Somewhere under that dirt is a Harris THE-1.   Late 80/s early 90’s these were the replacement for  the MS/MX series. 

Not much different other than the addition of a 50W power amp. 


Problems: Random AFC unlocks,  failed multimeter, power output unstable.   

We’ll start by disassembling the entire unit and cleaning each component.  


Not surprisingly most caps on the AFC board were dried out.   These units also use a ZIF (zero insertion force) edge connector that requires a lever be locked to clamp the edge connector into the socket. 

Over time these become intermittent and cause a host of issues. 


VCO module was the same.  Aging capacitors and a oxidized edge connector. 


Power supply/regulator board needed all new caps.  I also replaced the voltage regulators as operating them with heavy ripple over an extended period of time does not help their lifespan.  And they’re cheap. 



Reassembled unit except for the front panel.   The multimeter on this unit had failed and Harris no longer stocks the part.  A bit of digging turned up the OEM manufacturer:

Modutec, P/N 2S-DUA-100 100uA.  Allied electronics stocks them at $78.  Just swap in the harris meter face. 



And it’s back to making RF.  A quick audio test into a Belar monitor set and ready for burn-in. 

55W forward into a dummy load for 24 hours before being returned to service.