[TowerTalk] Rotation Tower for 160m?

[K9MA]

If in understand correctly, the bottom 10' of the tower is stationary, 
and all above that rotates.

FWIW, here's what I would do:

Install a temporary gamma feed to find out where it needs to short to 
the tower.

Then run the permanent gamma feed up to just below the rotating joint. 
Make a loop of braid outside the tower to connect to the upper part of 
the gamma feed, but support it very carefully so it can't short to the 
tower. (Voltage could be very high.) A couple pieces of PVC conduit 
should work for the supports. It could be further from the tower than 
the gamma feed. Add a loop of braid around the bearing so the current 
doesn't flow through the bearing.

To get past the guy bearing(s), if necessary, run a wire into the center 
of the tower below the bearing, then straight up to just above the 
bearing, then back out to the upper section of the gamma feed. This 
should be easy to support, as there's no motion relative to the tower. 
Be sure the lower support is low enough to clear the guy wires.

It seems a bit weird to have the lower part of the gamma feed stationary 
and the upper part rotating, but I don't see why it wouldn't work. On 
160, the discontinuities shouldn't have much effect.

73,
Scott K9MA

On 10/26/2019 08:15, Richard Thorne wrote:
> And the wire would have to be real close to the tower in order to go 
> between the tower and rotating ring.
>
> Probably the only way to do this is shunt or gamma match the tower as 
> long as the matching wire was less than 30' long as that's where the 
> first rotating ring is located.
>
> Rich - N5ZC
>
> On 10/26/2019 7:41 AM, Richard Thorne wrote:
>> I have a 140' rotating tower.  130' above the rotation point with 
>> several yagi's mounted from top to bottom.
>>
>> Has anyone gamma matched a rotating tower on 160m?
>>
>> Or would it be possible to run a 1/4 wire up the side of the tower, 
>> spaced a couple feet away and insulated from the tower and feed the 
>> wire as a quarter wave vertical? I'd have to come up with some method 
>> to connect the feed to ground/radials.
>>
>> Rich - N5ZC
>> _______________________________________________

-- 
Scott  K9MA

k9ma at sdellington.us