Subject: PK-232 Lockup Cures

Dear Reader!

There was such a response to my note regarding "Cures for PK232 Lockup"
that I've had to put out a general bulletin!

Here is a synopsis of some of the replies I got to my Help! cry:
Lenny (the sysop @GB7LIV) reported that he ended up putting 0.01 uF disc
ceramic capacitors between ALL connections to the radio (232 also? Derek) and
ground. He also fitted a heavy braided earth strap from the chassis of the TNC
to TRUE earth (onto the earth chassis of the computer or to an earth point on
a 13 amp socket outlet). The problem then stopped TOTALLY.

Chris (G6FCI @ GB7FCI) reported a problem with his PK232 locking up when
a fluorescent light (and other appliances sometimes) was turned  to spikes getting onto the earths in the RS232 between
the computer and TNC. Heto solve it and is not quite sure
which effected a cure.

1) Stick a decoupling cap between the RTS and CTS lines and earth (he thinks
that was where he put them).

2) Strap the signal and frame ground lines together at the TNC and computer
end of the RS232 cable. He knows that technically the two are supposed to be
separate, but suspects that the problem arises when the signal ground ends up
at a different potential from the frame ground. He hasn't had the TNC lock up
for 6 months or more.

Alex (G1FBY @ GB7BMX) reported that he has had his 232 for two years. One of
the first problems he encountered was lockup. All investigations of the unit
proved OK. One Sunday his XYL was using the washing machine and dishwasher for
long periods of time and the PK232 locked up 6 times. It was run on a fully
regulated power supply. He fitted a Radio Spares spike protection socket to
the mains plug of the power supply and all has been FB since.

Hope this is useful,
73 de Derek [G4UXD @ GB7OAR]
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GW1NGL NA7KR Kevin Roberts Ham Radio

Page last updated on 09/10/2012 by Kevin Roberts NA7KR a colection of Ham Radio and Electronic Information