[600MRG] Icom IC-735 600m transmit mod question

[William E. Isakson]

Mike, My recommendation is don't use it on 600.  That is the rig I was
using.   The problem is that you get about 3 to 5 watts out of it at 600,
but most of that power goes out in the middle of the broadcast band.  Yes,
you can filter it out, but what are you left with?  While I was able
produce a clean weak signal, there are some other problems that you can
introduce.  For example if you shunt the antenna through a coil to ground
to bring the SWR down that filtered out double signal goes back onto the
antenna, coming up from ground.   Also there is a series of switched
internal filters in the rig that do not bypass easily and an attenuator
between 500 and somewhere around 1700 KC.   Opening the rig for out of band
use is relatively easy.  I was once in MARS so needed it opened.  There is
a German modification site that will give you mods for most rigs.  Unless
you are a member, it only allows you to see one or two a day, so be
conservative in how you chose what to look at.  It is at www.mods.dk
Bill

--------


Bill Isakson
Roseburg, Oregon USA
bill.isakson at gmail.com




On Thu, Sep 5, 2013 at 10:13 AM, Mike-WE0H <we0h at yahoo.com> wrote:

> Over the years I have read about some of the guys using modified IC-735
> rigs on 600m and other Experimental bands. I finally broke down and bought
> one of those radio's. It is still on it's way but now I would like to know
> what the mod is to make it transmit on the 600m and below bands. I know
> about filtering and so forth, just need to know the specifics or what the
> guys have to say about the rig.
>
> Thanks a bunch,
> Mike
> WE0H
> WD2XSH/16
> WD2XGI
>
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