[R-1051] Alphabet Soup

[Barry Hauser]

Lee wrote:

> Thks to those who replied. Tell me what differnce is there between the
> various model of R-1051 receivers, models B thru H, perfermance wise. Do
> they all use the same turret module hence the front end is the same on all
> these models???

Better get a cup of strong coffee before you read on ...   I started to
write this early this AM, but got distracted by the
more-bad-news-department.  (Shuttle)  What will be a harrowing, ironic
reminder is that movie about the old astronauts with Clint Eastwood, Tommy
Lee Jones, et al.  I think the story has them riding the Columbia.  I seem
to recall remarks about its age.  Well ... anyway ...

You should start consideration with the R-1051 "plain". These were produced
in larger numbers, probably somewhat more than the B's. (anybody?) The only
real difference is in frequency stability when tuned in increments of 100
Hz. All of the 1051's have five main decade knobs and another switch/vernier
knob at the upper right. The plain has a 500 Hz position, so you can tune to
that precision while maintaining the very stringent stability spec (forgot
what is -- something like 5 cycles per 100 gigatroids per calender month
:-) -- It's impressive, whatever -- and, as I recall, the same across the
entire model line, provided the rx is not in vernier mode. The switches on
the B model and up have 100 Hz steps. In effect, they added a sixth decade
knob. However, the stability accuracy is also lower when using the vernier
on any model. That's why all the 1051's have the orange flashing light. I
believe this was designed by lawyers as a disclaimer or YMMV light to
indicate that due to the operator's engagement of the vernier, the receiver
is no longer delivering its official accuracy/stability specs.  When I go to
tweak an SSB signal in, I grab the vernier whether it's a the plain, a B or
a G.

Module-wise, this is what I sort of know: The plain vs. the B+'s have
different six-pack modules reflecting the 500/100 difference. You can't swap
those without some consequence -- or worse according to one guy. The other
modules are pretty much upwards and downwards compatible, (except some auduo
modules as Cecil pointed out) and I think the RF deck (with the 2
tubes/valves) are pretty much the same across the board.

However, while generally plug compatible, the later models' modules went
from discrete components to IC's. Some people like that. However, if doing
module-level repairs, the older ones may actually be more serviceable.
Replacements for the discrete components may be easier to find. (Cecil?) Not
necessarily the case for some of the IC's. Appearance-wise, the later six
pack changes to a one-piece alumium top. I have a "B" with a "G" six-pack in
it --seems to be fine.

The later models -- not sure if it started with the C, D or E, went to a
single R-390-style meter with a switch to view USB and LSB, whereas the
plain and B have the two cute little meters, one for each sideband. I think
that made room for the AGC control.  The later ones added one or two
modes --- RATT, I think. All are capable of ISB as equipped which is nice. I
think all have the same 3-pin round power connector and smaller 2 pin round
audio connectors.

Some other considerations. The later ones went to externally accessible dial
lamps. The older ones have an oddball screw-in type that's an inside job to
repair. I think they cost about $45 each and they're always burnt out. I
don't bother. Illumination isn't necessary and doesn't add much charm. The
early receivers may need some simple mods to the power supply board -- raise
up the diodes so they don't stop burning the boardand change the dial lamp
resistors to improve lamp life, etc. There are taps for the supply voltage.
There's also something to check in the audio modules. This is all described
on Nolan Lee's web pages.

What else? Manual availability. Partial repro's of the plain and B are
readily available for about $45 US. Manuals for the others are difficult to
find and can be expensive to duplicate well due to the very long foldouts. I
was quoted $100 US for a professionally made copy (roll fed copier) for the
G manual. I'm not aware of any downloadable ones.

It's possible to swap all modules from one mainframe to another in about 10
minutes, if that. So you may find that a particular radio has a mixture, so
caveat emptor applies, if you are concerned about such things and paid a
premium for a later one.

As far as servicing goes, I've managed to get all of mine working OK by
means of low-level tinkering and a bit of module swapping. While these are
mostly solid state, they're prone to mundane mechanical problems. For
example, if the radio has been sitting a long time, it will be clean inside
if the panel was screwed down (sealed), but the contacts in the turret will
have oxidized so some of the bands will work and some won't. Calls for a
liberal treatment of contact cleaner and working the MC knobs to rotate the
turret (motor driven). I doubt there was much improvement across the line
where this is concerned. They all have two mini-bicycle chains, but later
models may have nylon vs. steel. This is undesireable. You'd best replace
them with the original metal drive chains, as the plastic ones break. If the
receiver has been sitting or subject to casual tinkerers, it may be out of
mechanical synch, and there's a simple procedure to fix that. The
module/mainframe contacts look like compuder D-sub connectors from which
they are derived, but with some tiny coax connectors mixed in them. The pins
in the chassis connectors sometimes slip down -- i.e. back out, due to pin
misalignment when a module is installed. This can be fixed by pushing them
up from the bottom with the module in place. The megacycle encoders can
sometimes wear out or need attention, basically a stack of fiberglass PC
boards with rotor and stationary contacts formed of plated printed traces.

As for other servicing -- that's a whole other story. Some of the
adjustments are not accessible with the modules in place and require special
extenders. I've managed to collect a few of these for a rainy day (when Noah
comes back). I understand the one for the six-pack is forged of pure
unobtainium. Even Cecil who has set up shop to work on the 1051's hadn't
found one last we discussed it. (or did you?) Maybe Rich Baldwin and/or Tony
Snider have them.

I find the manual at minimum uninviting and at maximum, scary. None of my
1051's are tweaked. I have no immediate plans. ;-) Sooooo <yawn>

Bottom line: Go for the best radio you can find in terms of condition and
performance as found. (Unless you're experienced with this type of thing and
have appropriate equipment that's up to the task.) By all means, if you find
a nice plain or B at a good price, and it's working well -- grab it. Get
familiar with it and use it. If you must have the later ones, you may pay a
premium for relatively little gain. If you want a top performer, your best
bet is to buy one from an expert or send it to one of the guys on the lists
who work on them. (Though shipping cost might be a consideration -- do I see
a down-under domain?)

You might find a plain or B that's basically functional at a low price and
that will certainly get you famliar with these beasts and you can find out
if you want to go further. Again, they do not suffer the wandering
bandcruiser-knob-twiddler lightly. Try it and you will be punished -- unless
you have a black belt in several martial arts and have callouses in odd
places from thrusting your hands into boxes of rocks.  The detents are stiff
to make sure the radio stays on frequency in high seas with all 16 inch guns
firing. First, your wrist will get sore, then you'll notice your fingers are
red and a bit swollen. Later on it will be the elbow and the next day, you
might suspect a case of bursitis in the shoulder. However, they're great if
your working utilities, want to set and forget while doing long term
monitoring of specific ham frequencies, etc. Properly working they can't be
beat for that. And, the ISB is nice -- set up with two speakers for
monitoring AM, it sort of fills the role of synchronous detection and
sometimes adds a bit of pseudo-stereo as well..

OK, I've spilled my guts on the subject. That's about all I know. Of course,
I've probably muddied the waters -- and you might want to wait for other
opinions as I see the orange light on my forehead is flashing. ;-)

Barry