"Brenda Ann" wrote in message
...

snip


It is still probably healthy to maintain a little skepticism about
the SDR-IQ too. It reportedly has switchable lowpass
and highpass filters at 5 MHz and 15 MHz. It seems they
would cover most desensitization issues. The 5 MHz
highpass filter should prevent desense due to nearby lower
frequency broadcast band stations. But if you've got a ham
in the neighborhood who keys up on either 40 or 20 meters it
seems to me that could desense the SDR-IQ to
everything from 5 MHz to 15 MHz.

It's interesting.
I'll be watching the reviews and this group

Sounds very much like the front ends of most HF receivers. Both my Yaesu
FRG-7700 and my Kenwood HF transceiver have this type of rough bandpass
front end. I guess the days of tuned RF front ends have passed. I'm glad
my Grundig 600 has a preselector.

What kind of Kenwood do you have? I have
the TS-440. Hadn't thought about it before but
just read in the manual that it uses 10 filters to
cover HF. That is certainly better than the
SDR-IQ but it is conceivable that a
preselector would be advantagous with the
TS-440 is some situations.

There is a ham about a mile away that runs
25 W, PSK31, on 20 meters occasionally. When he
keys up everything else on my 3 kHz wide waterfall display
disappears. 20 meter falls in the range of the TS-440
10.5 to 14.5 MHz front end filter. I wonder if his
signal is desensing my receiver to everything in that
range. I'll have to check next time.

--
rb