[MRCA] Germanium diodes

[Doran Platt]

J Forster wrote:
> Are you sure sluggish operation at lowered voltage is not due to drying out grease. Generally the torque of motors increases with supply voltage, and dried out grease would need more torque to operate.
>
> It is possible older diodes may deteriorate. Can you do a V-I plot on a curve tracer. I'd suspect they are more likely to go leaky than anything else.
>
> FWIW,
> -John
>
>   
John,  Point taken, however I don't think that motors are the issue, 
here.  The ones used are the smaller, sealed type units that were 
checked at the last depot overhaul in 1984.  They also appear to run 
just fine.  Its the fact that the servo system hunts a lot and/or passes 
over the resonant point until the error voltage is sufficiently large to 
try and re-tune.   The TM relates this situation to, among other things, 
lack of sufficient error voltage being developed and/or error voltage 
symmetry.  I hope it diodes.  One doesn't see spare servo motors too 
often.  I don't have a curve tracer, per se, so wholesale 
resistance-matched diode replacement may be indicated, again per the TM. 

de K3HVG