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Re: ICOM 910H

Hi Joe

>  I own an IC-821H and would like to replace it with something than
> can do 23cm. I have been looking at the 910H. One of the issues I had
> with the 821H was that it did not have separate ground-on-transmit
> signals for each band (like the Yaesu 736R does). It appears from the
> ICOM 910H manual (available here
>  http://www.icomamerica.com/SUPPORT/DOCUMENTS/manuals/ic-910H.pdf )
> that this shortcoming (in my opinion) has not been corrected. To make
> things worse I don't even see a single ground-on-transmit signal
> available (the ACC and DATA sockets list PTT and SEND as inputs).
> While I can justify not using an external linear for 2m and 70cm,
> 23cm is a different story. I don't like to use RF sensed switching of
> linear amplifiers - I like to use a ground-on-transmit signal from
> the radio. So, what am I missing? How does one accomplish this with
> the 910H and an external 23cm linear AMP without RF sensing?

Its not quite that bad, but almost. I too have an external amplifier 
(and pre-amplifier) on 23cms and I use 2m and 70cms barefoot, so I have 
exactly the same problem. At least in our cases Icom has given us the 
tools to do the job, on page 58 of the manual you'll find that the SEND 
signal on the ACC socket can be switched on and off for each band via 
the menus. That way I have mine only activated on 23cms and things are 

I think it is a major oversight by Icom not to give more signals on the 
back panel. My line of thinking for other bands (if and when needed) 
would be to use a bias-T in reverse mode, and to use the Icom masthead 
pre-amplifier control voltage on the output socket for each band, and 
use that instead of the ACC socket signal.

Otherwise I like my IC-910H, it works great on AO-40, and its been fine 
on terrestrial DX work. It does tend to wilt in the presence of 1kW 
signals from 5 miles away beaming in my direction on 2m, but you can't 
have everything.

>  thanks.
>  Joe
>  k6sat

Jonathan  HB9DRD/G4KLX
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