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[TenTec] 509 PTO how hard to rebuild is it?

To: <tentec@contesting.com>
Subject: [TenTec] 509 PTO how hard to rebuild is it?
From: AC5E@aol.com (AC5E@aol.com)
Date: Tue Aug 19 14:50:58 2003
Well, I cannot comment about the 509 PTO because I never laid hands on one. 
But I have worked on plenty of other PTO tuned gear. Properly done, the cores 
have very little contact with the coil forms, making PTO tuning among the 
smoothest to tune I have seen.  One in particular had a four coil PT setup 
(preselector, RF amp grid, RF amp plate, Osc)  with about a two pound flywheel 
on the 
tuning shaft.  Start it spinning and it would travel from one end to the bump 
stop on the other end of the dial without effort.  

The bump stop was important because it used a dial cord on each end of the 
core to '"pull-pull" the cores through the coils.  Any binding would have 
resulted in the cord coming off a pulley. Which would have been a disaster 
because 
those things were almost impossible to get to track when something happened to 
the dial string. 

On the other hand, the ganged rotors on some of the five gang air variable 
capacitors used to tune some communications gear I had to maintain had up to 
six 
bearing points and even the slightest dust in a bearing made tuning rough. 
Cleaning the tuning cap was a necessary and almost daily chore when half the 
dirt in Wyoming was blowing in from the West. 

73  Pete Allen  AC5E

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