"Graham" wrote in message
ps.com...
On 23 Jun, 04:48, "Ron Baker, Pluralitas!" wrote:
"Graham" wrote in message


snip


You need to down convert the 12 kHz width of the
transmitted signal down to 0 to 12 kHz for input
to your sound card.

It won't work with the receiver in AM mode. An
AM detector destroys a drm signal.

SSB mode would work if the SSB receive bandwidth
were 12 kHz. I've never seen an SSB receiver with
12 kHz bandwidth other than the TenTec RX-320D
or similar SDRs. I don't know about Sony, Degan,
Sangean, etc. receivers but I doubt they can do it.

You might try with whatever SSB bandwidth you
have but I would be surprised if it works.- Hide quoted text -

- Show quoted text -


Ok , thanks for the info,

Im using a racal ra6790gm ,

Golly. Interesting.

which has 20 Khz wide filter, I can set
the bf o up to + - 8 Khz from center frequeny .. so if the signal is a
'12khz block' then setting cw, pass band 20 khz the bfo at either +6
or -6 Khz , that should produce the 12 khz down conversion ?

Yes. Sounds right to me.
The -6 kHz bfo setting is more likely to be correct
than +6 kHz. With -6 kHz the lowest RF frequency is
converted to the lowest audio frequency. +6 kHz would
invert that.

, the
audio bandwith is a littlw over 11 khz , looking of spectrumlab , so
it should handle the signal as 'audio'

So 20 kHz is the IF width and 11 kHz is the audio width?
I hope the drm demodulator doesn't miss that last kHz.
There is a fair possibility it won't.


I assume the published frequency is the 'center frequency' so setting
the dial at that and the bfo offset to 6 khz , should produce the
correct spectrum ?

Sounds right to me.


Rgds

G ..