. Most likely will order from there. Have not checked out the PIC chip yet. The 74HCXX are common and reasonable. That’s kind of a shame. I’m sure a redesign with modern SMD parts could be accomplished. The big question is how the stability of a wwvb disciplined oscillator would compare to a GPS disciplined one (all other things being equal). Well, it’s a big question for me, since I have no idea, but I imagine simply asking here will give an immediate answer. :) I’d have to guess that the PLL would behave better given a 60 kHz reference rather than a 1 Hz one. But how stable is that 60 kHz reference after going through, what, a thousand miles of ionosphere or so? ___ IC Parts List.pdf Description: Adobe PDF document ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Newbie
There's a good search utility at https://www.mail-archive.com/time-nuts@febo.com/ Cheers, Dave M Gary Woods wrote: Before I embarrass myself in public (again), is there an archive search for the time nuts list? I'll lurk for a while before posting... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Need Pinouts data for McCoy MC834X4 OXCO
I picked up a NOS McCoy MC834X4-014W OXCO today at the Huntsville AL hamfest. I've searched, but not found any really useful information about it. Does anyone have any data on it? I especially need pinouts and operating voltage. The rest, I can figure out. It seems to be similar to the Oak model 4834. The width and length dimensions match, but the height of the McCoy unit is about 1/4 taller than the Oak. The pin arrangements are the same, but I'm not really sure if their functions are the same. Help is really appreciated! Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] KS-24361 EFC Error
I have verified with MTI that the recommended tuning voltage for model 260-0624-C is 0 to 6V. The datasheet range of -10V to +10V is the available range of EFC for the entire 260 series, and may or may not apply to any specific model within the 260 series. Cheers, Dave M Dave M wrote: The OCXO in these units is the MTI-Milliren model 260. According to its datasheet, the tuning voltage range is -10Vto +10V. (http://www.mti-milliren.com/pdfs/260.pdf) Cheers, Dave M GandalfG8--- via time-nuts wrote: Bevor I heat up the big soldering iron to remove the OCXO, I wanted to ask if anybody else experienced this before and if anybody can confirm that tuning voltage range is indeed 0..6 Volt. If so, replacing the OCXO should cure the problem. Hi Mathias I've not experience your problem with the KS-24361, but I have tested a few of these oscillators stand alone and can confirm that the reference voltage output has always been approximately 6 Volts and they do accept an EFC tuning voltage range of 6 Volts. Other than one faulty unit, on all those I've tested the EFC voltage has been very close to 3 Volts when the oscillator frequency was within a few parts in 10^11 of 5 MHz. For example, looking back at a couple of test results, one was at 2.9725 Volts and another at 3.0970 Volts. Regards Nigel GM8PZR Hey, hows about that, It seems like I might finally have found a way to reply to list messages straight from the archives without receiving them by email:-) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] KS-24361 EFC Error
The OCXO in these units is the MTI-Milliren model 260. According to its datasheet, the tuning voltage range is -10Vto +10V. (http://www.mti-milliren.com/pdfs/260.pdf) Cheers, Dave M GandalfG8--- via time-nuts wrote: Bevor I heat up the big soldering iron to remove the OCXO, I wanted to ask if anybody else experienced this before and if anybody can confirm that tuning voltage range is indeed 0..6 Volt. If so, replacing the OCXO should cure the problem. Hi Mathias I've not experience your problem with the KS-24361, but I have tested a few of these oscillators stand alone and can confirm that the reference voltage output has always been approximately 6 Volts and they do accept an EFC tuning voltage range of 6 Volts. Other than one faulty unit, on all those I've tested the EFC voltage has been very close to 3 Volts when the oscillator frequency was within a few parts in 10^11 of 5 MHz. For example, looking back at a couple of test results, one was at 2.9725 Volts and another at 3.0970 Volts. Regards Nigel GM8PZR Hey, hows about that, It seems like I might finally have found a way to reply to list messages straight from the archives without receiving them by email:-) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP10811 vs 00105 OCXO
Ulrich, If you're interested in a very good 5MHz OXCO, then I recommend the MTI Milliren model 260. (see Ebay # 271915776504). The data sheet is available.from several places, including MTI's site. The daily aging rate for it is spec'ed at 5e-11, thermal stability is 2e-10 over -30C to +70C. That's roughly 10x better than the 10811, and much cheaper. The Z3812A GPSDO units both use the MTI OXCO, so you could buy 1 or 2 of the REF-0 units and get the good OXCO performance plus all the other stuff that surrounds it. Cheers, Dave M KA2WEU--- via time-nuts wrote: How good or bad is the 10811 and which one on ebay is a better choice ? I am looking for a very goo 5 MHz crystal oscillator with documentation . Thanks, Ulrich N1UL In a message dated 8/8/2015 7:16:37 P.M. Eastern Daylight Time, kb...@n1k.org writes: Hi Ok, so John’s observation was the correct one. The data we are looking at is *not* the performance of the OCXO’s but the strange behavior of the counter at short ADEV Tau’s. Sorry for my bashing your poor 10811. Bob On Aug 8, 2015, at 12:25 PM, tim...@timeok.it wrote: Hi all, I try to ansver to all you: Luciano, how was the blue trace taken? Is this from your DMTD project? If so, it's looking promising. The green and magenta traces are definitely in the right ballpark for measurements on a 5370-class counter. At 3E-11 @ t=12s the magenta trace is optimistic but not outrageously so, while the green trace looks exactly like I'd expect for a typical 10811 measured on a 5370. The observed noise is due entirely to the counter until about t=200s. We see a glimpse of the 10811's typical ADEV at about 250 seconds, just before either drift or ADEV uncertainty causes the trace to turn upwards. A longer run would be needed to distinguish between these two situations. -- john, KE5FX Miles Design LLC r: no, all the measurements are taken using an HP53132A in frequency mode. The difference can be the gate time. Using 1 second the resolution is lower than using 2 Second that permit the max counter resolution. Hi Well an un-stated assumption of mine was that they all came from the same measurement system and that it had the same floor under all circumstances…. Bob r: all the measurements are under the same conditions except for the gate time of the counter. Hi Luciano, Can you give me the link to your ADEV posting image about 10811 vs 105 oscillators? I had it and now can't seem to find it. I wanted to look at your plots as I read John Miles' comments. Many thanks. I have two very high performing HP10811-60109 OCXO units which I got from Corby. Many thanks. Jim Robbins N1JR r: Jim, I will load soon some files on my site. The 105B I have is a fantastic exception, unfortunately it have a defect, may be a bad solder inside cause randomly a phase jump and return to the original phase trend, so all The long term ADEV are distorted by this problem I have to fix. Tom VB, i will do all the cross measurements on 10811, 00105 and rubidium I have and i will upload they but I need time to do this. Unfortunately I have only the HP53132A as TIC and my best reference are four HP5065A. I normally use the counter function because the TI function on 1 PPS have 100 time less resolution. Will be interesting doing also the Phase noise tests. I will do it. please see: http://www.timeok.it/files/time_and_frequency_house_standard_201r.pdf Luciano www.timeok.it On Sat 08/08/15 02:23 , Bob Camp kb...@n1k.org wrote: Hi Well an un-stated assumption of mine was that they all came from the same measurement system and that it had the same floor under all circumstances…. Bob On Aug 7, 2015, at 5:21 PM, John Miles wrote: Hi If that data is correct, then the 10811 you have is defective. Bob Well... some of the data is reasonable for a scenario where a counter is being used to measure OCXOs. Looking at the ADEV plot, I'd say the blue trace (HP105B vs 5065A) is the most questionable one if it came from a standalone TIC or frequency counter, because 7E-12 @ t=1s isn't achievable with most counters under most circumstances. A Wavecrest box can measure at that level if it's set up _perfectly_ to take bursts of 100+ wrap-free averages within a small fraction of the t0 interval. It might also be doable with an HP 5370A/B under similar conditions, but I'd have less confidence that the averaging isn't distorting the measurement. So while It looks like a valid measurement of an OCXO with some minor crosstalk or other external interference, that may just be a coincidence. Luciano, how was the blue trace taken? Is this from your DMTD project? If so, it's looking promising. The green and magenta traces are definitely in the right ballpark for measurements on a 5370-class counter. At 3E-11 @ t=12s the magenta trace is optimistic
Re: [time-nuts] Vintage Crystal Oven
Thanks George, I used to work in a Motorola 2-way shop. The only heated ovens that Motorola used were the 6.3V thermostatically controlled ovens. Those were used in the old tube-style units. When they went solid-state, they used TXCOs in both base and mobile units. However, I'll check them out. Never know, there might be something useful there. Cheers, Dave M George Dubovsky wrote: I'm not sure I remember the exact one you are describing, but in the last month or so, there was a fellow selling crystal ovens on QTH.com. I think they were from land-mobile service, like Motorola base stations or some such. That's another place to search. 73, geo - n4ua On Fri, Apr 10, 2015 at 12:37 PM, Dave M dgmin...@mediacombb.net wrote: Years ago, (70s maybe) I came across an empty crystal oven. I know I have it in one of the storage containers of old stuff in my garage, but I can't find it. It was a proportional oven, but was otherwise an empty shell, so you could put your own circuitry inside (oscillator, voltage reference, etc.). Several small wires came out of it for power, temperature adjustment, e.g. Physical size was in the neighborhood of 1.5x1.5x3 inches. As I remember, it was manufactured by one of the major crystal manufacturers of the day (e.g., Knight, Bliley, etc.) Does anyone remember these ovens? I'd surely like to get my hands on a couple or three to play with. I search the net Ebay occasionally for them, but so far, no hits. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Frequency doubler 5/10 and distribution amplifierfor Lucent KS-24361
Count me in for one (maybe two, depending on cost of the board + parts). I have been working on a design for an elliptical lowpass filter following a diode doubler and a small amount of amplification.. I have most of the parts, using a couple of RFExtra's developer boards (Ebay item 150203651783). Only need a couple SMD inductors and can start building it. Will be continuing with that in a week or two, when I get over a minor surgery. Will be interesting to compare to two approaches. If it turns out to be a problem to duplicate the board in volume, I'd really like to get an actual-size PDF of it for my own use. Cheers, Dave M John Allen wrote: Hi Time-Nuts - FWIW, the is a 30 day free trial of Altium Designer at http://www.altium.com/free-trial?gclid=CKnpkaux38QCFQotaQodoaYAWQ The download requires a company name and email address. I for one, would like at least one of each of Gerhard's boards. Would anybody like to volunteer to create 10-20 boards and sell them? If people are interested in boards, they can pm me at j...@pcsupportsolutions.com And I will make a list and post it. In your email, provide your name and email address and how many multiplier boards and how many low noise 220pV/sqrtHz preamp boards? I have no time to do any more than that. Is this worth being a TAPR project? Trying to help, John K1AE j...@pcsupportsolutions.com -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Anthony Roby Sent: Saturday, April 04, 2015 10:12 PM To: g...@hoffmann-hochfrequenz.de; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Frequency doubler 5/10 and distribution amplifier for Lucent KS-24361 Gerhard - I would like to make the board if you could make the layout available. I don't have Altium, so would need the artwork to be able to toner transfer the board. Is it available? Thanks ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OXCO insulation
Great find, Arthur. I had already convinced myself to use fiberglass insulation to reinsulate my OXCOs, but I'm going to order 2 or 3 sheets of this to play with. Thanks a bunch!! Dave M Arthur Dent wrote: If you check the popular auction site you can find several listing for Aspen Aerogel SPACELOFT Insulation. One listing has a 10x14x.2 piece for $7 including shipping and another listing has 481 rolls for $1.8 million, in case you have several ovens you need to re-insulate. ;-) http://www.ebay.com/itm/171328843398? -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OXCO insulation
Ok, there has been a couple replies suggesting aerogel. I've read a bit about it, and understand that it's extremely light and effective, but quite difficult for a hobbyist to make. Also, probably very expensive. Is there a source for very small quantities of it? Is is flexible enough to wrap around a cubical or cylindrical object without destroying it? I've considered fiberglass as a cheap, available insulation, and will probably be what I use to repair my oscillators. I'm very leery of trying to use Great Stuff household foam insulation. I just don't want to risk having another failure because of it. Cheers, Dave M Brian Inglis wrote: On 2015-02-22 17:42, Charles Steinmetz wrote: Brian wrote: Thought of trying aerogel insulation? Dust free varieties avoid handling issues. Be careful not to over-insulate the oven -- it depends on a certain amount of heat flow to ambient to balance the heater. The stability of the heater control loop depends on having the correct amount of thermal resistance from oven to ambient (also, on the thermal resistance being distributed similarly to the original scheme). R-value for commercial aerogel insulation is about double rigid polyurethane insulation, so half the thickness would be about right. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OXCO insulation
Yes, I'm aware that the newer OXCOs don't have any insulation other than air inside the package. I failed to mention that in my post. I am primarily interested in the older OXCOs that have foam insulation inside. I have a couple of them, including the crystal oven from an old HP 5245L counter that needs new insulation. The old foam was destroyed by a heater that ran wide open for a while, burning a large portion of it to a crispy mess. Thanks for your response, Dave M Bob Camp wrote: Hi A lot of modern OCXO’s no longer use insulation…. the gaps inside are now so small that you get very little benefit from it. On the older parts that do use insulation 2 to 4 pound per cubic foot density urethane foam is a typical choice. You can buy it from most plastics suppliers. It can be machined with just about any tooling out there. The dust is a mess, but it’s not normally considered hazardous. Bob On Feb 21, 2015, at 7:09 PM, Dave M dgmin...@mediacombb.net wrote: What kind of foam insulation is generally used inside an OXCO? Do all manufacturers use the same kind? Is it available in small (hobbyist) amounts? I've read that some folks have used Great Stuff polyurethane-based insulating foam to repair an OXCO. I've used it to fill gaps around pipes in my home, but it's nor subjected to the high heat encountered in an OXCO. According to Dow's web site, it could present a fire hazard if subjected to temperature of 240F (115C). There is a Fireblock variety, but it appears to have pretty much the same formulation as the other varieties, so I can't see any advantage to it. Has anyone experienced any long term problems with Great Stuff in an OXCO? Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] OXCO insulation
What kind of foam insulation is generally used inside an OXCO? Do all manufacturers use the same kind? Is it available in small (hobbyist) amounts? I've read that some folks have used Great Stuff polyurethane-based insulating foam to repair an OXCO. I've used it to fill gaps around pipes in my home, but it's nor subjected to the high heat encountered in an OXCO. According to Dow's web site, it could present a fire hazard if subjected to temperature of 240F (115C). There is a Fireblock variety, but it appears to have pretty much the same formulation as the other varieties, so I can't see any advantage to it. Has anyone experienced any long term problems with Great Stuff in an OXCO? Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Frequency doubler 5/10 and distribution amplifier forLucent KS-24361
Good job on the doubler/distribution amp, Gerhard! Which PCB design software did you use to make the PC board? Could you share the files for it? Dave M Gerhard Hoffmann wrote: Hi, all, over the Christmas season, I have designed and built a frequency doubler from 5 to 10 MHz and a distribution amplifier for the Lucent KS-24361. A preliminary writeup is under http://www.hoffmann-hochfrequenz.de/downloads/DoubDist.pdf It features 4 or 5 10 MHz 10 dBm outputs and an optional 1PPS on SMA with CMOS levels into 50 Ohm. It is a small board to be mounted inside the KS-24361. Comments invited. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Looking for J1 pinout newly purchased 10811D
Mod Mix wrote: Hi, the HP 10811D I just purchased (one like ebay #300568433895) resides on a small pcb. Could someone pls guide me which voltage for the LM317 feeding the oscillator with 12V should be applied at J1/1 and J1/2 ? I would also be interested to learn for which devices these board were originally made - couldn't find anything. Thank you in advance Ulli Without knowing anything about the item in the Ebay listing, I can tell you that the input to the regulator supplying the 10811 oscillators in many HP counters is specified to be +15 - +18 Volts. Actually, any voltage within the rated input voltage range of the LM317 regulator is OK, so long as the power dissipated by the LM317 remains reasonable. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simple AC mains zero-cross detector
Charles Steinmetz wrote: Every so often, the subject of logging the zero-crossings of the AC mains comes up. There are any number of ways to couple the AC mains to logic circuitry (coupling with very high value resistors, capacitor coupling, and optical isolation have been mentioned). A simple AC mains ZCD that is transformer isolated and gives excellent results, is posted at ko4bb.com: http://www.ko4bb.com/manuals/download.php?file=05_GPS_Timing/Simple_AC_Mains_Zero_Crossing_Detector.pdf The ZCD uses a small, dual-primary power transformer, two transistors, and a few diodes, resistors, and capacitors. It produces a ~100uS logic-level pulse at every positive zero-cross, the leading edge of which is predictably and stably related to the AC mains zero-cross. Best regards, Charles I'm not trying to downplay the circuit in the link above, but I want to offer another possible solution to Zero-Crossing needs. Here's an Idea For Design from EDN magazine that I've used a couple times in non-time-nut circuits, and I must say that it works beautifully. I have no measurements that would satisfy a time-nut's curiosity, so if someone wants to Spice it or otherwise tear it apart, please do.. My use for the circuit was in a spot welder control; the output was used to sync and cycle a counter-driven trigger for an alternistor, all of which controlled the number of power line cycles that the welder transformer received for the weld. It worked well for me until I sold the whole contraption. Don't know whatever happened to it after the guy moved away from the area; never heard from him again. I hope it's still working. http://electronicdesign.com/analog/differential-line-receivers-function-analog-zero-crossing-detectors Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Choke Rings and Points North
Jim Lux wrote: On 12/16/14, 5:59 AM, Tom Van Baak wrote: Clever idea, but.. Most rotary joints have more phase and amplitude variability than the antenna. So you're stuck with rotating back and forth with a cable that's flexing and now you get to measure the phase variability of the coax. I was thinking of some sort of non-contact RF bridge that would allow either side to rotate independently. Converting to optical would make this easy, but there must be a way to do it at 1.5 GHz too. two nested coils forming an air core transformer or slip rings are the typical approach. (Waveguide at 1.5 GHz is somewhat unwieldy in size). The trick is in holding mechanical tolerances tight enough.I guess, 1mm mechanical tolerance (easy, easy) would be comparable to the phase center displacement. You really need to have your entire GPS system antenna and receiver on the rotating table (which will need to have temperature controls, etc.) Oh, what a pit one can descend into with the goal of reducing everything to a minimum error. In this case the goal is actually not minimizing error. The goal is to vary each possible error source with its own prime modulation period. Collect lots of data and the FFT tells you how much each error contributes to the pie. Yes, but how do you know whether it's coax flex or phase center displacement that's causing your 17 hour periodicity. I was thinking not so much reducing error in the overall measurement, but in reducing the uncertainty in the estimate of the size of each contributor to the overall system. For example, instead of temperature control you modulate temperature by 5C over a 13 hour period. Instead of voltage control you modulate the 5V antenna power by 10% every 1.7 hours, etc. Inquiring minds surely are in high gear!! And to think, all I wanted to know was how close I needed to to point to north!! LMAO!! Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Choke Rings and Points North
With all the discussion about surveys position accuracy, I have a question about my choke ring antenna. There is an arrow marked N on the underside of the rings. How accurately does the alignment need to be to North? True north or magnetic north (my thinking says True North)? Does the directional accuracy affect the precision survey? I'm assuming that it would have no effect on the accuracy of the 10 MHz frequency output. Or am I completely off base? Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Choke Rings and Points North
Jim Lux wrote: On 12/15/14, 5:46 PM, Dave M wrote: With all the discussion about surveys position accuracy, I have a question about my choke ring antenna. There is an arrow marked N on the underside of the rings. How accurately does the alignment need to be to North? True north or magnetic north (my thinking says True North)? Does the directional accuracy affect the precision survey? I'm assuming that it would have no effect on the accuracy of the 10 MHz frequency output. Or am I completely off base? If you're using a standard antenna, they've characterized them for the change in phase center with respect to the direction the signals are coming from. It's assumed you'll install it level, so elevation is taken care of. The remaining uncertainty is the azimuth, hence the north arrow. Now we can find out how much of a nut you really are. On choke ring antennas, I think the maximum shift in phase center with look direction is on the order of single digit millimeters, or a few ps. And how accurately do you know what direction is north. That could be a whole project in itself, ranging from moss on trees, to shadows of sticks and rocks, to observations of Polaris through a theodolite, and so forth. Thanks for the explanations. I'm not terribly concerned about time, other than knowing when it's time to eat and sleep... I'm more of a frequency nut than a time nut. I have a USGS map and recent survey of my property, so I know where North is, to a pretty good certainty. Thanks!! Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Frequency distribution isolation transformers YCL 20F001n arrived
The Pulse Engineering PE-68025 module from Electronic Goldmine (http://www.goldmine-elec-products.com/prodinfo.asp?number=G17078) has common mode chokes and LPFs on both Tx and Rx lines. On clearance for $1.00 each. Datasheet is at http://www.datasheetarchive.com/dlmain/Datasheets-9/DSA-179465.pdf Cheers, Dave M ed breya wrote: I investigated those 10b-t isolation modules a while back, and have saved every module from every network card and router/hub/switch that I have junked out. The very old 10b-t stuff is the best for getting LPFs and individual per-channel (port) type parts. When they started making 10/100 Mb/sec, the 17 MHz filters were eliminated, and the parts got integrated to ever-higher levels, with multiple channels in each module. You have to be able to find the data sheets to be sure of what's in them - some are transformers only, and some also have LPFs and common-mode chokes in various combinations. The filter sections can also be cascaded for even sharper cutoff, but there's quite a bit of crosstalk, so a lot of higher frequency stuff gets through, especially above 100 MHz, so it's mostly effective from around 20-100 MHz. It has been mentioned before that very sharp filters will tend to have more phase noise (phase shift with temperature/component variations), but the negative effects depend on the application - I only care about frequency reference distribution to SAs and synthesizers, for example, so I don't worry about exact phase and timing between equipment. There is a nice variety of magnetic parts from all types of network devices, including DSL an ISDN. Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] up converting 10MHz to 20MHz
lincoln wrote: Hello, I'm having a dumb idea, I have an MCU that uses a 20 MHz VC-TCXO. The micro, among other things, runs a loop and correct the oscillator by using a 1pps from a gps. I have a 10 MHz mv200 that I would like to try to use. I've got the control voltage handled but i will need to multiply its output up to 20 MHz. What would be the most kosher way do do this? I was having a look at Cypress's CY22381 because I have the programmer but the chips are not widely distributed. But nether are mv200's Silicon labs also make all kinds of clock chips as well. What do you guys think? What would be the best way to scale up by X 2? lowish phase noise / jitter is important, low power is not. Thank you, Lincoln A couple ways to go on a doubler. Minicircuits makes a line of frequency doublers, such as the SK-2, RK-2, RK-3, etc. You could also roll your own using a balun and a diode bridge (http://www.techlib.com/files/diodedbl.pdf). Insertion loss is pretty hefty in both solutions, so you''ll need to follow with a 10-15db amp. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits specs
Gerhard Hoffmann wrote: Am 29.11.2014 um 20:01 schrieb Gerhard Hoffmann: Am 29.11.2014 um 19:08 schrieb Thomas S. Knutsen: 2014-11-29 16:24 GMT+01:00 Dave M dgmin...@mediacombb.net: Yeah, that's a good way to completely avoid the issue. Since I'm the only target audience for my efforts, then I don't mind the extra components. I'm beginning to realize, as I get deeper into building my own stuff, that a VNA is quite a desireable piece of equipment. Unfortunately, I'll have to make use of my spectrum analyzer and RLC meters instead. Ok, I volunteer to measure the S21 of a dc-force-fed T1-1 or T4-1 next weekend, when I'm back home. (DG8SAQ VNWA and / or WG TSA-2) Really, on osc, a voltmeter and a DC source are enough. Here it is: Mini circuits T1-1T, new very old stock, still in black case, not one of the new whitish ones that turn brown in the week after soldering. 0 / 25 / 50 / 100 mA on the secondary side from Agilent 6633B dc supply. It is nice that you can directly type in the voltages or currents. But you better do not take this thing for anything that is sensitive to noise. DG8SAQ VNWA, my best DC block from PSPL because it also has the lowest lower corner. It took some experimenting to find a choke that would not modify S21 and carry the current. Finally: a medium size red Amidon core two 220uH Siemens chokes with a looong air gap. https://picasaweb.google.com/103357048842463945642/Tronix?authuser=0feat=directlink The low frequency corner suffers already at 25 mA. The high frequency side is unimpressed by the current. Just what one expects from a transmission line transformer that gets ferrite as an anabolicum for the low frequencies. The transformer survived 1A for a short time and did not seem to suffer from that abuse s-parameter-wise. regards, Gerhard Many thanks for the graphs, Gerhard. I suspected that the low end would be the first to suffer, but didn't know how much. Those curves explain the reason for the 30ma limit; it's to keep the devices' specs definable. With a higher limit, the insertion loss specs would be terrible, and nobody would buy them. The text on the screen shots is a bit hard to read, but I think the curves told me what I wanted to know..As with most other devices, it's best to stay away from the Max figures on the datasheet. Thanks for taking the trouble to make the measurements and share the results. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Linear voltage regulator hints...
Dan Kemppainen wrote: Hi, In playing with some oscillators and a GPSDO here, I think I'm seeing a voltage sensitivity issue. So, I started looking at the output voltage of various regulators vs. temp. Using standard LM/UA type linear regulators and some LDO's, they all appear to be pretty sensitive to temperature. (millivolt / few degrees Fahrenheit sort of sensitivity). Most of the datasheets seem to ignore temp sensitivity. Almost like they are so bad they don't want to publish it... Does anyone have hints on TO-220 or D-Pak type regulators that have really good temp coefficients and good line regulation? A few PPM/Deg C might be nice, if possible. Or am I into a 'roll you own' type design... Dan Yes, in order to get low PPM stability, you are going to roll your own. No 3-terminal regulator or reference that I know of can run an OXCO (heater and oscillator). What are your voltage and current requirements? Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite
I finally took an ineterest in this thread, because I have needed (rather infrequently) a way to get LED light from a PCB to a front panel. I Googled flexible light pipe (no quotes in the Google search) and got loads of hits for them. So, I guess they're called pipes after all. And they're stocked at Mouser, in various sizel and lengths. How quaint! Check out Mouser's catalog page at http://www.mouser.com/catalog/catalogusd/647/186.pdf. There's probably more, but this was as far as I went. Cheers, Dave M Don Latham wrote: actually, Magritte had it: “this is not a pipe” Don On Dec 5, 2014, at 8:01 AM, Chuck Harris cfhar...@erols.com wrote: The OP said he couldn't find anything applicable when he was looking for light pipe. So, I offered him a suggestion for why. Ultimately, we are talking about locating something using a search engine. The public has taken to the high tech sounding term fiber optic to describe what used to be called a light pipe. If it is thin, and flexible, and moves light from one location to another, it will be known to most people as fiber optic. As an example, sitting here on my workbench is a light that I use to illuminate objects under my Olympus stereo microscope. It is made by Nikon, and has the following words inscribed on its panel: NIKON, Inc. MKII Fiber Optic Light Do you imagine that it is a precision glass or plastic waveguide, or just a flexible light pipe? -Chuck Harris paul swed wrote: That is a good suggestion. But I fall into the camp. Not really that important now. At least not to get me to pull it out of the rack. :-) The little LED are pretty bright and I remember some broadcast equipment used light pipes. OK now I am going to get silly but this is time-nuts. I think light pipe and fiber optics are two different terms. Yes they both pass light. But a fiber optic is a precision glass or plastic waveguide. A light pipe is a bulk piece of plastic that is not a wave guide in respect to the accuracy of the walls. Oh I am so doomed now that I said that. Regards Paul WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Bob Camp wrote: Hi On Nov 28, 2014, at 8:48 PM, Dave M dgmin...@mediacombb.net wrote: Gerhard Hoffmann wrote: Am 28.11.2014 um 23:42 schrieb Dave M: A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Try that: http://lmgtfy.com/?q=T1-1-KK81.pdf The first anwer looks like a hit. regards, Gerhard Thanks Gerhard, but I can't get that link to work. It sends me to Google, which tells me that I need to enable Javascript. Javascript has been turned on and running on my system for years, but apparently, that link doesn't see it. The link animates a Google search for the part number. The first thing that comes up here is the standard Mini-Circuits spec sheet for the part. It’s got the usual S parameter data, but nothing on DC current. Bob Thanks for clearing that up, Bob. I have had the spec sheet for quite a while, but its only mention of DC current is the Max DC spec of 30ma, but no data describing the effects of it on the device's performance. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits specs
Charles Steinmetz wrote: Bob wrote: My past experience with Minicircuits is that they will not give you any data the extends the spec on a part. Simply put - if you are after 1 MHz data on a part that stops at 10, they are not likely to supply it. I've had better luck getting data from them that is just not stated (as opposed to being outside a stated spec) -- for example, the nominal inductance of windings. I suspect the same might be true if someone asked, What exactly do you mean by 'DC: 30mA?' You probably wouldn't get hard data or graphs, but they might give you an idea of how they arrived at that spec. In the end, though, the only way to be sure a certain part will work in any particular circuit is to build and test it. Don't forget, you can generally keep DC out of transformer windings with shunt coupling (use an RF choke for the DC path, and capacitor couple into the transformer winding). It's an unwanted complexity, but some builders may prefer it to winding their own transformers. Best regards, Charles Yeah, that's a good way to completely avoid the issue. Since I'm the only target audience for my efforts, then I don't mind the extra components. I'm beginning to realize, as I get deeper into building my own stuff, that a VNA is quite a desireable piece of equipment. Unfortunately, I'll have to make use of my spectrum analyzer and RLC meters instead. Thanks for the responses. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Rick, Thanks for the brief review of MiniCircuits stuff (I'm not connected with them in any way except as a customer). Since you've characterized some of their parts, perhaps you could help answer a question that someone else posted, and one that I would like to have answered as well. Have you measured the effects of DC current in the windings of an RF transformer, such as is seen if the transformer is in the collector circuit of an amplifier? If so, could you provide a generalization of the effects, such as changes in frequency response, losses, etc.? Many Thanks!, Dave M Richard (Rick) Karlquist wrote: On 11/27/2014 7:07 AM, Tim Shoppa wrote: For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Tim N3QE You need the tiny cores to get the performance of the MiniCircuits transformers. You just can't get the same bandwidth using macro sized binocular cores. Now, if you don't need a lot of bandwidth, then what you are saying could make sense. Another issue is stray capacitance. Considerably lower with a tiny core. I have spent many hours characterizing MiniCircuits transformers beyond the data sheet specs, and dissecting them to learn how they do it. They really do have a lot of rocket science in them. In terms of the engineering I am buying (especially in a one-off application) they are ridiculously cheap. And I say that as a fairly knowledgeable transformer designer in my own right. I do keep binocular cores around for higher power transformers, and for emergencies when I need a transformer yesterday. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Distribution Amp
Bill, there are lots of us here that are well aware of the TAPR products, and recognize their merits. There are also lots of us here that like to roll our own (me included). Many of us aren't engineers or engineering students, but we still like to participate in the technology. A little help, in the form of a schematic or a detailed construction project, is always welcome, even if there is an available product for sale. Not reinventing the wheel, just that some of us like to do the mounting and balancing ourselves. Dave M billriches wrote: Any of the group using the TADD-1 from TAPR. Perhaps that unit along with double shielded cables would work for most folks. Looking at the past threads are we trying to reinvent the wheel for a distribution solution? 73, Bill, WA2DVU Cape May ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
The very tiny cores on MiniCircuits transformers will start to saturate at hundreds of mA. The effect is that the magnetizing inductance drops, which matters more at low frequencies than high frequencies. I try to avoid feeding DC to an amplifier through a transformer winding. Instead I use a separate RF choke for that. However, it would probably work OK for, say, up to 25 mADC for a small signal transistor, but why take a chance. If you are using a DC feed through a transformer winding, be careful not to accidently short circuit it, causing the full available current from the power supply to flow through the transformer. This can actually magnetize the core and permanently damage it. Saturation via DC is much more deleterious than saturation via AC. It is easy to calculate the flux density using Ampere's law, which is one of the four Maxwell's equations. H = I/(2piR). Since R (radius) is in the denominator, cores saturate from the inside first before the whole core is saturated. Multiply H by mu, (as any time nut knows) to get B. If R is 1 mm, and I is 628 mA, then H = 10 ampere turns per meter. If mu-relative is 1000, then B = 4piX10^-7 X 1000 X 10 = 125 mT. That is a hefty 1250 Gauss. Some materials may be affected at 1/10 this flux density. Now a days, a lot of RF is differential, in which case you are free to feed DC through the output transformer without worrying about this issue. I worked for several companies where those 6 hole cylindrical chokes were ubiquitous. I specifically characterized those and established a maximum current rating of only 100 mA. Of course, many production designs exceeded this limit and worked anyway. I actually observed someone try to put 20A through one of these. The tantalum capacitors on the cold side of the bead actually exploded due to RF current. Rick Karlquist N6RK Thanks for the insight, Rick. You confirmed many of my own assumptions about RF transformers and cores. I hadn't thought about permanently magnetizing a core with excessive DC current, but it makes sense. Same theory applies to line frequency power transformers and inductors; if the core saturates, inductance takes a nose-dive and current goes wild. A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Gerhard Hoffmann wrote: Am 28.11.2014 um 23:42 schrieb Dave M: A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Try that: http://lmgtfy.com/?q=T1-1-KK81.pdf The first anwer looks like a hit. regards, Gerhard Thanks Gerhard, but I can't get that link to work. It sends me to Google, which tells me that I need to enable Javascript. Javascript has been turned on and running on my system for years, but apparently, that link doesn't see it. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 10 MHz Filters
Electronic Goldmine has some Pulse Engineering LAN transformers (same as those used on many LAN boards) on clearance at $1.00 each. http://www.goldmine-elec-products.com/prodinfo.asp?number=G17078 Datasheet is at http://www.datasheet4u.com/download_new.php?id=541958 Quite cheap, in my opinion. Cheers, Dave M Perry Sandeen via time-nuts wrote: List, I have seen on the net a 10 MHz filter using 10.7 IFtransformers but have no idea how well they would work for isolation with thenew style Lucent boxes. Thoughts? On Ebay venders are offering 10 MHz crystals for almostnothing if you buy 30. My question wouldthese be good for making some type of simple ladder filter? In his article *Modifying Lucent RFG-M-RB Rubidium FrequencyStandard* the author used a 10MHz filter that was taken from an old 10MbitEthernet LAN board. The part number he used was 20F001N and I found them onEbay for low prices. Now I don’t have any access to any old ethernet LAN boardsso I’d have to build from scratch. Does anyone of these methods have an advantage over theothers on the new style Lucent boxes or in the making of a small distributionamplifier with good isolation? Regards, Perrier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Here are a couple of links to some Fair-Rite documentation that can help you determine which cores will work for broadband transformers Use of Ferrites in Broadband Transformers http://www.fair-rite.com/newfair/pdf/Broadband.pdf And the current Fair-Rite product catalog http://www.fair-rite.com/newfair/pdf/Fair-Rite_Catalog_17th_Edition.pdf HTH, Dave M Bob Camp wrote: Hi On Nov 27, 2014, at 5:10 PM, Gerhard Hoffmann dk...@arcor.de wrote: Am 27.11.2014 um 23:30 schrieb Bob Camp: Hi Finding the RF transformer parts is still a bit of a challenge. No. These work quite good for me: CX2074 4:1 CT CX2147 1:1 CT To get back to the original post: Which Fair-Rite cores listed on Mouser can be used for making transformers? There are a variety of people making pre-wound parts. Bob http://www.digikey.de/product-search/de/rf-if-and-rfid/balun/3539019?k=cx2074 The 1:1 is optimum for the NIST doubler at the sources, btw. The 4:1 as an autotransformer 9:1 at the drains. (2*BF862). Gives you 13 dBm @ 2f for 13 dBm in at 1f upto 40 MHz in. Still searching a good balun xformer for 800 MHz in.-- 1600 out. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucent KS-24361 Simple Doubler
Give them a call... they are more than willing to sell single pieces of almost any of their products, at the listed lowest quantity price, especially if you are a Ham. I recently bought several items, some of them in single quantities. Many of their MMICs are priced so low that you can easily buy ten at a time. Even with shipping, they are cheaper than buying from the Chinese Ebay sellers. Dave M paul swed wrote: Looks simple but trying to order 1 piece seems a challenge. Minicircuits wants 10 or $59. Not bad but don't need 10 :-) Regards Paul WB8TSL On Tue, Nov 25, 2014 at 6:08 AM, Mike Seguin n1...@burlingtontelecom.net wrote: Paul, W1GHZ has put together a simple doubler for the 5 MHz OCXO in the Lucent boxes. It's based on a Minicircuits part with MIMIC amp. Details here: http://users.burlingtontelecom.net/~n1...@burlingtontelecom.net/images/ Simple_Frequency_Doubler.pdf Mike -- 73, Mike, N1JEZ A closed mouth gathers no feet ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. When the people fear the government, there is tyranny. When the government fears the people, there is liberty -- Thomas Jefferson Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucent KS-24361 Simple Doubler
Paul, there's a list of sales office contacts (depending on your location) at http://www.minicircuits.com/contact/na_sales_reps.html (assuming that you're in North America; if not, go to the International offices link). Dave M paul swed wrote: Dave call?? I don't see a #. I have skype so easy enough. Happy to. Regards Paul WB8TSL On Tue, Nov 25, 2014 at 10:46 AM, Dave M dgmin...@mediacombb.net wrote: Give them a call... they are more than willing to sell single pieces of almost any of their products, at the listed lowest quantity price, especially if you are a Ham. I recently bought several items, some of them in single quantities. Many of their MMICs are priced so low that you can easily buy ten at a time. Even with shipping, they are cheaper than buying from the Chinese Ebay sellers. Dave M paul swed wrote: Looks simple but trying to order 1 piece seems a challenge. Minicircuits wants 10 or $59. Not bad but don't need 10 :-) Regards Paul WB8TSL On Tue, Nov 25, 2014 at 6:08 AM, Mike Seguin n1...@burlingtontelecom.net wrote: Paul, W1GHZ has put together a simple doubler for the 5 MHz OCXO in the Lucent boxes. It's based on a Minicircuits part with MIMIC amp. Details here: http://users.burlingtontelecom.net/~n1...@burlingtontelecom.net/images/ Simple_Frequency_Doubler.pdf Mike -- 73, Mike, N1JEZ A closed mouth gathers no feet Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5342A (18 GHz) vs 5352B (40 GHz) frequency counters
Dr. Kirby, The 5242A Option 001 (high stability) used a 10544 oscillator, which. IIRC, is electrically interchangeable with the 10811. The 5352B Option 010 (high stability) uses the 10811 oscillator. Cheers, Dave M Dr. David Kirkby (Kirkby Microwave Ltd) wrote: I am looking for a microwave frequency counter and won an auction for an 18 GHz 5342A with the GPIB option today @ £200 (GBP). I have just paid for that. I also have the chance to get a 5352B 40 GHz counter for £500. That has GPIB as standard. In the short/medium term I don't see much use for a 40 GHz counter, but I am giving consideration to buying the 40 GHz and selling the 18 GHz one. I would be interested to know if anyone has any opinions on the relative merrits of the two counters. Neither of these counters have ovens, but stability is not a major issue given they take a 10 MHz input. That said, foes anyone know if these take fairly common 10811A ovens? There is a chance I would use it in places where it would not practical to feed in 10 MHz. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] ks... answers The emails are getting long
I think those devices were in the same databook that had a page in the back of the book, containing only the text This page is as blank as a salesman's memory The person who did the final editing on that issue had a rare sense of humor. Dave M Dave Daniel wrote: I remember the Fast and Damn Fast Buffer Amp data sheet. LH0036? I may not be remembering the correct part number. I used to have a copy of that data sheet, as well as another that was labeled DC to Daylight on the data sheet. DaveD On 11/19/2014 2:42 PM, Mike Feher wrote: Hi Doug - Wow. Wonder how many on here remember or know about National's Damn Fast line, HI. I used them all the time, and, still have a few. 73 - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Quad Driven Mixer 5 to 10 MHz Doubler Atricle
I am able to download the files associated with the article, but not the article itself. Guess I need to be a paying member to get the article. The only files in the download are the XLS file for calculating the filter values, and the parts list. It's at http://www.arrl.org/qexfiles in the year 2011 listings, filename 3x11_Roos.zip titled Converting a Vintage 5 MHz Frequency Standard to 10 MHz with a Low Spurious Frequency Doubler Dave M John C. Roos via time-nuts wrote: Several list members contacted me expressing interest in the article. None of them were able to download much or anything from the ARRL QEX web site. That includes me and other ARRL members. I am working the issue with one call to ARRL so far today. I will contact Larry Wolfgang at ARRL and see what Ican bust loose. So hang in there. It is a cute technique, not originated by me, but useful. Right now I have to get the ARRL FMT done first. -73 john c roos k6iql ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Quad Driven Mixer 5 to 10 MHz Doubler Article
Just a few days ago, I ordered parts to build a couple of the Wenzel 2-diode doublers, described in the same article as your full-wave diode doubler, just in time to discover them on Ebay (via slow boat from China), item# 171511157159. I inspected the components and layout in the picture in the listing, and it certainly looks like the Wenzel FWB doubler. At $9.99 USD, the price is cheap enough, especially since you get SMA connectors on both ends. Might have to do a bit of solder work on the SMA connectors if you want to put it into a little box. The listing on the doubler on Ebay says that the low end is 10MHz, but I'll bet that it will get down to 5MHz quite easily If there's any trouble handling a 5MHz input, you could easily use a lower frequency ferrite for the balun and make it work. As you suggest, a BPF on the output and maybe a bit of amplification to get the level up to a usable level should get you a fairly clean 10 MHz. Dave M Brian, WA1ZMS wrote: Gentlemen- I have my paper copy in front of me with the original article. I am not certain that I can just scan it and send it around due to ARRL Author copyright matters. But I am willing to scan it. With all due respect to John, K6IQL the author who spent much time on his design..I would opine that an equivalent doubler could be made from the Wenzel doubler circuits that are on the Wenzel web page and from first-hand experience...I used such a 5-to-10 MHz doubler for all of my amateur radio projects up through 403GHz. The K6IQL design, in brief, splits the 5MHz signal into two paths. One passes to the LO port of a Double Balanced mixer, while the second path goes through a 90-deg phase shift network and into the RF port of that JMS-1MH mixer. The output is taken from the IF port. The output is then buffered filtered. He spent much design effort on the 90-deg phase shift network to keep it all temp stable. Personally, I'm lazy and like the Wenzel full wave rectifier design with a nice BPF on the output to obtain a clean 10MHz. -Brian, WA1ZMS/4 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5300B - HP 5308A Counter Time Base Question...
The time basse oscillator is only a crystal around a logic gate; not exciting at all. The adjustment is on the 5300A unit. There is a hole in the rear panel of the case that allows adjustment. You are going to need a calibrated standard of some kind to calibrate it against. The manuals for both the 5300A and the 5309A are on the Keysight web site at http://www.keysight.com/main/facet.jspx?t=79910.g.3cc=USlc=engsm=gno=0 Cheers, Dave M Burt I. Weiner wrote: I was recently given a HP-5300B / 5308A counter. I thought it might be handy when I'm at an AM broadcast transmitter and needed to make rough frequency measurements. It turns out that at 1000 kHz it reads about 4.5 Hz high. Looking inside I'm not sure if there's a time base adjustment. I looked at the on-line manuals available and I don't find any reference to adjusting the time base frequency. Does anyone here know anything about these counters? Is there a schematic available? I'm not looking for precision, but 4.5 Hz at 1 MHz seems a tad much. Burt, K6OQK Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] UPDATE: HP 5300B - HP 5308A Counter Time Base...
Are yu sure that it's an OXCO? According to the manual that I have, the only option for the 5300B counter unit was option 001, which added a TXCO. The manual doesn't give any data on the Option 001 oscillator, so can't confirm that your oscillator is TXCO or OXCO. If it's a TXCO, it won't get very warm, of course, and there won't be any oven control circuitry. Is there an HP part number on the oscillator module? Cheers, Dave M. Burt I. Weiner wrote: The closest it will adjust is -2.5 Hz of 10. MHz. This unit differs from the one in the manual in that it has a Microsonics OCXO with the adjustment on the side of the module. The oven does not feel warm but is written on the side is: Adjust at 25 Deg C, which is about 77 degrees F. The schematic associated with the oven is missing from the schematic. I suspect that the oven is either shot or not getting power. The unit will not power up with the boards separated so I'm going to have to spend some time hanging wires out the side to make measurements. Does anyone know of a schematic showing the Microsonics module and the associated circuitry for oven control? Not sure if it's worth the effort, but it would be a shame to toss it - that's against my nature. Burt, K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Some specs for MTI Millren 260 OXCOs
I contacted one of the MTI Milliren marketing guys a few days ago, and got some specs on the MTI model 260-0624C and 260-0544C OXCOs that are currently being sold on Ebay. the model 260-0624C is the one used in the Lucent /Symmetricom Z3810A systems. The model 260 is advertised as being close to a Rb in performance. This is all the data that he would give me since I wasn't the original customer for whom they were made. He also says these models are still in low volume production for the customers. 260-0624-C 5MHz, SC- cut crystal, 3rd overtone, 2E-10 over 0 to +75C Phase Noise spec: -100 @ 1Hz -130 @ 10Hz -145 @ 100Hz -150 @ 1KHz -155 @ 10KHz -155 @ 100KHz Also, the 260-0544C 260-0544-C 5 MHz, SC-cut crystal, 3rd overtone, 2E-10 over -30 to +70C Phase Noise spec: -110 @ 1Hz -140 @ 10Hz -150 @ 100Hz -157 @ 1KHz -160 @ 10KHz -160 @ 100KHz Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Z38xx rack mounts
I have a couple questions regarding the Z38xx type units. I have a Z3801A, and a couple other modules that don't need a full 19 rack space. The Z38xx units are 11 wide (10-9/16 mounting centers) , and obviously are not suitable for a standard 19 rack cabinet. Looking in the Z3801A manual, I see that the rack trays that these units are mounted in are 28.5 wide, with a dual mounting shelf so that two GPS units can be mounted side-by-side. Were the racks for these units custom built by Motorola and/or Symmetricom? Where in the civilized world might these cabinets and mounting shelves be found and purchased (preferably surplus)? I've searched Google until my eyes are crossed, but nothing shows up. Maybe I'm not using the right search terms? Don't know. I guess I could destroy an old rack cabinet and fabricate something that would fit the equipment, but I'd prefer to buy one (assuming that it doesn't approximate the cost of a new SUV). Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Some specs for MTI Millren 260 OXCOs
Alexander Pummer wrote: On 10/22/2014 1:57 PM, Scott Newell wrote: At 03:43 PM 10/22/2014, Dave M wrote: Content-Transfer-Encoding: 7bit I contacted one of the MTI Milliren marketing guys a few days ago, and got some specs on the MTI model 260-0624C and 260-0544C OXCOs that are currently Be careful. I bought a couple of those $15 MTI 260-0544-C from a surplus dealer out in California. They were new, from the warmup performance we agreed that they were SC cut, and it sure looked like a double oven. But...no EFC! Hi Scott may I get some copy of that datasheet? thank you in advance Alex Alex, The model 260 datasheet is on MTI's web site at http://www.mti-milliren.com Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Z38xx rack mounts
Mike S wrote: On 10/22/2014 4:44 PM, Dave M wrote: The Z38xx units are 11 wide (10-9/16 mounting centers) , and obviously are not suitable for a standard 19 rack cabinet. The Nortel GPSR (aka HP z3801a) was mounted vertically in a chassis which was itself rack mounted. It's 11 tall, not wide. ___ Wow, that helps explain things a bit. Wonder why, if they were meant to be installed vertically, they wouldn't have screened the legends to be read that way. Anyway, that insight might simplify things for me. I hadn't thought of mounting them that way. I have a couple pieces of rack mounting rails that I could cut and mount horizontally in my 19 rack and everything would fit (hopefully) just right. Thanks for the response, Mike. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Some specs for MTI Millren 260 OXCOs
Scott Newell wrote: At 03:43 PM 10/22/2014, Dave M wrote: Content-Transfer-Encoding: 7bit I contacted one of the MTI Milliren marketing guys a few days ago, and got some specs on the MTI model 260-0624C and 260-0544C OXCOs that are currently Be careful. I bought a couple of those $15 MTI 260-0544-C from a surplus dealer out in California. They were new, from the warmup performance we agreed that they were SC cut, and it sure looked like a double oven. But...no EFC! The model 260 OXCOs are definitely double-oven oscillators. I suppose that it's possible that some OXCO variations might not have the EFC function, but I find that quite unusual, since there is no other means to adjust the frequency of the oscillator (notable exceptions being the HP 10811 and 10544 models). The MTI 260 model, being a very high quality OXCO, surely needs some means to adjust the frequency. Is the EFC pin on the units that you have? If it is present, it's possible that the units that you have are defective. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Stu, Many thanks for the heads-up on htese units. Great deals. Can you advise the size of these units? Are they full-size 19 rack mount or the half-size units like the Z3801A? Can the REF-1 unit (the one with the GPS receiver) be operated separately from the REF-0 unit? There is a mod on Didier's site to add the 10 MHz output to the RFTGm unit at http://www.ko4bb.com/manuals/download.php?file=05)_GPS_Timing/Lucent_RFTGm_RFTGm-II-XO_GPSDO_modification_to_add_10MHz.pdf. I don't know if the mod will apply to the units on Ebay right now, but it's quite possible that it does. Cheers, Dave M Stewart Cobb wrote: Fellow time-nuts, This (long) post is a review of the HP/Symmetricom Z3810A (or Z3810AS) GPSDO system built for Lucent circa 2000. I wrote it because I looked for more information before I bought one, and couldn't find much. It's relevant because (as of this writing), you can buy a full system on the usual auction site for about $150 plus shipping. For those of you lamenting the dearth of cheap Thunderbolts, this looks like one of the best deals going. The description of these objects does not include GPSDO, so time-nuts may have missed it. Search for one of the part numbers in the subject line and you should find it. So what is it? It's a dual GPSDO built by HP as a reference (Redundant Frequency and Time Generator, or RFTG) for a Lucent cell-phone base station, built to Lucent's spec KS-24361. Internally, it's a close cousin of a later-model Z3805A. Externally, it looks to be almost a drop-in replacement for the earlier RFTG system built to Lucent's spec KS-24019. That was a redundant system containing one rubidium (LPRO, in the one I have) and one OCXO in two almost-identical boxes. That spec went through several revisions with slightly different nameplates and presumably slightly different internals. You can generally find one or two examples on the auction site (search for RFTG or KS-24019). ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system
Arg! I read the whole article on the mod but just didn't see the ruler. Oops! Thanks for the alert, Dave M Anthony Roby wrote: In the link below there's a photo of one of the units with a ruler against it - 11 wide. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dave M Sent: Monday, October 20, 2014 10:22 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system Stu, Many thanks for the heads-up on htese units. Great deals. Can you advise the size of these units? Are they full-size 19 rack mount or the half-size units like the Z3801A? Can the REF-1 unit (the one with the GPS receiver) be operated separately from the REF-0 unit? There is a mod on Didier's site to add the 10 MHz output to the RFTGm unit at http://www.ko4bb.com/manuals/download.php?file=05)_GPS_Timing/Lucent_RFTGm_RFTGm-II-XO_GPSDO_modification_to_add_10MHz.pdf. I don't know if the mod will apply to the units on Ebay right now, but it's quite possible that it does. Cheers, Dave M Stewart Cobb wrote: Fellow time-nuts, This (long) post is a review of the HP/Symmetricom Z3810A (or Z3810AS) GPSDO system built for Lucent circa 2000. I wrote it because I looked for more information before I bought one, and couldn't find much. It's relevant because (as of this writing), you can buy a full system on the usual auction site for about $150 plus shipping. For those of you lamenting the dearth of cheap Thunderbolts, this looks like one of the best deals going. The description of these objects does not include GPSDO, so time-nuts may have missed it. Search for one of the part numbers in the subject line and you should find it. So what is it? It's a dual GPSDO built by HP as a reference (Redundant Frequency and Time Generator, or RFTG) for a Lucent cell-phone base station, built to Lucent's spec KS-24361. Internally, it's a close cousin of a later-model Z3805A. Externally, it looks to be almost a drop-in replacement for the earlier RFTG system built to Lucent's spec KS-24019. That was a redundant system containing one rubidium (LPRO, in the one I have) and one OCXO in two almost-identical boxes. That spec went through several revisions with slightly different nameplates and presumably slightly different internals. You can generally find one or two examples on the auction site (search for RFTG or KS-24019). ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
Chris Albertson wrote: On Thu, Oct 16, 2014 at 7:51 PM, Dave M dgmin...@mediacombb.net wrote: Thanks, Chris. I've done a bit or research on the subject, and think I have a reasonable grip on the necessary steps. I have an 8' ground rod driven into the ground directly under the spot where my antennas mount. #6 solid copper from the rod to a heavy aluminum plate, where the arrestors will be mounted. A #6 solid copper wire from the plate to the antenna mounting structure. About the only thing you left out is the interconnection between this new ground rod and the existing house ground. Sounds like you must live in Florida. The best source of information is the lightening lab at University of FL. I've never read a good research backed paper on plastic v. metal conduit. I bet it does matter. I use iron pipe outdoors then after it gets indoors switch to plastic. Practical reasons. The flexible plastic conduit is just easier to use Actually, I lived in Florida for about 40 years, retiring to north Alabama about 5 years ago. about 6 of those years were spent working at a Motorola 2-way radio shop. So, yes, I'm pretty familiar with the damages that lightning can cause, and some of the precautions that help minimize susceptability and damage. As I posted earlier, I've seen writings promoting metallic and non-metallic conduit for the antenna coax. I can see reasons for placing the coax in metallic conduit. But, one thing that I've read that is consistent, is NOT to run the earth ground wire in metallic conduit. That's to keep the current to ground in a solid, unbroken path, which the fittings used to join conduit can't provide. OK to run it in non-metallic conduit to keep it out of the weather. Since my coax run is only about 20 ft, I'm thinking that I should be OK with the coax in 1/2 galvanized steel conduit. I agree that the metallic conduit should stay outside, and not be connected to the equipment ground inside. I'll run a separate ground wire from the equipment rack to the ground rod outside. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
John Allen wrote: Hello All - There is a 500+ page document on grounding, lightning protection and more - Google for: STANDARDS AND GUIDELINES FOR COMMUNICATION SITES Motorola R56 2005 Regards, John K1AE Great document! Thanks for the link Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Lightning arrestors for GPSDO antenna
I'm looking for effective coaxial lightning arrestors for my GPSDO antennas. I've seen several types; those completely enclosed in a one-piece metal enclosure (no replaceable components) and those having a replaceable gas discharge tube seem to predominate the list. I'm looking closely at the gas discharge tube types, and am curious as to their effectiveness and durability. I'd like to know stuff like; are they effective in dissipating a static charge, how do I know when the gas tube needs to be replaced, are the gas tubes of a special type, are replacement gas tube easily available, etc. I'm interested in opinions and experiences with arrestors and recommendations for which type is most effective. Thanks for comments, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
Thanks, Chris. I've done a bit or research on the subject, and think I have a reasonable grip on the necessary steps. I have an 8' ground rod driven into the ground directly under the spot where my antennas mount. #6 solid copper from the rod to a heavy aluminum plate, where the arrestors will be mounted. A #6 solid copper wire from the plate to the antenna mounting structure. I will also have an arrestor at the antenna input of each GPSDO unit, which will be mounted on a 2 wide copper strap, which will be then run to the outside ground rod with a doubled 1 wide copper braid. I realize that extremely low ground resistance is fantastic, but I don't have access to a ground resistance set, so I'll have to accept what I have and accept the consequences if something happens. A second ground rod isn't out of the question, but will have to wait until my broken wrist heals so I can swing a sledge hammer. I'd still like to hear comments on the effectiveness of gas discharge type arrestors. A question has bothered me for a while, but can't find a definitive answer. Should I enclose the antenna feedline in metal conduit or nonmetal conduit? I've seen documents that state that metal conduit is the best way, and others stating that metal conduit shouldn't be used Anyone have a good answer (talking about antenna feedline; not the grounding wire)? Thanks, Dave M --- Chris Albertson wrote: Lightening arrestors are an important part of a protection system but just installing some in the antenna cable is not going to help so much. You need a system approach. If you do it right you can take a direct hit The big problem with grounding is Ohm's Law. That is if any current flows in a conductor that has resistance there will be a voltage across the conductor equal to the current times the resistance. But with lightening you can have 100,000 amps of current in a ground wire. If that wires has 0.01 ohms of resistance you have 1,000 volts above true ground on your ground connector on the lightening arrestor. Your ground is no longer at ground. You need some very tiny resistances and to get that you are going to need to do things like using multiple ground rods and large conductors. And connecting grounds together. On Thu, Oct 16, 2014 at 4:34 PM, Dave M dgmin...@mediacombb.net wrote: I'm looking for effective coaxial lightning arrestors for my GPSDO antennas. I've seen several types; those completely enclosed in a one-piece metal enclosure (no replaceable components) and those having a replaceable gas discharge tube seem to predominate the list. I'm looking closely at the gas discharge tube types, and am curious as to their effectiveness and durability. I'd like to know stuff like; are they effective in dissipating a static charge, how do I know when the gas tube needs to be replaced, are the gas tubes of a special type, are replacement gas tube easily available, etc. I'm interested in opinions and experiences with arrestors and recommendations for which type is most effective. Thanks for comments, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. When the people fear the government, there is tyranny. When the government fears the people, there is liberty -- Thomas Jefferson Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Pete, I see a ZAPD-30 on the miniCircuits web site. Might those be the models that you have? If so, (and assuming that you can find them), how much for a couple? Thanks, Dave M Peter Loron wrote: Dave, I think I have a MiniCircuits ZAPD-3(?) splitter or two kicking around. I'll try to get a look in the stash this weekend. -Pete On 2014-10-06 13:01, Dave M wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Thanks, Tim, I have wondered about the available antenna current from GPSDO units, but haven't been able to find a spec on any of them, or at least, the GPS units that I have. I have an HP Z3801A and a Nortel GPSTM NTBW50AA. Have you (or anyone) any information on typical available antenna current, or alarm conditions for antenna overcurrent? I know the Nortel unit spec says that it can survive a shorted antenna/cable without damage, but no info on alarms or current limits. My guess is that the unit won't see any satellites and will just go into holdover. The Z3801A must have an active antenna connected (no passive antennas allowed), but no specs in the manual on antenna current limits. I guess I could substitute an active load (transistor or FET) for the antenna so I can vary the current drawn, and see what alarms pop up. Thanks for more info, Dave M Tim Shoppa wrote: At the very low end, a F-cable splitter for like Cable TV will likely (*) get the job done. Many of us are already using RG-6 type cable for the GPS antenna run anyway. (*) Some GPS units may get confused if they have active sensing on the antenna preamp current and this goes out of tolerance. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
I haven't been able to find any information on antenna spacing on any of the GPS mfr's or antenna mfr's web sites. Maybe I just don't know the correct search terms. Can anyone point me to a source for that kind of data? There's a LOT of information about GPS, GPSDO and antennas on the web, and I'll admit that I haven't read it all, but there's just not enough time in a day, and my eyes can't stand the strain to read everything. Point me in the right direction and I'll take it from there. Thanks!! Dave M Bob Camp wrote: Hi You might want to check the spacing spec’s on the antennas you have. Some of them have fairly large spacing recommendations (like 10 feet). Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Bob, Thanks for that. My intent was to mount the antennas on yardarms on a mast. Both antennas will be at the same elevation, just separated horizontally by a couple feet (not 10ft). My concern (and I think you answered it) was how far apart could I place the antennas without having to do another survey when I switch them around. As an alternative, I could enter the antenna coordinated manually into each GPS when I switch antennas. That should avoid a new survey each time. Then, the distance between the antennas shouldn't matter. Thanks for the info!! Dave M Bob Camp wrote: Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
John, I found a couple Mini-Circuits ZAPD-2 splitters on Ebay for around $22 each, including shipping. There's still more on Ebay right now, connector style and pricing varies. They're passive splitters, but my antennas have 26 and 35 db gain, respectively, and the cable run is relatively short (about 15 ft of RG-223 from each antenna). There should still be adequate signal available at the receivers, even with the passive splitters. Cheers, Dave M John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Thanks for that link, Brooke. I might give that a try, just because it's so cheap. I'll need a couple bias tees to get power to the antennas, regardless of which splitter devices that I settle on. Cheers, Dave M Brooke Clarke wrote: Hi: This works great and has minimal cost. http://www.prc68.com/I/4GPS.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] WTB: GPS Antenna Splitter
Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Have some Leica/AeroAntenna Tech Inc Choke Ringantennas for sale
I'll speak for one of the antennas... Shipping will be to zip code 35750. Let me know the cost and I'll pay immediately. How do you prefer to get payment? Paypal is good for me, or personal check if you desire. dave M Pete Lancashire wrote: I've acquired a few new in the box Leica/AeroAntennas. Some boxes have been opened. https://plus.google.com/u/0/photos/111617808980322733757/albums/6052074218781475313 The complete assemble is Leica P/N 10147 The 'puck' antenna is P/N 10160 I would like to have Time-Nuts get first dibs Does $100 + shipping sound reasonable ? The box is 16 x 16 x 16 and weighs 11 lbs. -pete ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Practical Survey-In Accuracy?
Attila Kinali wrote: On Thu, 28 Aug 2014 06:30:14 -0700 Bob Stewart b...@evoria.net wrote: Is wood, nails, and asphalt shingle really that big of a problem at these frequencies? The antenna is within 2 ft of the highest point of the roof. Consider this: A lot of people complain about the reflections caused by trees. But what is a tree? It's mostly air and a few leaves, with a branch here and there. Also: 60cm is less than 2λ. ie the roof is in the near field of the antenna, where everything causes a change of the antenna behaviour (resonance frequency, radiation pattern, phase centre etc) Depending on what you do with the GPS signal, you might or might not care about that. If you are a nutty time-nut and want to wring out ever last bit of jitter out of your PPS, then you will care about the effect of the roof. Attila Kinali In light of these posts about antennae and reflections, etc., I have a similar question. I'm planning to move my workbench out of my attached garage into a separate garage building. The new garage is about 24' x 36', and has a metal roof. My plan is to mount my GPS antenna atop a metal pipe mounted at the peak at the end of the gable roof. How far above the metal roof should I mount the antenna so reflections will be minimized, at least to the point of diminishing returns? The antenna will have a pretty good view of the sky from that location. Any other issues that I should be aware of when dealing with a metal roof? Thanks, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFC info on Trimble 34310-T OXCO
I found the parameters for the X72's 1PPS input. The range of Tau is 5 - 10,000 seconds, or about 2 hrs, 45 min. at the longest setting. It defaults to 400 seconds. However, mine doesn't have the firmware to enable the 1PPS input, so it really doesn't matter. Out of curiosity, does anyone know of any Rb units that can be programmed to a 24 hr (or longer) Tau, either by EFC or 1PPS input? Dave M Bob Camp wrote: Hi It is not what is done in the Efratom Rb’s. Their pps input is set up to get things on frequency / on time quickly. The assumption is that you plug it into a pps to get it “right” and then take off on your mission. That takes them into the short (for a Rb) time constant region. Bob On Aug 24, 2014, at 5:56 PM, Brooke Clarke bro...@pacific.net wrote: Hi Bob: I think that's what's done in the SRS PRS10 http://www.prc68.com/I/PRS10.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Bob Camp wrote: Hi If you lock an Rb to GPS, you need / want / should do it with a *very* long time constant. Numbers in the one day to several days range are commonly seen. If you lock it up with a tighter (shorter time constant) loop, it will just wander around as it follows the GPS input. That’s what would happen if you hook your Rb to your Trimble and turn on the disciplining on the Rb. It will significantly degrade the stability of the Rb. If you have a temperature stable environment (or create one) you can get some very good results with an (good) Rb locked to a (good) GPS via a proper long time constant setup. It’s not easy, but it can be done. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFC info on Trimble 34310-T OXCO
Charles Steinmetz wrote: Dave wrote: does anyone know of any Rb units that can be programmed to a 24 hr (or longer) Tau, either by EFC or 1PPS input? The SRS PRS10 has a very versatile PPS input that can discipline its frequency with a truly comprehensive array of adjustments (to the point of potential bafflement). The PRS10 and a good PPS source can make an excellent GPSDO. (Note that the PRS10 is, by itself, one of the best compact Rb oscillators available.) The PRS10 manual has a good explanation of the PPS operation at pp.14-17 and 33-36: http://www.thinksrs.com/downloads/PDFs/Manuals/PRS10m.pdf Best regards, Charles Thanks for that, Charles. I've seen a number of articles about the PRS-10, but never really read them closely. I'll download the manual and see if I can understand what it's all about. I might have to put a PRS10 on my wish list. Thanks again, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFC info on Trimble 34310-T OXCO
Hi Dave, On 8/23/2014 3:51 PM, Dave M wrote: Thanks for that suggestion, Ed. After a bit of reading in the X72 Reference Guide, it appears that the X72 does have a 1PPS input. That would be considerably easier than trying to interface the Rb into the GPSDO. Still trying to understand what the manual is telling me. Next thing is to determine if my unit has that option enabled (firmware option). That will be a chore for after the holiday... really busy next week. What would that (1PPS disciplining) do for me... in terms of maintaining the Rb frequency accurately set? Would it be as accurate as having the Rb disciplined via the EFC input? It's kind of overkill, but by connecting the 1 PPS from the NTBW50AA to the X72, the X72 will be disciplined to the 1 PPS so the frequency will be accurate. The question is how well will it be disciplined, i.e. what will the Allen Deviation graph look like. I have a few X72 and SA-22c (X72's cousin), but none of them have that option. I don't know of any published data on it. Maybe you can tell us how well it performs. In general, I just don't see the point of disciplining a Rb standard to GPS. I don't understand what will be gained by doing it. I have a Z3801A and a Tbolt plus a free-running FRK as a house standard. I occasionally compare the FRK to the Z3801A but the drift is so low (~1e-12 per month over 9 months) that I see no reason to link them. One exception that I recently discussed on another forum was a guy who lives in a ground floor, north-facing condo. He might need to have a disciplined Rb standard due to poor GPS visibility. Ed Sorry for forgetting to change the Subject line on my last post. I see the futility of trying to integrate a Rb oscillator into a GPS receiver. As it turns out, my X72 doesn't have the 1PPS input option enabled, so that's a moot point. end result: I now have a couple of GPSDOs and a Rb that I can use separately, as needed. I would like to have a frequency comparator that can handle 10 MHz inputs natively without having to divide them down to 5 MHz. I have a Fluke/Montronics model 103A Frequency Comparator, but its max frequency input is 5MHz. I have a TADD-2 divider board, but I want to build a two-channel divider board to dedicate to the Fluke comparator. Which logic family is most suitable for such use; ALS, AC, etc.? Low jitter would be the critical parameter? I only need to divide by and 10, and maybe 100. My original dream, and the impetus for this thread, was to have a frequency standard having the excellent short-term stability of the Rb, but have it disciplined to the GPS to maintain its long-term accuracy without having to correct the Rb manually. My conclusion; it's now quite obvious that the old-school manual method is probably easiest and best. I'll set the frequency on the Rb, watch its performance for a few months, and use it as the main frequency source for my bench. Thanks for all the advice. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 121, Issue 65
Thanks for that suggestion, Ed. After a bit of reading in the X72 Reference Guide, it appears that the X72 does have a 1PPS input. That would be considerably easier than trying to interface the Rb into the GPSDO. Still trying to understand what the manual is telling me. Next thing is to determine if my unit has that option enabled (firmware option). That will be a chore for after the holiday... really busy next week. What would that (1PPS disciplining) do for me... in terms of maintaining the Rb frequency accurately set? Would it be as accurate as having the Rb disciplined via the EFC input? Thanks, Dave M Message: 5 Date: Fri, 22 Aug 2014 16:19:45 -0600 From: Ed Palmer ed_pal...@sasktel.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] EFC info on Trimble 34310-T OXCO Message-ID: 53f7c201.5070...@sasktel.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Have you checked your X72 to see if it has the 1 PPS discipline option? That would be a lot easier (and probably better) than your proposed transplant. Ed On 8/22/2014 12:39 PM, Dave M wrote: Does anyone have any info on the OXCO in the Nortel/Trimble NTBW50AA-17 GPSTM receiver? The OXCO is labeled as Trimble 34310-T. I see some Trimble 34310-T oscillators on Ebay with pinouts labeled, but no other info. Specifically, I'd like to know the EFC characteristics for it. I'm thinking of the possibility of pulling the OXCO out of the GPSTM and subbing in a 10 MHz Rubidium, and using the GPSTM to discipline the Rubidium. My Rubidium is a Symmetricom X72, recently purchased. It seems to be working well. Does anyone know the differences between the three OXCOs used in the GPSTM receivers (T, T2 and Oak)? Thanks for some insight, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] EFC info on Trimble 34310-T OXCO
Does anyone have any info on the OXCO in the Nortel/Trimble NTBW50AA-17 GPSTM receiver? The OXCO is labeled as Trimble 34310-T. I see some Trimble 34310-T oscillators on Ebay with pinouts labeled, but no other info. Specifically, I'd like to know the EFC characteristics for it. I'm thinking of the possibility of pulling the OXCO out of the GPSTM and subbing in a 10 MHz Rubidium, and using the GPSTM to discipline the Rubidium. My Rubidium is a Symmetricom X72, recently purchased. It seems to be working well. Does anyone know the differences between the three OXCOs used in the GPSTM receivers (T, T2 and Oak)? Thanks for some insight, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP5370 extender cards?
Count me in!! Approx how long should they be ready to ship after you decide to proceed with the order? I can prepay if necessary. Thanks!! Dave M From: Mark Sims hol...@hotmail.com Well, after doing my TM500 extender cables, I was thinking of doing an extender board for the HP5370 boards. It would take two 36 pin extender cards to extend a card out of the card cage (the count chain board has a different connector spacing than the other boards so splitting the extender onto two boards lets one be able to extend the count chain board also). The board at the front of the unit has a different pin-count connector than the other boards and may not warrant doing its own extender card. Is there any interest out there in HP5370 extender cards? Depending upon quantity, cost should be in the $15 to $20 range. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Setting Windows XP clock.
Max, In the Control Panel, click on Date Time. In the date Time Properties window, click the Internet Time tab. Make sure the Automatically synchronize with an Internet time server box is checked. In the Server: box, copy the following server name and paste it into the Server box: time-c.timefreq.bldrdoc.gov The time date gets automatically updated once a day. You can always open this window and click the Update Now button to get an immediate update. This should keep your clock on time. Cheers, Dave M time-nuts-requ...@febo.com Message: 3 Date: Sat, 12 Jul 2014 18:29:37 -0500 From: Max Robinson m...@maxsmusicplace.com To: Time Nuts time-nuts@febo.com Subject: [time-nuts] Setting Windows XP clock. Message-ID: 489AE09B208C407DBA46BA7A9EB415A2@BACKROOM Content-Type: text/plain; format=flowed; charset=iso-8859-1; reply-type=original As some of you no doubt know microshaft has stopped supporting windows XP. As part of this they have ceased to correct windows XP clocks. This seams rather small of them as it can't possibly be any inconvenience to them to continue to provide this service. I have a program on my old 98 box which runs my weather station program. On boot-up it contacts some place and corrects the system clock. I put it on that machine so long ago I don't remember where I got it or who it contacts. Does anyone know of a program I can download that will do the same for my XP box. I have no intention of upgrading until this box becomes absolutely un-operational. Regards. Max. K 4 O DS. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Ovenair OSC 49-38B
Date: Wed, 29 Jan 2014 21:31:36 -0600 From: dth854 dth...@airmail.net I have one of these oscilators and wanted to test it. I saw your post on time-nuts, do you still have the connection information and did you find a schematic? Thanks for any help you can give. Dave T Dave, if you download the service manual for the EIP Microwave model 545A counter, you'll have all the connections and the specs as well. The OSC 49-38B oscillator has an alternate part number of 2030010-03, and is used in the EIP 545A counter as a time base option. Download the counter manual at www.qsl.net/n/n9zia//test/EIP_545A_Service_Manual.pdf? It's about a 47 Mb download, so if you're on dialup, let me know and I'll extract the details for you. Happy downloading! Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFC divider resistors
To all those time-nuts (volt-nuts as well) who have been chatting about temperature controlled environments, here is my input. I found a very neat ready-built controlled oven at a number of hamfests in the southeast (Florida Alabama) that work quite well to enclose small circuits that need to be temperature controled I found them still being sold by Fair Radio (www.fairradio.com) for only $12 apiece. Schematic is included to increase their value to us hackers. Their catalog number is OSC-8004290G1. The outside dimensions of the box is 6.5x2x3.3 inches, with about 0.5 inches of insulation and inner enclosure. They were used in Army GRT-21/22 transmitters, and contain all the necessary temperature control circuitry, as well as a crystal oscillator. I bought a couple of these gems and removed the oscillator circuitry and had a nice oven assembly with enough room inside to house a lot of circuitry for just about any thing requiring close trmperature control. It's designed to run at 75C, but with a few resistor changes, the temperature can be lowered if desired. It's insulated pretty well, too. Not a power miser by any stretch, but it has lots of potential. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] ThunderBolt Display
Date: Thu, 15 Aug 2013 10:22:10 -0700 From: Eric Garner garn...@gmail.com Is anyone else having difficulty submitting a request for an order form? On Wed, Aug 14, 2013 at 10:36 AM, Chris Albertson albertson.ch...@gmail.com I sent an email requesting the order form; got a quick reply saying that he is getting a feel as to how many assemblies he needs to have made. He says that there are a number of repeat orders as well. I guess that we just need to be patient and he'll get back to each one that wants to place an order. Quoting his reply to me: === Hi David I am just getting a feel for numbers, but I will be able to send you an order form soon. Have you on the list though. I'm getting quite a few repeat orders from previous satisfied customers as well. I must have done something right. Will be in touch. Cheers, Adam, VK4GHZ Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
