[time-nuts] DIY Frequency extension for HP Agilent 53181A, 53131A or 53181A
pieter.ibelings at gmail.com
Sun Feb 15 19:41:49 UTC 2009
There is probably a voltage on one of the pins that detects the presence of
----- Original Message -----
From: "Rick Karlquist" <richard at karlquist.com>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Sunday, February 15, 2009 2:39 PM
Subject: Re: [time-nuts] DIY Frequency extension for HP Agilent 53181A,
53131A or 53181A
> Samuel D. [x86/CPC] wrote:
>> - How does the counter aware about the option used ? There is no
>> "intelligence" on the option board, so, the counter may detect the type
>> prescaler with some pull-up or pull-down resistors somewhere.
> Don't be surprised if the option is activated in software.
> Therefore, even installing the genuine board may not work.
> Of course, you can always build a prescaler in an external
> box and feed it into the front panel connector intended for
> low frequenices. You can use the math functions on the counter
> to scale the display.
> Rick Karlquist N6RK
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