• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

Motorola finally settled on the identify "Police Cruiser" for his or her first police receivers, all but the primary of which have been mannequin prefixed "P69", the preliminary drawing board offering possibly being referred to as only "Police," however apparently shortly modified to "Police Cruiser." Some prototypes are believed to exist from early 1936 which aren't identified on this listing. State police, counties and freeway patrol (and a few massive metro areas) typically broadcast on the 1550-1750 Kilocycle band, whereas cities and small towns used the other band of 2300-2490 Kilocycles. The basic frequency range of all Police Cruisers (besides the P-69-17 and 17A) is 1500-3000 Kilocycles. All P-69 Police Cruisers except the P-69-14 are crystal management, single channel. All models of P-69 Police Cruiser receivers except the P-69-14, and the very first Police Cruisers, contain two vibrators; but only one is in use at any given time. Particularly aggravating for the collector and historian is that no P-69 mannequin numbers appear clearly or usually on the tools aside from an obvious two digit number stamped on the lower housing shell, which was easily separated from the receiver, and on the paper tag which is glued contained in the lid to indicate components layout. In late 1940, Motorola began selling the "Deluxe" line of equipment, a large rounded-prime two piece radio set also known as "coffin units," "doghouse units," or "double humpers." Although primarily an FM product, the Deluxe line apparently was provided in a VHF AM version with a type quantity AMR-13(V) for the receiver and presumably AMT-30(D) for the transmitter, however this creator has by no means run throughout any nor discovered manufacturing documentation supporting a "Deluxe" AM transmitter.

Postwar receivers typically have ink stamped dates beneath the chassis and a few of the P-69-18's comprise an inked-stamped mannequin number. To this point, nevertheless, the efforts of the experimenters have been concentrated on telegraphy. The speedy fire system of telegraphy is patterned after the music roll of the mechanical piano player. As mentioned earlier than, these cables' musical traits have been decisely valid and intensely interesting, contemplating the excessive steadiness between parameters reminiscent of extension, refinement, warmth, dynamics and scene reconstruction confirmed both by the "Piano 6" and the "Piano 1". Considering these outcomes, I strongly recommend you do that DIY undertaking. And simply during a type of nights our "Piano 6" sign cable was brought to gentle. Should one vibrator fail, the officer might reach down and select the other vibrator, permitting the car to continue on patrol without the necessity to return to the station for radio repairs. The opening in the case on the upper left is to permit adjustment of the antenna trimmer once the set is installed in a vehicle. Other options included the "screen" antenna and an additional size "super" broadcast whip. The antenna enter was designed for either a traditional broadcast whip or a copper "screen" antenna contained in the automotive's headliner ("tarred fabric roof" sedans), aside 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 assembly.

Motorola's unique antenna was an odd three-legged tripod affair as proven under and within the above photograph of a T-69-20A in a police automotive, and featured an adjustable length whip. All Police Cruisers have been basically modified variations of Motorola's late 1930's AM broadcast automotive radios (even the "UHF" fashions !) and all are AM receivers. Police Cruisers". They should have a chrome nameplate on the front of the housing which says "Police Cruiser" in script, with a purple or blue painted background. The word Motorola doesn't otherwise seem on the exterior of the receiver itself, however is on the face of the management head in the type of a purple painted steel nameplate. With the exception of the P-69-18SP-2, and the P-69-17 when mated with a transmitter, all Police Cruiser receivers had been originally meant to mount on the automobile firewall, behind and beneath the dashboard. Again, with the exception of the "SP-1 and SP-2 variations of the P-69-18 (which makes use of a "DC" electrical volume control,) the amount management is positioned on the receiver itself and is turned through a 2 foot lengthy "speedometer" type jacketed mechanical cable which connects to a knob on the management head.

The sooner Police Cruisers typically have a black wrinkle end, whereas the late-war and postwar Police Cruisers have a blue/gray wrinkle finish. Once again, a warm thank-you to Andrea, and for you all: have nice enjoyable! Single vibrator. Color finish is believed to have been gray wrinkle. It's a standard mistake to assume the 1-2 swap on the face of the housing refers to channels, nevertheless it refers back to the vibrator in use! A swap which protrudes via the front panel selects the vibrator. Looking for designs that may greatest deal with the delicate musical sign, we often venture in direction of DIY tasks which are fairly troublesome and not at everybody's degree. The duplexer, a tough trying machine for the delicate work in hand, is a pair of wheels pushed together by a belt from a motor and touched by copper brushes. Stockton then did such efficient work that the system was accomplished. 8) at the cable's different end, utterly get rid of the shielding, reducing either the aluminum foil and the copper braid, then join every little thing to the RCA plug until you attain the external sleeve edge, soldering the Red/BLACK pair to the positive pole and the Green/ORANGE pair to the adverse pole; 9) repeat steps 1-eight for the opposite cable, and you are performed! Then, connect the cables in your system, with the shielded plug to the source side, and allow a couple of day of burn-in earlier than proceeding to a important listening.

If you have any sort of questions concerning where and how you can use insulated copper cable, you can contact us at our page.