[RFI] Broadband over Power Line (BPL) radio interference

Hare,Ed, W1RFI w1rfi at arrl.org
Fri Jul 16 19:49:41 EDT 2004


> If someone wants to do something useful they need to expend
> time and energy generating a web page telling people how to
> get meaningful data out of common equipment.

Actually, this can be done reasonably easily.  

http://www.arrl.org/~ehare/aria/ARIA_MANUAL_TESTING.pdf

What I need to add to that document is a table equating S units *approximately* to received signal level in dBm.  Also, some information on how to calibrate an S unit against a signal generator, or how to get a better estimate of dBm from the ARRL published S-meter values, etc.  One more thing on a very long list, though.

But in the case of BPL interference, the issue is not one of field strength. It is one of harmful interference.  If that can be demonstrated by any reasonable means, it is valid.  After all, we would not expect that we had to address our neighbors' TVI complaints only if they made traceable field-strength measurements.  

FS measurements have their place in all this, but, IMHO, they should not be central. Right now, the BPL manufacturers are hanging their hat on the claim that they don't exceed FCC limits, so they are not causing interference. A 30 uV/m field is pretty strong and typical antennas put in that field are going to pick up S9 noise. That is the issue, and it is harmful interference even if it is not measured.

And I do hope you got the :-) with the "hindrance" quip. I was picking back on the poster that told me that my BPL work was more hindrance than help.  It can always be better, of course, but hindrance?  I didn't think so. 

Ed Hare, W1RFI
ARRL Laboratory Manager
225 Main St
Newington, CT 06013
Tel: 860-594-0318
Internet: W1RFI at arrl.org
Web: http://www.arrl.org/tis
Member: ASC C63 EMC Committee
   Chairman: Subcommittee 5, Immunity
   Chairman: Ad hoc BPL Working Group
Member: IEEE SCC-28 RF Safety
Member: Society of Automotive Engineers EMC/EMR Committee
Member: IEEE 


> -----Original Message-----
> From: Tom Rauch [mailto:w8ji at contesting.com]
> Sent: Friday, July 16, 2004 7:32 PM
> To: Hare,Ed, W1RFI; rfi at contesting.com; bplandhamradio at yahoogroups.com
> Subject: Re: [RFI] Broadband over Power Line (BPL) radio interference
> 
> 
> Well, I guess you are now a hindrance instead of a help now,
> too, Tom. :-)
> 
> 
> To some I might seem like a hindrance, but I do have a point
> to make.
> 
> It's bad enough when we don't appear technically astute and
> supply FS readings that aren't based on anything useful.
> That just makes us appear as technically challenged people
> who use tube radio sets to chat about our hemorrhoids.
> 
> Of course the worse thing possible we can do is present
> ourselves as vengeful spoiled brats. that would be a huge
> setback.
> 
> If someone wants to do something useful they need to expend
> time and energy generating a web page telling people how to
> get meaningful data out of common equipment.
> 
> Let's try to keep some of the slobber off our chins, not get
> into a slap fight.
> 
> 73 Tom
> 
> 
> 


More information about the RFI mailing list