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

Prepping the Johnson Viking Ranger for Station Use, Part 2.

 

This is what I was facing.  Notice that the electrolytics are bolted to the chassis with a screw and nut.  Some of these screws are also holding down components above deck as well as below deck.  This requires a significant amount of accessing and removing screws from top mounted components.  Especially the modulation transformer, which required the removal of the meter shell in order to access that screw.  I will show you how I did this on the next installment.  In this installment I will show the below-deck work.

 

Before I go further, let me again refer you to Greg Latta's website resource.  On his site he provides a convenient list of components needed for basic replacement, and also where to buy them, mostly from Mouser Electronics.  His list has live links to further save you a lot of time and effort!  I will add that in the eventuality Mouser may be out of certain components, I also found Antique Electronics Supply to pretty much carry what Mouser does not.

 

I wanted to show this photo simply to illustrate just how fresh some of these parts actually were in my particular Ranger.  There are two pillars, or stand-offs on either side of that filter cap that will be used to mount the two series replacement caps and equalizing resistors.

 

I use a method of re-capping that is pretty controversial, it turns out.  Years ago I knew a TV repairman who would let me access his shop up in Casselberry (Florida) for used tubes and parts.  In the process he showed me his technique employed in replacing parts, especially hard to get to reaches where the soldering pencil may disrupt otherwise good factory solder points, or possibly melt the insulation on adjoining wires.  It was called "squegging", and involved the use of "squeggs" (sometimes called "squiggs" or "pigtails".  Mr. Collins, the TV repairman who owned the shop I mentioned actually had a box full of different sized squeggs, but I found I could replicate them easily with tinned bus wire.)

 

The technique involved using the original soldering joint if it was good and solid.  Most factory solder points are, especially in this era where factory solders were still made by hand.  The wire from that point was cut at the appropriate length, stripped at the end to expose the wiring, tinned, and the squegg was placed over it.  Enough room is allowed so the component to which you are solding to it will have enough room for its lead to slide next to it inside the squegg.  I go the extra length to slide a piece of heat shrink tubing over one or the other side of the connection.  Touch the pencil to the squegg just enough to flow the solder to secure the connection, then slide the heat shrink over the squegg and heat with your hot air gun on low.  I usually have a piece of angle aluminium to slide behind the connection so stray heat doesn't compromise the other components.  I've even used index cards for this purpose because the heat exposure is really minimal, and won't set your paper alight.  Aluminum foil can accomplish the same thing.

 

I use double round snipes, the sort florists use, to wind my squeggs.  Because of the conical shape of the jaws, I can actually create different diameter squeggs as required.  Other folks use a sewing machine needle or leather stitching needle held in a brace of some sort... I've used hand held drill handles for this... and simply wrap the wire around that needle.  Any way that works is good.

 

After the solder, slide the heat shrink over the connection and heat.  Note the angle aluminium piece that I use for heat shielding.  I have several different widths, depending on the situation.

Heat shrink tubing can also serve as a surface to label, as seen here when I wired in my K2 PTT from D-Lab.  When heated, the hand written labeling remained, so in the future I can pretty well tell where I am at.  I took this photo before I applied heat.  Here, the heat shrink is not yet slid over the squegg connections, all of which are in the clear, not under anything.

 

There are some connections where I did not need to insulate, such as grounds.  This photo was taken during the wiring of the HV filter caps.

 

I need not show every single detail in changing out the discreet components, every capacitor and such but I will touch on some issues I had to solve that were not readily apparent to me at the onset, most noteably, the removal of other parts to reach areas that, in turn, had to be removed.  These were the cases where the capacitor was held by a bracket secured to a transformer bolt which could not be safely removed from the bottom, but required access from the other side of the chassis.  These were the Low Voltage filter choke and the Modulation Transformer.

 

Referring to the top photo you can see the LV choke at the top of the inside chassis view, covering all beneath.  To get at these components required the removal of this transformer.  Even though the screws were readily accessed from the side apron, I discovered I still had to go inside with a short screw driver because the screw itself was pinned under the transformer yoke.  So I positioned a smallish screwdriver from the inside, and used a ratchet for the outside.  The other screw was not pinned, and so was easier to remove.

 

Here is a shot of that pesky screw.  Bolting back in was easy, especially since there was no longer a huge capacitor taking up all the space.

 

This cap required access to the screw that held down the Modulation Transformer.  Therein lies a tale.  That screw access was wholly covered by the meter shell housing.

 

This was the screw I needed to access.  No way to get to it.  In fact to get this close-up I had to use telephoto.  The on-line references that I could find dealing with the meter shield housing showed a different type, one that was more squarish with rounded corners.  This one is larger and seems to be more prominent.  It is meant to shield the meter from RF, and is a marvel of engineering, but taking it off was a bit of a process.

 

The meter shield is actually bolted to the meter connections themselves, which requires a bit of care.  There is circuitry that has to be removed, and the pilot light socket has to be pulled out.

 

 There is a terminal strip attached to the shell housing, connecting the bulb wiring, associated rf chokes and caps to the outside wiring.  These are removed.

 

 

 

Here is another view of the rf shell housing for the meter.  I believe the screws holding down the terminal strip are sheet metal screws, no nuts to fall off inside, as I recall.  In fact, in retrospect, it may not have to be removed at all.  Your mileage may vary on this.  I removed it because I didn't know how much room might be required to actually pull off the shell.  So I thought best to take everything off just in case.

 

 

 

 

Here is a clearer shot of the two screws and what is connected to them.  It's actually not a hard job to remove these components, just time consuming.  But don't be in a rush.  Use your phone to take photos as you go.  In fact, this was how I got all these photos.  Let technology work for you!  Photo as you go.

 

 

 

 

At this point it might be good to look at the screw mounting structure itself.  Here we have two insulated washers, a nut, the eyelet for the solder connections, a metal washer, and a nut.  Remember this order.  And those two fiber washers fit into each other, so don't mix them up.  As you remove them, note their order in place.  This will save you a lot of time in re-assembly.  Once you remove the upper nut and washer, lift off the eyelets, then un-tighten the bolt beneath.  Be careful, the screws are the meter's own connections.  Go gently here.  Remove the tightening nut, then the washers, keeping them together.  Then slip off the shell itself.

 

 

 

 

Here is what you will have "dangling".  Note that the meter circuit is connected to a terminal strip screwed to the VFO covering.

 

 

 

 

Here is the exposed back of the meter.  Notice the four small nuts surrounding the meter.  These are removed carefully to remove the meter.  This was necessary to get to the modulation transformer screw.  Needless to say, this was a project in itself.

 

 

 

 

I used tweezers to replace the nuts and to get them started.  They are small and it's a little tricky to reach them all.  They should not be very tight, just snug.  Once I got to the modulation transformer beneath, and removed the bolt and the cap it held below deck, everything was re-assembled in reverse order.  This is why I strongly recommend to take shots as you go, for your own reference.  

Next installment: replacing the power cord and installing an inboard fuse.

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