On Mar 12, 2:33 pm, "Pete KE9OA" wrote:
Using a Boonton Model 103D rf generator into a 50 Ohm thru load, the R8
easily hears signals at a 0.15uV level across the whole tuning range, preamp
off. This is using the "hard" measurement technique that results in a more
conservative measurement vs the "soft" measurement technique that the
Japanese manufacturers use in order to make their numbers appear better.
Every Icom radio I have ever used/measured is a brick on the MW range, until
you remove the full-time 10dB attenuator that they always seem to use. After
you remove the attenuator, Icom radios aren't too bad, except for the audio
quality.
Yes, I have two Icom receivers..........the R-72 and the R-75. The R-72 has
better sounding audio quality, but the IMD performance isn't in the same
league as the R-75. Opinions? No......................just hard lab data.

Pete

"SW4ever" wrote in message

...

R8B manual shows sensitivity on AM as 1.5 microvolt nominal...100
-30,000 Khz with preamp Off. and less than 1.0 microvolt with preamp
on. What does 'less than' indicate as to actual value ? R8B is a great
receiver, but R9500 is broad spectrum and in my opinion overall is a
better receiver, BUT here we go--lots of opinions coming.
To each his own, and time and a plethora of reviews probably won't
change too many minds. I am continuing my perusal of the PDF manual
and am really impressed. Icom, I believe has come up with a real
classic receiver. QST reviewer calls it "the best reciever I've ever
used" (January 2008 Issue.)

dxAce wrote:
SW4ever wrote:

Icom R9500 operating manual, almost 150 pages,available as a PDF file
at:http://www.radioworld.ca
Jan. 2008 QST ran a product review, and astonishing AM sensitivities
were shown, as follows:
At 1 MHZ 2.8 microvolts Preamp Off
0.82 microvolts Preamp 1 On
0.52 microvolts Preamp 2 On
However some confusion arises with AM sensitivity shown as 6.3
microvolts from .01-1.8 Mhz, still impressive. This latter sounds more
like it, but if 1 Mhz figures above are right. what an awesome AM
broadcast receiever !!

I just grabbed the manual for the R8B and at least according to that it
certainly has better sensitivity than the R9500.

It's a matter of dynamic range. On the pro-gear, they assume some sort
of external preamp or pigs of an antenna. The pro gear may not be as
sensitive, but if it can handle a wider dynamic range. So much the
better. The front end is where you set the SNR. Not so much preamp
determined for HF and MW since the natural noise levels there are
high.

We did a shoot out one day with the R8B and the AR7030. And by day, I
mean day. It was an afternoon. All we had to listen too were the
overseas aircraft. Then again, they were weak signals. The R8B was
fine. So was the AR7030. Its a matter of can your brain handle the
menus of the 7030. If you are an old fart, get the R8B. Plenty of
buttons.

Incidentally, the R8B computer control is really crap. I've seen the
interface. For computer control, the AR7030 is vastly superior. In
fact, AOR allows too much to be hacked since some of the adjustments
are done via the 232 port.

I saw some rant about the 9500 on radio reference. The buyer was not
very happy.