GM4ULS ham radio station

a QRM-free zone!

QRMed off 10m AM!

Posted by gm4uls on November 17, 2011

Of course it had to happen sooner or later. The little portion of 10m where AM operators congregate is from 29.000 to 29.100, and it is well-populated. Often it is difficult to find elbow room, but when I do I always find someone interesting to talk to. At present it seems to be stations in the USA and Canada mainly, many of whom are using old equipment such as Johnson Viking Valiant or Ranger. Contacts are hardly ever ‘rubber stamp’, there’s always a little conversation. So it is always a shame when something as good as this is spoilt by a station using weight to barge others off the band.

Here’s what I do, no matter what band, no matter what frequency, no matter what mode. I pick a frequency that seems on first tune-through to be clear. I listen. If I’m on AM or FM and think I detect something down in the noise, I switch to CW to see if I can hear a whistle from a carrier. Having listened, I put the rig in into transmit,  identify myself, and ask if the frequency is in use. I then wait and listen for a further fifteen seconds before asking once again. If I hear nothing after a further wait, I start to call CQ.

Of course all of this is dependant on skip distance. There may well be someone on the same frequency but located where I can’t currently hear him. All I can guarantee from listening and calling is that the frequency is clear as far as I can ascertain. Also propagation might change over even a fairly short period of time, and inaudible stations might suddenly become audible.

So there I was yesterday on 10m AM. I went through the routine described above. I heard nothing, so I called CQ. I had been calling CQ for about ten minutes, cutting transmission after every call of course, and had heard no one coming back to me. Then, letting go of the PTT after a particular call, I heard a signal and the words “… in use”. Naturally I thought it was someone asking whether the frequency was in use, so I said, “Yes it is. Thank you for asking”, and continued to call CQ.

The next time I cut transmission I heard the following: “… and now there’s a GM calling CQ on the frequency. I’ve told him the frequency is occupied but he’s still calling. He obviously doesn’t have a receiver. Get a receiver! Get a receiver, you Scottish lid!”

Well, okay, I lost it. I called him back. “One wonders why, if you are hearing me so clearly, you didn’t answer when I asked if the frequency was clear ten minutes ago!” I shouldn’t have said anything, of course, but I was angry. All I got back from him was more “… Scottish lid! Get a receiver!”

Nobody ‘owns’ a frequency of course, but it did leave a bad taste in my mouth when I decided to QSY in the face of on-air bad manners and bullying. It hadn’t occurred to this guy who was accusing me of being a lid, that the propagation had changed and suddenly relatively short European skip had rolled in. No, he simply started shouting insults at someone who happened to be on the same frequency. I could identify him, I have his call sign. I won’t. Let’s just say he’s on a beam heading of roughly 140 degrees from me, in a land not unknown for ops who use a lot of power. I checked his signal, by the way, and found it covered at least 30KHz. And he called me a lid – even most broadcast stations aren’t that wide. Oh well.

Below is a pic of part of the front panel of the FT-847 transmitting in AM mode. You can see that I have backed off the power setting so that the output is indicating 20W. An external power meter reading actually says 25W, but what the heck. The manual says to back off mic gain until speech peaks no longer appear, and you will see that the gain is backed off to about 11 o’clock, or half-setting.

The FT-847 isn’t exactly a brilliant rig for AM – the mode seems to be a bit of an afterthought. That’s why I have splashed out on an early Christmas present for myself. I’ll tell you what it is when it arrives.

Meanwhile I have removed the Team ME4 CB rig from under the shelf in order to make some room. The ME4 is actually a good little rig for what it is, and even though it has sat idle for several years it still works. I don’t know whether CB channels have changed in the UK or Europe since the last time I ever transmitted on a CB – this model switches between the UK and EU bands which were in force when I bought it. I tried a tentative “One-nine for a rig check” and got the reply “Getting out, breaker”, so at least there is someone out there, hi hi.

I’m still building this site, bit by bit. I’ll let you know when I have added pages…


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