[SCCC] IC7800 Impressions
W1HIJCW at aol.com
W1HIJCW at aol.com
Mon Jan 3 12:20:06 EST 2005
Ladies and Gentlemen,
I apologize if you receive more than one copy of the email, but I went
through my address book and I may have picked up your name more than once.
Through the courtesy of Icom America, I have had the opportunity to use a
7800 for the past few days over the New Year's weekend. While I did not do any
rigorous testing, I did spend quite a few hours in front of the radio (probably
10 to 15) and I thought I would share with you my subjective impressions.
First of all, let me say that I have never used a radio that was as good a
receiver as this one. Period. Now let me provide some specifics. My normal radio
is a Yaesu FT990 and the antenna here is a Butternut vertical, roof mounted
with the base at about 30 feet. Doing A/B switching with the 990, I found that
the raw sensitivity of the 7800 was no different from the 990. BUT (and this
is a big but) the ability to listen comfortably to signals was so different as
to be almost indescribable. Almost all the listening (and definitely all the
transmitting I did) was on CW.
One of my friends and customers who has a 7800 made a comment to me that this
was the first radio he has ever owned where the "DSP really works." Now I
know what he means. There are three controls (by the way an independent set for
each receiver) that have an incredible effect on the ability to listen to and
extract intelligence from a signal. They are "Noise Reduction," a "Noise
Blanker," and a continuously variable AGC attack time (AGC-VR). In various
combinations, I found I could use them to literally reduce white noise to a level that
made it essentially disappear. My QTH is not particularly noisy, but neither
is it super quiet, being a typical suburban setting with lots of neighbors
generating various amounts of EMI. If you can't get rid of 90% of the noise with
this radio, I can't imagine anything that would do a better job.
The DSP filtering is based on that which is in the 756 Pro 2 and Pro 3, but
is so much better in implementation that it's almost another animal entirely.
The second receiver and "dual watch" capability is excellent and each
receiver has a fully independent set of DSP controls, filter settings, RF gain, AF
gain, squelch, etc., etc. In short the radio truly implements two receivers in
one box. In addition to everything else, there is a variable preselector filter
implemented for each receiver, but since the bands were not particularly
crowded, I did not have the chance to evaluate its effectiveness.
Use of the radio was pretty much intuitive and I only had to go to the manual
a few times to find specific settings. I am not a spectrum display kind of
operator, so I can't evaluate that feature, except to say that it looks nice and
has a greatly improved set of parameters compared with the one in the 756.
The display itself is eminently readable. I did not connect an external
monitor to it at home, but I have seen that in other situations and it makes a
wonderful option for operating.
Speaking of options, I explored a little bit the RTTY and PSK operation.
Briefly put, it's a "piece of cake." I am not a digital operator, but I found that
even without a keyboard, I could program a couple of transmit memories for
the two modes and make contacts without any discernible effort. The setup
without a keyboard is a bit awkward and requires quite a few button pushes to switch
back and forth between displays and transmit memories, but on balance, I
could make contest style contacts on RTTY ... and that's more than I can say for
my own set up at home.
So "where the rubber meets the road" ... probably the best receiver I've ever
heard. Better for a "rag chewer" than for a contester (at least this
contester) because the control layout is not optimized for contesting.
Is it worth the price ... that's up to you. I won't be buying one simply
because I can't justify in my own mind paying more for a radio than I did for my
1999 Explorer a year ago. BUT, if you want to experience what real DSP can do
in a radio, this is the one to have.
Thanks again to Icom for letting me use the radio for a few days. It
certainly has raised my standards ...
73 de Bill, W1HIJ/6
aka FO8DX, FOOTE, Team NP4A, Team CO0US
Pina Colada Contest Club, KP2AA
More information about the SCCC
mailing list