[R-1051] Alphabet Soup

[Cecil Acuff]

Greetings,

Good Note Barry (as always).  No additional mud here!

I do have cables that cover all modules...some I had to painstakingly build
myself...some of the Hybrid connectors that have the soldered on caps on the
rear are re-buildable.  I am able to actually work on the individual modules
in the six-pack while extended via cables...

I will make a point about alignment...The tuned circuits in the 1051 are
very broad adjustments.  They don't employ Hi-Q circuitry in the RF and IF
areas.  I have found that adjustment of the coils most of the time result in
very little improvement and most times un-repairable damage to the coil if
ones not very careful.  They are very poorly made and I avoid adjusting them
unless there is no other option.  The AGC and IF gain are fully adjustable
and very much need to be set properly for proper performance.  Also the
Spectrum Generator and Frequency Standard alignment can greatly affect
performance.  That is usually all that is necessary to get the radio back to
factory specs or better.  Sometimes I have had to do adjustments to
individual bands in the RF deck to get proper performance on all bands.  I
assume the use of Low Q circuitry was to ensure alignment was minimally
affected by the vibration they were subjected to.  That's a good thing for
us considering how difficult it is to do a complete alignment....so far I
have found it to be unnecessary!

Thanks..

Cecil...


----- Original Message -----
From: Barry Hauser <barry at hausernet.com>
To: <r-1051 at mailman.qth.net>
Cc: <vulcan at nextcentury.com.au>
Sent: Saturday, February 01, 2003 11:54 AM
Subject: Re: [R-1051] Alphabet Soup


> 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
>
>
>
>
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