Monday, June 13, 2022

Experimental setup square halo (2)


 In between keeping an eye on 6m and 4m DX in the middle of the ES-season I tried to make some progress building the multiband square halo. Well, actually it is getting a multiband hybride square halo. Not that I really know what I'm doing but trying to build this antenna practically. Someone else can do the theoretical side if they wish. Reading the theory about the IL-ZX antenna W4RNL describes you have two options to multiband this antenna. Actually the first option is a second small antenna for 17m/12m above the one for 20m/15m. I'm not building 2 antennas but only one, so it is no option for me. The second option is sleeve coupling like my 6m/4m dual band yagi. I thought it was useful to investigate the option. So I took 8,2m of aluminium wire from the spool I bought for use with another project. I nested it between the 20m/15m wire. Well...I can write that it is no option. There is too much interaction and after installation of the wire 20m/15m lost their matching completely. Remembering my previous experiment using the 17m wire with open ends I thought just a single wire dipole would do the trick. So I nested a single wire connected to the balun, just a dipole for 17m. Yes, a perfect SWR on 18,1MHz. But again 20m/15m wire was totally not matching, could not even find a resonance point.

In the end I decided to get back to my previous experiment with the "open" loop, if you can call it like that. So, it is two wires together, only one is connected to the balun. It doesn't match perfectly but this is the best possible. Moving the wire closer to the 15m wire gives the best results. Moving it too close will affect the 15m wire, it is a case of experimenting. My best result was obtained at 20cm from the 15m wire. A side effect is that it seems that the bandwidth on 20m and 15m has increased now.

Now, I build an antenna to practically use. I want to hear something, work something. I really wanted to do some receive test and connected the FT-817 to see if I could hear something. Propagation seems to be not really good on HF but I was able to hear some signals on 20m/17m and 15m. I will now preparate the 17m wire for permanent installation and go on to the 12m wire...

So far I'm not disappointed. The station on 15m is from Bali, Indonesia. I believe I can hear a station from Dominican Republic in the background as well and an Irish station. The antenna is at about 2,5m height


Alexander PE0ALX said...

Wow, great results! I'm impressed. :-)

Alexander PE0ALX

Paul Stam PAØK said...

Hoi Bas, de antenne doet het goed volgens mij, zo te horen. Ga je de antenne ook geschikt maken om te zenden? 73 Paul

PE4BAS, Bas said...

Hallo Alexander, bedankt. En, gezien de situatie waar in jij zit, misschien ook een leuke oplossing voor bij jou op het dak. 73, Bas

PE4BAS, Bas said...

Hallo Paul, de antenne is geschikt om op te zenden. Maar zover ben ik nog niet. Ik wil ook nog 12m erbij hebben. Had ik maar elke dag tijd voor de hobby...73, Bas