[ICOM] ACC port vs. MIC port on IC-718

[Peter Markavage]

I haven't had a mike or mike accessory connected to the front panel mike
jack of my 756 PRO II since 1 week after I got it several years ago. All
my mike and mike accessories connect to the ACC1 jack. Never had a
problem with RFI even when running an amplifier.

Pete, wa2cwa
http://www.manualman.com
 
On Tue, 19 Feb 2008 09:55:29 -0800 "Gary P. Fiber" <gfiber at comcast.net>
writes:
> Christopher,
> 
> So far as I remember and Tom mentioned it too. The IC-718 mic is 
> connected all the time when transmitting through the ACC port. So 
> you 
> will need to disconnect it unless you want to listen in at the 
> remote 
> location.
> 
>  The other issue seems to be the ACC ports are far more susceptible 
> to 
> RFI intrusion than the mic as it is a higher impedance input. 
> Something 
> on the order of 10K vs 600 Ohms for the mic jack input. Lastly there 
> is 
> no gain control on the IC-718 ACC port. That input is after the mic 
> gain 
> control so you will need to preset up your gains. Again without 
> looking 
> at the specs which will be in the owners manual I think the max 
> input is 
> 100 millivolts.
> I think the newer Icom HF rigs have the ability to defeat the mic 
> from 
> the front panel the older designs did not.
> 
> Many have success injecting audio into the ACC jack though I used to 
> get 
> complaints of distortion and low audio due to RFI or even the 
> operator 
> leaving the mic attached. the issue is the mic element is not 
> switched, 
> would not work for VOX if it was.  W2IHY has had good success 
> utilizing 
> that ACC input for his audio equalizer over the years.
> 
> Good luck with your project.
> 
> Gary K8IZ