Re: [time-nuts] HP5065a cfield issue

paul swed writes: > Guessing far less than 3 ma. by adding up resistors. More like typical 4 mA: there is a factory select resistor in parallel with the current-setting resistor. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 Fr

[time-nuts] HP5061 Cesium ion pump question

During my HP 5061Cesium testing last week I was watching the ion pump current and am curious. What is the typical behavior people see on the tube after say 3 months of being turned off. With 3 units I see one that pumps doen from 8 to 2 in 40 minutes. Another maybe at 25 and takes 28 hours to get t

[time-nuts] HP5065a cfield issue

Hello to the group. Was time for the quarterly Cesium and RB checks in an effort to support our local power company. I discovered that there is an issue with the HP5065a Rubidium reference. The frequency has slowed and the cfield pot can not make up for the jump. Normally a few small tick marks ar

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

On 11/30/20 1:22 PM, Art Sepin wrote: To me it looks more like water ingress through micro-cracks in the plastic-dome, and the O-ring did its job and kept that water in. Interesting. That's the first we've heard about micro-cracks in the Radome but that's certainly a likely possibility wit

Re: [time-nuts] TWT's was: Re: Voyager space probe question

Dave it looks like I can not respond to you directly. I just wanted to say that I still appreciate TWTs and the magic in them. I have a number that are operational. 180 W on 10GHz using a Varian/CPI TWT. Anyhow would like to correspond offline since this is not Time-nuts. Regards Paul WB8TSL On Mo

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

This brings up a point I have made frequently, in my professional life. Do not try to seal in electronics (for me , satellite units mounted near or on the feed system) instead warm the area with electronics and place a weep hole at the low point. Short of true hermetic seals, any other gasketed b

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Lester Veenstra writes: > This brings up a point I have made frequently, in my professional life. > Do not try to seal in electronics (for me , satellite units mounted near or > on the feed system) instead warm the area with electronics and place a weep > hole at the low point. How to

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

> To me it looks more like water ingress through micro-cracks in the > plastic-dome, and the O-ring did its job and kept that water in. Interesting. That's the first we've heard about micro-cracks in the Radome but that's certainly a likely possibility with such a long exposure to U/V. The mo

[time-nuts] TWT's was: Re: Voyager space probe question

The power supplies for them are interesting too. Especially when you get to the multi kW beasties with multiple collectors etc.  Floating high power HV supplies, referenced to the more negative Cathode potential. That's one of the things I do for the day job, fix TWTA's.   99% of the time, it's a

Re: [time-nuts] Early Christmas - DMTD up and running

Hi When doing DMTD “noise floor” with a common oscillator, you need to use a “line stretcher” between the inputs to the DMTD. In the case of a 5 MHz system, you would need about 30 to 50’ of coax to get the job done. There is no need for infinitely fine steps, a set of 3 cables at 20 / 10 / 5 fe

Re: [time-nuts] Voyager space probe question

On 11/30/20 2:20 AM, Gerhard Hoffmann wrote: Am 30.11.20 um 07:00 schrieb Mark Sims: I once bought a spool of tungsten-rhenium alloy wire on ebay for dirt cheap. A few weeks later a guy contacted me and offered a lot of money for it. Turns out they used it to rebuild TWTs. 1. I used to live

Re: [time-nuts] Voyager space probe question

On 11/30/20 2:20 AM, Gerhard Hoffmann wrote: Am 30.11.20 um 07:00 schrieb Mark Sims: I once bought a spool of tungsten-rhenium alloy wire on ebay for dirt cheap. A few weeks later a guy contacted me and offered a lot of money for it. Turns out they used it to rebuild TWTs. 1. I used to live

Re: [time-nuts] Voyager space probe question

IIRC Tungsten Rhenium alloy is used for the rotating anode in X-ray tubes. Extremely high melting point. Cheers..Don C. Virus-free. www.avast.com

Re: [time-nuts] David Allan amusing notes on ADEV, MDEV, TDEV etc.

Hi, I managed to obtain the Lighthill book 'Introduction to Fourier Analysis and Generalised Functions' and I scanned it. It provides a different look on Fourier Analysis. Feel free to download it from my private cloud: ftp://dschuecker.dyndns.org/Lighthill_Introduction_to_Fourier_Analysis_an

Re: [time-nuts] Voyager space probe question

Am 30.11.20 um 07:00 schrieb Mark Sims: I once bought a spool of tungsten-rhenium alloy wire on ebay for dirt cheap. A few weeks later a guy contacted me and offered a lot of money for it. Turns out they used it to rebuild TWTs. 1. I used to live in Ulm, Germany, where there was? Thales TWT