Thank you for the feedback Charlie_Dont_Surf.
No LAN/pre-amp in use here., I do have a rather inelegant solution to running three receivers at the same time. I have three antennas feed a MFJ-1704 switch that outputs to an RF Systems SP-1 antenna splitter. One output goes to the NRD-545 and the other output goes to a PL259 "T" adapter to feed the other two receivers. Could this setup be the problem?
No. Those are all what are called "passive" circuitry; there is no active amplifier involved. As such, it's extremely unlikely. You would need to put kilowatts of RF power through them to generate the types of birdies we are talking about here and you are obviously not doing that in a receive application.
I'm running WSJT-X right now and I have the RF Gain control all the way to the 9 o'clock position to get it down to 40-60 range, thank you for that advice.
I don't know your receivers specifically but in general I always suggest setting the RF gain control wide open (maximum gain) and then controlling the audio to the computer using the AF (audio) gain, i.e., audio volume. The NRD-545 is by all accounts an excellent receiver that must have AGC that will fold back the RF gain automatically for you when it needs to. I think that you should be able to leave the RF gain setting on the front of the radio all the way up (maximum). This way you should probably get the best signal to noise ratio at all times. You can then use the volume control to provide a sufficient audio level to the computer input.
If for some reason you can't lower the audio input to WSJT-X enough to get it out of the red zone, then, yes, maybe decrease the RF gain slightly, just enough to back off the audio to the point where it is in the green zone.
Show Posts
