17 March 2007

bpl impact for shortwave radio: reader comments

A recent post here on Cobalt Pet collected user comments and reviews on the Redsun RP2100/Kaito KA2100. I started that post because I didn't plan to buy one, although people visiting this site demonstrated a lot of interest in it. I was very happy with the results, and I hope it provided benefits to readers as well.

I'd like to start another reader discussion on an important topic. Power Line Communication (PLC) or Broadband over Power Lines (BPL) is a subject of concern for both shortwave radio listeners and amateur radio operators. Both groups of users operate in the High Frequency (HF) range of 3 mhz to 30 mhz. BPL technologies also use this frequency range. Initial testing of BPL technology has generated interference reports from ham radio operators to the FCC, with varying degrees of success. BPL is an issue that is also starting to appear in national legislation.

I welcome you to comment here to discuss the potential impact of BPL for shortwave or amateur radio. Do you live near a BPL network? Are there plans to set up BPL in your area? How can shortwave radio listeners respond if BPL interference results in an effective denial-of-service for international shortwave broadcasts, and what will the broadcasters do about it?

5 comments:

Anonymous said...

ARRL, the US National Association for Amateur Radio, has been very concerned about BPL and its deployment. When operated at the FCC limits, on any spectrum that BPL is using, locally, its noise is as strong as all but the strongest of SW stations that can be heard in that area.

The industry has, after some degree of pain, essentially decided not to use the ham bands for BPL. With sufficient filtering, this can be a viable solution for any spectrum that BPL chooses to protect.

However, although I have seen BPL work well for Amateur Radio, at this time, I know of NO BPL system that is offering similar protection for the reception of international shortwave broadcast signals. In the systems that are okay for ham radio, BPL noise is "S9+" on the shortwave bands.

For an example of how bad it is for shortwave broadcast, see:

http://p1k.arrl.org/bpl/ppt/BPLSWLNoise.ppt

Click on the speakers to hear BPL interfering with shortwave broadcast near 10 MHz at various distances from the overhead line carrying the BPL signal.

Unfortunately, in most cases, those listening to SW BC stations don't know the source of the noise; don't know that they can complain; don't know where to complain and may choose not to literally make a federal case of their interference problem.

Ed Hare, W1RFI
ARRL Laboratory Manager
225 Main St
Newington, CT 06111
Tel: 860-594-0318
Email: W1RFI@arrl.org

Anonymous said...

Oops:

The correct URL is:

http://p1k.arrl.org/~ehare/bpl/ppt/BPLSWLNoise.ppt

Sorry about that!

Ed, W1RFI

Pete said...

The whole idea of shared bandplans is that the competing services not interfere in a harmful way. Nothing I have seen regarding BPL makes it seem like it fits the bill. What it really looks like is a lot of corporate money being poured into a misuse of spectrum. Sadly, the FCC, WARC, IARU... all seem to be powerless to hold BPL to the standards of the existing services. To say that the current situation is frustrating is a huge understatement.

weatherall said...

Ed, thanks very much for your comments and the powerpoint link.

weatherall said...

Pete:
I don't think powerless is the right description for the FCC on this matter. I think "complicit" is a better label.