Select your language

Specially commissioned by the editors "RL" developed a simple scheme of Amateur radio "RTF-92" with access to the PBX. With this device you can call from the car to the house, or camping trip, to turn the alarm apartment and office space, and use "RTF-92" the phone as a wireless phone.

The principle of "RTF-92" is based on a normal Foundation the radio. A block diagram of the "RTF-92" depicted in Fig.1 and Fig.2 and includes mobile and stationary part.

The mobile part comprises a full-duplex radio, tone generator of signals of three frequencies, low-frequency amplifier for receiving dial-tone and dial pad.

The stationary part consists of a duplex radio stations, three tone receiver (PTS, PTS, PTSS), differential system, thyristor device on / off dipsy the system and the transmitter, the relay call, tone generator call and the time relay.

A schematic diagram of a mobile part shown in Fig.3. Transistors VT3, VT4 collected tone generator, which is activated by buttons SB1, SB2, SB3 or dialer through the diodes VD1 - VD3, and the oscillator frequency selected by the resistors R8, R9, R10 under frequency tone receiver PTS - PDS. Transistors VT1, VT2 assembled amplifier, whose output voltage of the tone signals is fed via capacitor C1 to the MIC input of the transmitter. Transistor VT5 assembled electronic key for the dialer and the reset button SB3. The switch SA1 is designed to enable the transmitter.

A schematic diagram of a stationary part depicted in Fig.4. Transistors VT1, VT2 total assembled amplifier tone signals coming from the subwoofer output of the receiver through the resistor R1 and the capacitor C1 at the input. Receiver the tone signal with a frequency 1610 Hz (PTS-1) on the transistor VT3 and the elements L1, C5, K1 is designed to enable defsystem and transmitter contacts K1.1, KZ. G, K4.1.

Transistor VT6 and the elements L2, C7, K2 assembled receiver the tone signal with a frequency of 2400 Hz (PTC-2) for the return of the stationary part in the initial state of the contacts of K2.1. (All switching elements in the diagram - in the initial state). Tones on and off the stationary part are served from the output of the common amplifier via C2, R7, W, R5, R6 to the base of transistors VT3 and VT6.

Transistors VT4, VT5 made the amp tone with a frequency 3580 Hz for the dialer and reset. The transistor VT8, VT9 and elements L4, 11, CB constitute receiver the tone signal with frequency 3580 Hz for the dialer (PTS-3), which through contacts K6.1 controls defsystem (VT10, VT11), thereby generating the dialing PBX. When you call, PBX spoken voltage is supplied from the divider R18, R19, R20 through C16, a matching transition the transformer T1 and C19, R22 to the input of the transmitter and then is received by the receiver of the mobile part.

Spoken voltage of the subscriber mobile part is input to the transmitter of the mobile part and then is received by the receiver stationary part, with the LF output which through a chain R23, C20,. transition the transformer T2, C17 is supplied to the base VT10 and next - in-line PBX.

Differential system is powered from the line PBX via a diode bridge VD8. Another diode bridge VD9 - VD12 with capacitor 18 are designed to receive a call from PBX lines. Last loaded winding of relay K7, and the contacts (K7.1, K7.3) connect the tone generator call to the input of the transmitter, and the contacts K7.2 include a transmitter. A schematic diagram of a tone generator of the call is shown in Fig.5.

The thyristor VS1 is designed to hold in working order stationary parts RTF-92". Transistor VT7 collected time relay, contacts K5.1 which break the chain of thyristor VS1 when you turn on or off the power source stationary part, because when power is applied to the stationary part contacts tone receiver spontaneously triggered prior to the restoration of the operating mode (i.e. for 15-20 seconds - the interval to which the time relay).

The mobile part "RTF-92" made inside the housing landline phone dialer. In the receiver apparatus is opened from duplex radio telephone earpiece BF1 and microphone BMI. Lever (or Germanova) switch apparatus is used when removing the tube to activate the transmitter.

. The front panel phone see three buttons SB1 - SB3 and red led for controlling the operation of the transmitter. The stationary part of the "RTF-92" in a separate box (dimensions depend on being integrated both parts) and multi-conductor cable connected to the radio and a two - line to the PBX.

Work "RTF-92" is very simple. It is only necessary to observe the following procedure for using the device.

Lift the receiver of the telephone.
Click for a few seconds the button SB1 - to "on."
Hearing the signal the PBX to dial a number.
When dialing another number a few seconds to click on the button SB3 - "reset".
After talking a few seconds to click on the button SB2 is "off."
Put the tube in place. HL1 led is designed for monitoring dipsi the system.

Details for "RTF-92" you can use any. Relay K1-KB - reed type RASA (passport 0602).
The transformers T1 and T2-transition from radio "Mountaineer 405" or similar. Secondary conclusions are not used.
Relay K7 - type RCM-1 (passport RS4.500.873.).
Coils LI, L2, L4 are wound on a ferrite rings with an outside diameter of 10 mm and a height of 5 mm;
L3 - made together with L4 on the one ring. Wire for winding L1 - L4 - sew-a 0.1. L1 has 460 coils; L2 - 300 coils; L3 - 45 turns; L4 - 245 turns. R14 - composite, two serially connected resistors 470 K.
Diode bridge VD8 you can collect diodes D226, CD, etc., designed for Uo6p - 100 V. the Thyristor VS1-any.
Transistors VT10, high voltage VT11 - 80 - 100 V. Adjustment "RTF-92" is primarily in the organization clean duplex radio, and then the adjustment of resistors R22, R23 for better hearing talk subscribers.

Author: V. herdsmen (RV6ACM), Novorossiysk; Publication: www.cxem.net