31/12/2024

This morning I did some tests with W2VP on 80m
When I went north I had a sig report of 59 when I went south he said he could hardly hear me anymore.
It seems that it works after all..

In the meantime OT4A has made me an eznec.
My antenna is the blue line.

30/12/2024

In the meantime we have been testing the parasitic elements for 80m for a while now.
This old system has already given me a lot of pleasure!
Now that we have finally finished the renovations I have started thinking about a new TX system for 80m.

After a few days of testing in my garden I started tuning the first vertical with tophat.
The verticals are now around 14m long and have a tophat of 2x 4.5m (approximately)

It looks like an arrow, you can't see it in this photo but in the meantime they are also secured with nylon cord. (There can be a lot of wind here).
The tuning is still done via a coil.

The photo above is the south antenna but is identical to the north one.

When tuning north or south I always ground the other antenna so I can make them both identical!

Remember this is experimental, I'm not reinventing the wheel, this is also not simulated at the moment in Eznec but I'm going to ask OT4A to do this for me.

now that the antennas are made I started cutting coax as christman has devised.

Namely 2 lines of 84° and 1 of 71°.
How to do this can be found on the 40m antennas on this site.
You can do the same as I did with the 9RX circle array it is all the same to cut and measure these lengths.

I'm a little bit off, but you'll never notice.

This is the 71° measured at a frequency of 3.750Mhz

So this is the 84°, you need this twice, 1 for each antenna.

Go for the lowest Z and X and you'll be fine.

There are several ways to measure this, they are explained on this site, I suspect at tab RX9 cutting feedlines.

I had tested this in the past but it didn't work as I hoped. The difference now is that the antennas are 1/4 wave apart and the test a few years ago was when the antennas were still 1/8 wave apart.
Keep in mind that for 1/8 wave you have a different phase shift than the one I use now with the 1/4 wave distance between the antennas!

this is the combiner, nothing special don't let it scare you off it is 1 relay that is in there to switch between north and south.
Now the antennas are not really north south but 330° and at 150°

This is all built from waste!!!
The iron box is from the old traingle 80m.
The coaxes are a lot of pieces of coaxes put together.
This did not cost me a cent. I only had to put on a few new connectors also recovery from other tests.

To switch the relays (you will laugh here) I once bought RG58 but it was junk instead of copper they had made it in aluminum... I now use this as a control cable to the shed...

oh no I'm lying I spent money on nylon cord to stretch them.

The top is made longer with a KT34 element, which fits perfectly in my other aluminum tube so I can make the antennas bigger with old junk.