W2XO Ham Radio Stuff and Things
Boat Anchor repairs
Viking Ranger (original model)
I used to drool over rigs like the Viking Ranger when I was a 13-14 year
old running my Heathkit AT-1. I recently aquired a horribly mistreated
Ranger with many mods, which I "unmoded" and returned to original circuitry
as nearly as possible, planning to start over, but the plan was to get the
rig back to "bare metal" and begin again. After all the dust settled, the
rig worked well, but had annoying frequency pulling and chirp on 160 and
40 meters, much worse on 40.
So, after doing some "Googling" and other research, it was apparent that this
was a common problem with this rig. One suggestion was to remove the Johnson
"single point" grounding scheme and return everything securely to the chassis
instead of floating the frame of the plate cap and the bottom of the loading
caps above chassis on a single piece of #16 wire. This helped 160 out to where
it was acceptable, but 40 meters still had too much chirp for me to show myself
on 40cw with this rig.
The common denomenator between 160 and 40 meter operation is that the VFO is
on the same band as the output on those two bands. Also, the frequency
multipication is greatest on 10 meters (4 x) with the VFO on 40 meters.
(The rig does not chirp on 80, 20, 15 and 10 meters where the output is not
on the same band as the VFO). Also, there is sufficient drive on 10 meters with
the driver stages multiplying by a factor of 4. Since quadruplying works on
10 meters, why would it not work on 40 if the VFO could be convinced to remain
on 160 meters when the band switch was in the 40 meter position?
It turns out that this mod is non-distructive and merely involves loosening
the screws on the 'gizmo' (for lack of a better word) that switches the VFO
bandswitch, driven from the main bandswitch. All that is involved is to loosen
the two setscrews and rotate the 'gizmo' on the bandswitch shaft until it
switches the VFO between 40 and 20 meters! This sacrifices only the 11 meter
band (big loss ? ). The only other downside is you must read the frequency on
the 20 meter scale instead of the 40 meter scale. This is easily done.
This is a non-distructive, easily reversable mod that will make the operation
of the Ranger on 40 meters rock solid. Here is a picture of the "gizmo" and
the band switch mechanics.
SX-111 Repair
I have repaired two SX-111 Hallicrafters receivers that both had the same
problem, a ground in the 2nd mixer plate circuit. This is an ugly repair to
make as the 2nd mixer is a sub-chassis mounted on top of the main chassis
and there are numerous wires running though 2 holes in the main chassis up
into the mixer sub-chassis with NO connectors.
Carefully mark and unsolder all the wires going to the subchassis and remove
the screws holding the sub-chassis to the main chassis, being careful to
note which wires go though which hole! Change all components involved with
the 2nd mixer circuit. (I had one receiver in which all the components checked
OK, but it failed when voltage was applied and I had to dis-assemble it again).
Pay particular attention to the tube socket and change if it appears "funky" in
any way. Wrestling this sub-chassis and wires in and out of the receiver twice
far outweighs the cost of the parts for the 2nd mixer circuit (I did not change
the transformer).
Here is a picture of the wires and the chassis holes
This is a picture of the wires that go to the selectivity switch. Note they are
very similar in color! Be sure to make these or the sidebands will be reversed.
