SFI > 250 or bust!

A few weeks ago I must have strained a muscle or suffered an inflammation or something like that. The result was a stiff neck and a sore back. The doctor ordered rest. And so I had to stay in a couple of days. The best thing I could do was sit still and straight. And where better to do that than in the shack? My tower was still up from the LZDX contest and I even had the 80m vertical installed. The only thing missing was a 30m antenna. As you know 10.1 MHz is my favorite hangout when not contesting. Actually it’s the WARC bands in general but 30m is the only one that is productive right now. Or so I thought…

Since the central pulley on the tower and the 9m aux mast in the corner of the garden were in use for the 80m wire, I could not put up the 30m dipole. So I used another pulley to haul up a dipole from the stock and aired it as an inverted V. I attached long ropes to the ends and tied them to a tree trunk at both edges of the garden. Bottom line: this doesn’t work as well as it should because the inverted V apex’s angle is way too sharp. I couldn’t really get out as well as I wanted to and I decided that this wasn’t worth its while. I spent some time trying to work the DXpeditions that were on but with no success. This feeling was backed up by the RBN. So after the LZ DX contest I took down the 80m vertical and put up the inverted V dipole instead. The end of the dipole’s legs were much higher so the antenna was approaching a flattop configuration and it worked much better.

I haven’t done much DXing in the recent years. The lack of time made me focus on the contest weekends. But now I had a whole week to spare (and to recover). Boy there sure is DX to be worked. I was lucky to have quite a bit of semi-rare DX on the air. But if you want to work much DX, you need to be around 24/7. And it seems it goes much smoother when most people are at work.

Another thing that struck me is that there still is life on 17 m and even 12. So I took down the 30m dipole and replaced it with the homemade WARC triband wire dipole. Soon after I was working the DXpeditions on 17m and even on 12m (J5T).

I’m not superstitious but it seems my DX happiness triggered some instances of Murphy’s law.

On one occasion the SWR on the 40m dipole was more than 4:1. I discovered that when trying to call a European special event station barefoot. And that with CQ WW CW coming up with a planned SB40 effort. Now what? It worked just fine a few days before. I switched on the second radio and there SWR was below 2:1 across the whole band. So it wasn’t the antenna or the feedline. What else? The bandpass filters? I bypassed the 5B4AGN filter set and that didn’t change a thing. And when switched to dummy load, the K3 indicated SWR = 1.1:1. So it’s not the rig either. Running out of options here! Don’t know why but I decided to switch the amplifier out of standby and sent a dah on the paddles. That of course tripped the amp. But it had solved the problem! SWR was back to normal. My guess is that one of the relays in the microHAM relay box got flakey and a firm shock of 400-500W RF cleaned the contacts?

Murphy likes me. A few days later I was enjoying the 17 meter band. With the KPA-500 at 500 Watts and SWR 1.3 to 1. Suddenly the amp trips and the alarm buzzer goes off. SWR 5:1. Still OK on 12m and 17m. Now what? A quick look through the window doesn’t reveal anything out of the ordinary. Feedline problems would present them also on the other two bands, no? So I went outside and lowered the antenna. At first sight, nothing wrong. Then I noticed the ends of the 17m wire were curled up and pointing up.

A little information on the side. A few years ago I decided to put up a permanent WARC antenna in the form of a trapped vertical.

A permanent WARC antenna

I used this WARC dipole as a set of elevated radials. But to make them resonant I had to cut a few centimeters off. In the end this antenna sucked to I converted the radials back into the dipole. So I had to add the removed centimeters again. I just let these ends hang loose. Gravity pulls them down anyway.

But now the dipole had been coiled up in a box for a while. And it was cold so the wire was stiff. Which in turn made the loose ends point upwards instead of bent downward. Close to where the end meets the 17m wire. What happened? The RF power had caused the 12m ends to melt into the 17m wire, making the 17m wire actually way too long. The picture shows where the 12m end (white) got welded to the 17m wire (black). It was not just the plastic insulating jacket that got fused. The copper got bonded too. I tore the wires apart and bent the end firmly down. A few layers of PVC tape covered the burning hole. I just wonder why 12m didn’t show an alarming SWR? Oh well, the problem got fixed. Another lesson learned. And still none the wiser.

A few days later my DXing time was up. There was a period with strong winds on the maps and I had to focus on other things again. So I let the tower down for a few weeks. I had good fun on the bands. Once again it’s proven: when the HF virus has bitten, you’re in for life. Only few people have escaped…

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