Re: [Flexradio] Frequency on AM
One of the most helpful things (to me) that has come from this group has been the occassional well thought out treatise on we should do things this way My favorite examples are 1) Phil Harman's paper on agc which has led to a great improvement in that area (and will lead to more) and 2) the descriptions of what is needed to aid the audio processing given by the audio experts (W5GI, et. alia). This radio should be the very best AM transmitter period. If someone were to put together a paper like Phil's agc paper, where a concise description of the ideal was presented, it would be helpful. Bob Charles Greene wrote: Mike, Good tip. I reversed two phone plugs going into my Fire Box. Now I could zero the TX image when on AM. As measured on the spectrum analyzer, on AM, while transmitting into the dummy load, the image at 7.0785 Khz is 40 dB below the signal at 7.1 Mhz. Image down the same on CW. Settings on TX image reduction are phase -1 and gain 10. I redid the RX image reduction to be sure, and it came out a little different: phase -1.75 and gain 3.44. It sounds good now on SSB and AM. tnx, Chas, W1CG At 08:27 AM 2/1/2006, Mike WA8BXN wrote: I had a problem of transmitting two AM signals at the same time, one of the audio cables was not firmly seated in the SDR-1000. One of these days I ought to take it apart and enlarge the holes in the chassis so that is less likely to happen. If you just got one signal on 3.878 and little on 3.9, then it sounds like the left and right are reversed on audio going into the sdr-1000. 73 - Mike WA8BXN ---Original Message--- From: Charles Greene Date: 02/01/06 08:16:32 To: FlexRadio@flex-radio.biz Subject: [Flexradio] Frequency on AM GM, I was trying to do some image reduction on the TX signal, and I set up a distant receiver and set the PowerSDR Console to AM. The transmitted signal was on 3.9 Mhz and the receiver read 3.878 KHz. On SSB and CW, signal frequency is right on. Tried another receiver, the same. Put on a spectrum analyzer and tried to reduce the image using phase and gain. Best I could get it was the primary signal was 15 dB down from the image with the phase control all the way to the left. Recalibrated RX level and image rejection. Settings were phase -1, gain 2.63. Set the TX phase and gain to those settings. Can't see the image signal on the spectrum analyzer. Evidently there is a problem on AM, not that I use it, but is it my set or does anyone else experience it? 73, Chas W1CG ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Frequency on AM
GM, I was trying to do some image reduction on the TX signal, and I set up a distant receiver and set the PowerSDR Console to AM. The transmitted signal was on 3.9 Mhz and the receiver read 3.878 KHz. On SSB and CW, signal frequency is right on. Tried another receiver, the same. Put on a spectrum analyzer and tried to reduce the image using phase and gain. Best I could get it was the primary signal was 15 dB down from the image with the phase control all the way to the left. Recalibrated RX level and image rejection. Settings were phase -1, gain 2.63. Set the TX phase and gain to those settings. Can't see the image signal on the spectrum analyzer. Evidently there is a problem on AM, not that I use it, but is it my set or does anyone else experience it? 73, Chas W1CG
Re: [Flexradio] Frequency on AM
I just used a knife and whittled away the plastic near the end of the plug. No interference on fit now. Mike - AA8K Mike WA8BXN wrote: I had a problem of transmitting two AM signals at the same time, one of the audio cables was not firmly seated in the SDR-1000. One of these days I ought to take it apart and enlarge the holes in the chassis so that is less likely to happen. If you just got one signal on 3.878 and little on 3.9, then it sounds like the left and right are reversed on audio going into the sdr-1000. 73 - Mike WA8BXN
Re: [Flexradio] Frequency on AM
Mike, Good tip. I reversed two phone plugs going into my Fire Box. Now I could zero the TX image when on AM. As measured on the spectrum analyzer, on AM, while transmitting into the dummy load, the image at 7.0785 Khz is 40 dB below the signal at 7.1 Mhz. Image down the same on CW. Settings on TX image reduction are phase -1 and gain 10. I redid the RX image reduction to be sure, and it came out a little different: phase -1.75 and gain 3.44. It sounds good now on SSB and AM. tnx, Chas, W1CG At 08:27 AM 2/1/2006, Mike WA8BXN wrote: I had a problem of transmitting two AM signals at the same time, one of the audio cables was not firmly seated in the SDR-1000. One of these days I ought to take it apart and enlarge the holes in the chassis so that is less likely to happen. If you just got one signal on 3.878 and little on 3.9, then it sounds like the left and right are reversed on audio going into the sdr-1000. 73 - Mike WA8BXN ---Original Message--- From: Charles Greene Date: 02/01/06 08:16:32 To: FlexRadio@flex-radio.biz Subject: [Flexradio] Frequency on AM GM, I was trying to do some image reduction on the TX signal, and I set up a distant receiver and set the PowerSDR Console to AM. The transmitted signal was on 3.9 Mhz and the receiver read 3.878 KHz. On SSB and CW, signal frequency is right on. Tried another receiver, the same. Put on a spectrum analyzer and tried to reduce the image using phase and gain. Best I could get it was the primary signal was 15 dB down from the image with the phase control all the way to the left. Recalibrated RX level and image rejection. Settings were phase -1, gain 2.63. Set the TX phase and gain to those settings. Can't see the image signal on the spectrum analyzer. Evidently there is a problem on AM, not that I use it, but is it my set or does anyone else experience it? 73, Chas W1CG ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
