Topband: QRO un-un

[Roy Koeppe]

Was asked,

"...I am interested in the case of matching a 160 meter
inv-L with good ground (1.5:1 unun), for 1.5 KW with
a safety margin: perhaps a 2+ KW continuous rating.
This is a single-band application: only 160 meters. (etc.)"


All of this can be avoided by using the simple inductive Z-match shunt
coil across the feedpoint. A small coil on the order of 5 turns of
number 14 or 12 gauge about 2 inches in diameter is where to start.
Juggle between over all system resonance and 1 to 1 SWR (adjusting
number of turns) at your freq of choice. If you insist with an un-un,
use two of the common 2 3/8 inch by 1/2 inch ferrites stacked which are
supplied with most balun kits from such as Amidon.

GL & 73,    Roy    K6XK