JPS59205831A - Structure of remote switching circuit - Google Patents

Abstract

PURPOSE:To attain three ways of operations of changeover of a preamplifier and a booster and through-operation by means of only an existing feeder for the preamplifier and the booster installed near the antenna by giving a DC voltage used in common for a power supply voltage and a changeover control signal to a feeder wire tying a transceiver main body and the antenna. CONSTITUTION:The antenna 1 is connected to the transceiver main body by using a high frequency coaxial cable from a receptacle plug J2 through a path comprising brake contact of relay RL1a-direct circuit 11-brake contact of relay RL1b through a receptacle plug J1. Then, in applying a DC voltage of an intermediate value from the main body to a center conductor of the coaxial cable, the voltage is applied to a circuit 12 through a high frequency choke RFC from the J2, a transistor (TR) Q1 is turned on, and a current flows to a relay coil RL1c, then the RL1a and RL1b are switched into make contact and the device 10 acts like a preamplifier 2 of the receiver. In applying a high DC voltage to the center conductor of feeder at the main body side, a TRQ2 is also turned on and a current flows also to a relay coil RL2c, then a relay RL2 is operated, and a booster 3 is operated, and the device 10 acts like the booster of the transmitter.

Description

[Detailed Description of the Invention] This invention is particularly effective in the UHF band, where performance degradation due to feeder loss between the antenna and the transmitting/receiving device is a problem. The present invention relates to the structure of a remote switching circuit in this case.

In a high frequency coaxial feeder, transmission loss increases as the operating frequency increases. Since the antenna needs to be installed at a high place due to the direct propagation of radio waves at frequencies on the shortened VHFHF, the antenna feeder becomes longer, resulting in losses that reduce sensitivity during reception and reduce effective power during transmission. This causes a decrease in communication efficiency.

As a countermeasure for this, at the time of reception, a preamplifier (including the case of only a high-frequency amplification stage, a high-frequency amplification and mixer stage, or only a mixer stage) is placed close to the antenna, and its output is supplied to the receiver body through a feeder. During transmission, there is a method to compensate for feeder loss and prevent performance degradation by placing a booster (including the case of only the output amplification stage, mixer stage and output amplification stage, or only the mixer stage) close to the antenna. It is valid.

In the case of receiving or transmitting only, the construction is relatively easy because signals can be transmitted and power can be supplied through a high-frequency feeder, as is done in CATV and the like. However, in systems where the same antenna is used for both reception and transmission, it is necessary to switch the preamplifier and booster between reception and transmission, and a separate switching line must be provided for this purpose.

However, according to the present invention, by using only the existing feeder, the switching between preamplifier and booster, and the operating state of the 3-pass operation, which does not use preamplifier or booster, can be arbitrarily operated on the transmitter/receiver main body side. is obtained.

The structure and operation of the present invention will be explained in detail below with reference to the drawings.

The antenna 1 passes through the connector J1, passes through the relay RL, the break contact of a, the direct circuit 1 relay RL, and the break point of the b, and is connected to the main body of the transmitting/receiving device by a high frequency coaxial cable from the connector J2. In this case, the antenna is directly connected to the main body, so it is suitable for short-range communication.

Next, when an intermediate DC power supply voltage (for example, 6V) is applied to the center conductor of the coaxial cable from the main body side, a voltage is applied to the circuit 12 from J2 through the high frequency choke RFC. Since the collector of the NPN transistor Q1 is directly connected to the circuit 12 and the conductor is connected to the circuit 12 through the resistor R1, the supply voltage is VBE of Ql (usually 0.6 for silicon transistors).
(approximately V), Ql becomes conductive and allows current to flow through the relay coil 'RL in series with the emitter. Resistance R
If enough pace current is supplied to saturate vct by adjusting the
Since it is only about V, more than 90% of the power supply voltage is RLlc.
will be added to. Therefore, the specifications for RL and c may be selected from intermediate power supply voltages or slightly lower voltages, or the power supply voltage may be set 10% higher than the standard voltage for RLlc.

When Ql is turned on, current flows through relay coil RL1c, so RL, , and RL,b switch to make contacts, and the DC voltage flows from the break contact of relay RL2b to R.
Power supply voltage is supplied to the preamplifier f2 through the FC circuit 13 to operate the preamplifier. At the same time, the output side of the Noriamp is connected to the 52 circuit through the capacitor Cc, and the input side is connected to the antenna through the break contact/RI of RL2a and the make contact of 1a to J.
acts as a receiver preamplifier.

Furthermore, on the main body side, the feeder center conductor is connected to a high DC power supply voltage (
For example, when 12V) is applied, the potential of the circuit 12 rises and exceeds the zener voltage of the voltage regulator diode 2 that connects the pace of Ql and the pace of another NPN transistor Q2.
conducts, supplies a pace current to Q2 and turns on Q2, and the current flowing through RL2c of the collector circuit turns on relay RL2.
leading to turning on. Resistor R2 has the role of shunting current exceeding the pace of Q2, but the specified voltage of Z and vBB of Q2
However, depending on the pace current characteristics, it is not necessary to include an appropriate pace current limiting resistor in series with the pace 2, Q, and Q2). It is omitted.

When RI2 is turned on, RL2a and RI2. switches from break contact to make contact.

Therefore, the preamplifier is disconnected from the circuit, the booster 3 is connected to the circuit, and vBB is applied to the booster 3 through the RFC circuit 14. Since the current of vcc becomes large, it is better to supply it from the circuit 12 without passing it through a relay. The output side of the booster is RI2. Connected to the antenna through the make contact Jl of RLla, the device 10 operates as a booster of the transmitter.

Table 1 summarizes the above operating conditions.

×...Off (non-operating) O...On (operating) As described above, according to the present invention, the feeder line connects the preamplifier and booster installed near the antenna to the main body of the transmitter/receiver and the antenna. By combining the power supply voltage and switching control (DC voltage that also serves as No. 3), it is possible to operate in three ways: direct connection, reception preamplifier, and transmission booster, without requiring any additional external construction. Efficient and economical.

In terms of operation, the basic circuit is simple because no voltage is applied during direct connection, and when using a receiving preamplifier that operates at a relatively low voltage, it operates at an intermediate voltage (for example, 6V), and a relatively high voltage is desirable. Since the transmission booster is configured to apply a high voltage (for example, 12V), it is convenient in terms of operation.

Relay RL1 must operate with two types of voltage, intermediate voltage and high voltage, so there are problems with reliable operation and overheating of the coil, so voltage and current limiting devices must be considered. In the invention, a coil is inserted into the emitter circuit of the control transistor Q, and the pace voltage is stabilized by the constant voltage diode ZK.
Ql has a constant current characteristic above a predetermined voltage, and the operating current of RLlc is maintained at a constant value, so there is no fear of overheating.

As described above, the present invention is not only simple in its structure, but also extremely rational in its operation.

[Brief explanation of the drawing]

The figure shows an example of the configuration of a remote switching circuit according to the present invention. 1...Antenna, 2...Norian amplifier, 3...Booster, RL..."J%Q...NPN) transistor, 2...Zena diode. Patent applicant: Yaesu Musen Co., Ltd.-11 1 = 1 Procedural amendment June 13, 1980 Director of the Patent Office Kazuo Wakasugi 1. Indication of the case 1988 Patent Application No. 230437 2. Name of the invention Structure of remote switching circuit 3. Person making the amendment Relationship to the case Patent applicant 4, the date of the amendment order, May 9, 1980, the name of the invention stated on page 11, line 3 of the amended statement of contents as follows: 9
correct. Kirikani Cairo Kouzou “Structure of remote switching circuit”

Claims (1)

[Claims of Claims] In a system in which a preamplifier is placed between a radio transmitter/receiver and an antenna during reception and a booster is operated during transmission, the method includes: 1. A circuit that directly connects the radio transmitter/receiver and the antenna, the preamplifier, and the booster. So people switch between the circuits and
2. One or more second relays that switch between the Noriamp circuit and the booster circuit; 3. The drive coil of the first relay is used as an emitter load, and the collector is connected to the control power supply circuit. 4. A first transistor connected to the pace of the first transistor through a constant voltage diode, and connected to the pace of the first transistor through a resistor, and the second transistor connected between the collector and the control power circuit. A configuration of a remote switching circuit consisting of a second transistor connected to a drive coil of a relay, and a second transistor connected to a drive coil of a relay.