Mostly on strong AM ham transmissions on 80 meters, the homebrew receiver is
clear, the 3000 is nasty.
I do not remember anything like this on the 5000 I had a few years ago.
I think I would like to go back to an older version of psdr which seemed to
work better for what I use it for.
I tried all the agc settings, no improvement.
I do not know if any here used an sdr-iq from rf space, but the ability to
select one sideband, or the other, or both in sync AM was very nice indeed!
You can do it in psdr manually, but having a button was nice, and I don't
think it had that whoop as it locked up like psdr has.
Brett
N2DTS
----- Original Message -----
From: "W1AEX - Rob" <w1aex.f...@cox.net>
To: <flexradio@flex-radio.biz>
Sent: Wednesday, December 14, 2011 12:48 PM
Subject: Re: [Flexradio] grunge on rx audio..
Which version of PSDR are you using Brett? Version 2.2.3 fixed a very big
issue with AM reception (AGC tracking the sideband energy rather than the
carrier energy) that was present in all the previous 2.x.x versions and
the later 1.x.x versions. That being said, I do notice what sounds like
peak distortion on some strong signals when using the AM mode. I do not
hear it when listening with other conventional AM receivers that I use.
Adjusting the AGC-T slider in PSDR doesn't seem to stop it, but I wonder
if adjusting the variables in the DSP AGC/ALC setup tab might address it.
The "max gain" and "attack" values might be a good starting point for
experimentation. Curiously, I never hear that distortion with PSDR when
listening to strong signals on the AM broadcast band, so it may have
something to do with selective fading and the way PSDR deals with it.
As Tim may have been inferring with his question, the "peak distortion"
phenomenon is not present on those signals when listening in SAM mode.
Unfortunately, some of the older AM transmitters being used are not
perfectly stable and tend to move a few Hz when modulated. The SAM
detector warbles now and then with those stations as it tracks them on
peaks. It's most notable on 10 meter AM where there's a multiplication
factor being applied to the VFO in the older transmitters. So, at this
point, I find that I switch back and forth between AM and SAM to see what
seems to work best with different stations I run into. I'd be curious what
others may have noticed when operating AM or when SW listening in the AM
or SAM modes.
73,
Rob W1AEX
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flexradio.com/ Homepage:
http://www.flexradio.com/
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
