Topband: Antenna Suggestions for 160 Noise Sniffing?

[Michael Tope]

I have some off-property noise sources on 160 meters. Probably
computer monitors or switching power supplies. I was thinking
of picking up one of those little Yaesu FT-817ND battery
operated DC to light rigs so that I can walk around the
neighborhood and sniff for the QRN. Can anyone recommend a
good portable antenna design that will have a good enough null
that I can use it for DFing this noise. I was thinking that a ferrite
rod antenna would be a good choice. If so, where can I find design
data (ferrite material specs, # turns, etc) and parts? Any other
suggestions?

Thanks,

Mike, W4EF.................................