weekend electronics project


This weekend I spent some time building a digital mode interface rig based on the designs of Clint Hurd, KK7UQ listed here and Ernie Mills, WM2U at DX Zone. I ordered my parts from Mouser.com earlier in the week and dusted off the soldering iron this morning. It is 4 separate circuits within the enclosure, audio out from the radio passes through to the laptop microphone/line in connector, audio out from the laptop passes through to the radio mic connector, RTS from the laptop serial port is sent to the PTT control on the radio, and last, DTR is used to toggle the keyer on the radio for Software CW. Optical Isolators are used from the laptop RS-232 for both RTS and DTR signals, and 1:1 audio transformers are used, along with 1K variable resistors for audio signals in either direction.

It's been a long time since I've done any electronics soldering, probably since Engineering classes at UT back in 1990. Being eager to start once again, I probably should have spent a bit more time laying out the components a bit better. The underside is a bit of a wiring mess, but that will be pretty well hidden. I tested several of the circuit paths this afternoon and everything looks good so far. I have to build the RJ-45 to mic connector yet, and the DB-9 to 3.5mm audio jack connector, but I need a few more parts to complete that. I also still need to alter the plastic project case to allow access to the 3.5mm audio jacks. The end schematic I used is here.