[ICOM] Icom 746 Pro ATU

[VE5ZX]

For some reason my Icom 746 Pro ATU will not work on 15m when loading a 
C31XR feed with separate feedlines. The swr is below 1.5:1 from 21000 to 
21400 and rises to 2.4 at 21450. In particular I would like the ATU to work 
above 21400.

I have inserted short pieces of coax to see if the might remedy the problem. 
It didn't.

The ATU works fine if I try to load the 20m ant on 15m so I presume the ATU 
is working on 15m.

The impedance of the 15m antenna measured at the rig end of a feedline which 
is a multiple of lambda/2 long ranges from  53-j0 to 47+j30.

The ATU works fine on other bands under similar conditions.


Any suggestions for a fix for this problem?

tnx Syl


Sylvan Katz - VE5ZX
Saskatoon, SK