Sensitivity above 7.0 Mhz.
Problem: Low sensitivity above 7mhz. The
7mhz band was most severe. On a quiet band, especially the top bands you would
notice a lack of antenna noise. This is a late model FT-1000MP with little time
on it. Low sensitivity was intermittent, sometimes changing bands or
transmitting briefly would correct the problem.
Solution: Located on the HPF-UNIT (F3552101)
you will notice 8 tiny 12 volt relays made by Matsushita. I have noticed that by
tapping or twisting some of the relays on this board that sensitivity would
change. The twisting could actually be heard in the audio. Contact resistance
has shown as much as 30 ohms in the worst case.
Suspecting a bad batch of relays I chose to replace all with a different
manufacture. From Digi-Key I found direct replacement except for coil resistance
which was 960 ohms (Omron) verse the 590 ohms (Matsushita) otherwise the relays
are the same size and pin out.
DIGI-KEY ITEM NUMBER Z774-ND, OMRON NUMBER G5V-1 DC12.
At 2.33 dollars each, its not too bad of a fix. Minimum order is 25 bucks so you
will end up with 11 relays. The extras can be used as spares. Be careful working
on this board since there are components that you could damage working in a
small space. You can also replace the board form Yaesu. Rich/N2NA
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