[ICOM] original 706 issue

[Ed Brooks]

My 706 has purred along fine for many years, bought new 1997.  Recently 
it has begun to open up the
100uh RFCs going to the relays in the filter board.  This cuts out 
certain bands.   Have simply shorted
across some of these chokes as an experiment, and that returns the radio 
to operation.  Failure of a relay
opens an entire band, such as 2 to 4 mhz.  Currently 4 to 8 mhz has a 
thermal condition around RL4, not
likely to be the RFC.  After about 5 minutes of on time the relay 
operates and the 4-8 mhz band works
again until the radio is turned off for a while.  Eventually this will, 
if it follows the pattern of other bands,
result in the RFC L9 opening.

Has anyone encountered problems with the chokes opening?  I have not 
heard this problem reported by anyone before.

This rig is used on a linear 35 amp power supply, same supply it has 
used for years, and which runs other
radios and has  done so for years.   This 706 has, though, been  
operated mobile frequently, and has been
subject to vibration on rough roads.
Thoughts or comments welcome
Thanks
Ed Brooks, W5HTW




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