Jock, I also have a Scout.
The plug in band modules contain both an active circuit and separately,
the LC circuit for the final filtering for each band.
The most common failures are the modules beginning to be loose in their
socket. There is an edge board set of copper fingers that mates with a
standard edge board socket and a set of coaxial connectors made of the
power cord type DC coaxial connectors used on wall warts; but in this
case, for up to 50 watts of RF. Loose fitting of either type connectors
could be a problem. There are a set of coaxial connectors for input to
the filter and output back to the radio to go to the back panel UHF
antenna connector.
The fix for the edge board contacts are to examine the copper traces and
see if any are deeply scratched, or deeply worn down. Wipe on
re-plating might fix those. Before trying that, for loose fit, you can
take a Dental probe and GENTLY bend the spring contacts in the socket.
Don't overdo it, as too tight a fit can be a problem as well.
You want the board edge to be gripped firmly but not have to pull too
hard to lever out the plug in. Use the lever provided on each module,
to get the module moving out. I always brace a finger against the
cabinet while using other fingers to pull out the module.
When re-seating modules; I use my Thumb to make sure the insertion
completely seats.
An extreme cause of fit problems might be board warpage, but I have not
seen that come up yet. (The circuit board for the module is very thin.)
The more likely cause of poor contacts is dirt and dust build up in
either the socket in the radio, or oxidation of the copper fingers.
Cleaning these with DeOxit should help. Use a strong light to inspect
the edge board connector's depths for any build ups. This can be done
with the module extracted from the radio. It is not necessary to take
the radio case apart for this.
Likewise a strong light can be used to inspect the coaxial components
for proper fit and cleanliness. If the coax contact soldered onto the
radio side is not fitted squarely, that might be a cause of trouble.
The module covers are easy to disassemble, but these steps can be done
without opening a cover of the module. But, Pay attention as you open
a Module as to how everything fits inside; and capture the flat head
screw before it disappears under the shack desk.
To preserve the connections, I leave a module plugged in at all times.
I bought a plastic refrigerator or kitchen "bin" that is just wide
enough to hold the rest of the modules, contact edge down. Get one of a
length for the number of modules (less one) that you own. A refinement
would be to line the bottom of the bin with bubble paper to cushion the
thin module edges. This bin sits easily in the hutch of my operating
desk. For the static conscious, get pink (anti static) bubble paper.
I would expect over time, that solder joints for the coaxial parts might
crack, so that is a point to check on a very old Scout. That would be
a reason to open both module cover and to gain best access to the parts
mounted on the radio chassis.
Good Luck and with care, your Scout can give you many more years of service.
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