[R-390] Question from a newbie...

[Flowertime01 at wmconnect.com]

John, K5ENQ

Two part response.

Part 1 the R390 and R390/A are such fine works of art no extender cables 
are needed.

Part 2 using extender cables lets so much trash into the wire harness that 
you need a real shielded shop with no other equipment operating in the cage. 
Once you get the decks on a cable all kinds of spurious oscillations pop 
up. Aggregation exceeds return on investment. Cables have been used on the 
VFO's for doing lots of rebuilding and alignments. But you need to be doing a 
lot more than one to make that worth the effort.


You tip the receiver up on one end or the other as needed and swing the 
subassembly / deck out and work on it. This works for the IF, audio deck. You 
may want to prop the VFO up on a cardboard box of proper size. You trouble 
shoot the power supply with a meter and no power applied. The RF deck is most 
troublesome. You do not work it live. You do use tube extenders to do signal 
injection into the stages to isolate problems. Mostly you trouble shoot the 
RF deck down to a tube stage and then do ohm checks on the deck out of the 
receiver. The military never even had extender cables. Fellows in school 
were taught to fix them all without extenders.

These thing pretty much just do not exist for the R390 and R390/A.

Roger AI4NI </HTML>