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

[Gary P. Fiber]

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



Christopher J. Pilkington wrote:
> I have an Icom IC-718.  My computer interface connects from the sound
> card to the ACC port on the rig.
>
> What I'm contemplating doing is using VoIP software such as Skype to
> provide the audio path between my remote location, using a laptop, and
> the shack PC, connected to the radio.  I'll be using grig/hamlib for
> rig control and PTT, Skype will only be the audio path.  I've already
> locked down the Skype account on the shack PC so that it will only
> accept calls from my account.
>
> What is the ACC port bypassing, if anything, and what would this
> affect using speech through it?  Is there a disadvantage to using the
> ACC port over the MIC port?
>
> Also, when transmitting using the ACC port, is the MIC port muted on
> this rig?  (I've been pulling the MIC just to be safe, but I'm
> curious.)
>
> Thanks,
>