On Wed, 04 Feb 2004 17:52:39 -0800, engsol
wrote:

On Wed, 4 Feb 2004 08:45:08 -0800, "Steve" wrote:

I have a pair of speakers in the cockpit coaming for the AM/FM radio..

I would like to figure out a way to connect the VHF external speaker to one
of these, so I can hear any calls on it in scan or monitoring of ch16.

Both radios are below deck so I can only hear them in the cockpit on a
remote speaker..

I know I could just use a toggle switch, but would prefer to find a way to
combine both outputs so the VHF would be heard over the AM/FM output.

Is there a simple way to do this and prevent one unit from harming the
other??

Steve
s/v Good Intentions


Two methods come to mind:
The first is the "simple" way...use an andio transformer for each channel.
The transformer would have two primary windings, and one secondary, which
would drive the speakers. One primay is connected to the sound system, the
other to the VHF radio.

A little more complicated way would be to use a VOX (voice operated relay)
connected to the VHF, which would disconnect the stereo, and cut thru the VHF.
This has the advantage of cutting out the stereo when the VHF is active.

I lied..there are three methods....the third is a combination of the first two., except
now the stereo is reduced by a certain amount when the VHF is active.

HTH
Norm


No you can't do that with a transformer! The transformer is not going
to isolate one radio from the other. Just because it has two primary
windings will not keep one radio from feeding into the other. A
transformer does not know primary from secondary.

The vox idea would work though.

But it is so much simpler to use 2 speakers.

Regards
Gary