Progress

The weather was reasonable this last saturday and I had some time to work on the antennatower. I had planned to place the rotor but after all it went well and I placed it as well as the top bearing and the top tube. Some photos were made for my blog.

The tube is a 5mtr 50mm thick wall Alu tube. Should hold several antennas/beams with ease. The photo above shows a picture from the tower through the top bearing just before I placed the tube.






Top of the tower now is 16 meter (52,5 ft). The plan is to mount the vertical on top with the autotuner. I might increase the total length of the vertical to 11 meter and mount the antennatuner just above the top bearing and use the tower as counterpoise. The plan is to add a few radials at the base before I do the groundwork. However this will not be done in a few weeks I guess. The plan is to mount a 5 element 10m beam to test. I sell it in the future but it is waiting for over 15 years to get into the mast. I also have a 5 element 6m beam and will test that one as well. The ultimate goal is a multiband beam.

And just before it went dark at saturday I decided to find a not so elegant way to lead the 450 Ohm open line in free space. You might find me a idiot but I had really no idea that a open line should be hanging or mounted free from walls or in my case the roof of my garage (thanks for the tip PG0DX and PE1BVQ).

After testing the inverted-V now I noticed I had other tuner settings. And the signal increase I'm used to is back on 80m. Even on 20m the signal is better in average. On 40m it's about the same as the vertical and sometimes better. But overall the inverted-V has much less noise.

However I think the wireman 450 Ohm open line I use now is not the best anymore. I connected about 4 or 5 pieces together the get this 30m long feed line. So I ordered some material to make my own open line with ticker wire. I'm curious to see the difference (or not).

Today (sunday) the weather was not so good unfortenately. A grey day with wind and rain. I decided to finish my box that covers the cable outlet from the garage through the wall to the tube under ground to the tower. The box is made from concrete form plywood also called concreteplex.

At the same time I lighted the woodstove in the garage so I could continue some work. Decided to measure some coax cable. Not only the length but also the loss. I was very surprised with the outcome.

I will get back to coax in another post. But at least this measuring session did open my eyes again.

I can reveal at least one thing. The difference between Aircell7 and H2007 (previously called H1007) might not be obvious as it looks the same. But inside it's different, I wrote about that in 2013 already. Never did a loss test to compare these cable but I had the opportunity now. It surprised me that 9,5 meter Aircell7 had a loss of 0,8dB and 10,5 meter only 0,6dB. A difference of 0,2dB on 50MHz.

Look at the specs for Aircell7 and H2007 which you can find on the internet. Aircell7 - 0,45dB@50MHz for 10m length. And H2007 - 0,45@50MHz for 10m length. Could the cables degrade after a couple of years? A quick search on the internet reveals they do!




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