[time-nuts] Dual Mixer

K. Szeker szeker.k at gmail.com
Tue May 11 14:56:38 UTC 2010

Hi Bert,

I can help you in PCAD schema drowing(i.e. as xxx.pdf output too)_have a
litle experiance :-).
(so ca. 20 years, & with RF layouting so good 30 years)...

Best Greetings,

2010/5/11 <EWKehren at aol.com>

> The Dual Mixer project is nearing completion.
> Let me refresh every ones memory as to my goals.
> a)  Total cost less than $ 200
> b)  1 E-13 with a one second offset
> c)  use parts attainable by every one
> d)  easy to assemble only a few surface mount parts
> e)  a five channel counter that yields 1 E 15 resolution and  interfaces
> directly to a PC via  RS232 or USB
> f)   A counter that also gives you instant frequency  difference at the
> sample rate, not only Allan Variance
> g)  Modular so one can use only the Dual Mixer
> h)  Modular so one can use multiple units to do simultaneous  comparison of
> more than two oscillators.
> i)   Isolation between D/M and counter so that the counter can be  powered
> by the PC USB port
> I am happy to report that all goals have been accomplished, attached is a
> picture of the D/M, limitation of the file size does not allow me to attach
> an  actual board picture, but if you contact me direct I will send you one,
> the  final board is actually nicer since the first layout had to
> accommodate
> several  variances.
> The D/M part leans heavy on the original NIST unit with a few substitutions
>  and recommendations from Bob Camp. Also beside Opto Couplers SN65LVDS1's
> have  been included for those that want to use other counting methods.
> Selection of  filter capacitors allow the use at other offset frequencies
> such as
> 10 and 100  Hz. The D/M fits in a standard 74 X 111 X 20 mm Euro case and
> the counter can be  stacked below or next to it using the Opto Isolators as
> the inter connect. The  SYPD-1's fit right on the board but connections are
> included to use the HP 10514  A. As a matter of fact removing the HP mixer
> board from its housing   fits it nicely on the board and every thing is
> still
> inside the housing.
> The counter will handle 1 an 10 Hz offset with a 1 E 14 resolution at 10
> Hz. Thanks to Richard Mc Corkle we have great drawings and code, available
> to
>  every one.
> Code, drawings, list of material and PC board layouts and its  file, will
> be available to every one once the project is completed.
> I need help in the following areas
> a)  help me create a nice set of drawings that are computer generated
> something I am not able to do
> b) create the computer program that takes the output of the counter board
> and allows Allan Variance plots, frequency difference and dual temperature
> readings and plots using RS232 and USB.
> c) an independent test by a third party.
> As I said previously, I am not getting in the business of supplying parts
> but will work with people that will help achieve the three points listed
> above.  Presently I have boards on order and will have two uncommitted
> board
> sets and  probably also component kits.
> Please contact me directly.
> Again thank you Corby Dawson, Richard Mc Corkle and Bob Camp.
> Bert Kehren   Miami
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

More information about the time-nuts mailing list