Parts for interface

[DaveNF2G]

Not a trunking interface this time.

I found a schematic for a computer-to-radio programming interface for the Realistic HTX-420 ham transceiver at www.mods.dk. It's based on a pair of switching transistors with internal 4.7k bias resistors. Radio Shack doesn't seem to stock anything that fancy.

Does anyone know a source for any of the following transistors (probably all equivalent):

KEC KRC410
KEC KRC110
ROHM PTC143TU
NEC FA1L32

Also, has anyone written any software to program this radio? I was thinking I'd use Hyperterm unless there's something better.

Thanks for any help.

 

[pro92b]

For the Rohm device the correct part number is DTC143Tx, not PTC143Tx. It is just a general purpose transistor (2SC2412K) and a 4.7K Ohm resistor in one package. You can build the same thing with discrete parts. Buy two 4.7K Ohm resistors and two MPS3904 (276-2016) or two PN2222A (276-2009) transistors at Radio Shack and connect them as shown in the schematic at mods.dk.

-pro92b

 

[DaveNF2G]

For the Rohm device the correct part number is DTC143Tx, not PTC143Tx. It is just a general purpose transistor (2SC2412K) and a 4.7K Ohm resistor in one package. You can build the same thing with discrete parts. Buy two 4.7K Ohm resistors and two MPS3904 (276-2016) or two PN2222A (276-2009) transistors at Radio Shack and connect them as shown in the schematic at mods.dk.

-pro92b

Thanks. I was wondering about the discrete part idea, but I'm not familiar enough with the individual transistors to know whether they have similar characteristics. At least now I can get everything I need at Radio Shack. They are the only place around where one can buy individual small parts.