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Conference vmszoo::rc

Title:Welcome To The Radio Control Conference
Notice:dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:VMSSG::FRIEDRICHS
Created:Tue Jan 13 1987
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1706
Total number of notes:27193

157.0. "Transmitter pot failures" by LEDS::LEWIS () Mon May 04 1987 14:23

    I have an Airtronics CS7P-AM system (about 3 years old).  Last year
    the elevator pot developed a "dead spot" where the resistance wouldn't
    change over a certain range of stick movement.  Fortunately I noticed
    it while the plane was on the ground, and cleaning the pot solved
    the problem.
    
    Yesterday the same thing happened to my throttle pot.  Again, cleaning
    the pot solved the problem.  I don't like opening the pots up, but
    I'm wondering if I should clean the others as a preventive measure.
    
    I love the CS7P, and want to keep it for a while.  Does anybody know
    how much replacement pots cost?  If it's a lot of money I may try to
    find higher quality substitutes. 
    
    Has anyone out there had similar problems with transmitter pots?
    I'm curious because it seems like they should last longer than this
    without needing to be cleaned.
    
                                                          Bill
    
T.RTitleUserPersonal
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157.1Cheap pots.GOLD::GALLANTMon May 04 1987 14:308
    
    	I don't know what they will cost, but it sounds like they are
    	wire wound instead of cerdip type. In that case they should
    	be very inexpensive, that where the problem comes from in the
    	first place.
    
    				Mike
    
157.2Sorry.GOLD::GALLANTMon May 04 1987 14:434
    
    	Re: -.1 typo cerdip should have read Cermet, I believe that's
    		the spelling.
    
157.3Not wire woundLEDS::LEWISMon May 04 1987 22:4213
    No, these aren't wire wound pots, inside they have three wipers
    on a smooth surface - I thought they were carbon but might be the
    material you mention.  Anyhow, the CS7P was near the top of the Airtronics
    line a few years back, and I suspect the pots they used are similar
    to what everyone else (such as Futaba?) used.  That's why I'm curious
    about these two failures.  I should add that I used the transmitter
    a LOT in the past two years.
    
    Cleaning the internal wiper surface seems to do the trick, but I'm
    wondering how long it will last before next time.  Seems like an
    annual cleaning would be the best preventive measure.
    
    						Bill 
157.4Servo Pot LubeEARTH::SCANTLENTue May 05 1987 08:346
    ACE R/C sells servo pot lube, used to treat the surface of the pot
    to avoid 'hunting' and jitter.  You might give them a call and see
    if this is applicable or recommended for transmitter pots...
    
    			-Mike
    
157.5Try Cramolin or Tweek alsoCRVAX1::KAPLOWThere is no 'N' in TURNKEYTue May 05 1987 12:566
        You might also search out a good stereo store that carries Tweek
        or Cramolin. Both are contact preservatives, not just cleaners. I
        haven't used them on my RC gear, but do use them all over my audio
        gear to prevent deterioration of all of those pots, especially in
        my car cassette deck. The DSSDEV::AUDIO notes file should have
        more information and sources for these products.