[TowerTalk] Tower measurements & broadcast interference

[VE5ZX]

I have been trying to make some measurements on my tower using a Autek VA1
impedance bridge. However, I found that I could get readings that made
sense. There seemed to be something over loading the bridge. I put 500 ohms
to ground and used a scope to make measurements across it. I found that I
have about 8 v peak-peak @ 650 khz from a local broadcast station.

What I can do to remove this interference so I can measure the impedance on
160/80m with the VA1?

tnx
Sylvan Katz - VE5ZX
Saskatoon, SK