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Re: [TowerTalk] Prop Pitch Motor

To: "Tower and HF antenna construction topics." <>
Subject: Re: [TowerTalk] Prop Pitch Motor
Reply-to: "Tower and HF antenna construction topics." <>
Date: Mon, 15 Mar 2010 08:45:18 -0700 (PDT)
List-post: <">>
George is dead on with his comments. I used a "modified" PP for many years. It 
worked fine but needed to be fixed about every two years. The standard 
"modification" consisted of cutting off the top-most gear from the output 
shaft. This output shaft was then drilled and bolted to the planetary gear 
cluster buy drilling/tapping corresponding holes in it. The bolts can sheer or 
work loose at the very least (I've had both). I had custom-made brass pieces 
installed in mine and even with helicoil inserts, loktite, and hardened bolts 
it would all loosen up over time. BTW, I'm turning a TH6 and a 40-2CD - nothing 
really big.

Luckily, I obtained another PP (unmodified) And used the parts from it to 
return mine to stock configuration. It takes about a minute & 45 seconds to 
rotate a full 360 degrees now but you can turn just about anything you want 
even in high winds. I'm VERY happy that I returned mine to the unmodified 

I would not recommend turning anything big with a modified PP unless you like 
doing repairs.

73, Stew K3ND

--- On Mon, 3/15/10, Dubovsky, George <> wrote:

> From: Dubovsky, George <>
> Subject: Re: [TowerTalk] Prop Pitch Motor
> To: "Tower and HF antenna construction topics." <>
> Date: Monday, March 15, 2010, 9:51 AM
> It's worth noting that these
> "modified" pp gearboxes are no longer capable of doing the
> antenna rotation tasks usually asked of prop pitches. They
> trade off torque and braking capability (holding in the
> wind) for an increase in rotational speed. Please don't do
> this to a pp.
> 73,
> geo - n4ua


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