[ICOM] IC-706MKIIG And Ambient Noise

Wed Jun 16 19:49:44 EDT 2004

I have absolutely noticed the same thing.  I have noice at S5-7 all the time.  I can't even hear stations unless they're a true S9.  Other rigs I've tried haven't had this problem.  The noise floor should be much lower than S5.

I'm using an ATAS-100 antenna.  I'm not sure if that makes much difference.  And I'm only talking about HF operation.  VHF/UHF is fine.

Mike, WA9PIE

-----Original Message-----
From: Casey Raskob III <speedlaw at verizon.net>
Sent: Jun 16, 2004 11:49 AM
To: ICOM Reflector <icom at mailman.qth.net>
Cc: Doug.Davies at gems3.gov.bc.ca
Subject: Re: [ICOM] IC-706MKIIG And Ambient Noise

I think that it's just part of mobiling.  I have a very quiet car, with only
spark gap noise.  Here in NYC, Vhf and Uhf are quiet, but for occasional
intermod, when line of sight with a tower or building with a million
antennae.

I'm a mere Tech, so can't comment.  Using an 11 meter mag mount to listen to
shortwave on AM, I am hammered by the ignition noise until the stations
break s5.  On sideband, I can normally ignore what little noise there is,
and copy weak stations. Sometimes I'll tune a SW station by SSB.  Again, I'm
doing this with a nonresonant antenna, and on Sideband, the radio is much
more quiet than AM, so the BBC is noiser than W5XYZ calling CQ on 18 meters.
I spoke to the head of electronics at BMW, and he said there's nothing that
can be done about the noise from the spark coils.  The car makes zero other
electronic noise. (he also told me that the transmitter should not cause any
problems with the car's electronics, despite the nasty lawyer sticker on the
window)

I recently had some Qso's on 144.235 usb with very, very low signal levels,
and with the preamp on and AF gain all the way up, had no car generated
noise, while the car was moving over the Tappan Zee Bridge. I was able to
cover 35 miles mobile over water, and QSO from the Tappan Zee Bridge all the
way to Staten Island.

 Powerlines sometimes toss junk, and I can often tell how far I am from an
RF generator-car by the noise from that car or truck.

The dsp could be much better.  The NB on the 706 is pointless, but the NB on
the 746 Pro is wonderful.  I normally run level 2 or 3 for AM SW listening,
and 1 or 0 for SSB, turning it off totally for FM use.  I rarely get FM hash
unless right under a sloppy power line, but then the cause is clear and goes
away quickly.

I am very well grounded (at least the radio is) and have firm grounds for
battery, auto structure ground, and antennas.  I also have a bunch of
Toroids on all my lines.

Check to see if your remote cable is SCREWED into the radio side.  It is
also a ground, and I had mucho noize using only the plastic clip to hold  it
in.  When the screw was installed, the noise dropped substantially, leaving
me with only the spark gap noize from the spark coil packs.

Casey
K2FIX
The Icom 706.  ~Hams, cops, truckers, shortwave broadcasters, all in one box
!~

----- Original Message ----- 
From: "Davies, Doug A FOR:EX" <Doug.Davies at gems3.gov.bc.ca>
To: "'ICOM Reflector'" <icom at mailman.qth.net>
Sent: Wednesday, June 16, 2004 11:44 AM
Subject: [ICOM] IC-706MKIIG And Ambient Noise

> This may have been discussed before but I haven't seen it.  Has anyone
> noticed that their IC-706MKIIG is very sensitive to ambient noise?  I have
> been fighting a noise problem with my mobile setup for the past year and
> have determined that the majority of the problem lies with the radio
itself.
> In fact, when I'm driving, the 706 even picks up line noise just about
> everywhere, even on VHF, with a noise level in excess of S-7 most of the
> time.  As a test, I substituted my old IC-735 in the truck and most of the
> noise was gone.
>
> I have played with the DSP settings, filters, etc all with no success.
I'm
> wondering if I have a crappy radio or if this is common to the 706MKIIG.
I
> really like mobiling and am considering dumping the MKIIG if this problem
> can't be corrected. Your experiences with this would be appreciated.
>
> Doug  VA7DD
> ----
> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
>

----
Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
Icom Users Net: Sundays, 1700Z, 14.316 MHz
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