So, what kind of equipment would you have found in an FM radio station back then? WLDM was constantly evolving, and remained on the cutting edge of technology through it's 30 year history. From it's beginning as a 20,000 watt mono FM in 1949, the addition of a multiplexed background music service in 1957, it's conversion to stereo and 165,000 watts in 1961, adding 43,000 watts of vertically polarized signal in 1966 to better reach car radios, until being sold in 1978, Harold tried to deliver not only the finest quality programming but the finest quality audio to showcase the superiority of FM as a broadcast medium, one that he sincerely believed in. From beginning to end, here's pretty much all the gear WLDM used thoughout it's existence.



WLDM's first transmitters were a pair of General Electric 3000 watt Phasitrons. A main and alternate main. They consisted of a complete 250 watt transmitter and a 3000 watt power amp cabinet. This is a photo of just the 250 watt unit. Pretty blue, yes?

Here is a black and white photo of the complete General Electric 3000 watt Phasitron FM transmitter. You will see in following photos, the layout of the newer General Electronic Laboratories transmitters. These General Electric units were layed out in the same fashion, mirrored, 2 racks between them. When the newer GEL transmitters were installed, they were larger. So a wall (office) was removed to the right, to make room. The over-bridge with the call letters was extended and the call letters were re-centered and spaced a bit farther apart. Since the new GEL's were also blue, the color scheme remained the same. And... it was VERY IMPRESSIVE.

Here is another black and white photo of the complete 3000 watt GE Phasitron.

As mentioned in the "History" pages of this site, Phasitron tube exciters "weren't quite" true high fidelity, nor would they ever pass SCA or stereo in the future, and were rather tedious to keep properly "tweaked". In 1950, Gates came out with an exciter that utilized a superior phase modulation technique. The Model BTF, and WLDM immediately purchased 2, one for each transmitter, thus becoming the first "True High Fidelity" FM in Detroit.

The Hewlett-Packard Frequency and Modulation monitor from the "olden days".

This is an early 1970's photo of the top of the WLDM tower showing the original "8 bay" Wincharger horizontal antenna, it's main and only antenna until 1961. Below that you see the "newer" Jampro 16 bay horizontal antenna which was put up in 1961, and Jampro 12 bay vertical antenna which was added in 1966. Mounted to the Wincharger is the receive antenna for the Detroit Area Repeater Team (DART) VHF repeater. The DART transmit antenna was mounted on the WEXL-AM/WOMC-FM tower in Ferndale. Several miles east of WLDM. A leased phone line linked the repeater sites.

Here is photo showing the original control room with the original mono RCA BC-2 console. This was taken after WLDM's conversion to stereo in 1961, and also shows a lot of home-brew add on stereo mixers that enabled the turntables and reel-to-reel decks to feed the transmitter in stereo. Of course you can also see the turntables, and one of the two McIntosh pre-amps used on the turntables. Note that this room later became the new production room. The new control room was built out in the transmitter room (which you will see farther down page.) To the right of the console position (thru the window) was the large "live" studio. To the left and out of view were the window and door into another smaller studio. Looking forward while sitting at the console was the transmitter room.

Smaller color photo of the RCA BC-2(B) console

Another view of the old control room, showing Mike Murray. These of course are the reel to reel decks.

Another view of the old control room, showing the reel to reel decks. Again, the door you see goes into the large un-used "live studio".

After the "simplex" background music service was discontinued in 1957, and moved to the 67kHz subcarrier. WLDM became the Detroit MUZAK franchise. MUZAK provided the music tapes played by this primitive but reliable and nice sounding "automation" system. Also provided by MUZAK. Notice the Gates Level Devil limiter, all that was used on the subcarrier. These racks sat out in the transmitter room. The 2 top decks played the regular MUZAK selections. The lower deck on the right was only used for holiday music, such as Christmas. These earlier decks were made for Muzak by Presto, and the playback amps were made by Western Electric/Langevin.

WLDM added a Gates subcarrier generator to each of the Gates BTF exciters in order to get the multiplexed background service up and running. Very shortly thereafter in late 1957, a company called General Electronic Laboratories in Cambridge Mass. realized that as more and more broadcasters began to deploy multiplex services and that FM stereo was soon to approved, FM stations would need finer quality exciters, SCA generators and superb FM stereo generators. They began manufacturing exciters (with yet a further improved phase modulation method) and SCA generators as upgrades for existing transmitters. Later adding stereo generators and a full line of beautiful FM transmitters as well. WLDM purchased the GEL exciters and SCA generators right away and installed them on their General Electric transmitters. This is a photo of what the GEL exciter/SCA generator "package" looked like. 2 exciters, 2 SCA generators, power supplies at the bottom.

In late 1960, WLDM decided they would be the first to go FM stereo in Detroit. In addition to that, it was decided to do a major power increase at the same time. After being approved for stereo broadcasting and a power increase from 20,000 watts to 165,000 watts, Harold purchased two GEL 15,000 watt transmitters (licensed as "main" and "alternate main") and stereo generators. In addition to that, a 16 bay Jampro horizontal antenna system was purchased, as well as a water cooled dummy load. The new antenna was put up, and WLDM took delivery of their new GEL "main" transmitter (serial 10) with stereo generator. The new GEL exciter and SCA generator were removed from one of the old GE transmitters and connected to the new transmitter. The old GE was sold. Some renovation was done in the transmitter room to make space for this new GEL transmitter at the west (right end) of the transmitter room. the east (left) "alternate main" transmitter (serial 12) which was on display in GEL's booth #12 at the 1961 NAB Convention, it arrived later. Upon taking delivery of that, the other old GE transmitter was removed, the new GEL exciter and SCA generator removed from it and connected to the new GEL, thus completing the project! WLDM became the first stereo FM and first super-power FM in Detroit. This photo was taken around 1969, prior to the new control room and production room being built.

Here is a photo of the "alternate main" (right) transmitter taken at the same time. Here you see a better view of the racks. Notice the 2 GEL Stereo Generators in the left rack with power supplies above them.

Old advertisments for the GEL General Electronic Laboratories 15,000 Watt Transmitters specific to WLDM's purchase of 2 of them in late 1960. GEL transmitters were a beautiful powder blue with shiny polished aluminum trim.

In 1966 WLDM added Vertical polarization for improved reception in vehicles and on portable radios. A 12 bay Jampro vertical antenna system was installed on the tower, adding 43,000 watts of vertical power to the 165,000 watts horizontal. WLDM was the first station in Detroit to use vertical polarization.

Around 1970, as detailed in the "History" section on this site, the background music service and clients were sold to Fetzer broadcasting and the subcarrier turned off. This brought in some money to completely upgrade the Control room and production room.

Around 1971, the control room and production room underwent their complete upgrades. The old control room became the new production room. The new control room was built out in the transmitter room.

This photo was taken around 1972. Here they are! Those beautiful GEL Transmitters at WLDM! You can also see to the right in the picture the newly built control room furniture, Gates console, AMPEX reel-reel cabinet, cart racks and record racks. Note one of the two EV monitor speakers hanging from the pole.

Around 1973 or 1974, newer solid state FM exciters with stereo generator and SCA modules were available. WLDM purchased 2 of these, one for each transmitter. The McMartin B-910. The GEL tube exciters, stereo generators and SCA generators were retired to the attic.

So, how did the finest FM stereo stations of the day such as WLDM process their on-air audio before it went to the transmitter? With the state-of-the-art CBS Laboratories "AUDIMAX" and "VOLUMAX". The Audimax was a gentle AGC (automatic gain control) which kept the average level uniform. The Volumax was a high-frequency peak-limiter that permitted a bit more loudness without overmodulating the FM carrier . These were solid state units and resulted in clean natural sounding audio. A couple of minor modifications were made to them which improved the on air sound somewhat. The Audimax and Volumax were affectionately known as "The Maxx Brothers".

Ahead of those processors, the WLDM control room had a Gates "StereoStatesman" solid state mixing console. Again, state-of-art for the time, it had very clean audio and was quite functional for WLDM's simple basic operation.

While all of the other beautiful music stations in Detroit used primitive mechanical automation systems of the day, playing reels of taped music, WLDM always played the music direct from vinyl for maximum quality beginning around 1951. And back then, vinyl WAS maximum quality. The control room had 2 of these Russco turntables, with solid state Gray Research Pre-amps and Stanton 500 magnetic cartridges.

All of the turntables at WLDM were equipped with these Gray Micro-Trak tone arms. The arm was real wood, the rest aluminum. Very "audiophile" for anyone playing vinyl.

Commercials, Liners, Station ID's, PSA's, sometimes news, weather... All on cartridge tape. WLDM had 2 of the Gates Criterion cart players in the control room, which could be set to sequence back and forth using cue tones. While these were stereo, they were used for voice elements only, not music.

The AMPEX AG350 Reel to reel machine. WLDM had the roll-around console version in the control room. It was a stereo record/play unit. It was used for long-form programming, usually Sunday morning religious programs, weekday morning public service programs or other special programs run at other times. It could also be used to playback some cuts of music at 15ips from a number of LP's for "emergency" use, like a long restroom break or quick trip up Greenfield Road to Dunkin Donuts.


WLDM had some nice McMartin modulation monitors and a frequency monitor, and a Hewlett-Packard digital pilot frequency monitor.

Suspicious by it's absence here is a microphone. Not because i can't find a picture of it, but because THERE WAS NO MICROPHONE in the WLDM control room. Why? Because there was no need for one. WLDM was a beautiful music station. The Board operators were just that. Not announcers. The only voice elements were commercials, PSA's, and Legal ID's, recorded on cart, and voiced by either Harold Tanner, Jack Alan or Bob Conger. Breaks were always done at :00, :15, :30 and :45. There was a minimum of news, which was recorded on cart in production by Jack Alan in the morning and Harold Tanner in the afternoon and evening.and played shortly thereafter. If there was an important news bulletin or severe weather watch or alert, and you were all alone in the building, the board operator could either run into production and cart it up, or, if you were clever you figured out how to put yourself on the air live from the production room, do the announcement live, and go back to the control room without any dead air or anyone being the wiser. Another reason why there was no microphone in the control room is because the transmitters were in there. It was a LARGE room, and the transmitters were exceptionally quiet because of some creative ventilation. But at that time, board operators in control of the station were required by FCC rules to see the meters on the transmitter at all times, as well as the modulation monitors, etc. WLDM fully complied with that. The fact that the meters on the GEL transmitters were "waist high" put them at eye level of the operator sitting at the console. And back then, readings were required to be taken every 30 minutes. In addition to taking transmitter readings and so forth, it was the board operators responsibility to turn the tower lights on at dusk and off at dawn, or turn them on when it was dark during the day due to storms. No automatic photoelectric controls. Also, in the winter time, it was necessary to manually turn on the electric de-icers on the antenna system during snow, sleet, freezing rain or other conditions that may cause ice to form on them.. No automatic controls here, either.


Here there was a very simple and functional Gates "Stereo Producer" mixing console. Perfect for WLDM's basic production needs. Solid State, good audio quality.

There was another Ampex AG350 stereo record/play deck removed from it's roll-around and rack-mounted in the room.

And another Gates Criterion stereo cart machine with record section rack mounted. (but i've tossed in a color photo to show the record amp)

And a nice pair of old RCA BQ-51A transcription turntables which were previously used in this room when it was the old control room, updated with the Gray Micro-Trak tone arms (as shown farther above on this page)Stanton 500 magnetic cartridges but still using the McIntosh tube pre-amps.

The production room had an interesting assortment of Microphones. There was a single Sony C38B mic, which Harold was quite fond of and always used. Then there were a pair of ElectroVoice 636 mics, a gold and silver. These were set up so that the gold EV could be used as a mono mic feeding left and right channels. Or they could be used as a stereo pair, silver being the left, gold being the right. Jack Alan, would, during his morning show, get some evil pleasure out of annoying Harold by using the stereo mode, talking into the left mic, while having the right mic sitting in front of his perking coffee percolator. There were no mic processors and equalizers of any sort in the production room. Weren't needed.


This room was rarely if ever used since the early days of live music programming. It still had all of the original equipment, minus a few items. It was still functional to record news or whatever on reel if the production room was being used for recording or a live program.

This would be the mixer. An Ampex MX10 or MX35, which had no meters and a mic level output. The meters and program line output amps were on a separate rack mounted panel.

This is what the Ampex meter/line amp panel looked like. However, WLDM had a home-made version which looked essentially the same.

There were several Altec Model 639A and 639B Microphones in the room, on large booms and desk stands. This particular Altec model was actually originally designed by Bell Laboratories and built by Western Electric, and sold with the Western Electric name until Altec began manufacturing and selling them under the Altec name.

There was a fairly nice Ampex 354 reel to reel machine in a roll around cabinet in the room.


Oh my, we can't forget the WLDM switchboard! A fabulous old Western Electric 507 manual switchboard which could handle 5 lines, 12 extensions, and the operators phone. WLDM had 3 lines. 2 local (LIncoln 3-1000, 1001) and a Detroit line (JOrdan 4-5835)

Speaking of phone, the control room had one of these, with a REAL long handset cord. This is the phone the board operators would take requests on, put through from the switchboard. After hours, all 3 lines were connected to this phone, and the board operators answered them all. No answering machines or voicemail. When you called WLDM, you got a person EVERY TIME.

If you've never seen one, this is a teletype machine. WLDM had 2. One for UPI news and another for weather.



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