[AMPS] Tuned Input, what me worry

[Steve Katz]

Ron, doesn't a 1dB pad only provide 1dB of impedance stabilization?

Think about it, and then have a beer.  I'll have one, too!

"Hang loose," as they say there...

WB2WIK/6

"Each success only buys an admission ticket to a more difficult problem." --
Henry Kissinger

> -----Original Message-----
> From:	KG6DV@cs.com [SMTP:KG6DV@cs.com]
> Sent:	Monday, October 08, 2001 3:50 PM
> To:	amps@contesting.com
> Subject:	[AMPS] Tuned Input, what me worry
> 
> There is a lot of discussion lately on how to design a proper tuned input
> .... that topic and beer have dominated lately.  16 ways to figure the Q
> of the input circuit, 17 ways to tell a really fine beer.  I can
> understand the value of passing on your knowledge of how to judge a really
> good beer, but a tuned input ....why bother. 
> 
> I built way too many tuned input circuits till I gave it up ... too much
> work.  I ended up borrowing an approach from the old timers (you here know
> who you are) remember swamping.  A variation on the old method works for
> me.  I use a T-PAD attenuator. 
> The great thing about a T-PAD attenuator is the fact that the load on the
> output side can swing a great deal while the input will stay put
> wonderfully. Does this sound like whats needed for an input circuit, it
> does to me.  These transmitting tubes display a fairly large swing in load
> at different drive levels, not what your exciter needs to see. 
> I design the T-PAD for 1db attenuation, nobody needs to loose a lot of
> drive power. 
> I size the resistors (non inductive of course) in each of the three legs
> to handle the dissipation and ..... wallah, you have an input circuit that
> will show your exciter a nice consistent 50 ohm load.  What could be
> simpler. Its worked for me for years. 
> 
> Now we will all hear whats wrong with this approach .... or maybe just
> some more great beer theory.   
> 
> Ron   KH6DV 
> Kaneohe Hawaii 
> 

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