Laurie,

lawrence mayhead wrote:
> So that leaves SDR receivers like the Perseus, thanks Johan,
> but these are digital, can the AGC be turned off?

Yes, at least on Perseus. It has a dedicated "AGC OFF" button.

> and another problem if my computer sound card is tied up
> processing I/Q signals can it also do the FFT analysis ? at
> the same time.

Perseus uses the computer's default soundcard only for audio
output (for listening). High speed USB 2.0 is used to transfer
the digital I/Q signal from Perseus to the PC, up to 500ksps =>
max 400kHz panoramic display. With an additional VAC program
(Virtual Audio Cable), the audio output can be routed
(digitally - without any loss of quality) to any software that
expects an input signal from a soundcard (Argo etc).

Perseus is the "cleanest" receiver I have ever seen/heard!
Only a few very weak spurs and an exceptionally clean LO (or
rather ADC clock). The LO "noise trumpet" is very narrow and
the noise, measured with a crystal oscillator, is about
-142dBc/Hz at 2kHz offset.

Unfortunately, the receiver has no input for external frequency
reference. This may be a problem for the QRSS120 guys? Anyway,
the radio appears to be very stable.

(I am not affiliated with the Peresus manufacturer in any way,
just a very satisfied owner).

Winrad supports Perseus, and it works very well. It can be used
instead of the supplied Perseus software, however, Winrad does
not have an "AGC OFF" button (yet) but since...

...Alberto di Bene wrote:
> in case it is not implemented, just ask the author of the program...

this problem can be considered already solved.

Hi hi... :-)

73
Johan SM6LKM