Topband: Pennant XFMR help

k6se@juno.com k6se@juno.com
Sat, 28 Sep 2002 20:52:44 -0700


Hi, Luis,

Others have commented that the transformer on the FT140-43 core results
in anywhere from 3:1 SWR to 5:1 SWR.  W7LR solved the problem with his by
adding a capacitor in series with the 50-ohm winding to cancel the
inductive reactance on 160 meters.  Of course, that makes it a
single-band transformer.

Your results with the FT114-77 core are much closer, and I would
recommend that core for you.  The 77 type material has greater
permeability than type 43, and you might try using 17 turns on the
antenna side and 4 turns on the coax side when using the FT114-77 toroid.
 This might give even better SWR results.

Let me know if you try it and what the results are.

Hope to CU on 160m this winter.

73, de Earl, K6SE