[TenTec] Tech Question

[Lee WA3FIY]

Dave,

The simple answer is Yes.

The opto isolators appear to be open collector.  If that is so, you can treat them like switches 
and can parallel them as desired.  I feed my PTT line with a PTT switch, Opto from 
soundcard interface, Vibroplex bug and straight key for example.  No diodes needed. In fact 
adding diodes adds voltage drop on the PTT line which is not a desirable thing.

-Lee-

WA3FIY

On 12 Dec 2012 at 15:35, d.e.warnick at comcast.net wrote:

> 
> 
> I am keying my CW from an RS-232 port, and my PTT line when using RTTY
> FSK from an RS-232 port 
> 
> The rig is an Orion II 
> 
> My interface from the RS-232 to the Orion II is an Opto-Isolator (I
> use the W3YY interface as it is a nice board available as a kit) 
> 
> 
> 
> Now my question: 
> 
> In both cases above, I key the PTT line via the accesory cable
> supplied with the Orion II 
> 
> Can I just parallel theOpto-Isolator outputs, or do I nied diode
> isolation, that is a diode between the Opto-Iasolator and the PTT port
> (I'll have to check the keyed voltage polarity to determine which way
> to turn the diode? Or as a less convenient option, should I switch
> between the two keying interface chips? If I use diodes, I'll also
> route my foot switch through the interface box and put a diode in
> series with that. 
> 
> 
> Sorry for my complete ignorance of the Opto-Isolators. Please educate
> me 
> 
> 
> 
> 73 & thanks 
> 
> Dave 
> 
> WA3F 
> 
> 
> 
> ps - The FSK signal is via the TxD lead from the RS-232 port also via
> one of the chips in the kit. It is not an issue as it is not connected
> to either of the PTT keying lines
> _______________________________________________ TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>