[TowerTalk] Prop pitch question

[john at kk9a.com]

I have a medium prop pitch turning a home brew 60' boom 20m beam and a  
small 40m beam.  The medium prop pitch has a 7063:1 gear box and my  
antennas have never turned in the wind. The problem is that your 40m  
antenna is just too big! Would a smaller motor with a higher ratio  
gear box be a better choice - I would say definitely no.  It is  
impressive that the extra large prop pitch has held up for you. I do  
not see why you could not mount a Hy-Gain type brake on the motor, was  
a brake ever on the original prop pitch motors?

John KK9A



Stan Stockton K5GO wrote:


I have an extra large prop pitch that has been turning a large 40m  
Yagi for 13.5 years.  Unfortunately the gear reduction on the extra  
large prop pitch is only 5830-1 instead of 9576-1 for the small one.   
I am guessing the small prop pitch would hold it.  At any rate,  
although it does a fine job of turning the antenna, and would hold  
most any antenna you could imagine,  the prop pitch has never been  
able to hold this antenna in place.  I've probably replaced the coax  
jumper between the hardline at the top of the tower and the hardline  
on the boom a dozen times after big winds.

I know that mounting the prop pitch outside the tower with the proper  
gears and chain I could make it hold the antenna.  What I would prefer  
is to install a brake of some kind that would stop the shaft coming  
out of the bottom of the motor to keep it from turning.  I would think  
the torque would be small.  I haven't tried it but want to think I  
might hold that antenna in place with my fingers on the shaft coming  
out the bottom of the motor??

Anyway, the question is this.  Does anyone have an idea for an off the  
shelf product that could be adapted to stop that shaft when I wanted  
to "park" the antenna or after it is rotated with a delay?

Thanks... Stan, K5GO