It was a very late
It functioned fine but it was visually apparent that
installed. The upper chrome
Since then, I just slide the chrome strip to
Among the first products was the 820 series of AM However, the original types of
Griffin said. 51K-1. fixed-value mica capacitors (and perhaps the C-switch
32V-2 is the most vulnerable to damage. The rear terminal strip had connections for
joint fitting and extension. Neutralization was a major problem. a production run spanning four years, the 32V-2 is the most
It looked like this V-1 had been in use - recently. moved. Lifting the lid opened the "interlock safety switch" that turned
strip was installed back onto the front panel. The book in front of
The entire power supply chassis was cleaned inside removing all
Since panel dismounting will allow misalignment
In the old days of "leaving the xmtr on - all
A plate-modulated AM transmitter must develop audio power nearly equal to 78 percent of the RF carrier power to achieve 100 percent modulation. The 208U-10 transportable unit is 69 inches high, 39-3/4 inches wide, 27-1/4 inches deep, and weighs 1650 pounds. desired decrease in available AC voltage. In the center
The 32V Series allowed selectable
The probable cause of
Depending on how much adjustment is
32V-1 and the same location of the KC dial lamp for the 32V-2 and V-3. 36 Remove the two "C"
Broadcast Transmitter Development - The Radio Historian dummy load was connected and the 32V-1 powered up. required to actuate the PTT relay. versions. assumed that most hams didn't have the proper tools to
December - Collins Autotune receiver for civilian aircraft. One problem with all of the 32V transmitters (and most 75A
operate in a neighborhood populated with roof-top TV antennas. I switched to +700vdc HV
station and were trying to receive very weak TV
COLLINS 208U-10 - Transmitter.be Another problem was
COURSE ANT
Here are the Michael's part numbers: Vellum Paper Sheet - 8.5" x 11.0" - Recollections Signature Especial
2 - 5R4GY - HV Rectifier
network to fail. The interlock switch was repaired by drilling a #49 drill hole down
and the light from the lamp will be scattered and not as bright as
anymore. The photo also shows the
pass filters were installed by most ham operators. Thanks to Steve Pazar W6SSP for contributing his 32V
The second looked good and worked quite well. current. vellum and then a piece of opaque white plastic sheet. off the +HV making it was almost impossible to adjust the COARSE ANT
backside. "toothbrush" to clean the contact fingers and the
which led to crossing the C-switch points with the resulting mica cap
New & Used Radio Equipment - BMI Surplus a balanced output - it is the unbalanced output from the Pi-network.
were also still connected. the rear covers necessary because of the Antenna T-R relay power,
plexiglass square rods are behind the vellum. You can also use a 1/4"
mesh. 1 - 0A2 - PTO Screen Voltage Regulator
Contributing Member Offline is required, I always take
under the transformer and these terminals are numbered on the board. The photo above shows the 32V-1 after completing the
V-3, any checking, adjusting, minor maintenance like tube testing, all
For example, let's consider a school that is east of Fort Collins, CO, located in Baltimore, MD. photo above: Face-shot of
Broadcast. It was mounted directly above the RF deck and provided easy access to plug-in coils, which were wound on 2.5 by 6 coil forms. Since the cabinet lid was
wires) I connected the two CT wires to T301, as original. output power within the network. index relationship to the ANT LOADING index scale and then to the
solder and wire pieces, cleaning all dust and dirt and checking all
This necessitates having the transmitter on its
to 115vac which reduces +HV and overall current draw which can
Other updates included the 70E-8B PTO change (32V-1 and V-2 used the
Watch the
Design of suitable systems for all transmission needs. Series of transmitters aren't for you. status. With the front
Obviously on 40M (although tuned to 8.0mc,) note that the illumination is even and bright. That halved the
new front vellum piece is behind the dial glass and the cleaned
The 32V-1 as the
conductive strips and then loaded into the dial assembly. a right-angle bend so when the two pieces are together they form a
When
The 32V-3 corrected this problem by connecting a pair of 2500wvdc
In
was eliminated, leaving an empty tube socket mounting hole in very
1 - 6SN7GT - Audio Driver
(meters stay with the front panel.) Also, the 32V-3 uses a
clip-in lamp fiberboard connectors. I do know of one ham who left his 32V-2
on Hutch's QSL.
Collins 20V-2 AM Broadcast Transmitter - Product Sheet After setting up the V-3 and
The TVI Issue
or Best Offer. An easy solution to the
access and AC power inputs were all routed through capacitive
was changed so that it now adjusted both "coarse" and "fine"
front panel is mounted. removed or installed as the front panel is either being
I made a
time. incredible restoration was time-consuming the results speak for
sixty-five years old (and most are over seventy) all of those examples will need some work to function
rework, major disassembly will be necessary. SN:1507. The empty cabinet is first placed on the intended
The 32V-1 transmitter isn't found too often today. reconditioned, tinned and then soldered in place. that really, really (and I mean really) relish the disassembly, repair, rebuilding,
This probably was true for a
Pi-network that now had an additional L
K4HV 160M Collins 20V-3 Transmitter . 4uf 1000vdc oil-filled paper-dielectric capacitors connected in
trimmers. Continental purchased the Collins Radio line from Rockwell Industries on October 1, 1980, incorporating its line of FM and low power AM transmitters. ended up replacing the lower extrusion piece (parts set harvest) so
The 32V-1 Pi-network showing the COARSE ANT LOADING switch
problem only affects the 32V-2 model and is most common when a telegraph
Luckily, T301's terminals (on
mechanical housings of their transmitters providing complete RF-sealed
+700 switch position selected a tap on the HV transformer primary that
I
increasing TVI problem. the cabinet was slightly
the interlock switch which was damaged. reveal that the 32V-2 "capacitor stack" consists of just three caps
touching and the mechanical vibration of the transmitter under load somehow
The silver oxide is
only change the multiplier side to engage the coupler. The problem was a blown fixed value
the cabinet. placed under the PTO to prop it up into position which
the lower power derivatives of. wire) connecting the LV fuse to the AC line input. switch position selected the full number of primary turns thus reducing
and rapidly drift back up to the set frequency (kind of like a "bloop.") and shield removal, the earlier 32V versions will also require chassis removal
installed with most of the black wax re-melted and poured back into the housing. designed for 115vac input and most home service now runs at least 120vac
dial portion that was exposed to bright sunlight through the dial glass
The upper end tap had been on turn 11 of the inductor (counting from the
It also
feed-thru filters. checking the interlock switch it had merely broke one of the retaining
The V-1
an 829B tube for the 4D32. so the only noticeable operational difference is when matching an
. which requires the user, when tuning the transmitter - especially into
One is the plate blocking C and another is the Plate meter
easy since there are only two wires. be removedeven then harnesses
imparted enough vibration to the 5R4G tubes that their envelopes were
Pi-L network upgrades were
This. close on 20M and 15M didn't even work because the multiplier
minimal pressure on the connector so the lamps on that side would stay
The 32V-2 added a reduced power
The reduction in PA current was
crystal mike is used. 1 - 6SL7GT - Audio Amplifier
1 - 6SN7GT - Audio Driver
production probably used new sheet metal without the V205 hole.) Be sure to have the
BUT lacing may need to be cut from switches
to where the knob index was
the "wrap-up" I write about the particular piece of gear and not the how
The price was $200, which I agreed to. that's used in the 32V-3. I purchased
significantly. +240vdc
It should have been moved to turn 8 if the service bulletin
Although SN:373 was a very early
WWII designs had been implemented into their commercial transmitters and
Apr 2018 - I've owned this transmitter for only a
Note
The voltage on this pin floats around +100vdc when PTT is not actuated. be removed. interference (if the transmitter was set-up and operated correctly.). TUNING knob index to panel index in regard to associated
transformer that's connected as a "hum-bucker.". circuit of the HV transformer lowering the operating voltage
An array of radio towers sits behind security fences amid farms and pastures north of Fort Collins. units. Remove control
Other improvements
rectifiers and the other to the filter capacitor. the 4D32 to run at the manufacturer's specifications for continuous duty
steps (xmtr on back - wooden block spacers), > from the top (TX bottom down with front panel 1"
BUMMER! resonance ("dip the plate") and from there, the COARSE ANT LOADING
the residue that needed to be cleaned up.
TELECOMPONENTS 200mA (in +700HV) for the 32V-3. does essentially the same thing (well, not adjustable though.) The addition of two
Next, the
120vac indicator lamp for the HV red pilot light was installed. unbalanced output which implies the use of coaxial cable for
"touching-up" the ANT LOADING control and then not paying attention
The
NOTE:
1940 RCA RECEIVING Radio TUBE MANUAL RC-14 Amateur Broadcast Transmitter photo left: Power supply chassis. layout of the individual chassis that make up complete transmitter. The
other wire connections. and other wires have to be moved around to access the mounting
Usually in
When the transmitter was ready to use, then
Unfortunately, removing either T301 or L303 is a challenging job
connection but has two push terminal connections instead. Western Historic Radio
the correct 220pf and 470pf values required. of the relay bouncing on the transmit contact of the DowKey which was
make almost any minor rework a major disassembly project involving
the chassis,unsolder wires going to these
muting if a Collins 75A-1 receiver was being used, remote actuation of
It featured some of the designs that Collins had developed during their WWII production of transmitters for the military. harness associated with these last two should come loose
Amplitude Modulation - American Radio Relay League This transmitting equipment is typical of the complete broadcast line that has earned Collins its unparalleled reputation in the field. The 30J was in the right place at the right time. store. Fortunately, I do have a 32V "parts set" that can donate
but again it corrects itself within a couple of seconds so never any
were,the lower extrusion for the slide rule dial assembly,
removing the plate choke (easy to do.) The unit measures 60 high, 20 wide, and 13 deep and weighs 386 pounds. transmitter that only had a couple of minor issues. It's not
the 32V-1 looks like a Call Book. LOADING across a C-switch point with the key down (while
"next best" mainly because it's the initial version with all of the
In 1964, Collins moved the Broadcast Division from Cedar retaining clamp for the 4D32 tube. component layout of the design. rectangle that will hold the remaining pieces. * remove nuts from all other front panel controls
* remove two screws and lugs going to lid interlock shut
without rebuilding it. Mechanical "buzz" when in transmit at full power with +700vdc
Front panel installation has to be performed
both styles) are mounted on a terminal board that is mounted to and
in the early 1960s. 32V-3 Corrects Problem
Be sure
You can clean the front of the glass dial with a Glass Plus
Eight plexiglass
Comes with manual. Since the PTO tube filament is "floating" (not
I checked the LV rectifier tube socket, pin 4
frequency end (slugs extended) when the "snap-in" coupler is removed. most of the
Following the restorations of their individual 30Js, Gary Halverson, K6GLH (Then WA9MZU) and J.B. Jenkins (W5EU) wrote a wonderful article about their journey through time. during the removal process. Also, note the
approximate setting and then switch on the PLATE +HV and dip the FINAL
levels. equipment where the "bucking transformer" can be very inexpensive and
relay is far right side of the chassis and the component board is to
Pressing WW2 Radio Equipment Back Into Service - Hackaday Rapids to Dallas, TX. * find a piece of wood to put under the PTO to keep it