[TenTec] QSK or not?

Kim Elmore cw_de_n5op at sbcglobal.net
Thu Mar 20 18:44:21 EDT 2014

The Measures relay speed-up circuit will certainly make the relays close 
faster, but how does that affect the settling time? Won;t that still be 
an issue?

Kim N5OP

On 3/20/2014 10:51 AM, Rick - DJ0IP / NJ0IP wrote:
> It's not quite that simple, at least not always.
> "IF" your amplifier has a very fast T/R relay, such as a vacuum relay, then
> you are correct; a few simple switching transistors and a tiny relay will do
> the trick.  But that only works when the main T/R relay is fast enough to
> follow CW keying.
> If instead you have an amplifier whose T/R relay needs 20 mS to switch, AND
> you connect the hand-shaking just as the Ten-Tec keying loop normally works,
> the CW is not going to be very smooth.  Timing will get screwed up.  The
> open-frame relays are just too slow to do that.  The only way to make them
> work is to have hang delay such that they don't need to follow the keying.
> The Ten-Tec hand-shaking does not do this.
> And then if you have to work with hang delay, you don't need the complexity
> of the hand-shaking.  You just need sufficient pre-dit delay and adjustable
> hang delay - but you sacrifice true QSK.
> You never had it in the first place because you did not buy a QSK amplifier!
> No matter what you feed a mule or how you treat it, it will never be a race
> horse!
> (On the other hand, not everybody needs or wants a race horse and mules are
> wonderful animals!)
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
> -------------------------
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of
> bcarling at cfl.rr.com
> Subject: Re: [TenTec] QSK or not?
> I have to wonder why some guys will spend $500 for an external accessory to
> do QSK with their linear amplifier.  The system in my TT 422 is so simple. A
> couple of simple boards and a relay.
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec

More information about the TenTec mailing list