[TowerTalk] Tuning a 20m 4-Square Array - Resolved

[Mike Smith VE9AA]

I had been complaining of “no gain” on my new 20m 4-SQ array but great pattern and quietness and also low dumped power on my new beast.

 

To recap, it’s a bit of a compromise in that it only has 2 raised radials per vertical  up about 2’ and to make matters worse, is amongst a bit of metallic clutter.  I would’ve been happy with any gain at all, even 1-2dB

 

I was saying it has no gain whatsoever compared to an HF9V multiband vertical very nearby.

 

Well, in many email exchanges with K5WA and K8GL they got me thinking.  Greg K8GL had been very helpful a week or so ago furnishing me pics and a description of his 20m 4-SQ……then

I stumbled across Greg, K8GL totally by accident the other night on 20m and we did some typical A/B/C/D tests etc.

In a follow up email Greg surmised it must be my main feeder. DING DING DING.  Greg wins the prize.

 

Today after a full day of outside chores I spent the remaining couple hours of daylight doing a wattmeter test. 

With 20w at the radio, I was showing 11.5 w at the antenna.  That’s darn near 3dB.

So, with a bit of finagling, I swapped my main feeder from a vy old RG8 type to using my 6m array coax (which is currently down) which is a ¾” chunk of 75 Ohm hardline some 160’ long.

20w in the shack on 20m and now has what looks like ~19w at the antenna.  WOW!  Nearly no loss.

 

Of course, that is now echoed in the gain compared to the HF9V and I am seeing a solid 3-6dB gain in most directions over the 9V. (It’s pretty hard to detect ½ an S-unit, but sometimes it seems more like 1 S unit)

 Array seems to have less gain towards EU, but more towards the USA (go figure)

I’ve only played with it for 15 mins so far. but it’s pretty obvious that doing the A/B tests it now shows the 4SQ as the winner pretty much most the time.  It’s always hard to quantify numbers this small and as incoming signals arrival angles change, I except there will be times the HF9V or a ZS6BKW will win as they have different patterns than the 4SQ.

 

3dB? I’ll take it !

 

Special thanks to K5WA

 

Notable thanks to K1TTT, K4AB and of course Greg K8GL for his winning idea.

 

Mike VE9Antenna Antenna, dit dit