oldtime Wyo Radio
Here are the logos used by Wyoming Radio in the mid-80s. KRAL was in Rawlins. All AM except for KGRQ was gourmet FM rock. So much for FM being fine music. K2 was still a combination with K2 TV.
KVOC started out in the 40s as a GATES Radio (now Harris) complete radio station delivered in a portable trailer. Was stereo and FM on the Casper cable system. They had a bank of Dorrough processors that did nothing as Country record producers were putting the Dorrough sound on the original vinyl. The original Gates BC1 all tube transmitter had a window in the cabinet so the glow from the final plates could be observed when tuning. The replacement Continental transmitter was unique in that it employed a series modulation scheme.
KGRQ and KATI were co-located at 1400 Kati Lane in north Casper behind the Holiday Inn. That was also a modular building and housed a tape based automation system. Songs played off large tape reels, and spots were on a cartrige tape carrousel. The whole thing failed regularly, mostly the 5 volt power supply for the massive array of TTL chips. KATI lost most of its signal after selling off the realestate and the new landlord cut most of the ground radials landscaping for a parking lot.
KTWO AM had its studio downtown on 150 N. Nichols, right next to the railroad yards! That called for a lot of sound proofing. They were also famous for being one of the few stations to purchase the RCA Ampliphase 50kw AM transmitter. It was essentially 2 transmitters operated in opposition and a real bearcat to tune up properly. The principle advantage was it did not require the large audio modulator amplifiers of a plate modulated design. such as the BC1.
Another variation in modulation was the solid state MW1 Collins used at KRAL, a variation of progressive series modulation of the output modules. Most noted for regularly burning out the transistors. The KRAL backup was an RCA BC1 with laminations on the modulation transformer being so loose that it would sing along with the audio program.
Here is a further explanation offered by Tom Norman who was engineer at both KTWO and UW Laramie and now in Denver Colorado at Burst Video:
KVOC started out in the 40s as a GATES Radio (now Harris) complete radio station delivered in a portable trailer. Was stereo and FM on the Casper cable system. They had a bank of Dorrough processors that did nothing as Country record producers were putting the Dorrough sound on the original vinyl. The original Gates BC1 all tube transmitter had a window in the cabinet so the glow from the final plates could be observed when tuning. The replacement Continental transmitter was unique in that it employed a series modulation scheme.
KGRQ and KATI were co-located at 1400 Kati Lane in north Casper behind the Holiday Inn. That was also a modular building and housed a tape based automation system. Songs played off large tape reels, and spots were on a cartrige tape carrousel. The whole thing failed regularly, mostly the 5 volt power supply for the massive array of TTL chips. KATI lost most of its signal after selling off the realestate and the new landlord cut most of the ground radials landscaping for a parking lot.
KTWO AM had its studio downtown on 150 N. Nichols, right next to the railroad yards! That called for a lot of sound proofing. They were also famous for being one of the few stations to purchase the RCA Ampliphase 50kw AM transmitter. It was essentially 2 transmitters operated in opposition and a real bearcat to tune up properly. The principle advantage was it did not require the large audio modulator amplifiers of a plate modulated design. such as the BC1.
Another variation in modulation was the solid state MW1 Collins used at KRAL, a variation of progressive series modulation of the output modules. Most noted for regularly burning out the transistors. The KRAL backup was an RCA BC1 with laminations on the modulation transformer being so loose that it would sing along with the audio program.
Here is a further explanation offered by Tom Norman who was engineer at both KTWO and UW Laramie and now in Denver Colorado at Burst Video:
Ampliphase was an RCA product. It worked by vector addition of the oppositely phase modulated outputs of a pair of amplifiers operating at nominally 25,000 Watts. If the vectors were 180 degrees apart, the vector sum was zero transmitter output. If the vectors were 135 degrees apart, the transmitter output was 50,000 Watts (which was the case with zero modulation). If the vectors moved toward zero degrees apart, transmitter power was modulated upward. If the vectors crossed over each other, you had a Plate Current Overload.
The Gates MW-1 didn't have a single digital component in it. The way it worked was by delivering 70 Volts to the final amplifier transistors via a diode, to isolate them from the 140 Volt higher voltage supply that allowed higher modulation level. Both voltages were delivered through transistors modulated with the audio being transmitted. The 70 Volts were delivered via a single transistor that was saturated during zero modulation, and the 140 Volts via a parallel pair of transistors that were cut off during zero modulation. Audio would either cause the B+ to be modulated downward from 70 Volts or cause it to be modulated upward toward 140 Volts.
Tom Norman, CPBE
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