Message 21074 in TECH.WW
From: G8MNY
Date: Sun, 19 Apr 26 08:05:00 Z
Newsgroups: TECH.WW
Subject: Yaesu DTMF Mic YM-48
Message-ID: <57565_GB7CIP>
Path: N2NOV|VE2PKT|PY2BIL|HB9ON|VK7AX|GB7CIP
R:260419/0810z @:N2NOV.#RICH.NY.USA.NOAM $:57565_GB7CIP
R:260419/0810Z 5810@VE2PKT.#TRV.QC.CAN.NOAM LinBPQ6.0.25
R:260419/0810Z 42036@PY2BIL.SP.BRA.SOAM LinBPQ6.0.25
R:260419/0809Z 11267@HB9ON.TI.CHE.EU LinBPQ6.0.24
R:260419/0809Z 10784@VK7AX.#ULV.TAS.AUS.AUNZ LinBPQ6.0.24
R:260419/0805Z @:GB7CIP.#32.GBR.EURO #:57565 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To : TECH@WW
By G8MNY (Revamp Nov 08)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
I use mine with FT790/690/290 for DTMF control of a repeaters etc.
This is the diagram of the mic, I reverse engineered it ...
Here the UP & DOWN button are connected to earth, but they can be to +5V for
some rigs! So check your rig handbook to see which it needs.
DTMF SYSTEM
This uses two pure sine wave tones controlled from a 4x4 keypad matrix, a low-
frequency tone and a high-frequency tone, to specify 1 of the 16 options.
Pressing 2 keys in the same row/column, normal results in a single tone.
TONE HIGH 1209Hz 1336Hz 1477Hz 1633Hz
LOW
697 Hz 1 2 3 A
770 Hz 4 5 6 B
852 Hz 7 8 9 C
941 Hz * 0 # D
The 2 tones must not clip or mix on the Tx/RF path/Rx as the DTMF Rx IC uses
the presence of more than 2 tones to identify the signal non DTMF & ignores it.
Why Don't U send an interesting bul?
73 de John G8MNY @ GB7CIP
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