[Icom] 756 pro 2 rcvr externa speakerl low output

[Ken Brown]

Mike,

I looked through the service manual for the pro II to trace out the audio
path.  It looks like the audio at the external speaker jack should be the
same level as that to the internal speaker.  This is how my pro operates.
It also looks like the earphone jack should have the same level split to
two circuits of a stereo plug.  A single audio amplifier feeds all of the
output options so if the internal speaker will work without other devices
being pluged in then the amp should be OK.  One thing I did notice is that 
the external jack is specified as a two conductor jack.  If you are using 
a stereo type three conductor plug there may be a problem with that.  It 
also looks like (as you would expect) the signal loops through the external 
jack to get to the main speaker so that would reduce the chances that there 
was a poor solder joint to the jack.  I think the first thing I would try 
is to change to another cable and speaker to see if the problem may be 
external to the radio.

Ken, n5kuk

Michael Stoller wrote:
> 
> Hi Malcolm,
> For some reason I can not get enough output from the "speaker out" jack on
> the back of my 756 pro 2 to drive an out board speaker.
> My initial thoughts were to send the rig back to Icom for repair.  However,
> I knew that would take two to three
> weeks plus initial shipping. An easier solution , for me , was to place an
> audio amp. in the front headphone line to drive the speaker.  It works fine
> however, I was just questioning if anyone else had a similar problem.
> I don't want to attempt to repair the initial problem myself .  It could be
> as simple as a cold solder connection or a bad connector.  Then again it
> could be an output transistor or something more complicated.
> My solution works but, I should not have had to add the amp. after the cost
> of the Icom.
> Stay well,
> Mike
> ----- Original Message -----
> From: "Malcolm Ringel" <mringel@bluecrab.org>
> To: <icom@mailman.qth.net>
> Sent: Sunday, April 04, 2004 11:53 AM
> Subject: Re: [Icom] 756 pro 2 rcvr externa speakerl low output
> 
> > Mike: I deleted the message so I forget who said not enough output to
> drive
> > a speaker....mine works just fine and drives and external speaker very
> well.
> > Malcolm, K3KZ
> > ----- Original Message -----
> > From: "Michael Stoller" <k4rdd1@comcast.net>
> > To: <icom@mailman.qth.net>
> > Sent: Saturday, April 03, 2004 6:04 PM
> > Subject: [Icom] 756 pro 2 rcvr externa speakerl low output
> >
> >
> > > Anyone had a problem with very low aux. speaker output from the rear
> > connector of the Icom 756 Pro 2?