[WriteLog] W5XD Keyer Multi Keyer **Help**

N1HKO - Bill Fleming n1hko@arrl.net
Sun, 28 Jan 2001 15:06:12 -0500


Hi All,

Something got damaged in testing. My question is what. I fear it 
may be the CPU? Following are the symptoms:

When using Left Radio, PTT line on LPT port is good for only one 
cycle and a "click"is heard when actuated. The voltage drops on 
[ESC] but something appears to have latched. When the Keyer is 
powered off, you can hear a "pop". I say "pop" because it sounds 
more like the top of a soda can than a relay or switch.

When using the Right Radio, PTT line on LPT appears to be OK. 
Voltage cycles up and down as expected. However it takes two 
[ESC] cycles to get things going after testing the Left side.

In either case something has caused an interaction between the 
two ports such that neither can deliver enough current to drive an 
optoisolator. There is 40 ohms R from Pin 16 on either LPT to 
Ground and 80 ohms across the two Pin 16s.

Opinions please? Do I need a new Micro?

Bill Fleming
Amateur Radio Station(s) - N1HKO, 8P9AM, PJ2/N1HKO, P4/N1HKO
ARES District Emergency Coordiantor - American Red Cross Liaison
RACES Radio Officer
Manchester, New Hampshire

P O Box 5973
Manchester, NH 03108-5973
(603) 647-4669
Mailto:n1hko@arrl.net
PGP PUBLIC KEY ID = 0x069F01F6

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