[time-nuts] ACAM GP22 Chip
th.allgeier at gmail.com
Wed Nov 25 09:23:40 EST 2015
The book has been sourced and is on its way to me - a good pointer, thanks.
With it and the comments I have had from you guys I expect I will get pretty
much what I want, given a little time which thankfully I have.
I will report back any outcome that looks plausible / presentable.
----- Original Message -----
From: "Hal Murray" <hmurray at megapathdsl.net>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Cc: <hmurray at megapathdsl.net>
Sent: Tuesday, November 24, 2015 7:44 PM
Subject: Re: [time-nuts] ACAM GP22 Chip
> th.allgeier at gmail.com said:
>> I should say from the start that I am new to time and frequency
>> and not even an electronics engineer â but then I have been exposed to
>> high-precision electronics for the last 25 years hence have picked up
>> dangerous degree of half-knowledge.
> Do you have a copy of Art of Electronics by Horowitz and Hill?
>> In order to evaluate the chip I was planning to replicate John Aâs
>> experiment with the coaxial delay line from the HP5370b â but as my
>> is in âmeasuring range 2â of the GP22 I need a delay of 500 ns or
>> (actually 1 µs sounds a better start). This is the equivalent of a 200 m
>> length of cable. I fear trouble with this: Am I not getting unwanted
>> inductivities if I use a coil of that size?
> The trick is that your coil has 2 wires. It's a transmission line.
> Here is the handwaving explanation: The current on the return path is
> in the other direction and cancels out the inductance.
> Twisted pair will work almost as well as coax, maybe better than cheap
> AoE has an appendix on transmission lines. You can find lots of info on
> web. You need to terminate it. You will want a scope to check the
> These are my opinions. I hate spam.
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