Son of Mod Bob!

Son of Mod Bob!

Page 14-7 from the ARRL ON4UN Lowband DX-ing book

Chapter 14 in the ON4UN Lowband DX-ing book is a gem. John shows how to take a 40M half square and feed it just like the grounded loop – and where it then is a close array on 80M with gain. The dimensions in the book call for 72′ wide and 34′ tall. I might drop the height down to 34′ – maybe 35′ since I only have 70′ max width to play with. I doubt it really matters.

The feed and switching is like what I mentioned in one of the last posts:

if I add an Inverted L in parallel with the element on the left and the top wire, I get the best 160M performance where the wires fit in my back yard:

I will have to build a fairly simple switching scheme . . 

There is gain on 80M now – “close enough” to what John documents in his FB book . . . 

On 40M, I would switch the bottom wire out and its a half square . . . 

On 30M its close – but the 40M half square is kind to this band

So, besides my u.RAT remote L-C tuner, I would have an Inverted L parallel to the half square – and would need a high power relay to switch from one to the other. I would also need another relay to switch the right side to be a half square (un-ground the grounded loop), or ground the loop.

Because I have been building maker stuff, I’m more than happy to add  couple relays and the u.RAT and make this project sing!


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