JP2704505B2 - Receiver passband selection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention has a plurality of intermediate frequency stages, of which two or more intermediate frequency stages are provided with a plurality of filters.
It relates to a communication receiver for amateur radio or business use.

[0002]

2. Description of the Related Art FIG. 1 is a block diagram showing a general configuration (regardless of the present invention) of a receiver having three intermediate frequency stages. A conventional technique will be described with reference to FIG.

In FIG. 1, 1 is an antenna, 2 is RF
Section, 3 is the 1st mixing section, 4 is the 1st local oscillation section, 5 is 1
st intermediate frequency amplifying section, 6 is 2nd mixing section, 7 is 2nd
Local oscillation section, 8 is a 2nd filter selection section, 9 is a 2nd intermediate frequency amplification section, 10 is a 3rd mixing section, 11 is a 3rd local oscillation section, 12 is a 3rd filter selection section, and 13 is 3rd
An intermediate frequency amplifier, 14 is a demodulator, 15 is a BFO oscillator, 16 is an AF amplifier, 17 is a speaker, 18 is a display, 19 is a controller, and 20 is an operation unit. In addition, 6-9
Are referred to as 2nd intermediate frequency stages, and 10 to 13 are referred to as 3rd intermediate frequency stages.

For example, the first intermediate frequency is 70.455
M Hz, 2nd intermediate frequency is 8.215 MHz, 3rd
When the intermediate frequency is 455 KHz, there is a method in which a filter is provided at a lower frequency stage, that is, at the 2nd and 3rd intermediate frequency stages in terms of performance and cost. In FIG. 1, 2nd
The filter selection unit 8 and the 3rd filter selection unit 12 are provided. The reason for such a configuration is to increase the number of stages of the filter and to improve the attenuation characteristics outside the pass band.

[0005] For example, two types of filters having a pass bandwidth of 250 Hz and 500 Hz are often used in an A1A radio communication type receiver. In the J3E radio wave format, filters having three kinds of pass bandwidths of about 2.0 KHz, 2.4 KHz, and 6.0 KHz are selected and used according to the interference situation of the used frequency. If there is interference, 2.
Select 0KHz or 2.4KHz to prioritize the elimination of interference, and if there is no interference, increase the pass bandwidth to 6.0KHz
To increase the clarity and fidelity of the voice. That is, in the case of a dual-use wireless communication device of A1A and J3E radio formats, each intermediate frequency stage often has about five types of filters.

As described above, in a receiver using a plurality of intermediate frequency stages, if a plurality of filters are provided for each intermediate frequency stage and the pass bandwidth can be set independently, the number of filter combinations that can be selected is large. .

However, conventionally, when the pass bandwidth is selected, the pass bandwidth is set by circulating a filter selection switch provided for each intermediate frequency stage or directly by a filter selection switch provided for each filter. .

[0008]

First, the problem of the selection method based on the circulating operation of the filter selection switch provided for each intermediate frequency stage will be described. FIG. 2 is a layout diagram showing a filter selection display portion of a conventional display portion and a filter selection switch portion of an operation portion.

As shown in FIG. 2, when the filter selection switch K1 is provided for each of the second and third intermediate frequency stages, the number of switches is small. However, 6K, 2.4K, 2K, 5
Since the circulating operation changes one by one from the initial state, such as 00, 250, 6K,..., The number of times of pressing to set a desired pass bandwidth increases, and the operability deteriorates. Normally, it is sufficient to use the same bandwidth for each intermediate frequency stage. However, conventionally, as described above, the number of times the switch is pressed is large and the operability is poor.

Next, the problem of the direct selection method using the filter selection switch provided for each filter will be described. When a filter selection switch is provided for each filter of each intermediate frequency stage, the number of switches increases and the cost increases. For example, assuming that a switch is provided for each filter in FIG. 2, 250 to THR at the second intermediate frequency stage
A total of ten switches of 250 to 6 KHz are required in the U and 3rd intermediate frequency stages. At this time, 2nd · 3r
It is necessary to operate the switch at least twice when selecting the filter of d. Note that THRU in FIG. 2 means no filter (pass) at the second intermediate frequency stage.

Further, even when there are a plurality of intermediate frequency stages, if a filter is provided only in a single intermediate frequency stage, the selection of the pass bandwidth and the selection of the filter mean the same operation. Therefore, this is the first situation that has occurred in a communication receiver in which a plurality of filters are provided in a plurality of intermediate frequency stages.

From the above, it is an object of the present invention to speed up and simplify the setting of the pass bandwidth when there are many combinations of filter selections in a receiver having a plurality of intermediate frequency stages. Is about to do.

[0013]

SUMMARY OF THE INVENTION In a receiver having a plurality of intermediate frequency stages, of which two or more intermediate frequency stages are provided with a plurality of filters, a filter selection means and a filter selection display means for each filter are provided. It is composed of a pass bandwidth selection means for each bandwidth and an intermediate frequency stage selection means for each intermediate frequency stage.

[0014]

When the pass bandwidth is first selected by the pass bandwidth selection switch for each pass bandwidth, the pass bandwidth of each intermediate frequency stage is set to the same pass bandwidth in conjunction. Therefore, in the normal use state, quick operation can be performed by one switch operation.

To select a different pass bandwidth for each intermediate frequency stage, select an intermediate frequency stage to be changed by the intermediate frequency stage selection switch, and then press the pass bandwidth selection switch to select the intermediate frequency stage. Can only be changed.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A block diagram of the configuration of the present invention is the same as that of FIG. The differences in the configuration will be described with reference to the connection diagram of the control unit and the 2nd filter selection unit, 3rd filter selection unit, and the like of the present invention in FIG. In the connection diagram of FIG.
The switch group of K2 is a pass band selection switch (hereinafter abbreviated as a bandwidth switch), and the switch group of K3 is an intermediate frequency stage selection switch (hereinafter abbreviated as an IF switch). Hereinafter, K2 and K3 are collectively referred to as selection switches. Note that, in FIGS. 3 and 4 and this description, the number of selectable filters for each of the second and third intermediate frequency stages is five as a standard example.

The 2nd filter selectors 8 and 3rd in FIG.
In the filter selection unit 12, a set of switches is provided on each of the input side and the output side of each filter, and ON / OFF of the switches is all controlled by the control unit 19. When the operator presses the pass bandwidth setting switch K2 to select the pass bandwidth, the control unit 19 switches the corresponding pass bandwidth filters of the 2nd filter selection unit 8 and 3rd filter selection unit 12 to the switch-on state in conjunction with each other. .

In order to set an individual pass bandwidth at each intermediate frequency stage, the operator first selects and presses the IF switch K3, and then presses the bandwidth switch K2.
Only the filter corresponding to the pass bandwidth of the selected intermediate frequency stage is switched on, and different settings can be selected at each intermediate frequency stage. Note that, in the present invention, software other than the above difference in the number of switches, connection, and the like is configured.

The switch operation on the panel of the present invention will be described with reference to the layout diagram of FIG. 3 showing the filter selection display portion of the display portion and the selection switch portion of the operation portion. Normally, a pass bandwidth is selected from the bandwidth switch K2 in FIG. In this case, the other stages are set to the same pass bandwidth in conjunction with each other, so that quick setting is possible.

When different settings are made in the second and third intermediate frequency stages, (1) first, the bandwidth switch K2
Use to select the passband. (2) Next, a switch of the intermediate frequency stage to be changed by the IF switch K3 is selected. (3) Then, by selecting the bandwidth switch K2,
Only the intermediate frequency stage selected in (2) can be changed.

The operation of the present invention will be described with reference to the flowchart of FIG. First, in P1, the 2nd intermediate frequency stage is initialized to THRU and the 3rd intermediate frequency stage is initialized to 6 KHz with respect to the pass bandwidth. At P2, the control unit 19 determines whether or not the IF switch K3 has been pressed, and if pressed, jumps to the subroutine (described in FIG. 6) at P3. If the switch is not pressed, the control unit 19 determines which of the five switches a to e of the bandwidth switch K2 has been pressed after P4.

When a is pressed at P4, that is, 250 Hz is selected as the pass bandwidth,
4 is Y, that is, the process proceeds to P5, and the 2nd / 3rd intermediate frequency stage is set to a pass band width of 250 Hz in conjunction with it. afterwards,
Merge into the loop returning to P2. In the case of N in P4, the process proceeds to P6, P8, P10, and P12, and the pass bandwidth corresponding to each of the switches b to e is set in the same manner as in P4. Once the switches a to e are pressed, P2, P4, P6, P8, P10, P12,
It enters a loop of P2 and enters a standby state.

The operation of the subroutine will be described with reference to FIG. When g of the IF switch K3 is pressed, that is, when the second intermediate frequency stage is selected, R is determined by which of the switches in the bandwidth switch K2 is pressed next.
1, determined at R3, R5, R7, R9, 2nd
Only the pass bandwidths of the intermediate frequency stages are represented by R2, R4, R
6, R8 and r10 can be changed as shown in each box. This series of operations means individually selecting a filter from a plurality of filters of the second intermediate frequency stage.

When f of the IF switch K3 is pressed, that is, when the 3rd intermediate frequency stage is selected, R
In the decision box of 1, R3, R5, R7, R9, N
Is selected and passed, and in the same manner as described above after R11, only the pass bandwidth of the 3rd intermediate frequency stage is set to be arbitrarily selected. Then, the subroutine ends, the process returns to P4 in FIG. 5, and a loop in a standby state is formed.

After all, the conventional method is to select an individual filter for each stage. However, the present invention
This is a new method in which the pass bandwidth is selected, and in addition, individual filters can be selected as needed.

[0026]

A receiver having a plurality of intermediate frequency stages,
A plurality of filters provided for each of the 2nd and 3rd intermediate frequency stages are set in an interlocked manner during normal use, so that only one switch operation is required. Further, when it is necessary to set a delicate selectivity due to interference or the like, the filter settings of each intermediate frequency stage can be independently selected. That is, the selection of the passband is quick and simplified, and the operability is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a general configuration of a receiver having a plurality of intermediate frequency stages.

FIG. 2 is a layout diagram showing a filter selection display part of a conventional display part and a filter selection switch part of an operation part.

FIG. 3 is a layout diagram showing a filter selection display part of a display unit and a selection switch part of an operation unit according to the present invention.

FIG. 4 is a connection diagram of a 2nd filter selection unit, a 3rd filter selection unit, and the like of the present invention and a control unit.

FIG. 5 is a flowchart showing the operation of the passband selection method of the present invention.

FIG. 6 is a flowchart showing the contents of a subroutine of FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 antenna 2 RF section 3 1st mixing section 4 1st local oscillation section 5 1st intermediate frequency amplification section 6 2nd mixing section 7 2nd local oscillation section 8 2nd filter selection section 9 2nd intermediate frequency amplification section 10 3rd mixing section 11 3rd local oscillation section 12 3rd filter selection unit 13 3rd intermediate frequency amplification unit 14 demodulation unit 15 BFO oscillation unit 16 AF amplification unit 17 speaker 18 display unit 19 control unit 20 operation unit

Claims (1)

(57) [Claims] 1. An apparatus comprising a plurality of intermediate frequency stages, of which two
In the above receiver having a plurality of filters in the intermediate frequency stage, an intermediate frequency stage having a plurality of filters to be selectively set is selected.
Select intermediate frequency stage selection means and pass bandwidth
Pass bandwidth selecting means, the intermediate frequency stage selecting means and passing
A filter whose filter is selected by setting with the bandwidth selection means.
Display filter selection means and filter selection setting status
And a filter selection display means .