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G8MNY  > TECH     06.10.08 01:00l 62 Lines 2607 Bytes #999 (0) @ WW
BID : 4607_GB7CIP
Read: GUEST
Subj: Yaesu DTMF Mic YM-48
Path: DB0FHN<DB0MRW<DK0WUE<F4BWT<SR1BSZ<ON4HU<DB0RES<DB0GOS<ON0AR<GB7CIP
Sent: 081005/2247Z @:GB7CIP.#32.GBR.EU #:4607 [Caterham] $:4607_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EU
To  : TECH@WW

By G8MNY                                    (Updated Aug 07)
(8 Bit ASCII Graphics use code page 437 or 850)
I use mine with FT790/690/290 for DTMF control of a repeaters.

This is the diagram of mine I reverse engineered it ...

 旼컴컴컴컴컴컴컴컴컴컴컴컴쩡컴컴컴컴컴쩡컴컴컴쩡컴컫컴컴컴컴>+5v rd
 �               4x 1n     �           �   47u===  ===220u    pin 4
 � Keyboard    旼컫컴쩡컫컴)컴컴컴컴컴�)컴컴컴컨컴컴�
 �  Matrix  rd =  =  =  =  �           �            � PTT bk
 � 1�2�3휕탠컴�)컴)컴)컴�  �           �          bn쳐o\o컴컴>pin 3
 �  � � � � bn �  �  �  �  �           �            �
 � 4�5�6휖탠컴�)컴)컴�  �  �           �            쿏OWN bk/bl
 �  � � � � or �  �  �  �  �           �            쳐o\o컴컴>pin 7
 � 7�8�9휗탠컴�)컴�  �  �  �  3.52     �            �
 �  � � � � ye �  �  �  �  �   MHz     �            �  UP ye/bn
 � *�0�#휚탠컴캑  �  �  �  � 渼[]첼    �            쳐o\o컴컴>pin 6
 � v쿲쿫퀇� 旼컨컴좔컨컴좔컨컨컴컴좆   �            �
 � i쿻쿸쿴쳐�9 14 13 12 11 1 7 osc8�  47          wh�
 �  � � 쳐)캑5  c  row DTMF IC     �   �            �
 �  � 쳐)�)캑4  o      8202   o/p  �   �   220u     �
 �  쳐)�)�)캑31 l 10    6    16    �   쳐컴캑쳐컴컴캑
 �  = = = = 읕컴컴쩡컴컴쩡컴컫컴컴켸 �/    +        �
 �  읕좔좔�      15k    �    쳐�2k2컴�              �
 � 4x 1n  �      _�_    �    �       �\e     DTMF   �
2k2       �      / \e   �    �         읕12컴횸S컴컴�
 �        �     �   읕컴�    �              rd   bk �
 �    u1  �     � mute  �    �                      � MIC wh
 쳐컫컴늘�)컴컴컨컴컴컴�)컴컴)컴100컴컴컴컫컴�100컴�)컴컴컴컴>pin 2
Mic = +   �             �    쳐컴늘�47k�>3k3 DTMF   �
 �  �1n   �             �   10k +1u       � LEVEL   � Screen
 읕컨컴컴컨컴컴컴컴컴컴컨컴컴좔컴컴컴컴컴컨컴컴컴컴컨컴컴컴컴>Pin 1

Here the UP & DOWN button are connected to earth, but can be +5V for some rigs.
So check your rig handbook to see which it needs.


DTMF SYSTEM
Uses two tones in a 4x4 keypad matrix, a low-frequency tone & 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

Frequency tolerance:         +- 1.5%

The 2 tones must not clip & mix on the Tx/RF path/Rx as the DTMF Rx IC uses the
presence of more than 2 tones the identify the signal non DTMF & ignores it.


Why Don't U send an interesting bul?

73 de John G8MNY @ GB7CIP


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