There is probably a voltage on one of the pins that detects the presence of the board.
Pieter ----- Original Message ----- From: "Rick Karlquist" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> 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 >> of >> 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 > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
