Turntable problem

[ebtbob]

Good Morning All,

       I am working on an On30 railroad and my turntable is an old Wilson.   The table has been in place and operational for several months now.   Lately I have run into a problem that is a puzzle to me.
       I bring an engine in and onto the table.   Turn the engine 180 degrees.   As I turn the table,  at about 90 degrees a momentary short must occur as I hear the sound cut off and then start up again.   Then,  when I try to move the engine to another track or simply back to the same track,  as the first metal wheel set hits the gap,  a short occurs.   
       I cannot figure this out.   A friend suggested that maybe the Digitrax power reverser needs to have its sensitivity corrected.   I read the manual,  but am not convinced I understand whether to increase or decrease the sensitivity.   I am concerned I may do damage to one of my sound decoders.   Any thoughts?

Bob

[SteamGene]

Bob,
So the real question is a DCC issue and not a turntable issue, right?
Gene

[renniks]

     Bob,

        Is this an auto-reversing table ? Sounds as if the reversing is no longer working which would result in a short as soon as the loco bridges the gap between table and lead track .
        On an auto reverse there is a point in the rotation where the table has no power - this accounts for the momentary loss of sound. You get the same when loco hits a patch of dirty track  and  loco is not picking up power on all drivers ( sound decoders are more sensitive ). I have an On30 Mogul which I have converted to a 2-6-2 ST( with sound ) and needs looking at as regards pickups.

     Eric UK

[renniks]

     Bob,

        A thought just occurred to me.
       Do you  have a track on the 'back side' of the table i.e. before the 90degree point ? If so can you move the loco onto this track ? If you can the trouble IS with the table reversing mechanism.

     Eric UK

[glennk28]

Trying to recall the details of the Wilson table--it has a spun steel or aluminum pit with a plastic bridge--I think the track power leads go to the pit and the pivot shaft?  which is not typical turntable practice--usual is a split pit rail with the gaps at 90 degrees to the approach track--or such that the table does not line up with a track while on the gaps?  gj

[r0bert]

that's was my thoughts, that most turntables have one position where the bridge has no power as the wipers move from the positive to the negitive power rails in the table.
If so, it's not shorting, but the normal dead spot for the bridge.

[ebtbob]

Good Morning Guys,

      To Gene - yes I am using DCC,  but is the problem with the table or the system.....not sure.   I cannot understand why it would be the table itself.

      To Eric - I am using the Digitrax auto reverser for the table.   What I do not understand is the fact that I do not remember any of my sound engines loosing power at any point in a rotation of the table.

      To Glenn - your description of the Wilson is dead on.  Your point about the track misalinment etc is one that I do not totally understand,  but again I will say,  no matter which of the six tracks I can allign the table with,  I never had this problem originally.

      I will keep working at this,  playing with the sensativity on the power reverser,  but for those of you out there like Jim Banner or Hunt,  what would occur that would cause a need for an adjustment to the sensativity if,  in the past,  everything worked just fine.

     One more thought....it may be my imagination,  but it seems as if I have one certain end of the table positioned to any track to recieve and engine,  the engine can get onto and off the table just fine,  but with the other end facing,  that is when the shorting starts.

Bob

[ebtbob]

Good Morning All,

       First of all,  a Happy Father's Day to those of you to whom it pertains.
Now for the update.   I have adjust the Digitatrax reverser unit to less sensativity and that seems to have solved the shorting out problem with the turntable.   Now the only thing left is the sound loss.   But for me....the major problem is fixed so thanks to all who responded to my thread here and thanks to Tim for the phone call this morning.

Bob