TK-280 Audio Finagling

[EJLofgren]

Hello all,

I'm looking to buy a TK-280 soon, but had a technical question about it. I'd like to hook it up to my computer to be able to both record the audio output as well as send it audio input. I noticed that there is a connector with a serial port, but I don't know if it's possible to use that or not. Does anyone know?

If not (or even if it is), do you all have any recommendations for a radio (Kenwood or other) that lends itself easily to this sort of finagling?

Thanks!

 

[ramal121]

The accessory connector on the side of the radio has both receive output and mic input.

First the mic. You can send audio to the radio from your computer sound card via the mic input but it will be wayyyyy too much. The 280 wants only about 10 mV to drive the mic circuit but a sound card will put out 10 times that or more so you will have to pad this level down to keep from overdriving the input and causing major distortion and clipping.

Next the receive is speaker output and the setting of the volume control will affect what the level into your sound card is. This can go from nothing to way too much for the sound card depending on where the knob is set. Also there is a DC voltage on the speaker lines and the sound card may twist off on this at a minimum to blowing your audio amp in the radio at the worst. The best solution is to crack the portable open and pick off the receive audio at an option point which is around line level, is unaffected by the volume control and has no DC voltage on it.

What are you trying to haywire up anyway?

 

[EJLofgren]

Thanks for the reply, Ramal!

I'm doing some research on the security of analog scramblers and was looking at connecting them up to a computer either through a radio like the TK-280 or on their own. I know a fair bit about cryptography and security, but not too much about radios (gotta start somewhere).

 

[EJLofgren]

As a follow up, I talked to an electrical engineer buddy of mine and will just be connecting the boards directly to the computer. Thanks again for your help.