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Old 24th Nov 2020, 10:23 am   #40
Ian - G4JQT
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Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,323
Default Re: First project (mini mod)

Yes, L1 and L2 are the same. They are about 90 microhenries with the core approximately flat with the top, but they are adjustable by turning the core with a wedge-cut cocktail stick. The value applies to the main winding - the one with the three pins with the centre pin being the tapping. The other winding is for coupling and not used in the L1 position.

Don't know what you mean when you say yours are "90 uol" unless you mean that's what they are marked.

Here is the link to Spectrum Communication's page with all the data for their inductors. See the section "SPECTRUM 10mm RF/IF COILS"

SPECTRUM 10mm RF/IF COILS

The pinouts, 1, 2, 3 are the main winding. Pinout 3, 4 are the coupling winding. The table gives the resistance of each winding: 1-2 57R; 2-3 19R, 1-3 76R (57+19) and 4-6 5R. (There is no pin 5.)

Ian
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