[sdiy] reverb (FS)

[JH.]

> I think it's the accutronics 1FB2B1D.

Thanks!

>Interesting, but there aren't many of us who have a frequency  
>shifter, let alone two of them!

Me, I don't even have the reverb tanks, yet! ;)

Seriously: I don't think we'd need anything as expensive as a Bode,
or my homebuilt FS, for this.

Maybe it could work with quadrature _square_waves_ for modulators,
and simple transmission gates for multipliers.
This implies using a sub-carrier, as in shifting up a large amount of Hz,
and then shifting down a little bit more than the upshift was, plus
some filtering to get rid of the unwanted spectral components.
I think Martin Czech proposed something like this, many years ago.
It also apperas to be the standard method (square waves, I mean) for
SSM radio transmission.
Could be very simple, all in all, as we don't need variable shifting:
No VCO, no stability problems - all the carrier frequencies derived from a
HF clock and dividers ...
We could even do it without a dome filter, using the Weaver method.

JH.