Re: [time-nuts] HP 5065A super

FRK is possible candidate we are looking at it add filter, reduce time constant Corby did but forgot to reduce filter  time constant. 5065A is 0.05 seconds.  We have to many projects low on the list Juerg is right now doing the new A9 for Corby If any body wants to seriously get involved

[time-nuts] HP 5065A super

Perrier, The telecom Rubidiums don't leave much meat on the bone for improvements as they sacrificed pretty much everything else to be cheap, small, and low power consumption. Most of these tradeoffs work directly against trying to get better short term stability out of them. Bummer. Cheers,

[time-nuts] HP 5065A super

List, I've been following the ongoing mod process for the HP 5065A super on the list. Two questions: 1. Are any of these upgrades applicable to the Lucnet and other Rb units? 2. Are there any other Rb units available (that don't cost you your first born child IF they can be found) that could be

Re: [time-nuts] HP 5065A super

In message <2a6c14a0-823a-4177-aefd-bed8bcea8...@n1k.org>, Bob kb8tq writes: >It turns out that the nickel’s really awful magnetic properties at RF [...] The semiconductor industry has serious problems with electromigration of very tiny copper conductors. A large company in the

Re: [time-nuts] HP 5065A super

Hi > On Feb 23, 2018, at 6:17 PM, jimlux wrote: > > On 2/23/18 1:33 PM, Bob kb8tq wrote: >> Hi >>> On Feb 23, 2018, at 4:23 PM, Attila Kinali wrote: >>> >>> Hoi Bob, >>> >>> On Thu, 22 Feb 2018 21:58:09 -0500 >>> Bob kb8tq wrote: >>>

Re: [time-nuts] HP 5065A super

On 2/23/18 1:33 PM, Bob kb8tq wrote: Hi On Feb 23, 2018, at 4:23 PM, Attila Kinali wrote: Hoi Bob, On Thu, 22 Feb 2018 21:58:09 -0500 Bob kb8tq wrote: The same nickel plating effect gets into a lot of things. If you are shopping for very low IMD

Re: [time-nuts] HP 5065A super

On Thu, Feb 22, 2018 at 3:29 PM, Leo Bodnar wrote: > Here is ENIG fact that is not widely known at the moment but which some might > find useful. > > I could not understand why I get better TDR and insertion loss results from > solder-mask covered microstrip transmission

Re: [time-nuts] HP 5065A super

Hi > On Feb 23, 2018, at 4:23 PM, Attila Kinali wrote: > > Hoi Bob, > > On Thu, 22 Feb 2018 21:58:09 -0500 > Bob kb8tq wrote: > >> The same nickel plating effect gets into a lot of things. If you are >> shopping for very >> low IMD connectors, nickel

Re: [time-nuts] HP 5065A super

Hoi Bob, On Thu, 22 Feb 2018 21:58:09 -0500 Bob kb8tq wrote: > The same nickel plating effect gets into a lot of things. If you are shopping > for very > low IMD connectors, nickel plating is out. Things get non-linear (to a very > slight > degree) when it is present. If -180

Re: [time-nuts] HP 5065A super

Keep in mind that soldermask will also change the field distributions around a microstrip line, and will somewhat mitigate the microstrip's dispersive behavior as well. I once worked with some miccrostrip couplers at around 2-4 GHz and found that directivity was significantly improved by adding

Re: [time-nuts] HP 5065A super

Hi The same nickel plating effect gets into a lot of things. If you are shopping for very low IMD connectors, nickel plating is out. Things get non-linear (to a very slight degree) when it is present. If -180 db is the goal for those spurs, you might only hit -120 db with the nickel

Re: [time-nuts] HP 5065A super

On 2/22/18 12:29 PM, Leo Bodnar wrote: Here is ENIG fact that is not widely known at the moment but which some might find useful. I could not understand why I get better TDR and insertion loss results from solder-mask covered microstrip transmission lines than from otherwise identical

Re: [time-nuts] HP 5065A super

It appears that ENIG gold is extremely thin (2 - 8 microinches), and if so does not cause a solderability problem. -- Tom, N5EG On Thu, Feb 22, 2018 at 3:18 PM, Mark Goldberg wrote: > My reading of IPC J-STD-001F Paragraph 4.5 says that the gold embrittlement > issue

Re: [time-nuts] HP 5065A super

My reading of IPC J-STD-001F Paragraph 4.5 says that the gold embrittlement issue does not apply to ENIG or ENEPIG. Paragraph 4.5.1 does say other gold shall be removed so there won't be solder embrittlement. Is that still correct? The issue with ENIG and RF is interesting. I have not heard that

Re: [time-nuts] HP 5065A super

In general it's bad practice to gold plate SMT solder pads. The reason is that proper SMT soldering utilizes a very small amount of solder and the gold plating will partially dissolve into the molten solder. Because of the small amount of solder, the percentage of gold will be high enough to

Re: [time-nuts] HP 5065A super

Here is ENIG fact that is not widely known at the moment but which some might find useful. I could not understand why I get better TDR and insertion loss results from solder-mask covered microstrip transmission lines than from otherwise identical microstrips on the same substrate with

[time-nuts] HP 5065A super

Yes, have the board done with ENIG gold. It typically adds around $15 per run of boards. I do all my boards with ENIG gold... if for no other reason than the gold color makes it very easy to determine when your solder paste properly covers the pads. And, as Charles mentioned, the quality

Re: [time-nuts] HP 5065A super

On Thu, 22 Feb 2018 15:33:50 + "Poul-Henning Kamp" wrote: > >Then i would go for the LTC6240HV with a +/-5V power supply. > > Offset voltage (stability) is a, if not the, *very* important > parameter for the integrator. That's another reason to choose the LTC6240 over

Re: [time-nuts] HP 5065A super

In message <20180222160256.68d832a88fc2d7da91602...@kinali.ch>, Attila Kinali w rites: >Ah.. this looks significantly different than my 5065 service manual shows. > >So, I guess you want to build a new board that replaces this? > >Then i would go for the LTC6240HV with a +/-5V power

Re: [time-nuts] HP 5065A super

On Thu, 22 Feb 2018 09:24:53 -0500 ew via time-nuts wrote: > Attached the schematic of the A9 my file of the picture is to large it is the > integrator. Ah.. this looks significantly different than my 5065 service manual shows. So, I guess you want to build a new board

Re: [time-nuts] HP 5065A super

Hi The control loop (of which A9 is a part) ultimately locks the OCXO in the 5065 to the Rb transition. Gain in the control loop suppresses the noise of the OCXO, making it’s ADEV better than it would have been stand alone. Ok so far? Bob’s not off the tracks (yet)? The various processes

Re: [time-nuts] HP 5065A super

Attached the schematic of the A9 my file of the picture is to large it is the integrator. I just gave Corby my extra A12  RVFR that at one time I was going to do something along the way you suggested but age and the number of projects on our list have ought up with reality. Remember when you

Re: [time-nuts] HP 5065A super

Ais the LT1793 the best choice the time constant is 0.05 seconds with a 10 K resistor and 5 uF Capacitor Bshould we add resistors and decoupling on the + - 15 volt op amp supplies CGold plating the edge connecter, does any one know a reasonable source, or is doing it at home an

Re: [time-nuts] HP 5065A super

On Thu, 22 Feb 2018 07:00:54 -0500 ew via time-nuts wrote: > Now a step by step work over, including HP mods for later  units like > replacing the 74196’s in the synthesizer module with 74LS196. May have been > end of life of the 74196. With some slight change of the

[time-nuts] HP 5065A super

In December I lucked out buying a HP5065A for a very reasonable price, as is not tested. Turns out it was not working and I was not able to fix it. Corby to the rescue. Corby and I have shared many projects over the past, go back over 15 years, as a matter of fact he introduced me to