From cbfsb!att!linac!uwm.edu!cs.utexas.edu!swrinde!gatech!ukma!aunro!ve6mgs!mark Sat Nov  9 16:10:40 EST 1991 
Article: 10188 of rec.radio.amateur.misc 
Path: cbfsb!att!linac!uwm.edu!cs.utexas.edu!swrinde!gatech!ukma!aunro!ve6mgs!mark 
From: mark@ve6mgs.uucp (Mark G. Salyzyn VE6MGS) 
Newsgroups: rec.radio.amateur.misc 
Subject: IC-751 Switch Matrix 
Message-ID: <1991Nov8.064843.1771@ve6mgs.uucp> 
Date: 8 Nov 91 06:48:43 GMT 
Organization: Amateur Packet Radio E-mail Gateway  VE6MGS 
Lines: 44 
 
This following chart was generated by shorting out the matrix points and 
watching the function that is performed. Some are intuitive already from the 
schematic. There are only a couple of `extra' functions in the matrix (ie, USB 
and LSB, Reset 100&10 Hz [The TS switch does this as well]). The KEY? GENE 
switches (Y0) are accessed by the RC-10 controller, but I noticed that some 
`removed' circuitry in the rig was designed to switch the digit switches 
on the RC-10 controller to the KEY? HAM array (Y3), effectively making the 
switches directly access each band. However, the removed circuitry (a set of 
switching transistors) is replaced by a solid jumper to Y0 :-(. The `empty' 
slots in the following table showed no perceivable function. 
 
The Y5 matrix, acted like it was shorting some other behavior out causing 
the rig to switch to the specific memory channels (you can observe a 
binary + 1 selecting behavior) temporarily. 
 
Have fun, Ciao, 73 de VE6MGS/Mark -sk- 
 
  IC-751A Switch Matrix (W/ Function) 
      DB0     DB1     DB2     DB3     DB4     DB5     DB6     DB7 
   _________________________________________________________________ 
   | KEY0  | KEY1  | KEY2  | KEY3  |       |       |       |       | 
Y0 | GENE  | GENE  | GENE  | GENE  | SCAN  |       |       |       | 
   |_______|_______|_______|_______|_______|_______|_______|_______| 
   | MHZ/  | MHZ/  |       |       |  VFO  | VFO/  | HAM/  |Disable| 
Y1 | BAND  | BAND  |       |       |  A/B  |Memory | GENE  |RIT/XIT| 
   |__Up___|_Down__|_______|_______|_______|_______|_______|_______| 
   |       |       |       | Clear |  A=B  |       |       |       | 
Y2 | FUNC  |       |       |RIT/XIT| (B=A) |       |MWrite |M->VFO | 
   |_______|_______|_______|(->VFO)|_______|_______|_______|_______| 
   |  KEY0 |  KEY1 |  KEY2 |  KEY3 |       |       |       |       | 
Y3 |  HAM  |  HAM  |  HAM  |  HAM  |       |       |       |       | 
   |__BAND_|__BAND_|__BAND_|__BAND_|_______|_______|_______|_______| 
   |       |       |   AM  |  CW   | RTTY  |  SSB  |       |       | 
Y4 |  LSB  |  USB  |  (FM) | (NAR) | (NAR) | (REV) |  FM   |  LSB  | 
   |_______|_______|_______|_______|_______|_______|_______|_______| 
   |  M2   |  M3   |  M5   |  M9   |  M17  |  M33  |  M65  |  M29  | <Danger 
Y5 | Prio. | Prio. | Prio. | Prio. | Prio. | Prio. | Prio. | Prio. | <Will 
   |or_M1__|_______|_______|_______|_______|_______|_______|_______| <Robinson 
   | MODE  | Reset | Change|       |       |       |Disable| Scan  | 
Y6 | Scan  |100&10 |Memory |       |       |       |RIT/XIT| OFF   | 
   |_______|__HZ___|On_Dial|_______|_______|_______|offset_|_______| 
   |  I/O  |  I/O  |  HOLD |Altern-|Band W/|       |       |       | 
Y7 |Option | Option|  Scan |ate VFO|DB6&DB7|       |       |       | 
   |___RP__|___WP__|10_Sec.|_______|or_TS__|_______|_______|_______| 
 
 
 
 
