[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Crystal Question

The 'old' crystals, in HCU type holders could be taken out of the holder by
removing 3 screws.
To increase the frequency it was normal to rub them in a figure of eight
motion on a piece of glass, using a water based paste of scouring powder.
To decrease the frequency a few kHz the normal practice was to rub a soft
graphite pencil evenly on one side of the quartz.
For changes of up to +/- 30kHz at 7MHz we often used variable series
capacitors and inductors, to swing the frequency, but with some loss of
At current prices of up to £10 ($15) to have crystals made to your exact
frequency,dependant on the frequency, it's not worth the effort.

Mike G3LGR

Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org