Small transceiver schematic capacitor value

Thread Starter

upand_at_them

Joined May 15, 2010
766
I got this from the "Sprat Pixie File"; it's one variation of the Pixie transceiver. Schematic shows a 60pF (C2) cap switched in when keyed. But...

What the is value of the other Colpitts cap (C1)? Is that supposed to be 0.001uF?

I understand that the switching in the cap is done to create a transmit offset. But why switch the 60pF and not the 1000pF? The 60pF isn't going to produce much of difference when keyed...Going from 1000pF to 1060pF?

1-13-2021 10-05-13 PM.png
 
Last edited:

djsfantasi

Joined Apr 11, 2010
7,689
Is the schematic possibly a copy of a copy? The decimal point may have disappeared. I note that there is extra space where the decimal point would be.
 

Thread Starter

upand_at_them

Joined May 15, 2010
766
Yeah, I thought that too. You may be right. The original, I think, came from a club newsletter from pre-Internet days and must have been scanned. And probably copied first. The missing decimal does make sense.

I wasn't that into electronics back then, so I wasn't familiar with the convention of what to do with unit-less values.

Also found out that my suspicion about which Colpitts cap was being switched was right. Somebody found me the corrected schematic that shows the 1000pF as the one being switched.
 
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