[WriteLog] Dual Opto Replacement

[Ric Plummer]

Hi All,
There have been a lot of questions about the W5XD+ keyer and the dual opto
isolater
that is designed in.
I have recently built 3 of these and had no opto's, so:

If your rig ground is common with the keyer, very likely with all those
cables between them,
AND your rig has a positive voltage on the key input when not keyed ( less
than approx 50 )
AND the key down current is say less than 50 ma.
( All of the above is very likely on most modern rigs )
Then:

Buy a couple of 2n2222A transistors at Radio Shack and install in opto
socket as follows:

QA-Base to pin 1
QA -Emitter to pin 2
QA-Collector to pin 8
QB-Base to pin 3
QB-Emitter to pin 4
QB-Collector to pin 6

Then use Mono 1/8" plugs in the key jacks, This will cause the emitters to
connect to Gnd
since the jacks are stereo.

Works like a champ. For long term reliability I would reccommend soldering
rather than the socket
( although mine is in sockets ) as the sockets are designed for IC leads not
the larger transistor "legs".

Hop that helps a few folks out of the quandry.

Ric KV1W



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