[RTTY] Opto Couplers ?

[Jerry Flanders]

I use 4n33's here. Different ones have different "gain". Put a voltmeter on 
the rig side to make sure it is taking the keying voltage sufficiently low. 
Compare it to the voltage when the Kam keys it. I had a problem and it was 
because the opto couldn't take it low enough. A replacement opto fixed it.

Make sure your PTT is working.

HNY from snow-covered SC

Jerry W4UK

At 02:24 PM 1/3/2002 +0000, you wrote:
>Hi all and a Happy new year from sunny England. I have been building an FSK
>interface between serial port and 1000MP. All the designs i have seen use
>Opto Couplers but which ones ??. I have used a low current version from
>siemens SFH618-2 and seems to be working but no fsk out from the radio.
>Works ok with the FSK from a Kamplus and my meter suggests that the output
>from my interface is working but no joy. Any suggestions B4 saturday 16:00
>would be appreciated, all the very best de Robert G0URR K