TRANSMIT BOARD

CIRCUIT DESCRIPTION

U50IC is an amplifier whose gain is controlled by the level of audio entering the rectifier at pin 16. As the level here increases, the gain is decreased and this results in a 2:1 compression characteristic. Pre-emphasis is added by U501B. R504, R505, and C508 set this at 115uS. C531 rolls the response off above 10KHz to further attenuate the 20 KHz call signal (see Audio Board Circuit Description). Q501 is a Colpitts oscillator with the collector tuned to the third harmonic. T501, VVC501 and VVC502 are added in selies with the crystal to allow frequency modulation of the oscillator. The oscillator is operated 10KHz below the series resonant point of the crystal. This improves linearity at the expense of some stability. Q502 is a trip1er and Q503 is a straight through amplifier. The catTier frequency is thus nine times the crystal. C529, C530 and L503 function as a low pass filter and matching network.

ALIGNMENT PROCEDURE

EQUIPMENT REQUIRED:

o RF POWER METER

o FREQUENCY COUNTER o DC VOLTMETER

1.Connect the RF power meter and frequency counter to the Transmit Antenna jack. Make sure the Transmit switch on the reat· panel is set the the Cont position.

2.Adjust T502, T503, T504, VC501, and VC502 for maximum power. Note: If adjustments are severly out of alignment and no output can be obtained, it may be necessmy to first adjust T502 and T503 for maximum DC voltage at the emitter of Q502. Then adjust T504 for maxi- mum DC voltage at the emitter of Q503. Now adjust VC50 1 and VC502 for maximum power.

3.Adjust T501 for the COlTeCt frequency:

Y501 Marking

Frequency

 

 

154T570

154.570

177T800

177.800

 

 

183T730

183.730

 

 

4.Repeat Steps 2 and 3 as necessmy.

5.Deviation will be adjusted in the audio board alignment.

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Telex BTR-200 Series manual Transmit Board

BTR-200 Series specifications

The Telex BTR-200 Series is a well-regarded solution in the realm of wireless intercom systems, widely utilized in broadcast, film, and live event production settings. Renowned for its reliability, user-friendly interface, and robust performance, the BTR-200 Series has become a staple for professionals seeking efficient communication solutions.

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The BTR-200 Series also distinguishes itself with its digital circuitry, which enhances audio clarity and reduces noise. This reliance on advanced technology results in crisp communication that is essential for coordinating complex productions. The system also features a low-latency design, which is particularly valuable in live performance settings where timing is crucial.

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