Saturday, July 30, 2022

VarAC 15m activity day review

 Irad 4Z1AC the developer of VarAC invited all VarAC users to take part in a QSO party/activity day on 15m today. Unfortunately the propagation was not really the best. But VarAC is capable of decoding very low signals. I was testing the newest version 5.0.2 which has an ingenious slotted CQ feature.

You can click on the picture for a more detailed one to read about VarAC slots. I think it is well made and thought over. The slot sniffer is real handy to see if a slot is empty. 

I stopped monitoring now, I don't expect any propagation rise after sunset. This are todays results with ZR6WT as best distance (9000km). 

I only made a few QSOs:

The only real QSO was with Keijo OH2CBE, although signals were weak there was no problem to have a chat. Other contacts were just PING connects exchanging reports sometimes from me, sometimes from the other station.

Although propagation was not really good it was fun. Hope there will be another activity day in the future to test things. 

Saturday, July 23, 2022

Experimental setup square halo (3)


  PA9X Jean Paul wrote me an e-mail this morning. Asking if I already continued with the halo experiment. I didn't because of too much other things going on. But I finally had some time today.

And as you can see it was just beautiful weather, exactly what I need to do some antenna experimenting. 

The goal for today was adding the 12m band element. Actually it went well. Learning from the previous element cutting I made a 6m long double wire. I was afraid I would get an open ended loop wire again like the 17m band but was surprised to see a good resonance and SWR already at first sight with a closed loop "dipole".

This is the result so far:

I'm not disappointed at all. Except the 17m band, SWR is as expected. I wrote down the frequencies and peak SWR at one meter height and then raised the antenna to two meter height. I saw the SWR peak shifted up a bit, about 20-50KHz depending on band. Something to count on when tuning this antenna. The analyzer photos were taken with the antenna at two meter height.

The 17m dipole is not closed but has open ends. Previous experiments showed no resonance when closing the ends. It is not clear to me why 17m is behaving like that. The other "dipoles" are in fact all closed full wave loops. To see if SWR/resonance would change I messed around with the feedpoint. I bundled all the "loop" wires to see if this had any effect, it didn't. I tried to hang the balun in several different ways, it did only have a negative effect. In the end I cut back the long "tweaking" open ends of the 17m dipole and made the wire a bit longer. I managed to get the SWR down to 1,6 and X=6. Actually resonance is now around 17,9 MHz. It is not that bad and I'm satisfied for now. 

I decided to make everything watertight and park the antenna at the side of the garage. When removing the 6m/4m duoband beam for winter I will probabely mount the square halo on top of the tower. If time allows and I feel the time is right I probabely mount it earlier...haven't decide on it yet.

If you like to experiment yourself here is some tips:

Don't shorten the wires like you do with dipoles. Half wave is half wave. 300/f = meters dividing in half is the length to start with. You can always cut if needed.

Distances are probabely important because the wires will interact. It is to you to experiment. Starting points: Mounted balun on boom at 100cm from center. Mounted wires on spreaders 12m wire at 105cm, 15m at 126cm, 17m wire at 146cm and 20m wire at 191cm from center. I use shockcord to  connect the ends together.

Remember this is an experimental antenna. If it doesn't work as expected don't blame me ;-)

Saturday, July 9, 2022

Amazing 6m propagation 9 July

 Some amazing propagation especially to Japan/South Korea during local morning. It did last for hours, first station I worked was at 07:23 UTC and last at 09:48 UTC. When I switched on the station my screen was already too small to view all the Japanese stations both on 50.313/323. Worked 17 Japanese and 1 South Korean station.

Normally we can see Japan every year but propagation only lasts for 5-10 minutes if you're lucky. This time was different and I saw some of the stations with a -2dB signal. With other words....a SSB QSO would probabely possible!

Note that again PSKR does not register everything. This is probabely only half of the stations I really received. The south korean station was not even displayed despite his strong -5dB signal. Saw many other south korean stations by the way.

When I returned after lunch I saw DG4KLK on KST chat asking for a Q65 test. Well, so far I never made any Q65 QSO.

Till today that is. My first Q65 QSO is a fact.

#6m South Korea worked