[GreenKeys] RS232 to current loop dongle

[Jeffrey D Angus]

On 12/9/2014 8:03 AM, digitalham at gmail.com wrote:
> I'm not afraid to burn my fingers on a soldering iron, but rely on you
> smart people for the designs.
I don't claim to be the sharpest knife in the drawer.... But, I did put
together an RS-232 to loop converter at the shop.
I used an off the shelf RS-232 to TTL converter from eBay, followed
by a pair of opto isolators and some MOS-FETS to key the loop with
a bridge to sense loop current.

Worked quite well with the HAL DS-RTTY program and the Lorenz
Lo15c (Teletype Model 15 clone.)
Also with the HAL ST-8000a being fed with the tones from ITTY.


-- 
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com