*****SPAM***** [ICOM] ACC1 different in ICOMs??

[Gary Fiber]

Dave,

Pin3 3 - 8 are the same on both the 756pro and IC-970 ACC1 socket. I 
downloaded the manuals form Icom and printed out the pages.
On the IC-970 Pin 1 is Mic output main band for the  ATV unit and Pin 2 
is ATV Mic output ground.

I scanned through the IC-970 manual and could not spot anything that 
suggests the mic audio would be cut off when something is plugged into 
the ACC1 socket. It does however connect directly to the modulator. The 
mic gain control on the front panel will have no effect on the ACC1 MOD 
in line. In the manual on  Page 42 I looked shows a level switch, though 
the manual says its for the DATA jack it may also have some effect on 
the ACC! Pin 4.The manual is vague as on page 13 it says that Pin 4 does 
have some separate adjustment. Its been a long time since I have given 
the IC-970 any thought.

Generally you don't want the mic connected when using AFSK for digital 
modes. The mic element is wired directly for VOX operation so every time 
the rig is keyed the mic is live, any noise in the shack can mix with 
the transmitted signal.

I have seen rigs be loaded into partially switching into transmit by 
some external accessories. The IC-970 had troubles doing satellite 
tuning with some packet controllers. The opto isolators in the packet 
controllers would not provide a hard enough ground to the U/D pins. So 
the fix was to add a 2N2222A and let the opto isolator switch a driving 
voltage to the 2N2222A and that would make a hard enough ground to get 
the rig to tune up or Down in frequency. Food for thought something 
similar could be going on with the mic and the device attached to the 
ACC1 socket.

Gary K8IZ



Dave Edwards wrote:
> I give up for today.
> I can't figure this one out, I was hoping someone on the list could help.
>
> I have a sound card interface (RigBlaster) that works on my 756Pro 
> just fine. It is connected to the ACC1 port.
>
> I switch it over to my IC970 ACC1 port, and no audio gets in to the rig.
> Sound comes out, transmit/receive works...just no modulation.
>
> I tried the mic gain...no effect. It is as if you flip the 
> SEND/RECEIVE to send without a microphone connected....nothing.
>
> Another anomoly that I think is related...
> With the DIN connector plugged in to ACC1, the microphone no longer 
> works also.  Pull out the DIN plug, and the mic works fine.
> On the PRO, the mic works whether the DIN plug is in or out.
>
> Anyone have an idea??
>
> ....Dave
>
> ----
> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
>
>
>