LF: Re: capture 67hz.jpg

["Markus Vester" <markusvester@aol.com>]

Dear Henny,

 

my QTH is about 400 m from a railway line, and I regularly saw their 16.667 Hz power frequency and several ELF harmonics. The E-fields are relatively strong as the lines normally do not carry a grounded top wire for lightning protection. The "modulation" could be caused by some switching activity.

 

Another origin might be a controlled rectifier on the 50 Hz mains, which could be triggered at a subharmonic frequency.

 

Best regards,

Markus, DF6NM

 

----- Original Message -----

From: henny van elst

To: blacksheep

Sent: Wednesday, March 04, 2009 7:43 PM

Subject: LF: capture 67hz.jpg

Hi,Lf

capture unid signal 67hz,but who ?

henny pa3cpm

best 73s