Topband: Binocular Xfrmr

[kurt-erich.finger at arcor.de]

Hello Mike,

for my K9AY I used the version I found in Devoldere's "Low-band DXing" (a recommendation from W8Ji).
I glued 3 BN73-202 together,  and  used 3 turns primary and 1turn secondary ( 500Ohm:50Ohm)
For 500:75 it should be 2.5 turns:1 turn.

For the insulation I didn't used the trick with the straw, but heated a heat shrink tube that was a little to wide until it fit into the holes.

For me the transformer worked fine.

For a comparison of different transformer I also found Mark Conelly's (WA1ION) article "Broadband receiver antenna matching" (2003)  also very usefull. J. Briant's, B.Bowers, N Hall-Patch's "Impedance matching transformer for receiving antennas at mediaum ans lower shortwave frequencies" (2003) also contains a wealth of information.

Good luck

Kurt-Erich



Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren
ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT FÜR ALLE NEUEINSTEIGER
Jetzt bei Arcor: günstig und schnell mit DSL - das All-Inclusive-Paket
für clevere Doppel-Sparer, nur  34,95 €  inkl. DSL- und ISDN-Grundgebühr!
http://www.arcor.de/rd/emf-dsl-2