Has anyone else experienced what appears to be degraded carrier suppression
when the RF processing is switched in? Measurements suggest that without
compression, the suppression is better than -50dB but is only about -25dB
with the processing would up to full; the amount of suppression seems to
depend on the setting of the PROC control. I'd like to know whether this is
normal for the FT-990.
It seems to me that there is a less than optimum interaction between mic
gain, output power and compression level in the FT-990, which is especially
noticeable when driving an amplifier. My Alpha 87A needs about 40W pep for
full output, and at that there is no indicated compression even with the
PROC control set to maximum. Reports suggest there isn't much either.
To adjust things like the carrier suppression you need an extender card --
but the price of these, at least in the UK, is horrific. I've been quoted
400 pounds by two separate dealers, which is probably about half the
radio's second-hand value! Much as I like the 990, it's irritating to have
to take it back to the dealer for minor routine adjustments. Can anyone
suggest a less expensive source for extender boards?
John Nelson
GW4FRX
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