I must agree with all who recommend the Almost All Digital Electronics
L/C meter. It is one of my most-used pieces of test gear. It is about
the size of 2 packs of cigarettes, and battery powered, making it ideal
to carry around at flea markets to measure coils and caps. I have lost
count on the number of Pi and Pi-L networks that I have set up with this
little device. After L1, L2, C1, and C2 have been set to the W5FD formula,
I simply put a resistor from the plate cap to ground of a value that equals
the plate load impedance from the formula. I then insert the output of my
MFJ-259B into the amp RF output socket. I dial up the frequency of interest
on the 259-B and touch up C1 and C2 until the 259-B reads 50 ohms. Q can
then be checked using the handbook formula, and you are ready to apply
power. (don't forget to remove the resistor; it tends to stink when powered up!)
This entire exercise almost takes less time than it takes to tell about it.
I have had several dealings with Neil @ Almost-All Digital. All were extremely
enjoyable. Tech support and parts are as near as your phone. E-Mail for Neil
is neil@aade.com Tel. # is (253)351-9316.
(((73)))
Phil, K5PC
Subject: Re: [AMPS] Practical PI Nets
>
> Good enough ? It is excellent. It can even measure a difference of 1pF
> reliably. I think the 0.01pF resolution is a bit optimistic and the
> calibration is not perfect on my version, but it is good enough.
>
> > One not too expensive device is the Almost All Digital Electronics L-C
> > meter. It's cheap, pretty accurate, and comes as a kit that took me under
> an
> > hour to build. It is worth changing the 5 volt regulator to a low drop out
> > type, though, as you get a lot more effective battery life.
> >
> > Of course, it doesn't measure at the operating frequency, but for most
> > inductors at HF, it's good enough.
> >
> > 73
> >
> > Peter G3RZP
> >
> >
> >
> > --
> > FAQ on WWW: http://www.contesting.com/ampsfaq.html
> > Submissions: amps@contesting.com
> > Administrative requests: amps-REQUEST@contesting.com
> > Problems: owner-amps@contesting.com
> > Search: http://www.contesting.com/km9p/search.htm
> >
> >
>
>
> --
> FAQ on WWW: http://www.contesting.com/ampsfaq.html
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
> Search: http://www.contesting.com/km9p/search.htm
>
>
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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