Telamon wrote:
In article ,
dxAce wrote:

http://ndl-dx.se/icom_r9500/icom_r9500.pdf

and at:

http://ndl-dx.se/icom_r9500/
(via Bernt-Ivan Holmberg, Möklinta, Sweden, dx_india)

I'm not a fan of wide bandwidth receivers as the design usually favors
the higher end communication bands and scanning functions.

Looks like they paid more attention to the front end then normal with
RF relay switching and (relatively) large toroid coils instead of
smaller chip inductors that can more easily saturate. Although the
toroids are self shielding they look a little to close together on that
BPF board for my tastes and causes me to wonder if enough attention was
paid to isolating the sections. I'd need a closer view of the board and
layout to know what was up with it.

The spacing looks tight, but this is the kind of thing that is easily
tested on a network analyzer in the design phase, so I suspect it is
not significant, and of course, any problems would have shown up in the
end to end testing of the radio.


The relays are a better RF solution than switching diodes but the unit
will be making clicking sounds when you scan across bands and wear the
relays out so I expect that the operating manual will advise against
doing that.

At 70 watts whether it is on or off means it will run hot. The case
looks like it is meant to travel and sit on a desk but you may want it
to be in a rack with cooling. To get a feel about this imagine placing
a 70 watt bulb inside the case. The receivers I have take 30 to 40
watts and are ballpark around the same size so for the ICOM to stay as
cool it will all depend on that fan in the back, which will collect
dust over time.

Even the R-8500, with the external power supply, needs ventilation. At
it is in the 30 watt category.


With the USB and ethernat ports on the back means it could be controled
with National Instruments software instead of generating computer
control software from scratch. ICOM may even have a driver written for
it.

Nice looking unit and display. Looks like it belongs on a lab bench.

--
Telamon
Ventura, California