Thanks to N5KO for the bandwidth for this -- I've sent about 60 copies
separately so far.
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I became involved in evaluating the new Icom IC756 in January at the request
of Glenn Vinson, W6OTC, who was in possession of serial #002 and who wanted
some help with evaluation of the radio in contest situations. Glenn's
interest in the radio is primarily for use on rtty contest dxpeditions. I
was interested in seeing how it would stand up in general contest use,
particularly high rf multi situations. I used the radio in both of the
January NAQPs and the ARRL DX CW contest. The first two contests were
single op, low power: the NA cw contest was from N6RO, operating
single-multi <two radios, the other an FT1000MP>; the NA ssb contest was a
lesser effort from my home station. The ARRL DX was from N6RO as a three
station multi-multi; the other radios that time were the FT1000MP and a
Kenwood TS950SD. The amps were two Alpha 76PAs and one 76A.
My first impression of the radio was quite good. It's small, very dense,
but not totally covered with zillions of little knobs and buttons, and the
display is sort of intruiging, even when the radio is turned off. The
display is exactly the same size as the display on the 781 -- I'm not an
Icom wienie, but I felt the 756 display conveyed a lot more than the 781.
W6OTC says the monitor scope function is more useful because you can crank
the display bandwidth down to 25 KHz total, a big improvement over the 781.
This box is 12vdc only -- bring your own power supply. However these days,
with the little 4 pound switchers available from Astron and Kenwood, this is
moot, cost issues aside.
The following comments follow the product evaluation questionnaire supplied
by Icom:
Two major strong points:
----------------------------------------
Size
Ergonomics, especially the quantity and quality of information provided by
the display
Two major weak points:
-------------------------------------
Limited optional filter capacity
Unsatisfactory performance by and no adjustment for noise blanker <level or
width>
The following scores relate to radio characteristics rated from 1 to 10 with
10 being High/Good/Most Useful and 1 being Low/Bad/Not Useful:
Mechanical: Size <10>, Weight <8>, Cosmetics <9>, Readability of Display
<9>, Viewing Angle <9>, Backlighting of Display <9>, Illumination of buttons
<10>.
The 8 for weight -- it only weighs 23 pounds, but you can always wish for 15.
General operating impressions: Instruction Manual <10>, Ease of Use
(General) <10>, Quick Split Feature <DNT>, Scratch pad memory <DNT>, Antenna
Switch <10>, Dual frequency display <9>, Keypad entry of frequency and or
bands <7>, Tunable memories/band stacking registers <DNT>, Auto notch <8>,
Manual AF filter <9>, Tuning rates <10>, Filter selection method <8>,
available filters <3>, noise blanker <1>, Twin Passband Tuning <8>, Memory
system <8>, Dual Watch <8> (DNT = Did Not Test)
The noise blanker is not adjustable, at least it wasn't on this radio. It's
ineffective on the low bands. Available filters -- you can only install
one optional filter in each of the two available if's (9MHz and 455KHz.)
Keypad entry -- this radio is typically Icom with it's almost inscrutable
scheme for memories, scanning and the like. I'm always confused by this
stuff on Icom radios. I did set up some memories -- they worked fine.
SSB Transmitter functions: Overall transmit signal quality based on rec'd
reports <8>, Speech compression operation <8>, VOX operation <8>, Monitor <8>.
SSB Receiver functions: Noise level <8>, Received signal <8>, Quality of
internal speaker audio <6>, Receive volume level <8>, Passband tuning
operation <9>, RIT <8>, <RIT Clear '1'>, AGC Action <8>.
RIT Clear was not on the form, but I added it and gave it a 1 since it's the
time-honored Icom clear -- you have to hold it down for 2 seconds to get it
to clear.
CW transmitter/receiver operation: Quality of keyed signal <9>, QSK
operation <6>, RIT <9>, internal electronic keyer <DNT>, Keyer
memories/operation <DNT>, AGC Action <9>, Sidetone purity <9>, CW reverse
function <10>, CW Pitch control <10>.
The QSK sounded a little grotty, but don't they all? I once worked VK0IR
from home using the QSK with my amp, so I guess it works ok. The DNTs were
the internal keyer and internal keyer memories. Who needs this stuff when
you have TR?
Internal Antenna Tuner operation: Matching capability <9>, Speed <6>,
Flexibility <7>.
I never completely made friends with the tuner which I used only in the low
power contests. I wasn't sure it remembered settings when I changed bands.
Also it had an annoying habit of going key down on a band change until it
decided it had found the match. On the other hand, I may just have not read
or understood the manual on this point. YMMV.
And now to the essay portion of the exam:
Did the IC756 perform as expected?:
Better than I expected.
What could ICOM have done to make the IC756 easier to use?:
Use of the dual watch and memory keys is a little obscure. Because the
noise blanker is not adjustable, it is useless on the low bands.
If you could change anything about the IC756, what would it be?:
I would find room for one more set of optional filters, and add an
adjustable <working> noise blanker. A CW spot feature would be nice but
it's not essential.
Did you notice any anomalies in the operation of the set (i.e., flickering
of display, hiss in receiver, fan noise, etc.)?:
No.
What did you think of the available list of filters? What did you think of
the filter selection switch operation?:
The list is fine; the fact that you can only install one set of filters from
the list is not. <More on this below.>
Was there anything missing from the display?:
Because the display is monochromatic, some status information is quite
subtle in its presentation. It is difficult to know which vfo is set to
transmit when operating split. Ditto the XFC function. <I'm certain over
time this would not be an issue.>
How would you compare other manufacturer's sets to the IC756?:
Comparing the IC756 with the Yaesu FT990 and the Kenwood TS850, both of
which are in the same general price range and which I either own or have
used extensively in contests:
v. Yaesu FT990:
IC756 receiver is more sensitive; seems about the same in high rf multi-
situations.
FT990 offers more filter selections, cw spot, very effective noise blanker.
IC756 display is much more readable in high ambient light levels. <This is
a Big Deal [tm] on dxpeditions.>
The IC756 display conveys a great deal more information than either the
FT990 or TS850 display.
FT990 has no dsp functions, no cw reverse.
v. Kenwood TS850:
Comparable receiver sensitivity; IC756 better in high rf multi- situations.
TS850 offers one or two more filter choices.
Other comments:
I would pick the IC756 over the FT990 and the TS850 primarily because of the
dual watch function <second in-band vfo>, the spectrum scope, and overall
receiver performance. This radio has acquitted itself very nicely in cw and
ssb contests, including high rf multi- scenarios.
Not tested in any way, shape or form: Six meter operation. Sorry, W3ZZ,
N5RZ, et al.
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That's the end of the Icom evaluation. A few more subjective comments follow.
The display is terrific. Programming this radio is easy compared to the
'MP. No jargon or weird symbols -- it's all plain text and graphics.
The filter situation requires more experimentation. We installed a 500Hz
filter in the 9MHz if and a 250Hz filter in the 455KHz if and were able to
use them both and switch back and forth with relative ease during ARRL CW by
leaving the filter selection display up on the radio all the time when we
thought we might need to switch <W6RGG invented this technique, tnx Bob>.
This way you could turn on the 250Hz filter with one keystroke and switch
the 500hz back in with two keystrokes and not lose much time in the process.
It's not perfect, but it works. Still to be determined is whether you could
swap out either of the 2.4 or 2.9KHz stock filters to eliminate this extra
button-pushing. That way you could assign the 500hz filter as the default
filter for CW mode, and the 250hz filter for cw-narrow operation.
Other things I like about the IC756: two preamps, good attenuation choices,
two antennas plus receive antenna, variable bandwidth for the manual Audio
Peak Filter.
Things I don't care for: the continued use of rotten, little DIN connectors
on the back for lots of things. Not labeling individual connectors on the
back but rather putting all the information on a tiny, unreadable label in
the middle of the backside. Continued need for use of the dreaded Icom
computer interface box between your application<s> and the radio.
Some gripes from W6OTC: placement of the DINs along the bottom of the rear
panel is a lot less desirable than the placement of them on the 765 and 775
-- I guess this means along the middle or top of the rear panel. The fuse
is installed inside the radio and not accessible from the outside -- this is
a pain in any situation, but esp. on a dxpedition.
Glenn says the use of the Icom computer interface box can be defended for
those situations where you need to control multiple Icom boxes with one
computer, but suggests they should have also included a direct RS232 port
that could be used instead of the Icom box -- this would be what most of us
would use.
This concludes the internet version of this write-up. K2KW and I will be
doing an expanded version for the next NCJ. It will includes more marketing
phrases and lots of anecdotes from the BY4A operation (heh) in ARRL DX CW.
73, Steve K6AW
merchant@silcom.com
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