Hello group,
I run a RemoteRig setup to operate my TS-2000 station remotely but I also use
the station locally. Also, I've found that there are some computer control
applications that require use of the mic input - using the CAT PTT command
activates the mic audio input, not the back panel accessory jack audio input.
This means a lot of plugging and unplugging stuff, and it's easy to forget to
reconnect the RemoteRig when finishing a session in the shack.
I found myself with some spare time and knocked out a little design project I've
had rolling around in my head for a while which I'm calling a Microphone
Multi-source interface. It's a little interface that allows up to three
microphone sources to be connected at once to a transceiver.
Here's a brief description:
Three inputs:
- Local Mic. PTT on this takes priority and mutes audio from other inputs. Local
Mic audio unmuted if neither other PTT active, enabling local VOX operation.
- RemoteRig. Activating this PTT will mute idle local mic audio, preventing
pickup of shack noise.
- Aux (for use with computer or maybe a TM-D710 as Sky Command Transporter?)
Activating this PTT will also mute idle local mic audio.
Other design features:
- Individual trim-pot level controls on each input and the output for level
balancing, as well as test points for taking measurements.
- Four paralleled 3-conductor mini jacks for sharing Speaker Audio.
- Audio ground on pin 7 maintained separate from PTT ground on pin 8, with
optional jumper block to connect them through a small RF choke.
- Speaker audio common maintained separate, with optional jumper block to
connect it to audio common through a small RF choke.
- Power is drawn from the 8V present on the TS-2000 mic jack.
This project could easily be built on a breadboard, but I used ExpressPCB's free
software to design double-sided PCBs. I've uploaded image files of the three
schematic sheets and of the PC silkscreen to the files area of the RemoteRig
Yahoo! group.
http://groups.yahoo.com/group/remoterig/Although the mic connector pinouts are laid out with the Kenwood round 8-pin mic
connector used on the TS-2000 in mind, there's no reason why one could not adapt
it to other mic pinouts or makes of radio.
73
Brad KB9BPF
