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Single vibrator. Color finish is believed to have been gray wrinkle. All P-69 Police Cruisers besides the P-69-14 are crystal control, single channel. Crystal management, twin vibrators. All had been powered by normal 4-pin auto radio vibrators. Prior to this time, Motorola had produced small portions of cell police receivers by modifying customary car broadcast radios, nearly on a "request" basis for close by police departments. Those fireplace departments which did install radios, did so by licensing them as cellular police radio stations, and shared the police dispatch system. But massive jumps over area type but one of the seemingly miraculous accomplishments of the new system of wireless. This humming noise is eradicated by wireless. That's the reason some wireless methods still work exclusively at night. Police programs of the time broadcast on two ranges. The preliminary providing was a barely modified Model 60 "Golden Voice" car broadcast radio referred to as Model 60P, as proven under.

P-69-17 (P-69-17A): Eight tube VHF AM mannequin. The P-69-17A is basically the same because the P-69-17 apart from a redesigned squelch circuit. The "UHF" model P-69-17A is also mounted in the automobile trunk, but with a 20 foot lengthy speedometer kind management cable operating to the volume management knob underneath the automobile's dash ! The antenna input was designed for both a conventional broadcast whip or a copper "screen" antenna inside the automobile's headliner ("tarred fabric roof" sedans), apart from the P-69-17 "UHF" receiver, which shared the transmitting "whip" antenna on the vehicle's rear quarter panel and thus required a separate T/R relay field meeting. All Police Cruisers were essentially modified variations of Motorola's late 1930's AM broadcast automotive radios (even the "UHF" models !) and all are AM receivers. Below is a typical P69-14 management head, fairly obviously a modified automobile radio control head. Control head same as P-69-13 series. The primary police receivers made by Galvin in late 1936-38, before the P-69 mannequin series. The P-69-17 series coated 30-40 Megacycles.

The basic frequency range of all Police Cruisers (besides the P-69-17 and 17A) is 1500-3000 Kilocycles. This page is an index to the earliest Motorola police radio equipment. In late 1940, Motorola started selling the "Deluxe" line of gear, a big rounded-top two piece radio set also known as "coffin units," "doghouse sets," or "double humpers." Although primarily an FM product, the Deluxe line apparently was offered in a VHF AM model with a kind quantity AMR-13(V) for the receiver and presumably AMT-30(D) for the transmitter, insulated copper cable but this creator has by no means run throughout any nor found production documentation supporting a "Deluxe" AM transmitter. Also, special manufacturing tools, which carried an "SP-" suffix, just isn't listed here. There were some particular production units made for 24 and 12 Volt programs, primarily for large hearth engines and trucks. All equipment was designed for 6 volt DC operation. I'm on the lookout for other examples of previous police radio tools from the 1930's and 1940's - - don't let this tools wind up on the landfill! When you've got or are looking for old police radio data, printed supplies, equipment, components, photos, and so on. let me know!

Motorola also received various navy contracts with their new FM tools, which would later be given the AN/VRC-2 nomenclature. The Galvin Manufacturing Corporation began producing "Motorola" cellular police receivers in late summer season 1936, significantly later than some other manufacturers corresponding to American Bosch, RCA, Link and Philco. AM medium wave receivers were still being produced into the mid-1950's, regardless that the FCC began granting VHF 30-39 MHz licenses for 2-means programs in 1936 and granted everlasting VHF licenses on both low and excessive VHF bands in late 1945. After World War Two, most manufacturers abandoned AM gear other than as substitute components for existing techniques. In view of messages being sent from this metropolis straight by means of Mount Whitney, the highest peak within the United States, to El Paso, is now done each day, snows and winds cease to be factors. Poulsen hand despatched and the ocean cable run from 25 to 30. The speed of sending and receiving has thus its human limitations. To ship or to obtain 200 phrases a minute would be absolutely impossible for human hand or ear.