Thursday, July 16, 2020

2x 7 Element "WOS" LFA - up and running

Today I finally got two 7 EL "WOS" Innovantenna's up on my small tower.

One at about 43 ft, and one about 21 ft.  I'm using my home built 'splitter/divider'.

This isn't a very high stack, and I am actually wondering if it'll do more harm than good at this point.  BUT...

SWR on both antenna's respectively are 1.0:1.  (a FIRST for me! x2)

When I was putting the second antenna (the lower one) this morning there was an opening into EU.  I needed to test the lower antenna on the line back to the shack  and when I did I was still copying DL's.  Also a good sign :-)  But not unexpected.

The lower antenna is "fixed" at 50 degrees currently.  Because I mostly care about the Arabian Peninsula area for the remainder of the season.  I've had 9K2's in here up until 7/23 in years past since moved here in 2017.

Of course the top antenna still turns.  I expected the SWR to shift as I turned the top antenna, but it really doesn't;  maybe 0.0x.  

I have noticed my local baby monitors remain strong.  I've also noticed that the noise floor remain's low, even when the sun heads towards sunset.  In the past with a single antenna I've seen the noise floor raise in the afternoon.  That might have been some solar noise tho, so time will tell on that.  My point is signals remain high, but the noise floor stays low (yay for that!)

I'm so far East that it's hard to gauge forward pattern based on PSKR flags, but I did notice this morning that the tail behind me to the 220 deg remained reasonably narrow, more than in the past.  This isn't a really good indicator since propagation has a lot to do with that.  But it's something to consider along with everything else.

I've also added in a 'delay line' of 1/2 wave on the upper antenna to force 'BOP' all the time.

My thinking is that most of our propagation until gawd-knows-when will be "Es" and "BOP" (Both out of Phase - bottom one is 180 degrees out) will increase the take off angle by about 20-22 degrees.  I also added in about 5 degrees or so of mechanical uptilt.  This tower is quite low, and the trees are about 6-10 ft higher than the top antenna in most directions.  SO this BOP and slight uptilt may help.

I'm hoping that at least I've done everything correctly mathematically, and physically.  This is the first time I've ever created or even used a 6m 'stack'.  This is really just a dry run for future upgrades.

I'm hoping next season to raise the tower up another 20 ft so top would be 63 ft.  I'd also like to obtain a 'ring rotor' or build one of my own for the lower antenna.  I don't want a rotating tower here.   

I'm planning to add some switching so that I can bypass the divider, and go TOP-ONLY, and also by-pass the 'delay line' and go "BIP".


  1. By the way, the lower antenna doesn't show up well, because it's been painted cammo! Yes - really. Eventually the whole tower, and top antenna will be as well -)

  2. Had to laugh at your Camo comment :) I need to do the same thing with my low band vertical here at the HOA.
    Lar - K1UO