[Lowfer] Need education on Isolation transformers

[Jim]

> How do I determine the Impedance of this antenna setup for
> 500 KHz, 180 KHz, 137 KHz, for receive purposes.

I haven't done much with the LF antenna lately, but I was working on a noise 
bridge to do measurements. But it seems like a better approach is to just use 
a bridge fed by a signal source that's close to the frequency you want to 
measure at. That looked like a reasonable way to do it. A couple of 
references:

http://www.alan.melia.btinternet.co.uk/aelossbr.htm
http://users.tpg.com.au/users/ldbutler/LFBridge.htm

I was taking the approach of putting banana plugs by the variable resistor (in 
series) and variable capacitor (in parallel) so I could build plug-in 
fixtures with known values to increase the range as needed. It's about half 
done and setting around somewhere...

73 de
Jim W4JBM

http://www.hamuniverse.com/w4jbm/

"With a soldering iron in one hand, a schematic in the other, and a puzzled 
look on his face..."