Esa Heikkinen wrote: > Bruce Griffiths wrote: > > >> Attached circuit schematic illustrates how you could filter the harmonic >> content of the 10544A below -50dBc. >> > > Ok that's something what I can't build from shelf parts anomore... What > kind of coils should be used here? The transformer may be tricky, I > think only way is to build it but first it's needed to find right kind > of core. > > Esa
The inductors need to have a self resonance frequency (SRF) above 10MHz. Try Farnell's EPCOS range (at least they specify the SRF). The transformer is easy to do. I used air core inductors but powdered iron toroids would suffice. Just place a couple of windings on one core and adjust spacing turns, etc until you get the required mutual inductance and then add an additional inductor to the primary and secondary to pad out to the required primary and secondary inductances. This is easier than trying to wind on one air cored former and adjusting the spacings to achieve critical coupling. For 10MHz a #6 or #7 powdered iron core is appropriate. Just choose cores with an appropriate A: with sufficient room for the required number of windings. I dont know how easy it is for you to get these. >From memory my 3 air cored formers were about 15mm diameter and about 10cmm long. Bruce _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
