[Johnson] Ranger function switch Sparks

[Bill Evans]

Here is something that I posted about 18 months ago about
early Ranger mode switch  "spitting" problems.
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Many thanks to all those who responded to my early November
request for help on a Johnson Ranger "Operate" switch arcing
problem. I received about eight responses offering
suggestions, ranging from spraying the switch contacts with
WD40 (short term gain for long-term pain) to what I think is
likely a Johnson-authorized modification to stop this arcing
by changing the wiring on the Operate switch itself - SW4B.

Several reflector members requested that I advise them as to
my findings, given that they have this arcing problem on
their Rangers. Hence this response is being made to the
Reflector.

Garey Barrell, K40AH, provided the following suggested fix
for the arcing problem, based on his recollection of
official and original instructions that he could not find.
Garey thinks the modification was outlined in an official
Johnson Letter and has "recreated" it by comparing "early"
and "late" Ranger 1 schematics. This suggests that not all
Rangers suffer from the problem, as I also found out in
comparing my two Rangers.  The one of mine that arcs is an
"early" Ranger, as it did not have the keyer board installed
when I obtained it.

The following is reproduced from Garey's e-mail:

The switch in question is SW4, the Operate switch. The rear
wafer, SW4B, is the one we are looking at, and has Tag 1 at
the top. The Tags are counted counter-clockwise from there,
and Tag 9 is at about "4 o'clock" looking from the rear.
Look and see if your Ranger has a jumper between Tags 1 and
9. If this jumper is NOT there, and if Tag 1 has NO
connection to it, then it is probably wired as a "late"
model.

Step 1 - Remove the 0.02 uF cap and 220 Ohm resistor that
are in series from Tag 9 of the function switch to ground.
(Unfortunately, both my Rangers are "late" models, so I
can't say for certain that these parts are on the function
switch itself. Since this network is a "snubber", the parts
would normally be mounted near the contacts.)

Step 2 - Remove the jumper wire from Tag 1 to Tag 9. Tag 1
has no connection now.

Step 3 - Remove the wire from Tag 10 of the switch. (This is
the positive HV and is connected directly to the choke /
filter capacitor junction.) Connect this wire to Tag 9.
Remove the wire from Tag 2 and reconnect it to Tag 9. The
lead carries the HV to the modulation transformer primary
(center tab).

All other circuitry around this area is the same in both
versions.

What all of this does is switch on HV to the modulator and
RF final at the same time, through one set of contacts
rather than through individual contacts. The fix probably
has something to do with ameliorating the inductive "kick"
from the modulation transformer and "timing" of the two
switches. The Ranger II is the same as the "late" Ranger in
this area, so it must have been okay!

Bill Evans, VE4UD
313 Carpathia Road
WINNIPEG, Manitoba, Canada
R3N 1T2
PH:   (204) 489-7434
FAX:  (204) 487-7199
E-MAIL: bevans@ebsys.mb.ca

----- Original Message -----
From: "WILHITE, JIM" <w5jpwilhite@msn.com>
To: <johnson@mailman.qth.net>
Sent: Saturday, April 27, 2002 6:15 PM
Subject: Re: [Johnson] Ranger function switch Sparks


Jon:

There is a mod for that but I don't remember where I saw it.
Do a google search and chase links I know you will find it.
What ever you do, don't ruin that switch.

73
Jim
de W5JPW
Folks,

The Ranger II function switch (OFF TUNE PHONE STBY CW)
sparks but only
occassionally.   Does this ring a bell with any of you?
Didn't somebody
explain this once upon a time and come up with a fix?  Or am
I dreaming.

Jon, K6JEK


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