On Thu, 12 Sep 2002, Jim wrote:

>> What would a normal transmitter use, three to five
>> stages minimum pi output filter ?
>
>These "three to five pi output filters" (the key, operative word here
>is "output") remove *harmonics* (integral multiples of the signal)
>and do not influence in-band, channnel-to-channel (adfjacent channel)
>performance.
>
>THAT'S what duty of the sharp SSB filter (on a normal, pre-DSP radio).
>(That SSB filter is used in both xmit AND receive modes BTW).

We are talking CW only here. I did not suggest voice transmissions on a SG
 tx. You are right, the phase noise of a spark gap generator is terrible.
OTOH a real enthusiast could fill a room with 9-12 LC tank circuits built
on aircoils put in empty steel filing cabinets and homemade oil or
polyethylene capacitors and go on air legally with CW on a spark gap I
think. The point is, that it is possible to achieve, although not
economical and probably of interest only to dedicated amateurs.

Peter

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