Locked Re: problem with WSJTX receive

Henry Kiernan

thanks Martin.

- mine is set to "slow" - not Fast or Mid, the other 2 choices - there is no "off" choice. perhaps I should try "fast" per your comment.
- BUT, same rig used regardless of which computer, new or old. so don't see how that would change the fact that the new computer is receiving about 1/3 of the decodes of the old one.


-----Original Message-----
From: Martin G0HDB <marting0hdb@...>
To: main@WSJTX.groups.io
Sent: Tue, Jun 9, 2020 3:19 pm
Subject: Re: [WSJTX] problem with WSJTX receive

On Tue, Jun 9, 2020 at 04:52 PM, Henry Kieran wrote:

another thing I have noticed: when looking at the wide graph, the waterfall is very "blurry" compared to old computer. signals are somewhat ill-defined, colors are weak, and not nearly as plentiful. and the signal strength at the bottom of the graph only shows the peaks of the very strongest signals, not the entire spectrum line that I see on old computer.
appreciate any further help!
Hank - just another thought about your comment about your waterfall looking very blurry...

Do you have the rig's AGC turned on or off?  I've found that the Icom rigs I've owned, from the 735 and 746 then via the 756 Pro III and 7600 up to and including my present 7610, have all been quite prone to the audio output being overloaded when AGC is off when even relatively low-level (S3-4) input signals are being received.  The audio distortion products caused by the overloading somewhere along the receive signal path can manifest themselves as 'smearing' and blurriness on the WSJT-X waterfall.  A quick listen to the received audio should quickly reveal whether or not you're suffering from overload when the AGC is switched off.

For what it's worth, I now run my 7610 with AGC on and set to a time constant of approx 0.75secs, and I set up my audio levels so that the WSJT-X audio level 'thermometer' reads approx 60dB when receiving only band noise.  The rig's AGC ensures that the thermometer level never goes above about 74dB which is still in the green range for WSJT-X.

Martin G0HDB

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