Re: Inductors - RX Probs

Jim Strohm <jstrohm@...>
 

On Jun 29, 2004, at 8:13 AM, Mark Jones wrote:

Here's what I have:

L1,2,3 22 turns 24 SWG on T-50-6
T1, T3 13 turns triffiliar 28 SWG on FT37-43

Any thoughts?
That wire is large enough that it should not have fractured within its enamel coating. For L1 - 3, an ohmmeter will confirm continuity.

For T1 and T3 -- this is worth asking -- did you use multi-colored wire for the trifilar winding to ensure proper connections and phasing? And did you check continuity before and after you soldered? A trifilar winding of #28 is much likelier to break without showing visible damage than the #24.

The only other possible cause I can think of is that the toroids are mis-marked and are so far from providing the right inductances as to make the circuit fail. If you can trust your supplier, this should not be a problem -- to test, use the mfg. data sheet to calculate inductance, place a 1 nF cap across the inductor's leads, and hit it with a dip meter. If it's a good toroid, it'll test within 10% of predicted inductance.

Jim N6OTQ

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