[digitalradio] Need help with PSK-31 and my antenna tuner
Hi, I'm having a little problem with my antenna tuner when transmitting PSK-31 above 30 watts. I have a IC-706MKIIG with a MFJ-945E. Both are on their own powersupply and well grounded. When I transmit PSK-31, it locks up my IC-2820H (D-STAR) radio (unable to transmit DV, analog or control the radio). My IC-2820H is on a different powersupply and also grounded. The radios and tuner are about 3-4 feet apart from each other. Additionally, I use to have a KPC-9612 and it also locked up from time to time and had to do a hard reset. I didn't think anything was at fault and have sold my KPC-9612, but the PSK-31/auto tuner could have also been locking it up. Does anyone else have this problem? Can anyone give me good advise about my setup? --73 de Doug (N1OBU)
RE: [digitalradio] Need help with PSK-31 and my antenna tuner
Hello Doug, It sounds like you have quite a bit of RF in the shack. I have D-Star here with no problems on an Icom 91AD. Do you do a lot of transmitting into non-resonant antennae? Do your radios still lock up when transmitting into an antenna that is closer to being resonant? Try disconnecting the lines (power and antenna) one at a time to the radios to see where the RF is coming in. Once you figure that out, try a few turns of power wire or antenna coax around some toroids placed close to the radio chassis/enclosure. All the big box ham stores (AES/HRO etc) have these and you should be able to block your RF on the line with one or more - usually Type 43 material in the toroid if I remember correctly. And they are usually pretty cheap - I would start of with maybe a dozen and see what happens because you could be faced with it getting in on both lines. Rick - KH2DF _ From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com] On Behalf Of doug_tara2005 Sent: Wednesday, July 15, 2009 8:15 PM To: digitalradio@yahoogroups.com Subject: [digitalradio] Need help with PSK-31 and my antenna tuner Hi, I'm having a little problem with my antenna tuner when transmitting PSK-31 above 30 watts. I have a IC-706MKIIG with a MFJ-945E. Both are on their own powersupply and well grounded. When I transmit PSK-31, it locks up my IC-2820H (D-STAR) radio (unable to transmit DV, analog or control the radio). My IC-2820H is on a different powersupply and also grounded. The radios and tuner are about 3-4 feet apart from each other. Additionally, I use to have a KPC-9612 and it also locked up from time to time and had to do a hard reset. I didn't think anything was at fault and have sold my KPC-9612, but the PSK-31/auto tuner could have also been locking it up. Does anyone else have this problem? Can anyone give me good advise about my setup? --73 de Doug (N1OBU)
Re: [digitalradio] Need help with PSK-31 and my antenna tuner
It all shows a severe electromagnetic incompatibility in your shack. Check if all goes OK with dummy load, both at the HF radio and at the tuner output. If all goes OK with a dummy load, then you may have RF feedback (bad) into your power line, that feeds all the faulty equipment. It is quite normal that an efficient antenna induces RF in all wires parallel to it, and that includes the power line. To attempt to solve that you should use a low pass filter. That filter should have an inductor input so it effectively DIMINISHES the parasitically originated circulating RF current. I have had to resort to ferrites in many cables, when running 100 watts or more in RTTY, packet and SSB. I have had susceptible mice and keyboards, that have needed special treatment with extra filtering. Just isolate the origin and work step by step, evaluating the results and attempting to find sensible solutions. A single solution may or may not be possible.More often than not, multiple steps will be required, as RF may be induced in every wire in the neighborhood. . 73 GL, Jose, CO2JA --- doug_tara2005 escribió: Hi, I'm having a little problem with my antenna tuner when transmitting PSK-31 above 30 watts. I have a IC-706MKIIG with a MFJ-945E. Both are on their own power supply and well grounded. When I transmit PSK-31, it locks up my IC-2820H (D-STAR) radio (unable to transmit DV, analog or control the radio). My IC-2820H is on a different power supply and also grounded. The radios and tuner are about 3-4 feet apart from each other. Additionally, I use to have a KPC-9612 and it also locked up from time to time and had to do a hard reset. I didn't think anything was at fault and have sold my KPC-9612, but the PSK-31/auto tuner could have also been locking it up. Does anyone else have this problem? Can anyone give me good advise about my setup? --73 de Doug (N1OBU) Participe en Universidad 2010, del 8 al 12 de febrero de 2010 La Habana, Cuba http://www.universidad2010.cu - SEGUNDO SEMINARIO INTERNACIONAL LEGADO Y DIVERSIDAD. ARQUITECTURA Y URBANISMO. El rescate de los valores urbanos y arquitectónicos en tiempos de globalización Colegio de San Gerónimo, La Habana Vieja, noviembre 24-27, 2009 -
