Here's an easy one day (or less) project to use with the EZKIT Lite or any project using similar keying.

This provides sequenced keying when used with the UHFA.exe program running in "hardware 0" mode. Why ? well I want to use the DSP-10 with a 432 IF rig for 24192 Mhz, so this will allow sequenced keying of the IF rig and the transverter. The goal is more exploration of microwave propagation.

If your EZKIT is already mounted in the DSP-10 then check this link . ADD ext radio to DSP-10

Inspection of the accompanying schematic shows many of the components are tied to ground at one end. It is a simple matter to tie pins 18 -25 common and use that line as the mount for all the pieces. Each transistor is supported by a diode and resistor, and the emitter is left long enough to reach the common bus.. The external connection is made at the junction of the diode and collector and the shields of  the external cable tie to the ground bus. I used a Radio Shack "Y" cable and cut off the common end. It was handy, and had two colors on the other ends.

If anyone builds this for the KDSPX interface, I would be interested if it works... mailto kd7ts@aceweb.com,  it should since it is a computer operated unit.

Make sure UHFA.CFG has two lines :::

// hardware=1 normal DSP-10; hardware=0 audio processor
hardware 0

// lpt_port=0 for none, 888 for LPT1 (0x378),
// or 956 for LPT2 (0x3BC) (confirm your computer)
lpt_port 888  or possibly   lpt_port 956  and least likely,  lpt_port 632

Printer port address assignment is an interesting and confusing proposition.  There are three common addresses used, usually given as hex values. These are  3BC, 378 and 278. It should be possible to find the port address HEX value in your computer setup file. From this number convert to decimal to find the number to use with the UHFA.CFG entry. Or you can just try them all, and one should work.

HEX               DEC
3BC      =       956

378      =        888

278      =       632

4     4.7k 1/4 W resistors
2     1N4148 or 1N4001 Diodes or equiv
2     NPN Switching transistors 2N3904 or equiv RS part # 276-1617
1     25 POS Male D-SUB RS part # 276-1547b
1     backshell for D-SUB 25 male