Road sign interference 40m?

[VK3RX]

The last couple of days on 40m there is a widespread digital signal over the band, with spots every 15kHz.

Initially just listening on a single frequency I thought it was someone running FreeDV or similar, but then after looking at the spectrum scope I noticed it extended over the range of 6-8MHz then fell away, but that would be due to my doublet when tuned for 40m.

It went for some hours yesterday, I didn't check late in the day or overnight and its there again now. It's about strength S9+10 so not here but relatively local, and I suspect it may be a portable traffic lights setup, or more likely an electronic sign or something similar, because it has a 10 second cycle of on/off. There are roadworks a couple of blocks away so I will go out and check later today. It certainly renders the band useless.

Anyone heard similar?

I can't seem to attach an audio file here so this link to another site will hopefully work:
http://www.aurfscan.com.au/attachment.ph...1490083807

[VK5PJ]

Damien,
non members of that forum do not have access to the files so like me, can not listen to your sample, did you find out anything more about it?

Peter 5PJ

[VK3RX]

non members of that forum do not have access to the files

Ah, sorry Peter, I didn't realise that.

Note to Admin: allow audio file attachments e.g. .mp3

I'm pretty sure it was as I suspected i.e. some form of traffic control device a few blocks away. The cycle changed from time to time, suggesting it may have been due to traffic conditions.

When I went out in the car with a portable HF it had disappeared, and when I got to the roadworks area a guy in a ute with traffic gear in the back was just driving off :roll:

Hopefully its gone, if not I will update here.