The 530 has Positive 12v DC on the PTT line, it is -90v ~ on the key jack.

--
Clif Holland, KA5IPF
AVVid
Authorized Kenwood and Icom Service
www.avvid.com
1-800-214-5779
972-554-6801
"KA9CAR" wrote in message
...
I think even my 520 SE had positive 12 v keying. AS noted by another
poster, just check the voltage on the key line.

Here is how I do it with my current radio. Although the PTT is shown, the
CW key is done the same way. Just make sure you are using the correct pin
for the program you are using. SOME programs use the PARALELL output of
the
PC.

http://user.mc.net/~jdewey/KACHINA/s..._interface.jpg

Ignore the "DB25" pin numbers as that is the end connected to my radio.

If the radio has a relay on the keying line (not likely on the CW key
line),
connect a reverse biased diode across the keying line to ground. This
will
conduct the relay "magneto" decay and protect the transistor.

JD



"Zoran Brlecic" wrote in message
...
Krack Johnson wrote:
I have a question about keying my Kenwood TS-530s. I want to key this
directly from my computer but am having problems finding an interface.
What
kind of circuit does the ts530s use? Is it a grid block and if so can
I
use
a grid block adapter and a normal serial interface?


A reed relay should work just fine, unless you're into QRQ CW. You can
also make one with an opto-isolator. I believe that the keyer line
voltage is negative on the tube rigs. Very easy to measure directly on
your hand keyer and design appropriately.

73 ... WA7AA




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