The Unofficial VX-1R Modifications Page

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Schematic diagram for PC programming cable.
 

PC Programming Parts List

.  The abbreviation NC means no connection.  The DB9 connector can be
Radio Shack part # 276-1538 or equivalent.    A good place to start looking
for the 4 conductor plug is Tower Electronics: 1-800-662-3422.  The 2N2222 can
be substituted for any general purpose NPN transistor, while the 2N3906 can
also be substituted for any general purpose PNP transistor.  D1,3,4 are general purpose silicon
diodes.  D2 is any 5.1V zener diode.  All resistors are 1/4 or 1/8watt - 5% tolerence resistors.  This
PC programming cable can also be built with SMT (Surface Mount Technology) parts if desired.

The interface is a bidirectional level converter, changing TTL-level to RS232, and vice versa.  The supply
voltage comes from RTS, CTS and DTR, DSR and is stabilized with D2 to 5.1V with a zener diode.  Q1 works as a
simple switch, getting the data via R8 from the PC.  In the opposite way Q2 drives the push pull stage Q6 and Q4.
This cable works with the Yaesu FT-50, VX-1R, VX-5R.  The cable can also be adapted to work
with the FT-10 & FT-40 - which use a 3 conductor programming cable.

 A premade SMD PCB layout for this circuit can be found at:
http://www.qsl.net/eb4eqa/adms_pcb/adms_pcb.htm

**New**
Here is an alternative and simplified programming cable for the VX-1R and VX-5R

Suggestion:  If you can't get the above programming adapter working, try changing R5 (100K) to 47K
Thanks to Lars for pointing this out.

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