[Yaesu] Yaesu FT990 opinions wanted

[Steve Harrison]

At 04:21 PM 3/27/2007 -0400, Richard DiDonna NN3W wrote:
>I've found mine to be susceptible to near frequency pumping and that has 
>cause some problems in pileups on 80 meters.

Most modern radios have that issue but it can be reduced quite a bit by
using the attenuator on 160 and 80, and sometimes, especially if you have a
good antenna so weak signals are still audible, on 40. Even so, here in
southwestern Connecticut, Saturday nite of the ARRL DX CW test, W3LPL's
signal from Maryland was SO strong up here on 80 for 10-15 minutes that
they were still 50 dB over S9 WITH THE ATTENUATOR ON. Without it, they were
BLANKING my receiver and almost pinning the S meter. Freak conditions and
they happened to be transmitting on an antler that pumped exactly upward at
the right angle to get a lot of signal bouncing right into my own antler's
high-radiation lobe. I've been there and know they don't run over 1500
watts output so high power wasn't really the issue; we just had a pipeline
for a few minutes.

With the attenuator on, you may still experience some overload symptoms
within 10-15 kHz unless you have a close-in roofing filter. The reason the
manufacturers haven't put narrower first filters in these radios is mainly
because most of them are also intended to be used on FM (10 meters). On the
earlier models that don't have FM capability like the TS120/TS130 series,
the reason was because the noise blanker requires wider IF bandwidth to
detect noise and work properly. But even with the attenuator on, most noise
blankers can't cope with contest signal levels so you might as well not
bother. In that case, there isn't much reason not to install a narrower
first IF filter in the earlier radios.

Inrad doesn't market a roofing filter for the TS140S/TS680S line but they
do have "experimenter's specials" for the oddball 40.095 MHz first IF
(think that's what it is, I forget for sure). $125  ===============8-O
I've not tried one yet because I believe my 680S has other problems where
the balanced mixers around the first IF stage aren't working up to snuff.
Am hoping to dig into it soon and find out what's really happening. The
quad-active-mixers that are used in the new TS480S sound interesting.

Steve, K0XP