[TenTec] Re: Titan 425 keying info

Fri, 10 May 2002 16:48:11 -0400

Actually, I think what you asked for *is* right here.

Per the Titan 425 schematic, the keyer has to sink less than 3 ma
(28vdc through a 10k resistor).  I wouldn't think a 'keying
interface' is required, after all a Titan isn't a SB-220 with
120vdc on the key line.

open circuit: 28 vdc, current into short circuit:: 3 ma.
28 vdc is Not necessarily too high for icom gear.  Generally, keyers 
have open collector
outputs that can handle the medium volts with no issue.  If you icom 
gear specifies no more than 12 vdc,
then I think you would require keying a transistor that can handle the 
28 vdc.

On Friday, May 10, 2002, at 12:03  PM, [email protected] 
wrote:

> Message: 4
> Date: Thu, 09 May 2002 18:38:15 -0500
> To: [email protected]
> From: Matt Erickson <[email protected]>
> Subject: [TenTec] Re: Titan 425
>
> Well.  I was told everything, BUT what I wanted to know in the first 
> place.
> So, I'll ask it again, perhaps someone will simply use his VOM to read 
> the
> voltage and current on the keying line of the amp?
> How and why it keys are NOT what I want to know.  28VDC is TOO high for
> ICOM gear, but the current is low enough.
> Try is again guys.
> Voltage & currents in the keying line of the Titan 425, please? You 
> don't
> have to tell me how to hook it up, only answer the question.
>
> I don't have the amp or the manual yet, but I'd like to get the data 
> before
> it arrives.
>
"The object of war is not to die for your country but to make the  other 
bastard die for his." (General George Patton, 1885-1945,  American 
general).