[Collins] 32S-1 grid problem

[Gerald]

On Fri, 2005-12-02 at 10:41 -0800, Glen Zook wrote:
> I only met Art Collins three times during the two
> years that I was employed by Collins Radio (right out
> of Georgia Tech in the 1967 to 1969 time frame).  I
> did get to know him better after I was long gone from
> Collins Radio and he had sold out to Rockwell
> International.

I don't remember how many times I saw Art. He tended to dawdle in the
high power transmitter lab at Richardson playing with his slotted line
and vacuum variable capacitors. I was affected by his edicts more,
having been moved as the result of a couple, and I had to regularly
submit designs as "working papers" to the system and he'd call my boss
(Lloyd Winter) to say yeah or nay. That's not a good management
procedure for the CEO to be deciding circuit details and packaging
details. I know its not good, but I have demonstrated the same problem
when I've hired help, so I work alone. I don't know how to not do it
though in my radio club where I've been president so long I don't know
how many terms it has been that I am successfully delegating tasks and
not mother henning the tasks or the members doing them to suffocation.
> 
> The first time that I me him was about the third day I
> had been employed.  Art came over to Building 401 (the
> original Richardson "engineering building") to Eric
> Tedley's industrial design department to see the "mock
> ups" for the proposed KWM-3 transceiver cabinets (this
> was to be a modified 718T that would go down to 1.8
> MHz and had 10 Hz steps in tuning instead of the
> original 100 Hz steps).  Tedley's group was assigned
> to Harry Passman's Process Division as a matter of
> accounting convenience since the department didn't
> really "fit" anywhere in the Collins Dallas Region
> scheme.  Of course the KWM-3 never came about, at
> least in production runs.  The KWM-2 series was
> eventually replaced by the KWM-380.

There were at least a couple proposed rigs in Cedar Rapids in 1963/4
also. One used a 5894 for the PA. Then Art proposed that the new radio
should be remote controlled over a serial cable and should cost a lot
more than the S-line so that only the most elite hams could afford it.
> 
> As for the serial numbers:  All of the lower serial
> numbered 32S-1 transmitters that I have seen have all
> had the 2-diode balanced modulator and all of the
> higher serial numbered units have had the 4-diode
> balanced modulators.  Also, from what I have seen with
> the serial numbers in the S-Line / KWM-2 series is
> that when they started to become "scrambled" that
> there were 5 or 6 digits in the serial number and not
> 3 or 4.

Those might be valid observations.
> 
> Anyway, the first thing that can be seen in the grid
> circuit is that the fixed capacitor for the "converter
> output" (basically for the 62S-1) comes directly from
> the grids of the 6146 tubes to the miniature coaxial
> cable that goes directly to the RCA phono jack on the
> back of the transmitter.  There are no resistor/choke
> assemblies like on the schematic and in the 32S-3
> series.

Those resistor choke assemblies are parasitic suppressors. They
shouldn't have much effect on ordinary operation. I sure did ignore them
in my comparison. But they hardly have any effect other than being
slightly frequency selective (lossy at VHF) lead wires.
> 
> Tracing the circuitry is a "real pain in the
> posterior" because the wiring immediately goes into
> large bundles.  I can trace it out, but being that I
> am a sincere believer in the principles of the
> conservation of my finances and labor (you can read
> "cheap and lazy") I was hoping that someone had the
> schematic of what is actually in the transmitter.

Well that makes a quest for more manual variations.What edition is the
manual on the CCA web site? I have 4th and 7th edition 32S-1 manuals. It
would be even nicer to have the cabling to-from charts that specified
wire color codes.
> 
> As for the 6146W tubes from the Electronic Tube
> Company all that the vast majority of those were good
> for was audio.  They definitely did not work well (if
> at all) in r.f. circuits.

Besides not allow setting the idle current, I don't recall if the ETC
tubes actually produced RF in that 32S I was fixing or not. I think they
didn't have significant output. They obviously were a different internal
design and the best I recall (its been 35 years or so) they lacked the
grid rod shield just below the plate cap that would have made them
squirrelly at RF if they could have been tuned. Though I ran a 6BG6G on
6m without that internal shield characteristic of the 807 that had the
same curves but a 5 pin base,
> 
> Glen, K9STH
> 

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer