I am currently using the fldigi Linux alpha 3.12AF, primarily for testing with my pskmail_server on the Linux side. It has been difficult for me to make good connections with my my in-shack 2 computer/2 rig test bed. The other computer/rig side uses fldigi 3.11 with the javaPSKmail program.
At least part of the problem may be due to the Linux version not being able to hold to a given audio frequency. It is nearly impossible to lock it to a frequency unless you turn off the rig and quickly find the preferred center frequency (I use 1500 Hz) and get it locked. This may be due to minimal white noise being picked up.
The PSK modem configuration is set to the narrowest 10 Hz acquisition search range with 6 dB S/N but it moves around, hundreds of Hz and seems more inclined to move higher from the center frequency. I think that this may be making it difficult to connect or hold the connection since by the time a PSK250 burst comes through, it is too late to acquire the burst and decode the data. This is occurring with or without AFC or squelch. Even at maximum squelch it still moves away from the default center frequency.
I just discovered a few minutes ago that this is only a problem when I am running pskmail_server or pskmail. When fldigi is running by itself, it seems to be stable.
Another odd thing is that THOR22 does not seem to work well at all for connecting from pskmail to pskmail_server and that is opposite to what I would have expected considering that it is much more forgiving on frequency accuracy and does not even use AFC.
Any suggestions on any settings that I might have wrong? 73, Rick, KV9U
