7A18/Repairs

Attenuator solder joints

The pins of the attenuator modules are connected to conductive traces on the ceramic substrate inside by low-temperature soldering, which can go bad. Re-seating the module can temporarily restore the internal contact but will usually not fix the problem permanently. Repair is possible by opening the click-locked lid and carefully resoldering.

Variable gain pots

These pots (R237A,B and R437A,B 315-0241-00) are bonded together - that bond can break which stops the variable gain push toggle from working. Looking at a few 7A18s, I see that the design was changed at least once - some revisions don't use epoxy.