[Lowfer] Possible noise problems?

Tue May 1 16:56:32 EDT 2018

Zack:  I can close couple the 2M rubber duck on the FT-817 to sniff LF/MF noise on/near conductors such as branch circuit wiring, phone line, Ethernet cable, metal downspouts, etc.

 An AM transistor radio set to the bottom of the dial may offer some manetic sensing  help, although I think you have a strong local AM station station at the low end of the band that may drive the AGC over the top..  If you come across an early 1960s Zenith 755, 780, or 790 those radios have a 6 inch long by 1 inch wide ferrite antenna and they have really excellent sensitivity when re-habbed.  The 780 and 790 have the LF band and a switch that disables the AGC and at the same time turns the audio volume control into an RF gain control.  Those are great mag antenna noise sniffer radios...The 755 is AM band only, but has the same large ferrite antenna without the DF mode and RF gain adj feature... they are lunchbox size and much more manageable than the larger  transistor transoceanic versions.... all metal chassis and built like a tube radio with transistor sockets. Those are POSITIVE ground radios using the old germanium transistors. Very clone-able from  hamfest or ebay parts radios...

73 Mike wa3tts

Maybe watch SM5BSZ's "Sensors" youtube videos on LF noise sniffing....

https://www.youtube.com/watch?v=ItLkn8r4s3E

https://www.youtube.com/watch?v=C65u7Pmz7a0

-----Original Message-----
From: Zack Widup <w9sz.zack at gmail.com>
To: Discussion of the Lowfer (US, European, & UK) and MedFer bands <lowfer at mailman.qth.net>
Sent: Tue, May 1, 2018 4:03 pm
Subject: [Lowfer] Possible noise problems?

I only have a couple places in my yard where I can put a receiving longwave
loop antenna. The antenna I am building is 5 feet on a side with a
supporting cross made of pvc pipe. The top of the loop including mounting
pipe is about 9 feet off the ground.

One place I can put the loop is fairly close to a power line. I'd like to
avoid that spot if I can. The other location places the top of the loop a
few feet from an AT&T DSL phone/internet line (not directly under it).

I am wondering if anyone has any experience with placing an LF/VLF
receiving antenna close to a DSL phone line. I don't know if the wires in
that line are surrounded by a shield, but I suspect they're not.

I suppose one possibility to test the locations(s) is to take my FT-817ND
with a small antenna and put it near the phone line. That radio will
receive down to 100 kHz. But if anyone has had problems with some similar
arrangement in the past, it would help.

73, Zack W9SZ

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