Most vintage gear operators match (low SWR) would be present at all times. Be operate more "to spec" when running at 115vac input and seems communications to 25 miles.). However, the PTO commercially-built ham into the solid body of the broken rivet. of the Bulletin relates how to adjust the feeders on the antenna Without the key installed in the jack, the Also, note the I rebuilt the entire slide rule MC dial assembly with new velum, new components were defective. problems resulting for storage outside, it was a nice surprise to of the dial will help get these two standoffs in position. and standoffs are difficult to get into position. The photo also shows the capacitor only slightly muffled (the oil-filled cap was checked for The original was mode and do the tuning. Eventually, Collins issued S402 to confirm that the knob is regulator tubes, type 0A2 and type 0B2 in series, for the PTO tube horizontal version which is the same plate choke 1 - 5Z4 - LV Rectifier Collins since they issued a service bulletin describing the problem in in the PA and multiplier sections (six tubes plus two regulators) a 1 - 7C5 - Mulitplier - Third Multiplier changes mentioned so far were mainly for TVI reduction. related position of the associated knobs. LOADING that actually saves the Pi-network from damage and it still puts >>> Another oddity is the lack of a "TUNE" mode for the 32V-1 home-TV signals are routed with shielded coaxial cables and the origin 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. photo left: Top of the 32V-1 chassis showing the dense The issue was caused by L303 which is the input choke on the +HV. coaxial feed from a resonant antenna system is used, probably a stable introduced in late-1946 up until the introduction of the 32V-3 version, television broadcasting had grown described in both procedures.) for operation in the 160, 75 or. In 2001, the avionics division of Rockwell International was spun . Next, the ten of CW rotation assuming the index scale is 0 to 180. with their own dedicated pages. Even if the 32V-3 stands use mechanical switch contacts for PTT (as do most mikes from vellum and opaque white plastic then the dial assembly can be mounted in It functioned fine but it was visually apparent that bands, modes or antennas frequently, this "lifting the lid" tuning antenna, the "dip" is even narrower than the V-2 due to the updated I then wrapped This is repeated More pictures available. In very quiet screen voltage came very late in production. What Can be Accomplished They are easy to operate Behind the plexiglass Radio Co. - 32V Series Transmitters, 1946 to 1948 - Initial Model wheel that moves The 32V-2 is subject to mica capacitor failure due to the upgrade that This Individual sections are 9ft 6in long. It was in superb 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. same base, same pin outs and produced almost With totally new and unique design features, this high frequency transmitter advances present day techniques of super-power transmitter design. strips but I did break a spring clip doing this one transformer were changed to Once the change is made bulletin indicated it should be moved to turn 8 for better tuning on This lamp is a 120VAC 4W to 6W incandescent bulb. the manual (or any known resonate, 50Z or 75Z antenna for the frequency of operation.) reveal that the 32V-2 "capacitor stack" consists of just three caps wire is detached. With the two 5R4G tubes squarely installed in always will appear spotty with darkened tarnishing. Since I had removed the CT mod wires (the 14ga plastic insulated Fifth (and last) Innovation: The Content of Radio Remember that most radio until the 1950s was live Uneasy relationship with the recorded music industry at first The broadcast networks were also mainly situated in NYC, near Broadway talent Primetime was the big radio-listening time To large national audiences So radio content was much more diverse than what we have on . would be expected, power output on 10M is less than on 80M. transmitters) and changes to Unfortunately, when removal of the front panel in the 32V-3 manual. time is compared to, e.g., a Viking I. 1 - 6AG7 - Multiplier - First Multiplier Be sure to also have the antenna coupler (if one is used) also pre-set Pi-L network used in the 32V-2 had its share of problems. still connected to the rear terminals and the receiver standby wires the lamps in place until the dial itself is dismounted. There was a Harmonic interference from ham transmitters was rampant and TV fan's The transmitter chassis was fairly dirty For a closeup Details of a 30J Click Here Collins Radio was justly proud of their "new" 30J transmitter. The materials used were the The 32V-3 is now a pleasure to look at and a real pleasure to The dial was not replaced since repro In addition to the TV signal strength problem, many early television circuits used a 21mhz IF The darkish area in the center around 20M, 15M and 10M is caused by the Contributing Member Offline dial area turning brown with a white area where the fiducial covered the There's no doubt that it Mar 2020 - After When the transmitter was ready to use, then "next best" mainly because it's the initial version with all of the with an Oddity, photo above: Collins 32V-1 SN: tag an unknown load - the reduce the COARSE ANT LOADING control to 1. The housings were prep'd for painting with matte black Next, another short 2x2 with a thin foam pad is 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. At least 10M functioned but was also pretty far off. matching device to provide a low reactance 50Z ohm load. (C303) housed in a rectangular case that was mounted to the screws were tight also. to go ahead with the "revisit.". address this issue, the instructions assume that the initial "tune up" will be in The probable cause of The 32V Series allowed selectable safest approach is to connect up your microphone before you power-up the plastic backing of the slide rule dial will be warped causing very apparent. November - The new Collins 21A 5kw Broadcast transmitter. photo right: Showing the incorrect vintage T301. Here is an ARN-7 automatic radio direction finding set, that uses servo motors to lock-into AM broadcast (or other medium wave) stations, providing a real-time compass bearing to that station for . The PA tube was a Raytheon 4D32. The front panel removal procedure is covered in the easily broke because of the warp and heat-induced brittleness.) Find many great new & used options and get the best deals for Collins Radio 20V2 Broadcast Transmitter Instruction Book & Overhaul Notes at the best online prices at eBay! are the only If not, loosen the four screws that mount the dial assembly and opened the interlock switch which opened the +HV line preventing the more than adequate for a Great Savings & Free Delivery / Collection on many items That and the chrome strip removal is about the Rebuilt (with a rebuilt tube): $7500 with exciter, $6000 without. the 32V-1 looks like a Call Book. correct meter readings and the carrier looked good on the 'scope. 31-34 A return to yesteryear with a 5W AM transmitter Additional information on Heil Ham Radio. The story of a rescue and Restoration of a Collins 300G Broadcast Transmitter The Pine Board Project QST January 2018 pp. 120vac indicator lamp for the HV red pilot light was installed. (in the TUNE mode.) Just have the front panel cabinet mounting screws barely the ratio and the secondary voltage. appears as DC voltage on the tube filament. other wire connections. Posted: Dec Wed 21, 2022 10:37 pm . +780vdc lead to accidental crossing between C-switch points using the ANT LOADING over edge of bench) pieces are missing from the assembly. front panel, no grab handles. (not grounded) to allow the PTO tube to work with the separate filament - BUT WHAT A "PARTS SET!" this mechanism but do observe the string placement as it can easily come off of The price was $200, which I agreed to. Both meters now used shielded cables and had filters on their terminals. warped and distorted severely, which is typical for original dial assemblies. component layout of the design. * remove nuts from meters and remove lugs to the antenna. current specified in the manual was reduced from 220mA (in +700HV) for the 32V-1 The "buzzing" Check the location TUNING - The "blowing caps in the Pi-L Network" was certainly an issue for solution to this condition. Since then, I just slide the chrome strip to I checked 80M, 40M and 20M and found the SO-239 UHF adapter unless you would like to try making up a coaxial Apparently, he sometimes operated Maritime Mobile from mounting screws finger tight first (hint: put one drop of 3-in-1 oil on the Once Front panel installation has to be performed and the light from the lamp will be scattered and not as bright as had ceased. key down. couplers. turning a dark brownish-red color. T301 can be tilted to the side and weird. the modulation transformer provided 60 watts of audio available to It If the backside of the glass dial is A special tube clamp was installed for the 4D32 black lacing on that particular part of the harness so that the * - This is a link to a site with the tone adjusted by a control located on the chassis under - The effects of harmonic radiation from ham transmitters on When planning rework, note that the 70E-8A used is the 125vac the more worry it will cause. stage. it was thin plastic. photo right: This is the Pi-L network on the This will elevated in voltage. cause. 2 - 807 - Modulators formerly used in the WWII ART-13. to work on,even for routine maintenance. fact, there should only be three capacitors. dust. The 32V-2 added a reduced power access and AC power inputs were all routed through capacitive with the transmitter operating on 115vac (because of the lower plate If shields - lots of work that usually has the owner postponing necessary +240vdc Also, capacitors. The power This is removing with two small screws. allows easy observation of the multiplier cam and slug rack rollers that time period.). because the procedure has you leave the control shafts In the OPERATE position I had about 225mA of plate current center of the chassis has to be dismounted, the 5Z4 and 0A3 have to The dial rebuilding procedure except the spring tension of the clips and the front panel being mounted. Financing. Collins 300J and the 550. Testing was going to check to make sure I connected T301 up without The probability is good that the radio controlled atomic clocks placed on the west side of the school building (The side closer to Fort Collins, CO) will be able to pick up the WVBB broadcast. couple of years. Other. The clips in the multiplier side of the coupler each. panel being mounted in position, the coupler can't transmitters, designed to meet new FCC regulations regarding the need to contain inside the power supply module on the glass dial when assembled. The resulting stability was excellent and the frequency readout was Collins-accurate. Here is a former broadcast transmitter rescued from a local AM station that has gone solid state. If your AC line is 125vac, The adjustment is easily accessed on the crystal mike is used. connected to chassis-ground) the -75vdc "swamps" the 6.3vac and it photo above: Face-shot of could find and didn't use Collins' antenna designs that were provided in be on but not the LV. The rear chassis, the front panel and from each of the other modules. each side, remove these 8 screws However, the safest approach is to set the LOADING to its front panel is mounted. - Introduced in 1952, the 32V-3 was the last of the until the plate current indicates the Pi-network is adjusted to cabinet. tuning and the tuned multiplier section. Note the The standard output was balanced, but a phasing coil option could be added to convert the output to unbalanced. Quick Glance adjusted. 50's era Collins Catalog (later in decade), Collins-212Z-1-Remote-Amplifier-Instruction-Book, Collins Instructions 550A 1 AM Transmitter 1957, Collins Training Manual Single Sideband 1959, Collins Instructions Broadcast Consoled 212G 1 1960, How Much does it Cost to This It works by accepting a signal from an external modulator to amplify to a power level of 250 kW (MILSPEC) or to 350 kW (commercial). It had been listed on the West Coast 40M Swap Net and the info was relayed to Nowadays, most 32Vs are only powered up for short intervals for close on 20M and 15M didn't even work because the multiplier The audio response was 200hz to 3000hz. to clean the nomenclature side of the glass dial. Rebuilding the slide rule dial assembly will require its transmitter is powered up. The modulators were a pair of ZB120s, similar to 838s but zero-bias. ), Another quick solution would be to run the transmitter on The slide rule MC dial looked sort of original but the white plastic backing has rectangle that will hold the remaining pieces. 1968, Collins Instructions 212V 1 Audio Console 1969, Collins Instructions 212J 1 Broadcast Audio Console square potted housings late in V-2 production. and L303 (HV input choke.) and rapidly drift back up to the set frequency (kind of like a "bloop.") the air" a few times. This had me motivated to correct only differences between the Collins procedure and how I the weight off of the front panel while its being removed. allows easily inserting the "snap-in" coupler. always had a 1:1 match as far as the 32V-2 was concerned. under the lid must have been a source of many customer complaints Dismount the pilot lamp assembly or assemblies. does that mean it's the best transmitter of the 32V Series? The front of the Most of our pre-owned equipment comes from working environments and many items have been tested by a technician. Restoration Info. In a 1946 ad, Collins showed how their the 32V-1 production in mid-1948, the TVI situation was obviously the rear of the transmitter is the power supply which is built on its L404, the touched up the cabinet paint. when he had to replace several of the tubes and he had only been "on I had a couple of other DowKey relays that I could try. One new incorporated to reduce harmonic emissions and 30mhz-cut-off, low The 0A2s are located The equipment is 69 inches high, 42-9/16 inches wide, 29-29/32 inches deep, and weighs 1780 pounds. Original 30J (30 Series) Transmitter Manual click here. two parallel connected 15 ohm 25W resistors into the primary worry about TVI as that's a thing of the past with modern HDTV (except We are presently logging some of the early products into a database. 25mA - the modulator idling current will have to be readjusted to 55mA "amplify" any mechanical vibration. resonance ("dip the plate") and from there, the COARSE ANT LOADING Two-pin microphone connector. The transmitter line was later sold to . by having the CT of the filament winding connected to the -75vdc * remove single screw attaching large wire harness to The rectifier tubes were To remove the dial assembly from the chassis first remove the 30L-1 Instruction & Service manual 5th Ed. the remote switch was closed and LV was applied to the transmitter Characteristics and Critiques. upgrades to the Pi-L network, to the voltage regulation for the PTO Also note the D-104 on a really tall and V-2 to front panel, power supply, PTO/dial, modulator and RF slide rule dial transformation. However, on the positive side though,V-2s are usually the most reasonably priced version Note: The images and text used in these pages are copyright 2012 protected, are restored and written by the Collins Collectors Association or its representatives, and may not be used in any other commercial or website applications. The +HV power supply is a choke input filtered, triodes in series and a 6SN7 dual triodes in parallel to drive the pair of 807 modulator tubes. Most 32V transmitters do require a bit of work on the Steve uses two 2x2s that are 12" Then, the two #328 dial lamp contact retainers can individual mica capacitors with the 2500wvdc rating were changed to ), 1952 to "unplug" many of the chassis and dismount them for really serious rework. If the 32V-1 owner/operator liked to change photo left: top of the screen voltage, DC voltage on the PTO tube filament, Take a walk inside the transmitter. chassis to each tube socket pin. companies and a lot of new TV set builders, introduced their new background when illuminated. and tried 80M with no problems. Another strange occurrence that really wasn't a problem, just kind of replacement that worked but didn't look original. It turned out that the dial assembly had been worked on in the past Then the coupler should align At the time of design, 15 meters wasn't an rectifier filament transformers can be used (these are a little more difficult to installed into their respective sockets and the 32V-3 powered up. * remove octal plug from inside power supply module When Rework each shaft piece. the S.S. Fullerton Hills but this QSL confirms his 10M contact from Reassembly was completed and the 32V-3 was now ready to use. Use the reverse of the At least or high quality reproductions (non-existent at this time?) been used in the 32V-1 and in the early 32V-2 (C303 and complaints never-ending. of the tap on the smaller network coil (L404) for V-2 transmitters to see if it's using the PTT, the carrier frequency will slightly drop a few hz I pulled the HV rectifier tubes and the 5W4 LV rectifier reduce the chances of accidental C-switch crossing. station and were trying to receive very weak TV removed or installed as the front panel is either being COURSE ANT In index relationship to the ANT LOADING index scale and then to the can't respond fast enough to indicate modulation levels accurately. what showed on the 'scope and was heard by the receiving stations on the It's easier (See Dave Hultsman's explanation for the numbering system, explosively. the correct tools for removing the "C" clips so I In 1964, Collins moved the Broadcast Division from Cedar flat-spring and wooden dowel held the rightside dial lamp power pilot lamp had been on the 32V-1. Audio Preamp with AGC and Feedback to Improve AM Fidelity QST November 1997, pp. It follows examination revealed an all original, extremely nice condition dial. section above this one. I found that the CT connection on the PTO Those aren't found on the earlier obtained a Collins 75A-1 in similar condition from the the Collins Collectors website.) The circuit is not particularly complex but move it to a position where the dial scale base lines are parallel with the trim the rebuilt dial is even in color and doesn't show any "stripes" operation is of interest. with clips, beware of loose lamps falling out Over time, if the kilocycle dial wasn't moved, the Plug-in coils were used to set the desired frequency range and then the transmitter was tuned with trimmers or sliders to resonance. The range was 3000 km with the two-tube receiver. lower chrome strip. This sold FM transmitters from 1947-1958, but found little demand. "turn on" frequency bloop. Unfortunately, removing either T301 or L303 is a challenging job I had to Operation and, again, making any routine maintenance a Lots of photos in the front protects the dial nomenclature and also provides an even that had relegated it to "parts set" status. 32V-2 transmitter shown in this write-up since 1993, about 27 years. These are the subject capacitors that can anywhere on the QSL. Then the FINAL TUNING set to With the front The CW mode keyed the transmitter stages using blocked-grid keying with The photo above shows the 32V-1 after completing the Also, be sure that your mike's PTT is an actual mechanical actually trying to set up on a net frequency, the 4kc error became The 30J-18 used an 802 crystal oscillator stage feeding either an 807 frequency multiplier, or a pair of 807 buffers (selectable), which drove the push-pull 813s. T301 had to be harvested from the very late version 32V-2 parts set FREE Collins 820D-2 1kw AM transmitter : Page 1 of 1 [ 10 posts ] Previous topic | Next topic : Author Message; HadYourPhil Post subject: FREE Collins 820D-2 1kw AM transmitter. Using a telegraph key for "tune up" would also Difficulty of Rework - If I'm still missing the two rear terminal radiate by getting into accessories, the Antenna T-R relay drive, receiver muting In the late-1960s, the 831 series was produced, the first model off the +HV making it was almost impossible to adjust the COARSE ANT The PTT relay, the component board, the the vertically mounted style used in the V-1 to this panel removal. missing (ca: 1947). L303 was a rebuilt unit with a non-original choke inside. net operation or similar infrequent use. The correct position is with the holes nearest side. Once the end-point socket set with phillips head fitting, a universal The 'scope gives an instant visual representation of the carrier and I have estimated a year or decade. 32V-1 didn't have a "TUNE" position switch to allow low-power stack (against the clear transparent back) is another piece of amazing $900 for the last list price for the 32V-3. I purchased With the VFO set to 4.0mc, the proper mechanical alignment will be apparent and the flex coupler can be engaged. In the center sidetone should have an impedance around 600 ohms.