Actually, the Kenwood TKR-820 Repeater COR COS logic output
changes state with valid activity but the voltage transitions
are not standard values you'd expect. Measure the actual voltage
change because I've found some of them to be slightly different
per actual hardware version of the repeater.
I would not blindly connect pull-up or sink resistors/logic to
the output connection because the line ties direct back to the
uP board section. You don't want to make a mistake and blow out
the internal Repeater COR/COS logic by "back-feeding" the wrong
potentials on the lead... The fix is not simple or pretty....
You can use a simple comparitor circuit to level transition the
changing state to a more standard active low/high value as in
zero to +13vdc (or +5v) or the converse.
Some years back I designed and constructed a small interface
board to work with a large number of TKR-720 Repeaters and the
LDG Voters... not only do those circuits still function well...
the circuit pretty much interfaces (detect) ANY - COS, Squelch,
COR or logic state change and outputs a choice of active
low/high logic and or a form C type relay connection(s).
I use the interface boards for a fairly large number of commercial
radio projects. The logic board can be used to detect just about
any voltage change in a circuit and I've liberally used them in
many other applications.
I'm about ready to run off another batch of "Any Value Logic
Interface Boards" so that circuit will be available as a
complete product later this month (if the circuit board mfgr
finishes on time). I'll also have specific connection information
available applied to the Kenwood TKR-820 Repeater circuit.
If you need more Kenwood Repeater interface help before the
board/circuit is again available to the public, please do feel
free to Email me direct (I'm an Authorized Kenwood Service
Station) for more help. You don't have to buy anything from me
to obtain information and support.
cheers,
skipp
skipp025 at yahoo.com
www.radiowrench.com
> One thing to look at on the TKR820. The COS might require a
> pullup resistor to make it go high. Often they are open
> collector that just pull to ground and let float when wanting
> to go high.
The mentioned TKR-720/820 Repeater COS/COR logic ouput is not
a standard configuration.
> If a pull-up is needed probably a 4.7k will do.
> To check this measure the COS with voltmeter to make sure
> it is swinging high and low. High would probably be 5 or
> more volts and low less than 0.5 volts.
You will find the COS/COR line to change value from some point
about 4 volts to another value depending on any other attached
devices and/or parts.
> >From: [EMAIL PROTECTED]
> >Date: 2008/07/04 Fri AM 08:44:51 EDT
> >To: Repeater-Builder@yahoogroups.com
> >Subject: Re: [Repeater-Builder] TKR 820
> >does anyone have a controller model they can share as I have been
working with a nhrc controller and don't seem to be able to get it to
key the repeater. also using rus instead of cor, didn't see a cor
signal on this repeater ?suggestions welcome...N9exJack   In a
message dated 7/4/2008 3:52:35 A.M. Central Daylight Time,
> >At 04:29 PM 07/03/08, you wrote:
> >>Hi Guys
> >>does anyone out there happen to have a pin-out on
> >>the accessory connecter
> >>on the back of the machine....
> >>N9ex
> >
