In article Eric Greenwell writes:
wrote, On 8/21/2013 9:03 PM:

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.

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!

My experience with amateur radio Icom handhelds is that they do not have
the worlds best filtering, and are designed to operate as handhelds.

In fact, that latter part is true of most handhelds - they are designed
to operate with the attached antenna, so put more effort into a receiver
that can deal with weaker signals (and weaker interference). They are not
really built to be attached to that big outside antenna.

Intermodulation effects often are non-linear - if the signal levels double,
the intermodulation caused interference may quadruple (or worse). Thus,
the much stronger signal from the outside antenna overloads the front end of
the handheld radio's receiver.

Icom makes "base" radios, such as the A110 (and others that cost less).
They are much more likely to give good service.


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

Dependin on the problems and history of the radio, it may well be worth
the trouble.

Alan