International photographer (Jan-Dec 1934)

April, 1934 T 1 1 INTERNATIONAL PHOTOGRAPHE Fifteen TELEVISION AN ULTRA-HIGH FREQUENCY TELEVISION RECEIVER UNIT HE usefulness of the W6XS television receiver, described in the March 1934 issue of the International Photographer, is greatly enhanced by the ultra-high frequency adapter unit described herewith. The addition of this unit makes possible the reception of the Don Lee ultra-high frequency television ■RS B t-'VWvVVvV* — • station W6XAO, on 6-}^ meters, or other ultra-high frequency television or amateur station within a forty mile radius of the receptionists location, whether he be located in America, or abroad. With the unit disconnected, reception of the Don Lee television station W6XS, or police, aeronautical, and amateur stations in the band from 1500 to 3000 kilocycles, may be carried on as usual. The accompanying unit converts the W6XS receiver into a superheterodyne receiver. The first detector VTI and the oscillator VT2, act to change the incoming ultrahigh frequency signal to a frequency within the band of the W6XS receiver, by which latter receiver it is then amplified and received in the regular manner. Besides the list of parts, A is the ultra-high frequency antenna, which should be a straight No. 14 wire eight feet long. It should be moved about in the receptionists' home until the strongest signal is received. The output of the unit appears at "0", which is to be connected to the antenna binding post of the W6XS receiver. The W6XS antenna is disconnected therefrom, and the tuning dial of the W6XS receiver set at a point where a station in the 1500 to 3000 kilocycle (W6XS) band is not received. If desired, "0" may be connected to the top of L2 of the W6XS diagram. B is connected to the junction of L5 & C13, and supplies plate voltage to the adapter from the main receiver supply, while the heaters of VTI & VT2 are connected to the heater winding K of transformer T2 of the W6XS receiver. The converter unit should be thoroughly shielded. Coils LI & L2 should be placed in line, and two inches apart, as this arrangement provides the coupling between tubes VTI & VT2. List of Parts for W6XAO Television Receiver Superheterodyne Unit LI — 4 turns No. 14 enameled wire on J4" dia. form. L2 — 4 turns No. 14 enameled wire on */i" dia. form. L3 — 4 turns No. 14 enameled wire on ]/2" dia. form. L4 — Short wave radio frequency choke coil, 2*/2 millihenries. CO — 10 micromicrofarad condenser. CI — 0-50 micromicrofarad variable condenser. C2 & C5 — .01 microfarad condenser. C3 — 0-50 micromicrofarad split stator condenser (two sections 0-50 mmfd. each). C4 — 250 micromicrofarad fixed mica condenser. C6 — . 1 microfarad 400 volt paper condenser. Rl — 5,000 ohm carbon resistor. R2 — 250,000 ohm carbon resistor. R3 — 15,000 ohm carbon resistor. R4 — 25,000 ohm carbon resistor. VTI— RCA '24A, '57. or '58 vacuum tube. VT2 — RCA '27, or '56 vacuum tube. \^yke new ^(5-s/)eea K^jyemo gives the highest speed available in a portable 35 mm. camera The new 8 to 48-speed Eyemo 35 mm. hand camera, developed to permit taking pictures at twice sound speed, is now available on order. This convenient, versatile camera has already proved its value to Martin Johnson, who is using it for filming big game from the air. It will be a boon to any cinematographer who has to produce semislow motion scenes under circumstances which make the use of a studio camera difficult or impossible. Its speed range, 8 to 48 frames per second, gives it general utility. Known as Eyemo 71-CD, the new model has a three-lens turret head mounting the Cooke 47 mm. Fi.^ lens, standard equipment, and any two extra lenses selected from the Cooke line, ranging in focal length from 24 mm. to 2.0", and in speeds as fast as F 1. There is a hand crank for optional use, and a 11 or no-volt electric motor may be employed. The governor gives accurate control of any desired speed, whether spring motor, hand crank, or electric motor supplies the power. Model 71-CD, like 71-C, may be adapted to use external 2.00 or 400-foot magazines. Your present Eyemo 71-C can be converted to operate at 48-speed. BELL & HOWELL Bell & Howell Company. 1849 Larchmont Ave., Chicago; 11 West 42-nd St., NewYork; 716 North La Brea Ave., Hollywood; 310 Regent St., London (B & H Co., Ltd.) Established 1907. Please mention The International Photographer when corresponding with advertisers.