[gregb]

On my 40-180, which is basically the same chassis, one lead of the SW loop connects to the solder lug mounted on the top right side (looking from the back) of the tuner, and the other to the right most antenna screw connection on the back of the chassis.  Is that the way you tried yours?  

You might also try a random length wire at either point, with the radio tuned to 2.5 Mc (WWV), or in Canada I believe their time frequency is about 3.3 Mc.

I have tried the shortwave antenna with no change. The low band shortwave works just fine its the high band that won't work. It seems really strange to me that its both radios with exactly the same problem using two different tubes. Its got to be something really simple that I'm just not seeing.

Gregb