transmit signal test

[unregistered]

I am trying to have a look at the transmit signal of a GPX 4500 on a scope & would like some advice on this, i am new to all this.

Do i test this as DC voltage? I tried testing as AC but the signal doesn't appear to be correct & goes negative on the scope?

Also on the Coax, i assumed the centre wire was positive & the outer Braid was Negative but the signal looks strange like that.
The signal looks good with the Braid connected to the positive probe & the negative on the centre wire.

Not sure if i am testing this correctly or not, could someone offer some advice how to test this correctly please.

Thank You

[Unregistered]

This will be helpful:

http://www.geotech1.com/forums/showthread.php?t=13005

[allan.au]

if you just want to look at the tx rate, and not the dc, just wind a small simple coil and place it near the search coil, and hook your cro to that. cheers, al.