[TowerTalk] Tuner SWR won't stay down

[Tom Osborne]

Hi

I picked up an MFJ-989C tuner that has a problem (don't want to hear 
about 'mitey fine junk).

The problem is that the SWR goes down and then slowly creeps back up.

I got a new roller inductor and installed it and the SWR still doesn't 
stay low, even at low power.

I took the roller inductor out and put in a switch/coil combo to 
eliminate the coil problem.  SWR still climbs up.

Bypassed the SWR circuitry and ran the input from the antenna directly 
to the capacitor.  Still won't stay low.

I thought it might be the SWR circuitry but I put another tuner in front 
of this one and when I tune the SWR down with the other tuner, it stays 
down, so don't think it should be the SWR circuit.

This really has me puzzled.  Can't see anything left to check.  Any 
ideas?  Thanks and 73
Tom W7WHY