[AMPS] Re: Parasitics

[Tom Rauch]

> Date:          Sat, 16 May 1998 15:33:04 -0800
> From:          Rich Measures <measures@vc.net>
> Subject:       Re: [AMPS] Re: Parasitics
> To:            amps@contesting.com

> Jon Ogden wrote:
> >.......
> >A pi network Tank is a resonant LC circuit consisting of both parallel 
> >and series resonances.  

Rich replied:
 
> The next time you have your amplifier tuned up, shut down, pull the mains 
> plug, couple a dipmeter to the tank L  measure the resonant frequency and 
> check f with an electronic counter.  

There seem to be a few flaws in that method. The most evident is 
that GDO's "pull" quite a bit. If you do use a GDO and see a dip,  
it still tells you nothing about system impedances or circuit 
voltages. The GDO only indicates the frequency at which maximum GDO 
coupling occurs. Nothing more, nothing less.

Second, one should at least use a receiver WHILE the GDO is coupled 
to the correctly terminated tank. GDO's, by nature of the device, 
pull drastically when coupled to loads. 

Making measurements is always a good idea, if they are made 
correctly and with care.

73, Tom W8JI
w8ji.tom@MCIONE.com

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