[GreenKeys] tapping ST-6 for RS232

[k0bx at arrl.net]

I am the first to admit that I am more of an operator than a technical person.  But maybe WA5CAB is referring to more commercial equipment instead of the popular ST-6 series that was used in Ham Radio.

Here is a link to RTTY.Com and shows a clear diagram on how the FSK was generated from the current loop.  This is from a ST-5.  The Hal ST-6 uses the same circuit.  In the ST-5 circuit it show that the FSK output would go to the transmitter or AFSK keyer.

Back then, most commercial made ham transceiver did not have the ability to operate FSK.  So we used AFSK on both HF (LSB) or VHF.

http://www.rtty.com/development/tu/st-5/st-5_basic.htm

Joe K0BX
on HF rtty since 1974.


Stop the insanity!
Please do not add me to any distribution lists (Joke, Stories or Junk) without my permission.


--- On Mon, 1/26/09, WA5CAB at cs.com <WA5CAB at cs.com> wrote:

> From: WA5CAB at cs.com <WA5CAB at cs.com>
> Subject: Re: [GreenKeys] tapping ST-6 for RS232
> To: greenkeys at mailman.qth.net
> Date: Monday, January 26, 2009, 10:25 AM
> I'm not picking on Joe.  But simply using what he wrote
> as an example of 
> what's puzzling me.
> 
> I never used any of the civilian converters back in the day
> so I'm not 
> familiar with their transmit capability.  I assume that for
> AFSK (for VHF AM 
> transmitters or to drive an SSB or ISB HF transmitter) they
> would have a block 
> diagram similar in a generic sense to something like the
> AN/SGC-1.  But I don't 
> understand how you could get HF FSK output from one that
> was comparable in 
> stability to the VFO's or PTO's of the contemporary
> better quality civilian to 
> high-end military HF transmitters.  At least without having
> the cost of the unit go 
> into the stratosphere.  The converter would have to include
> a very good HF 
> oscillator or an IF one with mixer compatible with whatever
> transmitter it was to 
> be used with.
> 
>