Having an A6 too, I can confirm what Eric is saying.
This radio is simply too sensible to RFI of any kind, and the only
workaround is to set squelch to nearly the max.
At home, in the car, in other houses, the A6 is quite unusable.
At the same time, side by side with other UHF and VHF radios, even cheap
chinese 40$ radios, they have no problems.
So the problem is the way the A6 is made, beginning with the ancient NimH
battery which lasts nothing, the non-intelligent battery charger that cannot
stop charging once the battery is full, and so on.
In the air the sensibility of the A6 is just sufficient.
The best place to use the A6 is in the middle of a desert. Right were the
Icom engineers deserve to be left.




"Eric Greenwell" wrote in message ...

wrote, On 8/21/2013 9:03 PM:
Eric I know nothing about your particular setup and your environment.
But let me speculate a bit. 25 years ago, you bought a radio with the
technology of that day. The radio had reasonable sensitivity and you
did not have a cell phone, a tablet, a laptop and so on in your
motorhome. Now, you got a new radio with latest technology, having
much better sensitivity. Probably also a couple of cellphones,
tablets, a laptop and maybe other electronic toys in your RV. All of
these gadgets nowadays are using efficient switch mode power supplies
as chargers. Unfortunately these chargers have very high levels of
spurious RF noise emissions. This holds particularly for cheap
non-branded cigarette lighter USB chargers.

So, if you are using any of these switch mode power supplies as
chargers (this might include an power inverter in your RV), take your
handheld radio. Dial in on the problem frequency. Get away from the
RV until the squelch does not get broken by the noise. Then approach
the RV and try to zoom in on the area that might be emitting the
noise. If it leads you to a charger, confirm by disconnecting this
charger (keep in mind that a charger under load might have a
different emission spectrum from a charger that is idling)

If your radio noise problem is indeed caused by a charger, move the
charger away from the radio (and antenna) or try a different
charger.

I bet there is nothing wrong with your A6.

I also suspect there is nothing "wrong" with the A6; ie, it is
performing as designed. The fact remains that when operating the Tentec
in the exact same environment (comparing them side by side, switching
the roof mounted antenna between them), it does not need it's squelch
set high to block interference.

It's true the A6 is bothered by the laptop power supply, the speed
controller in the motorhome roof fan, and random clicks, clack, hisses,
and other noises, some of which are from outside the motorhome. The
Tentec is oblivious to most of these. The same thing happens at home. A
new set of fluorescent lights in the house drives the A6 nuts; the
Tentec squelch just needs a tiny tweak to stop the noise.

I have tried to mitigate the problem by tracking down sources, but there
are some that can not be located, are beyond my control, or are too
desirable to eliminate (like the air conditioner in the motorhome -
eliminate that and it eliminates some interference, but then my wife
will stay home, so I don't even need a crew radio ... too drastic a fix!)

I did talk to an iCom support person about it, and his answer seemed to
be "The A6 is designed to be used in an aircraft or on the ramp, and not
in buildings, homes, etc, where there are many potential noise sources".

My guess is the digital signal processing in the A6 is simply not as
effective as the analog filtering in the Tentec against some common
forms of interference. I'm hoping there are modern transceivers that do
a better job than the A6. My first thought was that possibly the radios
designed as base stations would work better as base stations, but I'd
like confirmation of that before spending four times as much as the A6 cost!

I am considering trying to fix the Tentec, but it's old and not
supported. She really likes that radio, though.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl