See typical T69-20A set up photograph under. The -SP2 modification consists of the -SP1 modification, but additionally allows trunk mounting of P-69-18 by including a cable connector box (see picture beneath) which allows the receiver to interchange with a Deluxe Line FMR-13V VHF FM receiver and be compatible with an FMTR-30D radio accessory set. P-69-18 SP-1 and SP-2: Probably 1941 or later-dated modified P-69-18. Also included in the SP-1 manual is an instruction on how you can wire the squelch to even be managed by the remote head, the manufacturing facility squelch control on the chassis then being unused. Squelch was adjusted at the receiver chassis itself and never accessible by the operator. Somewhat common. The squelch management was moved to the front panel and provided with a knob, not like previous versions, the place it was situated behind a plug button on the facet of the housing, as proven on the P-69-thirteen above. The unique microphone used with the above control head would have had a straight cord, and would have had a more flush-showing, "push up to speak" button which recognized the earliest Shure Mfg.

The Motorola P-374-A control head bodily appearance is unknown; it's just like other Cruiser heads however has a squelch on/off swap and mechanical quantity management knob. The head for the P-69-17A added a toggle switch for squelch between the pilot lamp and the volume control. The relay within the upper right nook has been added by somebody for functions unknown, most likely a receiver muting relay for use with a transmitter. The sq. field on the higher left corner is a transmit-receive relay to allow use of a single antenna. Were a catastrophe to wipe out a single station, another at an attainable distance may be used. It isn't an undramatic scene to receive within the darkened room, when the wet, slippery tape worms out of its case into the palms of the operator. The tape comes prepared with a central line of small holes, insulated copper cable the dash or the dot being punched on its respective side of this line. The -SP1 modification used a small round connector on a short pigtail result in electrically remote the quantity and squelch controls.

As originally configured, the ability provide was normally installed on the firewall of the car, next to the receiver and underneath the glove field, while the RF part was positioned in the trunk and attached to its antenna through a short braided copper rope. The one through which the conducting and nonconducting segments alternate at brief intervals signify the dots, whereas the other two wheels with fewer and longer conducting strips ship out the dashes. No sooner does the customer get a glimmering comprehension of those info than he is put up towards a machine that should scare a married man out of his wits. On examination the machine seems less formidable. Instead of waiting for the wires to clear, the operator sits in entrance of a punching machine feeding from a roll of tape. He should be capable of perforate the tape at a speed a lot in excess of the speed of telegraphing by hand.

Otherwise, the set is similar as the usual P-69-18. Typically supplied by 1942 was the usual underneath-sprint P-254 head as additionally shown below, which was usually used with a microphone. This was the standard control head for the T-69-20A although there were at the least two different kinds which were earlier, such because the one proven within the photo above, which has the connector on the underside apron, and another, upon which the cradle for a Western Electric "E" type handset was hung. The T-69-20A was launched in August, 1939. Production continued by way of roughly late 1949. The control head was available as a "handset" sort, wherein a push to talk Western Electric "E" collection telephone handset hung alongside or on a cradle on prime of the control head, which was a gray sq. field with Amphenol connectors on the bottom for the management cable connections. The management head solely controlled the transmitter; the receiver retained its own control head . This control head was primarily used with the "Deluxe" line of FM tools, launched in late 1940. Also notice that coiled microphone cords are a postwar development. For instance, they have been used within the trunks of Signal Corps staff automobiles for the 1940 annual War Games at Camp McCoy, Sparta, Wisconsin (believed to be P-69-17A / T-69-20A combinations, (in a TR 20-17 setup.) Advertisements in CQ Magazine in the late 1940's by surplus dealers provided these as having come from "army police service." There were several kinds of steel platforms used to mount these "one piece" sets.