RA6790/GM - R-2174A(P)/URR
RA6790/GM
Following the impressive RA17 HF receiver Racal developed and produced some professional transistor based receivers.
I decided to buy a RA6790/GM from a professional dealer: Toronto Surplus in Canada.
Interesting stuff for the RA6790/GM can be found here:
The complete manual in 1 file in the BAMA: Technical Manual for HF Receiver RA6790/GM
Another source with scans of the manual and the schematics: RA6790/GM Manual
A Yahoo Group: RA6790/GM Newsgroup
I mounted the receiver in a 19" desktop case.
Actually only 1 filter is installed, the 3.24 kHz filter for sideband operation.
This is the complete list of filters (from the manual):
The audio output of my receiver is connected to an active DSP filter, a Timewave DSP599zx. This gives room to improve the audio signal. I've never heard other DSP filters for comparison, but the effect of the Timewave filter is very audible and helps a lot to make bad stations better.
For the speaker I decided to go for a Kawai active monitor, with 25w power.
Antenna is a Dressler ARA60, which is an active antenna for 40 kHz - 60 MHz. This antenna is no longer in production, but Thiecom in Germany can still deliver.
Actually only 1 filter is installed, the 3.24 kHz filter for sideband operation.
This is the complete list of filters (from the manual):
The audio output of my receiver is connected to an active DSP filter, a Timewave DSP599zx. This gives room to improve the audio signal. I've never heard other DSP filters for comparison, but the effect of the Timewave filter is very audible and helps a lot to make bad stations better.
For the speaker I decided to go for a Kawai active monitor, with 25w power.
Antenna is a Dressler ARA60, which is an active antenna for 40 kHz - 60 MHz. This antenna is no longer in production, but Thiecom in Germany can still deliver.