In a message dated 14/10/06 09:01:37 GMT Daylight Time, pc5m, Carel" <[EMAIL PROTECTED]> writes:
Verified setting of C22 with both methods (parallel freq counter on TP1 and measuring the offset of TP1 and TP2 with a 10MHz signal). ------------------------------------------------------------------- Hi Carel, Have a care connecting an extra frequency counter in parallel with the K2 counter as the loading capacitance of some counters may pull the readings off what they really are. The K2 frequency counter via the supplied probe gives relatively light loading on the circuits you are measuring. The extra frequency counter may not cause a problem in the case of TP1, but better to play safe and isolate the parallel frequency counter with a high impedance probe. I fell into this trap when setting my K2 4MHz control board clock oscillator with a Racal Dane counter. This has a ovened xtal clock, hence retains a fair degree of accuracy from calibration. However the extra load capacitance of the frequency counter input undid all that and gave an erroneous reading. A high impedance scope probe gave enough level to operate the frequency counter, yet still provided sufficient isolation not to affect the K2. May not be causing problems in your case, but something to be aware of. Regards, Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
