Here is a mail from Peter Martinez, G3PLX. The frequencies mentioned are all from DK4XI, pse adjust your transmitters so that no sidebands are generated!! (Roberto, your sig on 10148.0 also has too much audio on the sync preamble). Please check your signal on a waterfall. The last thing we want to do is generate qrm to other stations! 73, Rein PA0R -----Ursprüngliche Nachricht----- Von: "Peter Martinez" <peter.martinez@xxxxxxxxxxxxxx> Gesendet: 21.10.08 16:45:45 An: <Rein@xxxxxxxxxxxx> Betreff: PSKMail operation Rein: I am hearing a number of transmissions, on 7038, 10147, and 14078, transmitting 250 baud PSK. All these signals are heavily over-driven and emitting lots of extra sidebands. At first I feared that someone had been sending out PSK software with no envelope filtering on the transmit signal, but after asking around, I understand that these signals are coming from PSKMAIL stations, which are using your software, and the modulation is implemented by fldigi, and this DOES filter the transmit signal properly. So it ooks like the PSKMAIL operators have not set up the drive levels correctly, and are splattering badly. I have tried to identify the signals, but they do not appear to be including their own callsigns in the transmissions. By watching the logs on the www.pskmail.de website, I can begin to guess that maybe DK4XI and PI4TUE may be responsible, but I cannot be sure. Could you please contact the PSKMAIL operators and try to get them to check their transmitter set-ups, and correct the overdrive. This will greatly reduce the QRM that these signals must be causing, especially on the crowded 7MHz band. I attach a spectrum waterfall which shows the kind of thing I mean. By the way, can you answer a question: What are these stations actually doing? I can see no useful information being transmitted and no mail being passed! 73 Peter G3PLX (The originator of the PSK31 mode) -- http://pa0r.blogspirit.com
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