WA5LNL

Page 3,  MFJ-1270 MODS.

 

RESET  CIRCUIT

If  power drop outs confuse or locks up your tnc ,try replacing  the reset capacitors.

Replace  C-58 [ 1 uF ]  tantalum

Replace  C-22 [ 10 uF ]  tantalum

 

SET TNC DIP SWITCH

 # 5  on     to computer com port  9600b

 # 7  on     radio baud rate 1200b

 

1270 JUMPER SETTINGS

JMP 1    OFF            JMP 11 , RIGHT

JMP 2  , 1 TO 2        JMP 13 , ON

JMP 4  , OFF            JMP 15 , 1 TO 2         

JMP 5  , OFF            JMP 18 , 1 TO 2

JMP 7  , OFF            JMP 26 , 1 TO 2

JMP  8 , ON              J4,  1-2,  11-12 , 13-14 , 17-18

JMP 9 , 2 TO 3         JMP 12 , 1 TO 2

JMP 10,  OFF

 

Interesting

I have done these mods to over 12  MFJ –1270s (no  B or Cs) and it seems I never see the same circuit board. I guess there was alot of on going  changes.

 

UIDIGI

To run  U-23 with  UIDIGI or tnc V1.19 you must have  32 k of ram U-25 (43256) and  JMP-12, 1-2 .

Do not  use the battery  back-up on the tnc.

Uidigi PROM chip (27c256) always goes in socket U-23.

Check to make sure U-21, pin 22 ( z80/sio) goes to ground.

To  talk to a UIDIGI via computer  com port  , type ‘esc key’, ‘c’, ‘return key’.

 

SOME COMMANDS:

Clock                             duplist

Connect                          btext

Info                                restart

Mheard                           retry

Reset                               led

Test                                 uinly

Quit

Sysop / pairs up with your password / netrom password request

Do not forget to program in ‘The New-N Paradigm’ to unclutter  neadless  digipeating!

 

19,200 BAUD TO YOUR COMPUTER

Cut the trace at pin 1 (300b SW) and run a wire from pin 1 (SW2)  to U1(4040), pin 10. Set the baud switch  #1 to on. 300 baud now becomes  19,200 baud!

 

 

Revised: 12/05/04 08:30 PM by N5VRP, Dennis Rogers, Webmaster
Copyright 2006 by Intertie, Inc. All Rights Reserved
No use of these symbols or phrases is allowed without the express written permission of Intertie, Inc.