[ARC5] A crystal Substitute

[David Stinson]

Concerning the "nasty square wave" output of these:
as I've said before- take a look at the output of
an untuned Pierce crystal oscillator or similar
without an output tank circuit.  It's nasty
pulses full of harmonics, not sine waves.

This is not a "real" issue;
If one is building a QRP transmitter going directly to
the antenna from this oscillator, the filters are
needed, just as they would be if you were to hook
an untuned 6J5 Pierce to an antenna.

In our applications, the oscillator (crystal or silicone)
is followed by tuned stages which pick the needed freq.
just exactly as they do with any
crystal oscillator-buffer-PA type rig.
In the Heathkit transmitter in question,
the gentleman left the tuned circuits
on the right side of the board to "clean up"
the signal just as it did for crystals.
I'd be worried about the RFI from the thing
as well, but the fellow hasn't lodged any complaints
as yet.

73 DE Dave AB5S


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