Re: [digitalradio] Really beating the AGC issue with PSK ?
shift set right on the money), there is no qrm. 73, .hasan, N0AN.. p.s., notice when you close down the rx bandwidth your waterfall/spectrum display changes dramatically, showing the actual shape factor of your received bandwidtha nice idication of how well the dsp filtering is working in the TS-2000 - Original Message - From: Andy obrien To: digitalradio Sent: Thursday, May 28, 2009 5:08 PM Subject: [digitalradio] Really beating the AGC issue with PSK ? From time to time we have had discussions here about the problem with PSK (and other modes) when a strong stations appears to grab the waterfall and wipe out all the other stations within a 2-3 Khz range. Because of this phenomenon, when I purchased a new rig, I looked for one that could have AGC totally off (when needed) and one that can employ narrow DSP filtering. I must say that I have not really solved this issue . I can see a marginal difference with AGC turned off but strong signals still essentially desensitize other stations in the waterfall. The DSP features do better and I can get rid of the phenomena by turning to a narrow filter. However this does not help if the offending station is with 300 - 500 Hz ( a lot when dealing with narrow digital modes). Does anyone have any advice on how to once and for all solve this issue? My rig is a TS2000 Andy K3UK .
Re: [digitalradio] Really beating the AGC issue with PSK ?
to retune very often...you just use the waterfall/spectrum display and your mouse click for tuning. I've used this trick successfully with both a TS-870 and the new TS-2000, and it works beautifully. QRM on psk31 is a thing of the past with the outstanding dsp filtering in this radio. Once one learns the method for setting things up that I described above, it is psk31 heaven! At 50 hz bandwidth (and your shift set right on the money), there is no qrm. 73, .hasan, N0AN.. p.s., notice when you close down the rx bandwidth your waterfall/spectrum display changes dramatically, showing the actual shape factor of your received bandwidtha nice idication of how well the dsp filtering is working in the TS-2000 - Original Message - From: Andy obrien To: digitalradio Sent: Thursday, May 28, 2009 5:08 PM Subject: [digitalradio] Really beating the AGC issue with PSK ? From time to time we have had discussions here about the problem with PSK (and other modes) when a strong stations appears to grab the waterfall and wipe out all the other stations within a 2-3 Khz range. Because of this phenomenon, when I purchased a new rig, I looked for one that could have AGC totally off (when needed) and one that can employ narrow DSP filtering. I must say that I have not really solved this issue . I can see a marginal difference with AGC turned off but strong signals still essentially desensitize other stations in the waterfall. The DSP features do better and I can get rid of the phenomena by turning to a narrow filter. However this does not help if the offending station is with 300 - 500 Hz ( a lot when dealing with narrow digital modes). Does anyone have any advice on how to once and for all solve this issue? My rig is a TS2000 Andy K3UK .
Re: [digitalradio] Really beating the AGC issue with PSK ?
PSK31: 100 Hz filter (not dsp unless the agc is generated before) PSK250: 300 Hz filter. (see above). A K3 can do it all with its superior dsp. Rein PA0R -Ursprüngliche Nachricht- Von: Andy obrien k3uka...@gmail.com Gesendet: 29.05.09 02:09:34 An: digitalradio digitalradio@yahoogroups.com Betreff: [digitalradio] Really beating the AGC issue with PSK ? From time to time we have had discussions here about the problem with PSK (and other modes) when a strong stations appears to grab the waterfall and wipe out all the other stations within a 2-3 Khz range. Because of this phenomenon, when I purchased a new rig, I looked for one that could have AGC totally off (when needed) and one that can employ narrow DSP filtering. I must say that I have not really solved this issue . I can see a marginal difference with AGC turned off but strong signals still essentially desensitize other stations in the waterfall. The DSP features do better and I can get rid of the phenomena by turning to a narrow filter. However this does not help if the offending station is with 300 - 500 Hz ( a lot when dealing with narrow digital modes). Does anyone have any advice on how to once and for all solve this issue? My rig is a TS2000 Andy K3UK Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked Recommended digital mode software: Winwarbler, FLDIGI, DM780, or Multipsk Logging Software: DXKeeper or Ham Radio Deluxe. Yahoo! Groups Links -- http://pa0r.blogspirit.com Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked Recommended digital mode software: Winwarbler, FLDIGI, DM780, or Multipsk Logging Software: DXKeeper or Ham Radio Deluxe. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:digitalradio-dig...@yahoogroups.com mailto:digitalradio-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: digitalradio-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Really beating the AGC issue with PSK ?
A Phil pointed out, the only real fix is on the TX end - the transmitting station should be putting out a clean signal. Universal distribution of the following info will help there. Clean PSK signal: Turn your power control to full power, Mic gain in its normal position for SSB phone use, and start off with the audio out from your computer turned way down, so when the PSK program is in TX mode ( transmitting ) no output power is shown on the rig's power out meter. Now slowly raise the computer's audio-out until you see the maximun power your rig will put out with no AGC action observed. That is, crank up the computer's audio out until you see AGC action on the rig, then back off until you do not. At this point, you can use the rig's Mic gain to fine-tune the signal further, if necessary on different bands. What you idealy want is 25-30 watts output power with absolutely no AGC action. - You then have a clean signal. More power out is OK, as long as no AGC action is observed. BUT - there is a simple trick to use on the RX end of things, if your rig has a notch filter. While watching the waterfall display, turn on the rig's notch filter, which will produce a narrow dead area on the waterfall display. If you do not see the dead area after a few seconds, move the notch control until you do. Note that by watching the waterfall display as you tweak the notch control very slowly, you can literally steer the notch around to cover up any signal you wish. Steer the notch to cover up the offending signal. You can put it right up against the signal you wish to receive if necessary, wiping out an adjacent signal that is crashing your QSO. This may be crude, but it is also quite effective. On my Kenwood TS-450S, the notch is just the right width to effectively cover splattery, overdriven PSK signals. Hope this information is useful! 73 DE Charles, N5PVL Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked Recommended digital mode software: Winwarbler, FLDIGI, DM780, or Multipsk Logging Software: DXKeeper or Ham Radio Deluxe. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:digitalradio-dig...@yahoogroups.com mailto:digitalradio-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: digitalradio-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Really beating the AGC issue with PSK ?
in my ic 765 i have passband tuning and notchfilter great things to have for psk i can not switch in the cw filter in ssb mode :-( yet :-) but i am thinking of a mod like i did on my ft 757 cw filter switched in in ssb receive and passband tuning ... would give variable bandwith down to zero ... good dxing dg9bfc sigi - Original Message - From: Charles Brabham n5...@uspacket.org To: digitalradio@yahoogroups.com Sent: Friday, May 29, 2009 9:31 AM Subject: Re: [digitalradio] Really beating the AGC issue with PSK ? A Phil pointed out, the only real fix is on the TX end - the transmitting station should be putting out a clean signal. Universal distribution of the following info will help there. Clean PSK signal: Turn your power control to full power, Mic gain in its normal position for SSB phone use, and start off with the audio out from your computer turned way down, so when the PSK program is in TX mode ( transmitting ) no output power is shown on the rig's power out meter. Now slowly raise the computer's audio-out until you see the maximun power your rig will put out with no AGC action observed. That is, crank up the computer's audio out until you see AGC action on the rig, then back off until you do not. At this point, you can use the rig's Mic gain to fine-tune the signal further, if necessary on different bands. What you idealy want is 25-30 watts output power with absolutely no AGC action. - You then have a clean signal. More power out is OK, as long as no AGC action is observed. BUT - there is a simple trick to use on the RX end of things, if your rig has a notch filter. While watching the waterfall display, turn on the rig's notch filter, which will produce a narrow dead area on the waterfall display. If you do not see the dead area after a few seconds, move the notch control until you do. Note that by watching the waterfall display as you tweak the notch control very slowly, you can literally steer the notch around to cover up any signal you wish. Steer the notch to cover up the offending signal. You can put it right up against the signal you wish to receive if necessary, wiping out an adjacent signal that is crashing your QSO. This may be crude, but it is also quite effective. On my Kenwood TS-450S, the notch is just the right width to effectively cover splattery, overdriven PSK signals. Hope this information is useful! 73 DE Charles, N5PVL Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked Recommended digital mode software: Winwarbler, FLDIGI, DM780, or Multipsk Logging Software: DXKeeper or Ham Radio Deluxe. Yahoo! Groups Links Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked Recommended digital mode software: Winwarbler, FLDIGI, DM780, or Multipsk Logging Software: DXKeeper or Ham Radio Deluxe. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:digitalradio-dig...@yahoogroups.com mailto:digitalradio-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: digitalradio-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Really beating the AGC issue with PSK ?
From time to time we have had discussions here about the problem with PSK (and other modes) when a strong stations appears to grab the waterfall and wipe out all the other stations within a 2-3 Khz range. Because of this phenomenon, when I purchased a new rig, I looked for one that could have AGC totally off (when needed) and one that can employ narrow DSP filtering. I must say that I have not really solved this issue . I can see a marginal difference with AGC turned off but strong signals still essentially desensitize other stations in the waterfall. The DSP features do better and I can get rid of the phenomena by turning to a narrow filter. However this does not help if the offending station is with 300 - 500 Hz ( a lot when dealing with narrow digital modes). Does anyone have any advice on how to once and for all solve this issue? My rig is a TS2000 Andy K3UK
Re: [digitalradio] Really beating the AGC issue with PSK ?
When I use MultiPSK, I make sure the mic input is high (say 30% - 50%) then use MultiPSK's waterfall AGC which often shows the weaker signals as well as the loud one. I also use the manual notch on the rig to help out. 73 Sholto Andy obrien wrote: From time to time we have had discussions here about the problem with PSK (and other modes) when a strong stations appears to grab the waterfall and wipe out all the other stations within a 2-3 Khz range. Because of this phenomenon, when I purchased a new rig, I looked for one that could have AGC totally off (when needed) and one that can employ narrow DSP filtering. I must say that I have not really solved this issue . I can see a marginal difference with AGC turned off but strong signals still essentially desensitize other stations in the waterfall. The DSP features do better and I can get rid of the phenomena by turning to a narrow filter. However this does not help if the offending station is with 300 - 500 Hz ( a lot when dealing with narrow digital modes). Does anyone have any advice on how to once and for all solve this issue? My rig is a TS2000 Andy K3UK
Re: [digitalradio] Really beating the AGC issue with PSK ?
Andy obrien wrote: From time to time we have had discussions here about the problem with PSK (and other modes) when a strong stations appears to grab the waterfall and wipe out all the other stations within a 2-3 Khz range. Because of this phenomenon, when I purchased a new rig, I looked for one that could have AGC totally off (when needed) and one that can employ narrow DSP filtering. I must say that I have not really solved this issue . I can see a marginal difference with AGC turned off but strong signals still essentially desensitize other stations in the waterfall. The DSP features do better and I can get rid of the phenomena by turning to a narrow filter. However this does not help if the offending station is with 300 - 500 Hz ( a lot when dealing with narrow digital modes). Does anyone have any advice on how to once and for all solve this issue? My rig is a TS2000 IF DSP is much better at handling this than AF DSP. On my IC-746Pro, the AGC sees only signals that make it through the filter, which can be narrowed to 50hz. Allowing for the sharp slope setting, this is pretty effective at limiting to about 100hz down to about 25db down from the peak. Of course, you can't fix a splattered signal that is actually interfering on the frequency where your weaker target it. Nothing can fix that except to clean up the transmitter that is battering the spectrum.
RE: [digitalradio] Really beating the AGC issue with PSK ?
My Icom 746 suffers the same problem. I had hoped that the Elecraft K3 that I had in mind would solve this issue for me as well but maybe not. The review in QST was the best they ever gave but maybe I hope for too much. Rick - KH2DF _ From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com] On Behalf Of Andy obrien Sent: Thursday, May 28, 2009 7:08 PM To: digitalradio Subject: [digitalradio] Really beating the AGC issue with PSK ? From time to time we have had discussions here about the problem with PSK (and other modes) when a strong stations appears to grab the waterfall and wipe out all the other stations within a 2-3 Khz range. Because of this phenomenon, when I purchased a new rig, I looked for one that could have AGC totally off (when needed) and one that can employ narrow DSP filtering. I must say that I have not really solved this issue . I can see a marginal difference with AGC turned off but strong signals still essentially desensitize other stations in the waterfall. The DSP features do better and I can get rid of the phenomena by turning to a narrow filter. However this does not help if the offending station is with 300 - 500 Hz ( a lot when dealing with narrow digital modes). Does anyone have any advice on how to once and for all solve this issue? My rig is a TS2000 Andy K3UK
