[TowerTalk] Roof mounted tri-bander and rotatable dipole

[Bruce Jungwirth]

Tony,
I have the GM 9ft quad pod on my garage with an OB9-5. It works good, but I found that I need a little extra power on SSB fo some DX work (just 500 Watts). Be sure you follow GM’s mounting instructions and don’t just bolt to the roof sheeting. I’d mount the A3 and go with wire dipoles for 80 & 40.
Good luck.
73, Bruce.   K0SON

Sent from my iPad

> On Jun 30, 2021, at 2:28 PM, Tony Casciato <kx3h.radio at gmail.com> wrote:
> 
> Hello to the group. Will be getting a 35' used R25 next week but it looks
> like installation at home might not be safe due to proximity to trees and
> power lines. Plan B is a roof mounted Glen Martin 4 1/2' tower which I
> bought recently plus rotor, thrust bearing and 5 1/2' mast.
> 
> I have some questions for those that have done this. Single story house
> (15' roof peak) + GM quadpod, rotor and mast would make the yagi a minimum
> of 5' above the roof (20' above ground). Top of the mast would be 8' over
> house and 23' above ground respectively. Coming from a yard mounted 6-BTV
> this should be an improvement.
> 
> I have a refurbished CC A-3 (20-15-10) and new D4 (40-10) that I can
> install. Given the short mast, my options are:
> 1) A3 just above the thrust bearing and D4 3' higher, same orientation,
> separate coaxes.
> 2) Turn the D4 90 degrees offset, same spacing and separate coaxes.
> 3) Replace the A3's driven element with the D4 so same plane and one coax.
> 4) Mount them on same boom and short-wire the feedpoints as one.
> 5) Just do the A-3 and build a dipole for 40m (+80m).
> 6) Roof mount the 6-BTV as a last resort.
> 
> I will be using W2FMI style current baluns and not the coaxial coils often
> seen.
> 
> I've been toiling if this is even worth doing given the effort at such a
> low height to poke holes into a new OSB/shingled roof. I have a few tree
> branch options around 30' for wire antennas instead.
> 
> I do mostly domestic contests and CWOps from the Midwest US (Wisconsin) and
> don't expect rare DX results.
> 
> Hope this makes sense and appreciate any guidance.
> 
> 73,
> Tony, KX3H
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