[time-nuts] Method for comparing oscillators

[Dave M]

> Date: Mon, 3 Aug 2009 12:36:40 EDT
> From: EWKehren at aol.com
> Subject: Re: [time-nuts] Method for comparing oscillators

<snip>
> My goal is to keep the total material cost below $200. I have  received
> valuable suggestions from Bruce, some I am incorporating as long as it 
> does
> stay with in the $ 200.00. I am a strong believer in KISS and have almost
> completed the total PC layout. All IC's are DIP! The board  is partitioned 
> in
> such a way that it can be cut up in three sections  or be left as one. Two
> parts are Isolation amplifiers and mixer with all  associated circuits the
> third section separating the two sides is the counter.  Price quote for 
> the
> board is $ 22.00 in fifty and $ 30.00 in ten quantity. When  complete and
> tested all information will be made available to every  one. The only 
> component
> I have trouble buying is the 74 AC 112. Newark has  them, but you have to
> buy thousands. Material cost based on part searches is  below $ 200.00.
> Let me make clear I am not trying to push the limits of technology but 
> take
> a conservative and KISS approach. Many will be able to make meaningful
> tests  where the limit will be their sources not the test set up.
> What is missing is the two u Processor choices and the programming. I have
> only limited knowledge in that field. I am looking for some one that is
> willing  to perform that task. The proper u Processors need to be picked 
> and
> they will  have to be programmed. Two of the identical three may be 
> something
> like the PIC  1220. Once selected I can complete the board and order
> prototypes. The  programming should be simple, but that is easy to say for 
> someone
> that never had  to do so. Any body willing to help, please contact me.
> Obviously PC software  also has to be created, to use the data from the 
> five
> counters. Any body that  will do the programming will be a recipient of a
> prototype board.
....<snip>
>
> Bert Kehren

Digikey stocks the 74AC112E, and is available in unit quantities for $0.68 
USD each.  Price breaks for larger quantities.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=296-4223-5-ND

Dave M