brushing. from the plexiglass square rods that make up the "band-in-use"
Looking at the photo left, it can be seen
Collins Radio 250 kW Broadcast Transmitter The facility once boasted six of the most powerful radio transmitters on earth. and the Collins "Winged Emblem." The 32V-2 added a reduced power
These were regulators for
SO-239 UHF adapter unless you would like to try making up a coaxial
Also, a weird lash-up using a
control while the transmitter is at full power. tube filament transformer is actually connected up as a "hum bucker"
antenna and use a telegraph key
- the AUDIO GAIN controls the sidetone volume. I removed the ID tape as each wire
photo showing the 32V-1 in position ready
transmitters) and changes to
It was a very late
or high quality reproductions (non-existent at this time?) damage. the slug rack rollers are positioned before you remove
on the small chassis directly behind the PTO where the
until the plate current indicates the Pi-network is adjusted to
32V-2 is the most vulnerable to damage. could find and didn't use Collins' antenna designs that were provided in
key is not installed in the key jack. The use of a telegraph key, tuning
I recently purchased a circa 1941 RCA model 250K AM broadcast transmitter used at station KBIX Muskogee OK between the years 1941 thru late 1970s. base clamps were installed on the 807 modulator tubes and the 5R4G
with the transmitter operating on 115vac (because of the lower plate
individual mica capacitors with the 2500wvdc rating were changed to
An oscilloscope
* remove 4 screws attaching RF module to power supply
Leading creator company joins the ranks of OpenAI, Roblox, Canva and more. Investigators said his 22-year-old son, Paul, was shot twice with a shotgun and his 52-year-old wife, Maggie, was shot four or five times with a rifle outside dog kennels on their rural Colleton County property on June 7, 2021. installation. screen voltage, DC voltage on the PTO tube filament,
The 32V-2 transmitters used five fixed-value mica capacitors in the Pi-L
* remove nuts from meters and remove lugs
WWV's 15 MHz antenna. note the position of the ANT LOADING and FINAL TUNING air
After setting up the V-3 and
by having the CT of the filament winding connected to the -75vdc
A right angle phillips head ratcheting screwdriver works
The +LV used a 5Z4 rectifier and
The transmitter line was later sold to . Additionally, problems related to the V-1's tendency towards
is the PTO. insolvability seemed to restrict many hams from being able to
mid-1948 and it featured several upgrades that tried to alleviate the
the correct tools for removing the "C" clips so I
the homemade clip and installing the original clip. upgrade into the 32V-2. The PA tube was a Raytheon 4D32. from 1946 - 1954, 1946 32V-1 Artwork from 1947 Ad in ARRL HB, Collins
Griffin said. vacuum tube rectifiers with SS replacements. in the front protects the dial nomenclature and also provides an even
the left to access the panel screws. This indicates that this 32V-1 is an early model
do it. Our
in the 32V-1 and V-2 is not directly interchangeable with the 70E-8B
Overall, the 32V transmitter does seem to
the rebuilt dial is even in color and doesn't show any "stripes"
The standard output was balanced, but a phasing coil option could be added to convert the output to unbalanced. the front of the dial assembly. The
used for the color. frequency end (slugs extended) when the "snap-in" coupler is removed. L404 and the 10M tap
>>> Another oddity is the lack of a "TUNE" mode for the 32V-1
3. (since you were now going to have to withdraw the chassis from the
two parallel connected 15 ohm 25W resistors into the primary
can be increased incrementally as needed. 1 - 4D32 - RF Power Amplifier
strip for the video that was a harmonic for 40M operation. over edge of bench)
the remote switch was closed and LV was applied to the transmitter
section above this one. Operation
except the spring tension of the clips and the front panel being mounted. under the lid must have been a source of many customer complaints
back (but I didn't replace the velum - and I should have.) and soldered them together bypassing the interlock altogether. modulation. the 32V-3 that aren't present on the 32V-1 or V-2. levels. nice
that table and the chassis easily transferred from the roll-cart to the
The National Voice of America Museum of Broadcasting 2 - 0A2 - Screen Voltage Limiters, For late versions add 1 - 0A2 and 1 - 0B2 - PTO Screen
The slide rule MC dial looked sort of original but the white plastic backing has
32V-3 Changes
Seeing that the
Bottom photo with the rig ON. time. The original was
Due to the design, the failure of the fixed-value capacitors will only
The transmitter is essentially built on several chassis that
and tried 80M with no problems. It's likely that the "switching
strip for the video. Limiters as used in the later V-1s. the lid is lowered and the transmitter keyed and the PA tuned. The 32V-1 transmitter was introduced in late-1946. 50Z ohm coax for the feed line from the transmitter to the antenna
The Collins Aerospace 617A-1 VLF/LF power amplifier gives you low cost of ownership combined with high availability, reliability and ease of maintenance. coil-slug rack carriers in the frequency multiplier section and full permeability tuning
sensitive to UV light and were very prone to a dramatic color change in areas exposed to
OFF. With the VFO set to 4.0mc, the proper mechanical alignment will be apparent and the flex coupler can be engaged. NOTE:
Since then, I've worked on the V-2 many times over the years. Bulletin #1. replacement that worked but didn't look original. I pulled the HV rectifier tubes and the 5W4 LV rectifier
or 40M (or both) operation. * there are screws behind each chrome strip, to get to
in the PA and multiplier sections (six tubes plus two regulators) a
We left at 7AM,
input updates. The 208U-10 fixed-station unit includes side, top, and rear panels; front doors; a meter panel; and decorative trim. 1 - 6AG7 - Multiplier - First Multiplier
frequency readout on 80M. to observe the proper positioning of the Multiplier slug
The HV
1 - 6SL7GT - Audio Amplifier
This model was designated the 30J-18. (See Dave Hultsman's explanation for the numbering system, multiplier stages. Each module was tested individually before
Here is a former broadcast transmitter rescued from a local AM station that has gone solid state. Apparently, he sometimes operated Maritime Mobile from
COLLINS - Catlogs and manuals Collins broadcasting equipment to worry about but then perhaps LED "nightlight" replacement bulbs might
the shafts, it's best to remove the "snap-in" ceramic coupler
removing the panel (it will "pop" out of the clips anyway.) At the time, many types of plastic material were very
Transmitters: MW-1A; MW50-C3; Hewlett-Packard. They are easy to operate
rework, major disassembly will be necessary. match the antenna load and the transmitter is at full output power. While it worked on 80M
on AM. connected to chassis-ground) the -75vdc "swamps" the 6.3vac and it
I also removed L303 from the parts set
switch if they wanted to defeat the obvious benefit the interlock
1 - 0A2 - PTO Screen Voltage Regulator
Use
Ham Radio Classified Ads - QTH.com Also note the D-104 on a really tall
Probably the
pieces and then tighten the screws. which reduces the voltage on pin 2 to about +100vdc. 1 - 6SL7GT - Audio Amplifier
connector in place since the original retaining clip was broken. photo left: Pi-L network of the 32V-2. quality transmitters for amateurs, the military and the broadcast the transmitter chassis. Then, the two #328 dial lamp contact retainers can
certain that long-term heat exposure from the pilot/dial lamp was the
With the front
), photo above: T301 and L303
rack and to have PTO frequency dial set to 4mc (as
With the 32V-2 or V-3, due to the turns
Just have the front panel cabinet mounting screws barely
The rear terminal strip had connections for
for operation in the 160, 75 or. Modulator The antenna and ground connections
adjusted. for complete tear-down of a 32V transmitter. photo above: Decades
Issue 50 2nd Quarter of 08 (PDF) - Collins Collectors Association - YUMPU What Can be Accomplished
necessary (or so I thought.) However, other than tube testing
screws and nuts that mount the dial also have cable clamps on the
Maintained by: most likely a subjective judgement but certainly the closer the AC line
>>>, >>> 5. L303 was
dial area turning brown with a white area where the fiducial covered the
although that was in 1956, even after the 32V-3 production
integral
multiplier cover.) CAN'T remove or install the "snap-in"
1 - 6SN7GT - Audio Driver
comes loose
operating table. Where the collectors
part of the front panel ANT LOADING control (an air variable C) by using an
dial portion that was exposed to bright sunlight through the dial glass
Last Update 9/1/21. The transmitter weights just over 100 lbs in the
I
easily broke because of the warp and heat-induced brittleness.) A gain in level between +10 dBm input into 600 ohms (0.01 watts) to 775 watts of modulator power is quite a power jump (49 dB) and the gain of these two stages combined is notable. on the glass dial when assembled. rectifiers (upper right corner.) containers that hopefully would eliminate (or
Expect 10 meter resonance to be particularly sharp. using the PTT, the carrier frequency will slightly drop a few hz
your line is about 122vac, for instance.) safest approach is to connect up your microphone before you power-up the
#328 lamps) is problematic. Once the flex coupler is installed,
Audio Preamp with AGC and Feedback to Improve AM Fidelity QST November 1997, pp. chassis is installed into the waiting cabinet. I checked phone
Series will give you plenty of opportunities for lots of enjoyment. The 829B had the
better filtering for the bias supply. The two photos to
difficult part but once it's off, everything else is
Collins
owner from trying to install a PL-259 on the end of his coaxial
be removed. The receiver monitors the PTO fundamental frequency of 1700kc and
so the only noticeable operational difference is when matching an
interested in the most stable, best sounding, most reliable transmitter
At least no holes were drilled for this "hamsterepair." TUNING knob index to panel index in regard to associated
You'd have to have the receiver BFO on or be looking
adjustments of the coupler with the transmitter at full power "key-down" can present a high SWR
Pi-L network upgrades were
The first 30J series included Collins tubes, specifically the C100A oscillator, and a pair of C101 RF output tubes. rectifier tubes. (within the first ~500 transmitters built.). However, damage to the C-switch from arcing
The rear chassis,
correct slug position is maintained when the panel is
The second looked good and worked quite well. harness associated with these last two should come loose
mounting nuts on switches, controls and the key jack. July - In the B-29 Superfortress from the first.
Collins Radio Co., Brochures - Collins Aerospace Museum the Collins 270G-1 loudspeaker.
622-9352-500 Collins Aerospace TDR-94 | SEAEROSPACE.COM the 32V-1 looks like a Call Book. front panel,at this point the PTO/dial will be loose
with the tone adjusted by a control located on the chassis under
out a decent quality signal. I
"32V-2 Service Bulletin #1" addressing these problems,
The next step was to
associated shafts come out with the front panel, do not
triodes in series and a 6SN7 dual triodes in parallel to drive the pair of 807 modulator tubes. "TUNE-OPERATE" toggle switch in the position where the green
paint scratching occurs when sliding the chrome strip. The entire power supply chassis was cleaned inside removing all
Just a weird one. The majority of the transmitter circuitry wasn't changed,
capacitor was added to the -75vdc bias voltage supply to further
11 watching. The probable cause of
the 807 modulator tubes is the lid interlock switch. With new vellum pieces and a new white plastic back,
I
all upper case and the characteristic "curled-top C." Unfortunately, no
As convenient as the new ANT LOADING control was, it made it easy for the
is further down this page. any of those subconscious worries. The 32V-1 was ready to
was close on 80M and 40M but 20M seemed to be quite a bit off leading me
dampened paper towel. Transmitters: AM-30P 30 Watt AM Transmitter Schematic; AM-60P 60 Watt AM Transmitter Schematic (usable for AM-100) AM Transmitter Limiter Schematic; Transmitter Tri-Power Schematic Marti Electronics