Re: [time-nuts] Test equipment / work benches...

My lab/workshop is my dining room (it's great being single) and I just went out and bought a very sturdy workbench that was on our auction site from a person just across town. The top was pretty poor and grubby so I just skimmed it with a sheet of plywood and it came up nice. I had to assemble the

Re: [time-nuts] Z3815A

Murray, 2010/1/19 Murray Greenman : > There are at least 20 Z3815A units in ZL Amateur hands that I know of, > and many more in VK. They were 'rescued' by a friend in VK, and have > been distributed with firmware and manual that we've worked out for > them. As far as I can make out, they were not

[time-nuts] DMTD Question

Allow me to add some comments to this subject. Five month ago I set out to make a DMTD that would be $ 200 max and be such that any one can build it with readily available parts. The unit also includes five counters yielding a resolution of 1 E-15. Using five counters not only gives Allan Va

Re: [time-nuts] OT: DMTD Question

Hi I will be running with both of the input ports on the mixer saturated. In that case, it's not clear that I'm worried about harmonic distortion in the isolation amplifiers. I get plenty of that when I saturate the mixer ports. There are indeed other kinds of distortion in an amplifier and the

Re: [time-nuts] DMTD Question

Hi I think you will find that the SYPD-1 (or RPD-1) is the better choice compared to the SRA-1. Are the schematics out there for the curious to look at? Thanks! Bob On Jan 25, 2010, at 7:01 AM, ewkeh...@aol.com wrote: > Allow me to add some comments to this subject. > Five month ago I set o

Re: [time-nuts] DMTD Question

FWIW 100 boards will likely cost not a great deal more (say $5-20 depending on board size than ten. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: 25 January 2010 12:01 To: time-nuts@febo.com Subject: [time-

Re: [time-nuts] DMTD Question

I am not familiar with FWIW 100. Tell me more. ThanksBert Kehren In a message dated 1/25/2010 8:22:30 A.M. Eastern Standard Time, david.partri...@dsl.pipex.com writes: FWIW 100 boards will likely cost not a great deal more (say $5-20 depending on board size than ten. Dave -Origi

Re: [time-nuts] DMTD Question

Translation: FWIW == For What It's Worth So, one hundred boards will probably cost only a little more than ten boards. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: 25 January 2010 13:27 To: time-nuts@feb

Re: [time-nuts] DMTD Question

Bob, the mixer/Filter op amp schematic is a direct copy of the NBS unit with late model op amps, comparator and an opto coupler in stead of the transformer. Isolation amps are actually MINI CIRCUITS the next version will be op amps. I will ask Richard to release the counter schematic. Since

Re: [time-nuts] Test Equipment Tables

You can make a lighter, stronger, more rigid tabletop using torsion box construction. Use 1/2 plywood for the top and bottom. Use 1x1 strips of a hardwood such as poplar to crate a lattice spaced at 6 inch intervals in between, glued along the lengths of the lattice. I use brads during construc

Re: [time-nuts] DMTD Question

Going from 10 boards to 100 will reduce board cost by about 10%. Depending of the final version the qty. 10 cost will be either $ 29 or 36.That is for mixer and counter board. Take out $9 if you will not use the counter. Bert In a message dated 1/25/2010 8:44:29 A.M. Eastern Standard

[time-nuts] Conducting Bench Top Material

My electronic bench is an old commercial one made with steel stampings and a steel top covered with Masonite. The Masonite is still in fair condition. Although over the years the non-conductive top has been an asset in avoiding short circuits, etc., I am concerned about static discharges

Re: [time-nuts] Conducting Bench Top Material

I use "Stat-Les" anti-static floor finish on my benches. You can find it at Legge Systems, http://www.leggesystems.com/c-177-static-control-floor-care-products.aspx The price is pretty good for the 1 quart size bottles ($20 or so) and that does a lot of benches. -Bob, N3XKB On Mon, Jan 25, 201

[time-nuts] Migrating to heavy duty work benches...

Mike, That vice outta hold those LNB and feed horns while you work on them! I have a metal working table that is actually an old TDZ transmitter case. I gave away the three transmitter doors about 40 years ago and just kept the case. It makes a great storage place for scrap metal and such.

[time-nuts] DMTD Question

Your board costs are WAY out of line... Are the boards 2 layer or 4 layer? You can get 2000 square inches of 2 layer boards for 12 cents/sq in + $120 setup. 4 layers are around 20 cents/sq in + $320 setup. See mylydia.com I would layout the two boards side by side and connected like th

Re: [time-nuts] DMTD Question

> -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Mark Sims > Sent: Monday, January 25, 2010 8:53 AM > To: time-nuts@febo.com > Subject: [time-nuts] DMTD Question > > > > Your board costs are WAY out of line... Are the boards 2

[time-nuts] Low temperature coefficient capacitors for DMTD

Bert Kehren and I are working on a low cost DMTD system. We are cloning the NBS 106D design with modern components. You might want to check out PPS dialectric capacitors. (Polyphenylene sulfide) Readily available in many values including large ones. For stability from –55° to +85°C, PPS is virt

Re: [time-nuts] DMTD Question

Before any body gets upset, I said before I used the wrong price calculator. The present mixer/counter takes up 4.3 by 5.3 inches, can be separated into two boards and in 100 qty would be $ 9.60 with silk screen and solder mask. Bert Kehren In a message dated 1/25/2010 12:10:43 P.M. Ea

[time-nuts] Low temperature coefficient capacitors for DMTD

Almost forgot! The reason I posted the original message was the reference to "four inch long plastic capacitors" The PPS capacitors are quite compact and available in surface mount too. Corby Diet Help Cheap Diet Help Tips. Click here.

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

Hi The plastic capacitors I have sitting in stock last saw service with the Soviet era navy. They probably are rated to survive a direct torpedo hit on the submarine. Small and compact did not seem to figure into their design. Bob -Original Message- From: time-nuts-boun...@febo.com [mail

Re: [time-nuts] Conducting Bench Top Material

Bruce wrote: Although over the years the non-conductive top has been an asset in avoiding short circuits, etc., I am concerned about static discharges when handling modern semiconductors. Would it make sense to spray the Masonite with a weak copper sulphate or similar solution so as to make

Re: [time-nuts] Conducting Bench Top Material

In message <20100125182712.7014911b...@karen.lavabit.com>, "Charles P. Steinmet z" writes: >Bruce wrote: >I notice that many folks who have contributed on this thread use >anti-static benchtops, but I have never found it necessary [...] My worktable has a surface of hardwood-floor-boards and a p

Re: [time-nuts] Conducting Bench Top Material

Hi Charles, I'm in a similar boat where I've worked with static sensitive parts without any problems without having so much as put on a wrist strap. It's just never been an issue, even with our RH sitting around 12% here in New Mexico. I've been shoulder deep in Cray and SGI supercomputers witho

Re: [time-nuts] Conducting Bench Top Material

> -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Charles P. Steinmetz > Sent: Monday, January 25, 2010 10:27 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Conducting Bench Top Material > >

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

Corby Dawson wrote: > Bert Kehren and I are working on a low cost DMTD system. > > We are cloning the NBS 106D design with modern components. > > You might want to check out PPS dialectric capacitors. (Polyphenylene > sulfide) > > Readily available in many values including large ones. > > For stabi

[time-nuts] Hp 3750A

Hi TN's I have an Hp 3750A interval counter for parts. Front panel bezel is missing, as is the time base. It had a 10544A in it, I think. All other boards, etc. are there; condition unknown except no smoke escapes when fired up, and all 8's on reset. I want to clear up some shelf space so I'd rath

Re: [time-nuts] Conducting Bench Top Material

I've still got a paper copy of an HP Bench Brief from 1983 that was one of my first introductions to the dangers of ESD. I've used a wrist strap and antistatic mat since then. ESD protection in the ICs has improved since then, but I think that the article is still mostly applicable today. h

Re: [time-nuts] Hp 3750A

At 01:57 PM 1/25/2010 , Don Latham wrote: > >Hi TN's I have an Hp 3750A interval counter for parts. Front panel bezel >is missing, as is the time base. It had a 10544A in it, I think. >All other boards, etc. are there; condition unknown except no smoke >escapes when fired up, and all 8's on reset.

Re: [time-nuts] Test Equipment

Late to the party, I know, but I'd like to put in another recommendation for the DG8SAQ VNA. It's cheap, accurate, and best of all -- SMALL! It occupies 4"x3"x2" and so doesn't take up a whole desk. If 1.3GHz is enough for you, that might be the way to go. You get about 90dB of dynamic range. Y

Re: [time-nuts] Conducting Bench Top Material

So looking at ESD mat material at Digikey, there appears to be a bewildering array of choices. Elastomer, rubber, vinyl, thermoplastic, laminate, foam rubber, and polyethelene. Any guidelines about what to choose? Scott On Jan 25, 2010, at 11:59 AM, Ed Palmer wrote: I've still got a pape

Re: [time-nuts] Hp 3750A

Don Latham wrote: Hi TN's I have an Hp 3750A interval counter for parts. Front panel bezel is missing, as is the time base. It had a 10544A in it, I think. All other boards, etc. are there; condition unknown except no smoke escapes when fired up, and all 8's on reset. I want to clear up some shel

[time-nuts] HP58534A - Got it working and found manual.

I finally got back to working on the HP58534A GPS Timing Antenna. Because it uses RS-422 instead of RS-232 I had put it off after initially scoping it. I got an RS422/RS232 to Ethernet converter on ebay to connect it and finally got it working. The output is NMEA with additional Private $PFEC s

Re: [time-nuts] Conducting Bench Top Material

My first job was in a blasting cap plant in 1960. There were military devices so sensitive they could be set off by turning on a nearby fluorescent desk lamp. I learned that the human body has a capacitance of 400 pico F. Getting up from a chair could raise a couple of kilovolts. We walked on cond

Re: [time-nuts] Hp 3750A

Hi Jim: Did you send a message? Don Jim Cotton > Don Latham wrote: >> Hi TN's I have an Hp 3750A interval counter for parts. Front panel bezel >> is missing, as is the time base. It had a 10544A in it, I think. >> All other boards, etc. are there; condition unknown except no smoke >> escapes when

Re: [time-nuts] DMTD Question

I'm not learning anything from this thread because I don't know the purpose of DMTD or how it would produce a beat note for a phase error. Now, DTMF I understand. Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to http

Re: [time-nuts] Hp 3750A

Scott: I appreciate that! But I need to get rid of the whole thing. If I do peddle it, I can let you know who bought it, and maybe...; Don Scott Newell > At 01:57 PM 1/25/2010 , Don Latham wrote: >> >>Hi TN's I have an Hp 3750A interval counter for parts. Front panel bezel >>is missing, as is the

Re: [time-nuts] Hp 3750A

At 03:26 PM 1/25/2010 , Don Latham wrote: >Scott: I appreciate that! But I need to get rid of the whole thing. If I >do peddle it, I can let you know who bought it, and maybe...; Yeah, that's what I'm thinking too. -- newell N5TNL ___ time-nuts maili

Re: [time-nuts] DMTD Question

DMTD = Dual Mixer Time Difference It's a system for improving resolution of frequency stability measurement. You use a common low noise oscillator to separately mix both the device under test and the reference source down to a low frequency (usually between 1 and 100 Hz), then use a time inte

Re: [time-nuts] Conducting Bench Top Material

> -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Bill Hawkins > I learned that the human body has a capacitance of 400 pico F. > Getting up from a chair could raise a couple of kilovolts. We > walked on conductive rubber floors we

Re: [time-nuts] DMTD Question

Bill Hawkins wrote: I'm not learning anything from this thread because I don't know the purpose of DMTD or how it would produce a beat note for a phase error. Now, DTMF I understand. Bill Hawkins A dual mixer time difference (DMTD) system for 10MHz with a 10Hz beat note frequency would u

Re: [time-nuts] Conducting Bench Top Material

Natural materials like wood, cotton, wool and even concrete have an equilibrium water content that changes with ambient relative humidity. This makes these materials conductive but not conductive enough to carry dangerous currents. They are still good insulators for mains voltage. The texti

[time-nuts] Low temperature coefficient capacitors for DMTD

The NBS DMTD uses a .15uf polycarbonate capacitor for the filter channel. The polycarbonate TC is a bit better than the PPS but they are hard to find for the "mini" DMTD at a decent cost. Most manufacturers no longer make polycarbonate capacitors. The substitution of the PPS capacitors into the

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

In message <20100125.140436.3508.5.cdel...@juno.com>, Corby Dawson writes: >Most manufacturers no longer make polycarbonate capacitors. The advent of CD's made polycarbonate ridiculously expensive and priced them out of the market... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

Corby Dawson wrote: The NBS DMTD uses a .15uf polycarbonate capacitor for the filter channel. The polycarbonate TC is a bit better than the PPS but they are hard to find for the "mini" DMTD at a decent cost. Most manufacturers no longer make polycarbonate capacitors. The substitution of the PP

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

Polycarbonate film production ceased about 10 years ago. Bruce They're not quite dead yet... http://www.polycarbonatecapacitors.com/ But I wouldn't use them unless forced to at gunpoint, since they are quite the boutique item these days. I too have had good success with the PPS capacitors

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

> -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of David Forbes > Sent: Monday, January 25, 2010 2:22 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Low temperature coefficient capacitors for

Re: [time-nuts] Conducting Bench Top Material

Good golly Neville,? you were a young boy in 1910?? Jerry From: Neville Michie Subject: Re: [time-nuts] Conducting Bench Top Material A great insight to the static electricity problem came from articles I read as a young boy in old (1910)articles such as "

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

In message , "Lux, Jim (337C)" writes: >Seems that boutique item and time-nut might go together, if there >was an actual performance advantage. Besides, think of the bragging >rights from some of this stuff. It could be worse than audiophile >craziness: [...] Thanks for pointing that little sho

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

And if my recollection from my days running a product validation lab many years ago is correct, the failure mode of most polycarbonate caps was shorted and flaming. Regards, Tom Holmes, N8ZM Tipp City, OH EM79xx -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun..

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

> > Why would JPL study obscure production details of polycarbonate > film capacitors in 1990, if they fell of the market six years earlier ? > We study all manner of obscure stuff here. Comes from using 20 year old parts in spacecraft that will last another 20 years. Consider Cassini.. laun

[time-nuts] 5370A

The 5370A is gone, thanks to all interested. I have one more piece of TN gear to get rid of; a Datum model 9150 Time Code Generator. 24V aircraft chasssis type (can be mounted in aircraft). Has a 1 MHz crystal, day and time LED display, 1,10,100k pps as well as several IRIG B output BNC's. Working,

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

Hi My understanding is that it was part of a several decades long multi-billion dollar Coast Guard program to enhance the long term reliability of the Loran-C transmitter chains . Bob On Jan 25, 2010, at 5:47 PM, Poul-Henning Kamp wrote: > In message > PL>, "Lux, Jim (337C)" writes: >

Re: [time-nuts] DMTD Question

DMTF is used to "see" time interval info in the very "near" term, say the 0.01 to 10 second range, with high accuracy and more measurement complexity. Most folks use a time interval counter and compare 1 PPS signals between standards and references. The problem with this method is limited by

Re: [time-nuts] Conducting Bench Top Material

Bill Hawkins wrote: My first job was in a blasting cap plant in 1960. There were military devices so sensitive they could be set off by turning on a nearby fluorescent desk lamp. I learned that the human body has a capacitance of 400 pico F. Getting up from a chair could raise a couple of kilovo

Re: [time-nuts] Conducting Bench Top Material

Lux, Jim (337C) wrote: -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill Hawkins I learned that the human body has a capacitance of 400 pico F. Getting up from a chair could raise a couple of kilovolts. We walked on conductive r

Re: [time-nuts] Variable Conductance Heat Pipes for temperature control

I have the book now. The VHCP used to control the temperature of a Cesium (not Rubidium) clock utilized in a GPS ground station is stated as maintaining clock temperature at 57 C +/- 13 C despite a ambient temperature range of -25 C to +55 C, while handling 5 watts of heat. This is a 3: reduc

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

> -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Poul-Henning Kamp > Sent: Monday, January 25, 2010 2:48 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Low temperature coefficient capacitors

Re: [time-nuts] Conducting Bench Top Material

No, my grandfather used to buy mechanics type magazines, and I used to love reading them in the 50s, about the weird things you could make. He also passed on a little of the old world technology to me. He was a brass founder, making things like locks and hinges etc. In the great depression (19

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

Finding an old 1992 MTT paper by Mysoor, et al., that describes the design of the Deep Space Transponder (DST), which is what's in Voyager.. There's a second order lowpass filter in the tracking PLL. The two time constants are 3556 seconds and 0.0556 seconds (time constant of the pole, timecons

Re: [time-nuts] Low temperature coefficient capacitors for DMTD

Jim, I was one of the guys who suffered from the incident while in the DSN. If my memory doesn't fails, the loop bandwidth became smaller, one Hertz or less (we routinely used 12 Hz BW in the downlink receivers so it was quite smaller) making the spacecraft unable to track the Doppler rate of

[time-nuts] Rb Mag sensitivity

Hi I finally found a number listed for the external magnetic field sensitivity of a fairly small Efratom rubidium. It's specified as 3 x10^-11 per 0.1 mili tesla. I did *not* make up those units, that's the way they stated it. If that's correct *and* my very rusty physics is also right: A 1 A

Re: [time-nuts] Test equipment / work benches...

Solid concrete floors here. I wouldn't have trusted my bench and all the kit I have on it (and under it) on floorboards alone, I'd probably have laid down a thick piece of ply to cover the area under the bench and therefore spread the weight or at least put some pieces under each 4x2" leg. Steve

Re: [time-nuts] Rb Mag sensitivity

Bob Camp wrote: Hi I finally found a number listed for the external magnetic field sensitivity of a fairly small Efratom rubidium. It's specified as 3 x10^-11 per 0.1 mili tesla. I did *not* make up those units, that's the way they stated it. If that's correct *and* my very rusty physics is

Re: [time-nuts] Rb Mag sensitivity

Actually, Hp made a Rb vapor magnetometer in the '60s. We had one attempted to measure the total electric charge moved by lightning strokes. A sensitive compass can be used too... Don Bruce Griffiths > Bob Camp wrote: >> Hi >> >> I finally found a number listed for the external magnetic field >> s

Re: [time-nuts] Conducting Bench Top Material

Back about 1981, we had piles of 6502s, etc and decide to some "antistatic testing". We put a 40pin ZIF socket into a VIC-20, and then set about trying to fry the uP using carpet, a cat, car seats, etc. The DUT was then put back into the VIC and series of tests run to verify operation. I don't t