Amps
[Top] [All Lists]

[AMPS] Amps in Sept QST

To: <amps@contesting.com>
Subject: [AMPS] Amps in Sept QST
From: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net)
Date: Wed, 27 Aug 1997 21:40:08 +0000
> >I wish the ARRL would go back to the same standard the rest of the 
> >world uses.
> 
> Wouldnt it take pressure from the manufacturers?

Nope, they do what they want to do. All that stuff about 
manufacturer's influence is sour grapes. 
 
> How many would want to
> give up their 6dB smoke screen? Be honest now. 

I always use the conventional method in spec sheets. The AL-800H is 
speced at 30 some dB if I recall correctly.  Think about it, using 
fluffy ratings helps no one at all.....everyone just moves right up 
together.

The only thing the below PEP rating does is prevent us from getting 
state of the art equipment because everyone thinks the -25  dB 
transceivers are in the -30's.

> >Are you sure? Why does a HF PA have a 4:1 transformer in the tank?
> >That seems non-conventional.
> 
> That is simply a copy from Command who claims it is the key to their
> superior IMD. They (Command) state that  they transform the Rp down to
> 200 Ohms the conventional way and then use the toroid to get to 50 Ohms
> on all bands. 

That's strange. As far as I knew inserting a toroid will NOT 
reduce IMD, it will do exactly the opposite with one exception.

It is possible to add non-linearity that will cancel other 
non-linearity.

But it isn't practical to cancel IMD when the device causing the 
non-linearity is coupled to random load impedances and the distortion 
source is also random. It only works in two tone tests and dummy 
loads using one certain exciter at one power.

I'm certain the reason can't be IMD related.

73, Tom W8JI

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm

<Prev in Thread] Current Thread [Next in Thread>