[TowerTalk] Prop Pitch Speed Up

[K7GCO@aol.com]

In a message dated 8/22/00 3:35:19 PM Pacific Daylight Time, 
w7ni@teleport.com writes:

<< 
 Boy, I certainly hope no one ever again ruins a perfectly
 good prop pitch by chopping out some of the gears.  Another
 way to speed it up is to use AC on it with a small variable
 auto transformer (Variac) and run it at about 35 VAC.  This
 does not reduce its torque.  It may wear out the brushes
 faster but mine have still lasted more than 20 years.  It is
 directly proportional to how much you rotate your antenna.
 
 Once you chop out the gears, it does not have sufficient
 friction to stay put with a sizable antenna on it in a
 wind.  I know of no way to reverse a gear modification.  If
 your antenna is small enough that the wind will not windmill
 it with a gear modified prop pitch, use a smaller rotator
 and save the unmodified prop pitch for an IMPORTANT job.
 They ain't making these anymore . . .
 
 Stan
 w7ni@teleport.com
   >>
Stan:  The original method of PP Motor speed up cuts metal off the big top 
bell gear as you know, all the bolts holding it to the planetary gear are in 
a small radius and won't hold.  The 2nd method bolts the small bell gear 
below the planetary to the planetary above but the center post of the bell 
gear has to then be cut off after the bolts are installed.  This will last 
for ever.  I have pictures on how to do this and will have them on a Web Site 
and perhaps a booklet.  I have a 3rd way anyone can do near the bottom of the 
gears that can be returned to original but no one ever does.  I have pictures 
of this also.  I've explained many things that has to be done and this is all 
my material free for everyone to use themselves and not republish.  The only 
big problem with the older used ones now is if the top spine bearing gets 
water on it as it's no longer available and did cost $175.  I developed a way 
to salvage it from even major damage.  From minor damage a clean up and new 
balls will work.  It can be a sloppy fit also.  In the worst case I regrind 
the races deeper in a jig I made for my lathe and use larger balls.  
Insertion notches have to be made in each race the right depth and I 
experimented and came up with the right depth.  It's a long job even with a 
heavy high speed grinder as that race steel is very very hard.  All the rest 
of the bearings are easy replacements or ones that can be fixed like the ones 
in the planetary if you know how to get them out (a bit tricky and any 
mechanic should be able to figure it out) and disassemble the bearings for 
new balls which is very easy.  Proper drain holes added on top, perhaps a new 
oil seal which is available and the proper cover etc and direction indicator 
and you have the best ever rotator -- if speeded up.  M Squared has all this. 
 Do a maintenance check on it at least every 50 years.  

I don't recommend 35 VAC on it although it will take it for speeds higher 
than this stupid too slow 3/4 RPM.  Use DC at half the voltage and 1/4 the 
brush wear for the same speed.

Inregard to any 40M beam movement in the wind so what??  If your beam has a 
twisting torque to it, any turning of it will reduce the tower, guy wire, 
rotator and beam stresses.  THAT IS JUST WHAT YOU WANT OR AT LEAST BE IDEAL.  
I have a 44' boom 7 element 10m beam on the small PP motor speeded up and it 
never ever moved in any wind.  A "big to do" is constantly made over what is 
really a "non existent problem" and a "desirable asset."  I spun it at 3 RPM 
also.  The wind jerks the beam around far more than even 6 RPM from a PP 
rotator.  Wake up hams, you have been saddled with a stupid 1 rpm limitation 
all these years and are destined to live with this limitation forever unless 
you wake up and smell the "New Roasted K7GCO Rotational Coffee."  Just try 
it.  This is the year 2000 and lets advance the state of the beam rotational 
art.  I often use 6 rpm with PP rotators as it's a smooth acceleration and 
deceleration--that's the key.  I speed up all rotators.  On non PP rotators I 
use a smaller beam on it.  I even speed up the small TV rotators.  I use a 
voltage step switch for 1 rpm step changes.  It works just fine and those who 
now have it just love it.  It's great for contestors.

I think there is a way to independently control the brake in a PP motor (it's 
always removed) so it can be applied after the beam stops rotating.  If I had 
a big 40 or 75M beam I might consider using it if I ever felt I needed it.   

If you are sick and tired of all the typical rotator problems and band aids 
constantly taking space in TT, move up to the No Band Aids Needed trouble 
free PP rotator.  K7GCO

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