Yes, I have the original coil specs, but only in frequency and the
schematics do show whether they are coil only or have an internal capacitor
present. The problem I'm facing is that I know the new frequency I want to
use, which is about half as high as the current frequency, but I don't know
how to figure out the correct number of new windings I'll need. The coils
are all Toko in shielded cans, so there are a lot of unknowns. Even knowing
the frequencies they are on now, I still haven't been able to measure it and
that is where I must start. I guess if I have to remove each one, break the
internal capactor, and then form a loop around the dip meter coil with a new
cap in parallel with the coil, I could, but I was hoping for a simpler way.

Jer


"Michael Black" wrote in message
mple.net...
On Wed, 5 Oct 2011, Jerrold Jones wrote:

I have a project where I am going to modify an internal receiver circuit
that uses Toko style coils for the various stages. I want to be able to
determine the resonant frequency of these coils. I'm told I can do this
with a dip meter, but I'm not sure how. The Toko coils are shielded. If
I just bring the dip meter coil near, I don't get a response. Am I going
to have to remove the Toko coils from the circuit, remove the metal
shield, and then move the dip meter close and adjust for the dip or is
there a simpler way?

So if it's a commercial receiver, the information may already be out
there, but nobody would know until you reveal the receiver, and the stage
you want to modify.

Michael VE2BVW