[1000mp] IC-756Pro II Transmitter Issues

[Adam Farson]

Hi Mike,

Having spent nearly 40 years in the telecom industry, I tend to look for the
same things in an HF amateur transceiver as I do in a commercial or military
telecom system - the ability to "get the message through" accurately, under
a wide range of transmission-medium conditions. If this parameter is met -
if I can understand what the distant operator is saying - then my
requirements are fulfilled. If the received audio quality is slightly
degraded in the process, due to severe filtering and/or noise reduction,
this is an acceptable price to pay for optimum articulation and virtually
perfect copy.

In a telecommunications system, I rank audio quality lower than
communications efficacy. Of course I like to transmit a signal of which I
can be proud - and invariably, the IC-756Pro2 with the Heil GL/HC-5 earns me
good audio reports. I like a received signal which is pleasant to listen to,
and does not cause listener fatigue; the IC-756Pro II has very good receive
audio to my ear - specially when driving a good telecom-optimised headset.
However, if I have to bring the radio's DSP tools to bear to "pull up" an
otherwise unintelligible signal, and the end result, whilst perfectly
intelligible, is a little "rough" - well, I am ahead of the game because we
"got the message through". Here is an example: During a recent sked on 15m
with an old friend of mine, a band-limited noise spectrum about 2 kHz wide
popped up on our frequency. By engaging the DSP Manual Notch and turning the
control, I was able to pull my friend's signal right out of that stuff with
optimal articulation and 100% copy. I defy any analogue radio to emulate
this.

In the Icom PRO series, the DSP is the radio.
http://www.qsl.net/ab4oj/icom/pro_dsp.html

Ultimately, the radio purchaser will have to make his own decision according
to what he prefers and values most. From my perspective, the
signal-management power which DSP technology places in my hands has settled
the debate in favour of a 100% DSP-based radio architecture.

Cheers for now, 73,
Adam VA7OJ/AB4OJ

 

-----Original Message-----
From: 1000mp-bounces at mailman.qth.net [mailto:1000mp-bounces at mailman.qth.net]
On Behalf Of Mike MacDonald
Sent: 11 June 2004 08:01
To: All about Yaesu 1000mp
Subject: RE: [1000mp] IC-756Pro II Transmitter Issues

I had an Icom 756 Pro I sold it, It never did sound quite right to
me(Artificial?).

(SNIP)

=====
Harry - AB2PN

There were the same kind of complaints about the difference between all tube
receivers and solid state receivers. However, I think the difference between
solid state with analog filters and dsp receivers is even more pronounced. I
had a TS-870 which is a fine radio. Probably the best rtty rig made but for
voice work it bothered me. It sounded fine but dsp has a quality to it that
is even less warm than the previous generation. One of the reasons I bought
the Field was to have a choice whether to use dsp or not.

Mike WA2E