.: ICOM IC 271 frontend mod.
I just have bougt a used IC 271 and the it seamed deaf . I
made some msurement on the sensetevity it were 0,23uV for 10DB S/N. I replased
the Q7 3SK48 on the RF.YGR bord with a BF988 and replased R18 100ohm with a
47ohm after that the sensetevity where 0,11uV on 144.3MHz and 0,06uV on
145.9MHz. And after justing helexfilters 0.05uV on 144.300MHz.
i have made the same replasedment of O7 on a a IC271H. Before 0,09uV for
10DB S/N after 0,05uV for 10DB S/N
.: ICOM IC 271 bad modolation on SSB
My IC271 alsoe hade a bad modolation on SSB , but not on FM.
after a invistagition i fond out that the BFO frequency on the main board where
wrong and the sideband hit the SSB filter at rong frequency resulting cutting
the low freqency of the modolation. After adjysting the BFO USB to 10.7485MHz modalation wehere perfekt.