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THE AM BULLETIN BOARD => Technical Forum => Topic started by: af6im on April 28, 2010, 07:02:03 PM



Title: My new old Johnson Ranger
Post by: af6im on April 28, 2010, 07:02:03 PM
Bought a Johnson Ranger (not a Ranger II) for $75. It's well used but no dents or gouges, all old caps, line cord crumbling, needs a bath, but it's all there. Looks kit built, I'd give it a 6 on assembly and soldering quality.

I will replace all the old caps, but what else should I do?  It hasnt been fired up in many decades. Case needs repainting, any suggestion for a good color match?

All advice appreciated.

73,
Mark
AF6IM


Title: Re: My new old Johnson Ranger
Post by: KA0HCP on April 28, 2010, 10:52:52 PM
Check continuity on the transformers....

clean the tube sockets with some pipe cleaners and some contact cleaner...

Great price, with a little elbow grease you will have a treasure!

Bill


Title: Re: My new old Johnson Ranger
Post by: K6IC on April 29, 2010, 03:27:26 PM
Hi Mark,

Great find.   Good luck.

Should make a great Jump Radio ... a few car batteries,  Dynamotor,  vertical wire with its own chute,  etc.  Will look for you under canopy.

73  Have Fun,   Vic


Title: Re: My new old Johnson Ranger
Post by: KA1ZGC on April 29, 2010, 03:35:18 PM
The list is endless, but one thing does come to mind. There is an 18K dropping resistor inside of the VFO compartment (R3) that goes bad. The wattage was too small in the very beginning. What most people do is just replace it with a 10 watt to 20 watt 15K or similar. The bigger the better.

If it's still original the VFO will jump around on frequency because of that resistor.

Ah, crap... you beat me to it. That's the infamous "Chernobyl resistor".

It'll do a whole lot more than make the VFO jump around if it lets go on you (and they always do).
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