Philco-Radio-and-Television-Corp-39-55 电路原理图.pdf

《Philco-Radio-and-Television-Corp-39-55 电路原理图.pdf》由会员分享，可在线阅读，更多相关《Philco-Radio-and-Television-Corp-39-55 电路原理图.pdf（8页珍藏版）》请在收音机爱好者资料库上搜索。

1、MANUAL OF 1939 MOST POPULAR SERVICE DIAGRAMS COMPILED BY M. N. BEITMAN. SUPREME PUBLICATIONS AND SOCKET VOLTAGES- Copyright 1989-2025 Nostalgia Air 收音机爱 好者资料库 RadioFans.CN MANUAL OF 1939 MOST POPULAR SERVICE DIAGRAMS IPJHaJL TTbddiu 39-55, 39-m ADJUSTING MYSTERY CONTROL FREQUENCY AMPLIFIER The Myste

2、ry Control receivers are shipped with five (S) dif ferent control frequencies which range from 350 to 400 K.C. These are identified by code numbers appring on the serial number ticket and on the rear of the chassis. These code numbers and frequencies are as follows: Code 53SS K.C. Code 6367 K.C. Cod

3、e 7375 K.C. Code 8383 K.C. Code 9395 K.C. The purpose of the different control frequencies is to prevent interaction between two Mystery Control receivers which are on the same floor or are exceptionally close together. When several Mystery Control receivers are to be located close together, it. wil

4、l be necessary to use different control frequencies to avoid inter action between the receivers. In order to prevent interaction between receivers, there should be a difference of 20 K.C. between their control frequencies. If three receivers are to be operated at the same time and are closely situat

5、ed, it will be advisable to adjust the control frequency of the first set to 355 K.C., the second set to 375 K.C. and the third to 395 K.C. When realigning or changing the control frequency of the Mystery Control circuit, a Philco Model 077 Signal Generator with a coil of wire (about 4 or 5 turns12

6、in diameter) attached to the output terminals is required. The leads between the coil of wire and Signal (ienerator should be long enough so that the coil of wire can be placed near the large secondary inductor in the bottom of the receiver cabinet. With this apparatus, the Control Frequency is adju

7、sted as follows: I 1. With the temporary coil of wire in the center of (orj near) the secondary inductor, the control frequency to| which the Mystery Control Amplifier is tuned can bej determined by tuning the Signal Generator between 350 and 400 K.C. When the Signal Generator is tuned to the contro

8、l frequenqr, the Thyratron (2A4G) tube will glow (blue haze). If this frequency is to be used, leave the Signal Generator indicator at this point or turn the indicator to any other frequency desired between 350 and 400 K.C. j 2. When the control frequency is selected, turn the sensi-i tivitv control

9、 (117) in Model 116 and (89) Model 55, located on the left rear of the chassistowards the posi tion marked “extreme.” Using the 2A4G Thyratron tube as a resonance indicator, adjust padders (103), (115), (119) in Model 116 and (74), (85), (90) in Model 55 for maximum signal. This will Iks indicated b

10、y the brilliance of the glow in the 2A4G Thyratron tube. As the padders are adjusted, gradually turn the sensitivity control to the “near” position or reduce the output from the Signal Generator. When the padders are correctly adjusted to maximum, the Thyratron will glow with the sensitivity control

11、 (117) at the “near” posi tion and with a very weak signal from the Signal Generator. 3. Next, adjust the padding condenser (121) in Model 116 and (92) in Model 55 on the secondary inductor located in the bottom of the receiver. The padding condenser is located in one corner of the secondary inducto

12、r and is encased in a cardboard container. This padding condenser should be carefully adjusted for maximum glow in the 2A4G tube. Use the weakest signal possible from the Signal Generator that will cause the 2A4G to glow. Also, have the sensitivity control as close as |X3Ssible to the “near” positio

13、n. Extreme care should be used in adjusting the padder to the exact point of resonance, as the secondary inductor is a very sharply tuned circuit. After adjusting the circuit, remove the Signal Generator and loop from the receiver. 4. The Mystery Control unit is now adjusted as follows: A. Dial any

14、one of the stations indicated on the remote unit by pulling the selector to the “Stop” position. Then, as the dial is released at the “Stop,” press the “Stop” down and hold it in this position. B. Holding the “Stop” in this position, bring the Mystery Control unit close to the receiver. Using the pa

15、dding wrench, tune the padding screw (126) located on the bottom of the unit until the 2A4G Thyratron in the receiver glows at full brilliance. Now, turn the sensitivity control on the receiver towards the “near” position until a point is reached where the 2A4G tube almost stops glowing. Then, readj

16、ust the padder (126) of the unit again for maxi mum brilliance in the 2A4G tube. The Mystery Con trol unit should now be adjusted to the same fre quency as the control frequency in the receiver. 102 Locations of CompensatorsModel 39-55 and 39-116 COMPILED BY M. N. BEITMAN. SUPREME PUBLICATIONS 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN