[Icom] Antenna Balun/IC-756PRO

[Cletus W Whitaker]

de WB2CPN South Central Pennsylvania   2002.10.16

First, the coax between the radio and the balun must be just
a couple of inches long.  A greater length will be adding to the
capacitor that's in the output of the radio's tuner, and it may
not want to see any more than what it already has.  Second, the
range of admitances and reactances the tuner has to work with
over all the frequency ranges may be more that it can handle. 
Internal tuners usually are not designed to handle much more that
a slightly mismatched 50 ohm load.  You might want to try the
internal tuner on the bands you work, and snip the ladder line
for a possible compromise.  I use an AH-4 which does work
on all the ham bands plus MARS.  If the Q of the antenna system
is high enough there may be some odd ball frequency that will need
to have the ladder line snipped a little bit.  I recommend the
1:1 balun, not the 1:4 because its isolation is not as good.
                       73  Clete