[TenTec] Tech Question

[d.e.warnick at comcast.net]

Thanks, Lee. This morning I drew the circuit and it all made sense. I just had to see it and have a sanity check. For some reason, when it was not drawn, I had a problem with separate grounds coming from 2 different COM ports. DUH! they're isolated. That's the whole point of the thing 

My PTT lead is fed with a foot switch, the opto-isolator for PTT from my COM 7 & the opto-isolator for CW from my COM 6. The split COM ports caused my hangup. N1MM with MMTTY says that both CW & FSK/PTT can be the same serial port as long as it is not the radio control port. Not so on my setup. Took a long time for me to split them apart and everything worked. I'm an old computer and data-comm guy, but this  had me fooled for quite some time. 

Now I can put it all together in a black TenTec box 

Thanks again 

73 

Dave 

WA3F 



----- Original Message -----


From: "Lee WA3FIY" <wa3fiy at radioadv.com> 
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com> 
Sent: Wednesday, December 12, 2012 4:20:57 PM 
Subject: Re: [TenTec] Tech Question 

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 
> 


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