> "na4it" <na...@...> wrote:
> I am in need of help in adding a TS-64 tone board to a
> Hamtronics COR-3.
Depends on what you're expecting the TS-64 board to do
for you. If you want to use the tone filter the input
connection point is kind of limited to the receiver
discriminator circuit. If you only want the decoder portion
of the TS-64, then things are a bit less cumbersome.
Internal (on the board) to the TS-64 the tone voice high-
pass audio filter input and the decoder inputs are tied
together, which in my opinion really limits the boards
potential for use in other more straight forward
applications. Comm Spec assumed everyone would want to
drive the voice high-pass audio CTCSS filter from the
discriminator, which is really silly. When forced, I have
to separate the filter out by doing pain in the fanny
surface mount de-soldering and re-routing of Capacitor C12
(to a separate connection point).
If you are using the receiver discriminator as your main
or only audio source then I guess all would be well...
except the Voice Audio High-pass Filter is not muted.
Normally, when using the earlier TS-32, the Voice Audio
high-pass filter would connect to an internal receiver
location like the high-side of a volume control (pot).
You'd have to look at the receiver diagram to see where
the receiver audio is de-emphasized and hopefully muted
off. Some receivers don't mute the low-level audio
circuit... relying on speaker audio gating (on/off)
with tricks like an enable line to the audio power
amplifier section, well after the volume control (pot).
And most modern commercial radio receivers have a CTCSS
filter capacity available so you have to know where that
filter is if installed in the path.
So a TS-32 properly connected would provide you with gated
(on/off) voice audio, de-emphasized and no CTCSS passing
through. You would apply that audio filter output direct
to your Hamtronics COR-3 Input Pin. If all the mentioned
conditions aren't met, the audio to the COR 3 might not
result in what you want on the COR-3 output.
In the case of your TS-64, if you can't separate the Audio
Voice filter then you need to figure out if you really
want to use it with your specific layout. You can use the
CTCSS decoder and not the voice audio filter, maybe relying on
the radios internal CTCSS Filter and gating (on/off) at
certain connection points. Another way to obtain voice
audio "trick" is to terminate the speaker audio into a 22 or
27 ohm 5-watt resistor and tap across the resistor for
repeater audio... knowing the speaker audio doesn't have
CTCSS and is normally muted with no signal. Caution is
advised using this method to ensure you only couple the
AC (and not any floating DC Voltage) from the audio
amplifier output circuit.
If you have no problem dealing with the un-muted discriminator
voice audio from the TS-64 then go for it... but I'm fairly sure
the COR-3 doesn't have that sort of audio input mute function
included.
> It is connected to 2 Mitreks, with COS and PTT both positive
> voltage for action.
There are a lot of different mods and connection points possible
in the Mitrek, so we'd have to know a bit more about how the
radios are connected. I've seen three or four different Mitrek
Conversions posted at various web sites and all are different
variations...
Don't be scarred by active high or active low TX keying or COS.
It only takes a simple (properly connected) fet or transistor
circuit to invert the logic to the converse.
> Anyone have a diagram or point to point description?
> de NA4IT
Probably not without first making some choices based on
your current connections. But then a diagram or connection
information table is possible.
s.
