Hi,

Where is the tuner and where are you measuring the SWR?

Your range of antenna impedances is probably too great
for your particular arrangement. A ferrite cored balun is
not a magic device for matching oddball impedances to coax.
In this case it will be seeing about 50 ohms on 80m and a
1000 ohms or more on 40m.

Also they aren't a simple device but part transformer
and part transmission line and even their 1:1 ratio can be
in doubt unless presented with a certain range of
impedances. The much-used G5RV with balun suffers from this
problem but there at least Louis Varney did pick an antenna
and feeder length/impedance to try to keep the numbers
reasonable.


Cheers - Joe, G3LLV