[Drake] Early R-4B?

[w7fe]

To those familiar with the R-4B:

I recently acquired a somewhat corroded but working R-4B.  During my initial 
inspection and subsequent cleaning and repair process, I've run across some 
rather puzzling things:

1.  This one has no chassis markings at all, not even a serial number. 
There is enough of the original copper plating left to indicate that no 
markings had ever been applied.  There are no silk-screened switch/jack/pot 
i.d. markings on the case exterior either. Unusual?

2. The passband tuning/selector assembly is not as described in the 
alignment procedure or as pictured in the manual.  The passband tuning shaft 
is connected to a little butterfly variable capacitor, not to a mechanism to 
vary the position of the slugs in the coils.  This is visible because there 
is no can over the passband tuning circuitry, just a u-shaped mounting 
bracket, open on the right and left sides.  The passband selector is 
actually a rotary switch, with a lot more components around it than are 
shown on the schematic. Does this perhaps suggest a very early model, maybe 
before they developed the mechanism to tune the coil slugs and simplified 
the circuit for passband selection?

3. L6 in the output filter on the PTO is not present at all. The center 
conductor of the co-ax (which goes to the xtal-vfo slide switch) is just 
lap-soldered to an unshielded wire which comes from the PTO output.   C132 
and C149 are in place (on the nearby audio board), however.  I can see where 
L6, the co-ax, and the PTO output lead should probably have been connected 
on the adjacent audio board, but it appears that nothing has ever been 
connected to those points. Does anyone know what value L6 should be, or its 
physical characteristics?

4. There is a black/white wire coming from the PTO and connecting to 
nothing.  This must be the FSK connection as per the schematic, but it's 
just flying free.  Should it connect somewhere, like to one of the lugs on 
the adjacent audio board?

5. Generally, many of the solder joints are poor, some cold, most with 
excess solder, and several places exhibit wire insulation which has been 
melted by an errant iron.  The wire harnessing and lead dress are quite 
sloppy; in fact, there are wires attached to the filament pins on V2's 
socket which have been clipped off to about 1/4" and left in place, 
connecting to nothing. Also, there is a wire attached to a ground point near 
V8's socket (which is the same color as V8's filament lead which connects at 
an adjacent terminal point) which is clipped off to about 1" and goes 
nowhere. Is this lack of  good workmanship  weird, or what?

6. Finally, another goofy observation for those who have were interested 
enough to read this far:

The brass shaft coupling to the passsband selector switch shaft was cracked 
and split!  I'm baffled as to how this might have happened. It looks almost 
as if water got into it and froze, splitting the coupling.  Has anyone seen 
this condition before?  Anyway, it results in unacceptable excess play in 
the little lever actuator for the passband selector. Now that I have removed 
the coupling (in several pieces), I think that they used 5/16 OD brass 
tubing, with a little flat spring wedged inside to produce a tight 
connection between the two shafts...looks fixable with some hardware store 
tubing. Has anyone else had occasion to do this repair?

73 de Stu   W7FE