Subject: [NEXTEL-1] ALERT - Mike Powell in NC - BPL PR

From: Marcelrf <[email-masked]>
Date: Fri, 05 Mar 2004 13:48:17 -0500

-------- Original Message --------
From: "Todd Ellis" <[email-masked]>
Subject: RE:  ALERT - Mike Powell in NC - BPL PR

Paul:

I raised that issue as well with Gary.  His thought was that the
frequency
used by the Progress Energy folks was going to be higher than 7 MHz, and
that NVIS issues may not be an issue.  I thought of Mark Krotz, and
suggested that hanging what is essentially a long wire antenna at about
a
half wave length above the ground should provide some very interesting
propagation issues.

For about 5 years, I informally studied an antenna design I came up with
for
3.8 MHz (75 meters).  I was interested to see if a low-hanging dipole
antenna at roughly 1/4 wavelength, with a wire mesh buried in the ground
below it, would provide an excellent NVIS pattern.  Instead I found that
the
take-off angle was lower, and was able to RELIABLY (read: 7 days a week)
talk to a station in Australia using 650 Watts PEP at 5:30-6:00 in the
morning for months on end utilizing gray line propagation.  Yes, I have
the
QSL cards to prove it.

That tells me that there may be some interesting over-the-horizon
patterns
that the BPL stuff, when hung above ground, could be causing that may
not
have been looked at yet.

Todd Ellis

-----Original Message-----
From: Paul J Zawada [mailto:[email-masked]] 
Sent: Friday, March 05, 2004 1:34 PM
Subject: Re: ALERT - Mike Powell in NC - BPL PR

I understand the NTIA study was pretty extensive and they collected a 
LOT of raw data from BPL trial areas, hence the delay in analysis and 
release of the report.  If there is a lot of negative data, that would 
explain the Commissioners' haste to get the rule-making process 
completed (or at least well under way) if they see BPL as a way to 
secure their legacy in bringing broadband to rural areas.  If 
interference problems are real, they probably won't have to be dealt 
with until another set of Commissioners are in charge.  Let me make my 
mark now, if there are problems the engineers will figure out how to 
clean it up later...  Does this scenario sound familiar?

IMHO, the interference issue is being addressed incorrectly.  I think 
most folks are focusing on how individual BPL systems affect nearby HF 
users.  The Commission themselves partially dismissed the interference 
issue because they said existing problems hams have with power 
companies compel the hams to locate their antennas "away" from power 
lines.   My question is what about the combined effect of many of these 
systems bouncing energy all over the ionosphere?   I can envision BPL 
interference "hot spots" occurring hundreds of miles from any single 
BPL system.  Many hams enjoy low-power (QRP) HF operation that requires 
only a few watts of RF power to communicate over hundreds of miles yet, 
depending on the band conditions, the same configuration not allow 
communication 10 miles away.  Wouldn't the same hold true for BPL?  And 
if the interference (raising the noise floor) is has cumulative over 
long distances, what good is a database of individual BPLS systems and 
their location?  What good is real time interference control for any 
particular BPL system if it only contributes a part of the 
interference?  Do HF users have to comb the database and start calling 
all the operators on a particular frequency to get them all to adjust 
their systems?

I am not an expert in non-line-of-site HF communications, especially if 
you are talking about tens or hundreds of transmitters.  Perhaps it's 
not a real issue given the hundreds or thousands of noisy power line 
insulators that exist without completely polluting the HF bands.   
However I have seen little if any information addressing this issue for 
BPL.  It seems everyone is concentrating on the local, line-of-site 
interference issue.  Or have I missed something?

--zawada

On Mar 5, 2004, at 10:24 AM, Ron Haraseth wrote:

> The NTIA has conducted a study on this issue.  It is complete, but is
> pending internal review.  We are patiently waiting.
>
> Ron
>

-- 
    "NEXTEL-1 IT'S NOT JUST NEXTEL"
  Note The New address 
Subscribe to Nextel-1: http://www.groups.yahoo.com/subscribe/NEXTEL-1

  "NEXTEL2 FOR iDEN SOFTWARE DEVELOPERS"
Subscribe to Nextel2: http://www.groups.yahoo.com/subscribe/NEXTEL2

  "WIRELESS FORUM HOMELAND SECURITY GROUP"
     The Complete Resource for Wireless Homeland Security.
Subscribe to WFHSG:  http://www.groups.yahoo.com/subscribe/WFHSG

Yahoo! Groups Links

<*> To visit your group on the web, go to:
     http://groups.yahoo.com/group/NEXTEL-1/

<*> To unsubscribe from this group, send an email to:
     [email-masked]

<*> Your use of Yahoo! Groups is subject to:
     http://docs.yahoo.com/info/terms/