Brian Whatcott wrote:
On 22 Oct 2005 11:19:02 -0700, wrote:
Diodes are not the way to go... They will rectify the audio (AC) signal
such that only 50% of the waveform will remain. This will sound very
bad... and is likely to upset the audio amplifier(s) in your radio(s).
Look instead for an audio output transmformer with a low impedance
primary and a center-taped, low impedance secondary. Say the Stancor
model TA-112. Your radio wants to 'see', and your PA horn is rated at
(probably) something like 4 - 16 ohms. So, connect radio #1 to one
half of the center-taped secondary, radio #2 to the other half, and the
PA horn to the primary.
This is a more expensive solution that the "diode", but isn't this
always the case when you want to do it right?
MW
Unfortunately both windings of the center tapped primary can drive the
other, so you haven't helped to isolate the respective audio outputs.
Brian Whatcott Altus OK
Another alternative is to wire a 4 to 8 ohm 5 watt resitor in series
with each speakerlead, and then parallell the outputs. This will
enable and protect the radios and will also suck up about half of
the output, weakening the fog horn and public address functions.
Liveable?
I prefer the mixer / power amp with annunciator priority function,
overall, if two speakers is anathema.
I have seen audio horns with two driver coils and two compression
throats sharing one end horn, some where, kind of like a "y" for
your garden hose with two drivers.
Terry K