Gary's Awesome Adventures in Amplitude Modulation (AM Radio Transmission & Reception) :

Prepping the Johnson Viking Ranger for Station Use, Part 1.

 

Fresh from the Fest.

 

 The Orlando Hamcation occurred in February for the first time since 2020.  I wasn't really sure what I even wanted, it's been so long.  I did have in mind a Kenwood AT-120 and remote speaker to go with my off-grid portable station, a 40 year-old Kenwood TS-120S, which serves as my bench receiver, currently, but I have it ultimately sighted for camping duty.

I had just entered the entrance, showed the guard my ticket, and walked a few steps.  It had to be on the first table.  A Johnson Viking Ranger.  Literally glistening in the 9am sun.

For some time I had been joking with the guys on AM that yeah, I'll get a Viking Ranger one day..... when I find a pristine specimen, and it falls into my lap for nothing - or something that approaches that.  Slim chance that happening, Rangers like that sell at $400 and northward.

I walked over to the table more out of curiosity as to how "NIB" this Ranger actually was.  Not a scratch, not a mark, the screening on the front panel looked new!  In fact, it looked better than the Ranger I had back in 1973, which was eighteen years old at the time.  Dare I say it looked.... new?

 

"So, what are you asking for the Ranger?"

"Uhh..... a hundred?"

The Johnson Viking Ranger glistening in the 9am sun was very shortly in the back of my Toyota Matrix!

But I did not open her up immediately.  There were some things I needed to know about Johnson Rangers before I went diving in.  I downloaded both an assembly manual and an operations manual for the Viking Ranger 1 from BAMA, which was a pretty good set of copies.  On line I found the best resource, for my purposes, to be Greg Latta, AA8V's excellent and very detailed web site.

Presently I did open the Ranger up.  Like the exterior, the interior was amazingly clean.  No sign of rust.  I could tell this was a factory wired version, as the tube sockets are riveted.  The presence of the keying circuit subchassis signaled that this was a later model Ranger-1.

 

The only sign of oxidation are the iron leaves of the power transformer and the filter choke.  Anyone who has worked with trannies know that unless varnished or painted with a few coats, the ends of the iron plates oxidize after only a short time....especially in Florida.  Even with climate control, thus this is easily addressed: a light brushing with 220 grit sandpaper, and a clear Krylon coating or a coat of industrial black Rustoleum... if it's a thing that bothers you.  Me?  it's not even an issue.

Whenever I see a rig that is my age (66 years of age) and shows no sign of even being used, I have to wonder why.  There was nothing to clean up or restore!  Not complaining, but this is not the normal Hamfest-find Ranger.  Either: something is wrong and it couldn't be operated, or it just went into storage in a very dry environment.  Fingers crossed.

This side shows the rectifiers and keying circuit.  The earlier models did not have the differential keying as this one does.  So much focus has gone into the AM prowess of the Johnson Ranger that it is sometimes forgotten that to us code guys, this rig is also kind of a "holy grail" as well.  This was the only non-commercial rig I knew, aside I think, from the Johnson Valiant and maybe the Vik-500, that has true adjustable electronic differential keying, which has the VFO engaged a split nanosecond before the buffer and finals, which is a practical guarantee against chirp, but more than that: you can also adjust the shape of the keyed signal as well, assuming all circuits are functioning well.  

E.F. Johnson has a deep background in commercial transmitters and quality component parts for those commercial and military rigs.  I have broadcast transmitter ads going back to Armistice showing that familiar Viking logo and iconic name.  This legacy is accurately portrayed in the Johnson Transmitters for the Amateur Radio Service, the same quality components and materials.  Even the front panel has a jacketed steel braiding that surrounds the edge curve of the front panel, to ensure a positive grounded contact with the chassis.

Here is the rear apron.  One thing this radio did not have that was vital to its operation is the accessory plug.  That I had to later obtain and wire.  But wow, it s a clean chassis, this one.

The bottom side.  The components are strikingly clean... to the point of new.  Now, even if per chance this rig was never actually turned on, those electrolytics at very least must be replaced because the chemistry changes with age, as much as with use.  In fact, an argument can be made that use is actually what preserves electrolytics.   The paper caps all looked good...and may have, in fact been fine.  But by practice I replace these as well. Both the molded as well as cardboard covered tubulars.  It just makes sense if you want to pass down a usable device to the next generation of BA users.

This was an amazing Hamfest find.  And, you might probably surmise, not the usual economy find.  But it does go to show that you never know what can turn up, even in this day and age.  Following installments will show what I did to go about bringing this rig up to current safety specs,  as well the various capacitors and resistors.  Also the eventual installment of a PTT relay, the "solid stating" of the low-voltage rectifier, the wiring of that accessory plug, the wiring of the D-104 microphone for use with the Ranger, and finally the tuning and operation of this transmitter on AM.  Spoiler alert: I basically used Greg Latta's excellent work on the subject (see the link above.)

More to come.

de wd4nka.