[time-nuts] Oscilloquartz BVA 8600-3, Turn-on hysteresis or parasitic resonances?

Greetings forum, I have an Oscilloquarz BVA 8600-3 that exhibits an erratic behavior (?) after having been power cycled. The frequency error following such a cycle is in the order of200 milliHerz. Bringing the oscillator back to (at least) E-11(compared to a GPS-locked HP105B or my 5065A

[time-nuts] GNSS-Store

The GNSS-Store site was new to me. Thanks for the suggestions. Cheers Ulf KylenfallSM6GXV   ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the

[time-nuts] Looking for a new GNSS-receiver for a diciplined oscillator - Which one to buy?

Greetings forum, Since my GPS-receiver ceased operation recently, I need to purchasea new one. Please suggest a suitable module preferably from DigiKey sinceI have a customer account with them. 1PPS and a computer interface to check the performance is needed. Cheers Ulf KylenfallSM6GXV

[time-nuts] Regarding HP 5065A upgrade to 10811-oscillators

Greetings forum. Yes - I have performed this upgrade, having obtaineda 10811 / high performance option. While the complete original HP kit was not available, I salvagedthe 10->5 MHz divider/connection board from a 105Band re-designed the back PCB with the 2 x 15pole 3.96 pitch connectors and

[time-nuts] 5065A - A15 (PSU)

Since the A15 regulator board is mentioned... I recently decided to try to improve the Voltage Regulator board A15in order to use a better voltage reference than CR5 (9V) and alsosee if I could reduce the drift and noise of the Magnetic Field winding. After some experimenting, I am reasonable

[time-nuts] 5065 - No 2nd Harmonic...

Jared, A 5065 is a piece of technological historywell worth preserving and keeping. Just put it away for some time and wait.Inspiration will come back. There are plenty of knowledge on the internet. Once you get the hang of troubleshooting ityou will feel rewarded. I cannot count the number of

[time-nuts] Re: 5065A - Replacement of A14CR13 (Logic Ass:y)

I guessed that CR13 was an old part, and I know about the "Q" creationof an equivalent device. I will use that approach. Thanks for all advice. Best Regards Ulf KylenfallSM6GXV ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe

[time-nuts] 5065A - Replacement of A14CR13 (Logic Ass:y) Thyristor "Continuous Operation" ?

Greetings, Having experienced a repeated condition of unlock in spite of all DC levelsfrom the Rb Phase Lock circuitry being correct, I traced the problem to A14,the logic ass:y. I went about to replace almost all discrete transistorsthere after testing and discovering that some of them was

[time-nuts] BNC connectors for the distribution of frequency or time...

Greetings. At my work, all connectors used for the distributionof frequency or time are types N, TNC or SMA. Bayonett types are prohibited for useexcept where they cannot be substitutedi.e. "EXT REF INPUT" on rear side ofsignal generators or similar... Cheers Ulf Kylenfall

[time-nuts] Low declination satellites...

What we found at the Onsala Space Observatory, was that satellites in low declination added some error due to atmospheric tindering. What was also discovered was that conical radomes on the Leica antennas also was not optimum. Therefore, spheric radomes was substituded and the antennas was

[time-nuts] Varian R20...

Actually - I did look in the archives of KO4BBbut appearently did not search enough. His copy is excellent. Best Regards Ulf Kylenfall ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

[time-nuts] Manual: VARIAN R-20 Rubidium frequency standard.

Gentlemen.  I have salvaged a manual for a Varian R-20 Rubidium Frequency Standard.   It was left when my employer borrowed such a unit when performing the first cross-atlantic VLBI Experiments some time in the late 70's. The unit must have been returned to its owner but they forgot to

[time-nuts] 5065A Rb Cavity Rx - SRD repair

Disassembled the surplus Rx cell by first disconnecting the short jumper cable and then unscrewed the brass part. Inside was a tiny diode, color coded "391" as have been previously discussed in a thread some years ago. I recon that if a diode would some time in the future breakan external

[time-nuts] 5065A Rb Cavity RX - SRD Repair

Thanks for the picture. The small coax link cable is even more brown  than the one i my cavity  I did realize that it should be possible to test the diode  using a 20k/V resistance meter. There has been no more "hick-ups"  and what the cause was is unknown, but many repair sessionscan

[time-nuts] 5065A Rb Cavity Rx - SRD repair

I see. Is the SRD in the Rx module accessible at all? What type of package is it? Is it possible to dismantle the Rx unit without risk of cracking the glass enevlope? Does anybody know the power level at 6 GHz? BR  Ulf Kylenfall  SM6GXV 

[time-nuts] 5065A Rb Cavity RX - Varactor repair?

Strolled into my little lab only to find the 5065A's Red Integrator Limit  light on. Control negative fsd. PhotoCurrent OK. No 2nd harmonic. Was just about to power off and start to disassemble the unit. All of a sudden, the Integrator light went out. Control went to zero and by pressing

Re: [time-nuts] Aging 5065A ?

Regarding the quest to keep a 5065A running... The 5065 in my hobby corner was equipped with the firstversion of the AC-Amplifier (A7) that did not have a frequency selective 2nd harmonic detector. So I copied the later design but made possible the use of selected polyester precision audio

[time-nuts] Aging 5065A ?

Having been shut of for several months I fired up the refurbished 5065A a few weeks ago. It has since been equipped with a new AC-amplifier (A7) and a new Rubidium cell with the repaired lamp (thanks to Corby Dawson) and a receiver with a TED that was connected according to HP instructions.

[time-nuts] Distribution amps for 200 MHz

We have a Timetech 5/10 MHz distribution unit at my work whohad one output burned. Inside, the circuit board was full of IC'smarked "A83A" which I tried to decode. I got one hit on "Google"which was Texas Instruments LMH6702MF This is a broad bandOP-Amp in a SOT23-5 package. Maybe it will

[time-nuts] 5065A A3 (Series 2644A) Schematic

Corby, Thanks for the schematic.I will sneak into my work and print an A3-copy of it. I could of course fabricate a board myself but thenit will be a version without silk screen, no solder maskand no thru-hole vias. Layouts that I CADmyself are always made so that thru-holecomponents takes care

[time-nuts] Dead 5065A - Att: Corby

Yes please. As the dedicated hobbyist I am I have of coursea little PCB manufacturing lab where I can do2-layer PCB's with all UV-lights and liquidsnecessary. The problem is that while there are1.6mm laminates in abundance, finding 2mmcould be difficult. Anyway, I will look forwardto the

[time-nuts] Dead 5065A - Some comments - Some questions... (III)

Paul, A 60 MHz xtal oscillator divided by 12 and comparedwith the incoming 5 MHz. Then there is this thing how to acheive a good symmetrical FM injecting the 137 Hz signal without affecting the loop filterparameters. Keeping the original design with modern typesof semiconductors is less

[time-nuts] Dead 5065A - Regarding A3 (Series 2644A)

Ah.. The two A3-units I have are labelled Series 820 and 836. Luckily, there has been no problem adjusting thetrimmer capacitors. The inductor I do not dareto touch. I know too well how brittle a stuck ferrite core is... Can someone point to a downloadable manualwith schematics/parts list for

[time-nuts] Dead 5065A - Some comments - Some questions... (II)

Luciano, Yes, the ovens in the cavity are working correctly. What destroyed the 5065A in the first place 1988 wasa very high raw input voltage approaching 40V(something wrong with the AC Xformer that possibly caused the original cavity windings to short circuit ?) I got help from Corby Dawson

[time-nuts] Dead 5065A - Some comments - Some questions...

..Continued. Having discovered that the A3 multiplier went bad the firsttime after a few hours of service, I checked the A3 unitfrom a scrapped 5065 on my bench. It was neverinserted in the once working unit : DOA The problem with some of the plastic packaged FETs wasthe same. Also that

[time-nuts] Dead 5065A - Some comments - Some questions...

Greetings. Having had my 5065 disconnected several months due to all sorts of things, and started it up yesterday. It was dead. "Pining for the fjords" No 2nd harmonic. Just PhotoCurrent. Quick Phase Checkusing a scope in X/Y-mode returned a "U" instead of a bump And most of the rest was noise.

[time-nuts] "The Penultimate HP5065 A15"

Regarding 5065  "A15" When I was about to repair my 5065, the first thing I noticed was the quite high "+22-30V" and its impact on the dissipated heat from the series regulator Q1. Therefore, I replaced the power transformer T1 and the rectifiers with a linear regulated power supply providing

[time-nuts] Regarding HP 5065A Nifty A9 repair...

:-) Thanks for sharing this Corby, Much appreciated! Best Regards Ulf Kylenfall ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions

[time-nuts] What to do with a dead Cesium...

You can be pretty sure that the week after scrapping/modifying/found other uses for itsomeone offers a "Look what I found on a shelf" brand new unused tube for next to nothing. I would tuck tthe dead unit away for some time. Cheers Ulf Kylenfall ___

[time-nuts] "Ancient 5065..."

Hmm... On one hand the seller claims ..."is fully functional" On the other hand the seller writes..."untested" Strange that it has the light brown type cover plates. My old s/n 848-00131 has the dark blue covers. for $333 I would have baught it untested but the shippingto Sweden is another $209.

Re: [time-nuts] 10811-Parts... (Using the thermal regulator circuitry)

Yes, I have more or less cloned the temperature regulation circuitryand used it for various heat control circuitry using other/similarsemiconductors that can handle elevated temperatures. The basic principle is nothing exotic. It can be found inmany applications all over the internet. What

[time-nuts] Att: Hugh Rice

This is a note of Encouragement. Best Regards Ulf KylenfallOnsalaSweden ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.

[time-nuts] Oscilloquartz 8600...

Regarding the Oscilloquartz 8600-3 that was 1 Hz off the frequency...  I have received information off the listthat I think will be helpful. I will give it another try. Cheers Ulf KylenfallSM6GXV ___ time-nuts mailing list --

[time-nuts] Still looking for a schematic drawing for Oscilloquartz 8600-3 (945.860.011.03 S/N 422)

Many monts ago I approached the list regarding an Oscilloquartz 8600-3(945.860.011.03 s/n 422) 5 MHz Ovenized Crystal Oscillator. It had aged and was 1 Hz off and couldnot be braught back to 5.000.000 MHz. Since I did not have "an account" with Oscilloquartz or what they are calledtoday, I

[time-nuts] RF Isolation Amplifier ...

The BFT66 if that is the type ( a bit difficult to read ) is a really "wild one" on VHF. I have used it and unless surrounded by proper decoupling networks in a well designed circuit it can and will oscillate. I would have used a spectrum analyzer to check for any unwantedoscillations well

[time-nuts] 5065 SRD's - Some notes about A3 Multiplier Ass:y

   Gentlemen, Some days after I fired up my 5065 after initial repair of the RV Cavity,it became unstable and lost lock. No output signal from the A3 Multiplier Assembly. Q9 (final) was dead and was replaced with a 2N5109to which I added a thermal pad between the case and the PCB. Q5