fig 1 Original I/F and VX-7
(connecting via the microphone adapter (CT-91))
VX-7 is domestic (Japanese) version of YAESU's VX-7R. I tested VX-7 for this experimentation, but the most of this description is probably apply to VX-7R.
I made the original interface(I/F) for connecting VX-7 and
PC(Personal Computer), because the software or the connecting
cable in order to edit the memory of the VX-7 are not sold in
Japan.
Using RS-232C / TTL Interface chip (MAX232), my I/F works certainly
with any portable PC.
| Part | Type and constant | RMKS |
| IC1 | MAX232 | RS-232-C - TTL level converter (Maxim Integrated Products) |
| IC2 | 74LS04 | Hex INVERTER (Texas Instruments) |
| IC3 | 7805 | +5V 1A Voltage-Regulater IC (Matsushita) |
| Q1 | 2SC2120 | Small-Signal NPN transistor (Toshiba) |
| Q2 | 2SC2120 | (the same as above) |
| LED11 - LED15 | (General-purpose LED) | LEDs for line monitor. (LED 14 and 15 are spare for future ) |
| R1 | 10K (1/4W) | - |
| R2 | 10K (1/4W) | - |
| R3 | 47K (1/4W) | - |
| R4 | 47K (1/4W) | - |
| R5 | 100K (1/4W) | - |
| R6 | 10K (1/4W) | - |
| R11 - R15 | 1K (1/4W) | - |
| C1 | 2.2uF(50V) | - |
| C2 | 2.2uF(50V) | - |
| C3 | 2.2uF(50V) | - |
| C4 | 2.2uF(50V) | - |
| C5 | 0.01uF | - |
| C6 | 47uF(25V) | - |
| C7 | 0.1uF(50V) | - |
| C8 | 0.1uF(50V) | - |
| C9 | 2.2uF(50V) | - |
19,200bps, 8bits, Stop-bit:1bit, Parity:none, XON/XOFF control:none
When continues transmitting at 19,200bps, VX-7 at receiving end lost some data. So, the suitable waiting time after transmitting each one-character is needed.
| Operation of transmitting end | Operation of receiving end | |
| 1)
Push Power key while pushing [MON] 2) Indicating "CLONE" on LCD. |
1)
Push Power key while pushing [MON] 2) Indicating "CLONE" on LCD. 3) [V/M] 4) Indicating "CLONE WAIT" on LCD. |
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| 3)
[BAND] 4) Indicating "CLONE TX" on LCD. 5) Transmitting 1st block of data (10byte). |
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| 5)
Indicating "CLONE RX" on LCD. 6) Transmitting ACK(06H). |
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| 6) Transmitting 2nd block of data (8byte). | ||
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| 7) Transmitting ACK(06H). | ||
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| 7) Transmitting 3rd block of data (16193byte). | ||
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| 8) When it finishes to receive the data, the same operation as the time of "power on"(graphic presentation of opening is shown), it returns to normal mode. | ||
| End | End | |
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I wrote the software for loading, saving or analyzing the cloning data of VX-7 by N88-BASIC. N88-BASIC is a kind of Microsoft BASIC(Beginner's All-purpose Symbolic Instruction Code) for NEC's PC-9801 series(very famous and popular Japanene PC in 1980's, but it is not IBM PC clone!).
If you want to download this program, See This page.(but in Japanene....)
Copyright by Heian Software Engineering (C)H.S.E.
2002 Allrights reserved.
A summary in English - Created : Nov 11 2002, Last updated : Nov
16 2002