[ARC5] BC-455 IFT - measurements

[Kenneth G. Gordon]

On 30 Oct 2014 at 9:24, AKLDGUY . wrote:

> This is a confusing thread to follow because some are talking of a dual
> winding, others of a single winding. If there's a single winding with an
> inductance that seems too high to some, perhaps the following will 
> help.

Neil:

To help get things straight, the IFT has two "coils" in it, both wound on 
the same form. 

The top coil, which is the secondary, is a pie-wound type coil, about 
1/16" thick. It measures around 2+ mH (millihenries).

It appears to NOT be resonant at the IF frequency. There is no fixed 
capacitor anywhere near it.

The lower coil, which is the primary, and is in parallel with a nominally 
"180 pfd" capacitor, is a single-layer coil which covers the bottom 3/4 
of the coil form, and is spaced about 3/16" below the pie-wound coil.

That combo is resonant at about 2830 Khz. Its inductance is about 17 uH 
(microhenries).

Does that make it a bit clearer?

I can send you a photo and a schematic if you would like to see them.

Ken W7EKB