[RFI] HomePlug Experience?

Thu Oct 7 18:58:57 PDT 2010

On 10/7/2010 6:42 AM, Hare, Ed W1RFI wrote:
>> I do know the CAT5e and CAT6 do radiate making the use of 2-meter HTs
>> problematic within about 75 feet of the cable runs.
>
> That almost sounds like something could be wrong. At ARRL HQ, we have an extensive Ethernet and radio operation continues pretty much noise free.  There is some noise on HF to the W1HQ club station, but I wouldn't think that we are hearing the network at W1AW about 300 feet from the HQ building.
I had never noticed any RFI from the gigabit network, but when we were 
taking down the big antennas for maintenance, I discovered the HT's were 
almost useless on 2-meters. Nothing on the 440 band.  Also there is 
nothing noticed at either end.  I can set the HTs on the computers in 
the shop or the box where the network runs come into the shop and not 
even break the squelch. I do not hear anything on the big 144/440 
verticals with one side mounted on the big tower at 50', or the one 
(same make and model) mounted at roughly 16' on the N side of the shop.

Of course it is possible the source was something else, but the tower area seemed to be the most affected. I didn't get a chance to power down the network.  Possibly I can do that in the next couple of days to see if it still bothers.

73

Roger (K8RI)
> All in all, the wired technologies, other than power-line, have been reasonably benign. We have gotten some reports of AT&T Uverse RFI (to and from), but from all indications, most of the installations appear to be pretty clean in both directions.  We are working with one of the AT&T engineers to determine what the differences are between the sytems.  When this question first raised, I hired a consultant on the West Coast to do some measurements of a nearby Uverse system. He reported that the system was pretty much inaudible on the ham bands and that 100 watts to a dipole 10 feet from the control box did not affect it, based on test downloads being done in a nearby home.  So far, what appears to be happening is that some of the units are not properly internally grounded and/or some of the premises are using substandard telephone wiring.  It's a slow process, but I think we can ultimately get a service bulletin out of AT&T so that when hams have problems, they can at least be
>   addressed.
>
> 73,
> Ed Hare, W1RFI
> ARRL Laboratory Manager
> 225 Main St
> Newington, CT 06111
> Tel: 860-594-0318
> Email: W1RFI at arrl.org
>
> ________________________________
>
> From: Roger (K8RI) [mailto:k8ri at rogerhalstead.com]
> Sent: Wed 10/6/2010 11:50 PM
> To: rfi at contesting.com
> Subject: Re: [RFI] HomePlug Experience?
>
>
>
>
>
> On 10/6/2010 10:07 PM, Hare, Ed W1RFI wrote:
>> It's hard to believe that it goes back over 10 years now, but the HomePlug protocols do not use the Amateur bands, with the exception of the 5 MHz band, which was allocated after the protocols were written.  I worked with HomePlug engineers to do testing of the protocol with and without the notches.  HomePlug operates at 4-20 MHz. The HomePlug AV spec runs to 28 MHz and there is a new HomePlug Gigabit spec that runs to 200 MHz.
>>
>> In the Gigabit spec, the 6- and 2-meter bands aren't filtered, but the levels are about 30 dB lower than the HF operating level, so the noise levels are correspondingly lower.  I think, however, that VHF interference is possible. I just haven't had the time to go get a pair of the Gigabit modems and do some measurements and testing. Repors are most welcome.
> When I get my 4CX3000A7 version of the 2-meter amp in the handbook
> finished, maybe we can give it a real test.<:-))
> I do know the CAT5e and CAT6 do radiate making the use of 2-meter HTs
> problematic within about 75 feet of the cable runs.
>
> 73
>
> Roger (K8RI)
>> But the spectral masks that HomePlug has applied to the Amateur bands is successful. There are about 20 million HomePlug modems sold in the US to date, and to date, ARRL has received zero reports of interference to the Amateur bands traced to HomePlug products.
>>
>> See:
>>
>> http;//p1k.arrl.org/~ehare/bpl/HomePlug_ARRL.pdf
>> .
>>
>>
>> 73,
>> Ed Hare, W1RFI
>> ARRL Laboratory Manager
>> 225 Main St
>> Newington, CT 06111
>> Tel: 860-594-0318
>> Email: W1RFI at arrl.org
>>
>> ________________________________
>>
>> From: K1TTT [mailto:K1TTT at ARRL.NET]
>> Sent: Fri 7/16/2010 7:29 AM
>> To: rfi at contesting.com
>> Subject: Re: [RFI] HomePlug Experience?
>>
>>
>>
>> I was afraid of that also when I put in a pv system.  The pv inverters talk
>> to a monitoring box using 144khz plc which is very narrow band and no
>> problem.  But because of the limited range the monitoring box had to be too
>> far from my router, so the company sent me a pair of homeplug bridges.  They
>> are supposed to be 4-20MHz, but I can't hear them.  Perhaps this is only
>> because of the relatively low data rate and intermittent transfers actually
>> used, but they don't seem to be a problem here.
>>
>>
>> David Robbins K1TTT
>> e-mail: mailto:k1ttt at arrl.net
>> web: http://www.k1ttt.net<http://www.k1ttt.net/>  <http://www.k1ttt.net/>
>> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>>
>>
>>> -----Original Message-----
>>> From: Ian White GM3SEK [mailto:gm3sek at ifwtech.co.uk]
>>> Sent: Friday, July 16, 2010 07:09
>>> To: rfi at contesting.com
>>> Subject: Re: [RFI] HomePlug Experience?
>>>
>>> Eric Rosenberg wrote:
>>>>    It looks like I'll need HomePlug to get from my router in the basement
>>>> to the second floor, as no wireless devices penetrate this 70-year old
>>>> plaster and lathing house.
>>>>
>>>> I presently have five Ethernet runs in the basement and two to the main
>>>> floor above the shack.  They don't appear to be noisy or have an impact
>>>> on my urban station.
>>>>
>>>> Do any of you have experience with HomePlug in/near the shack?
>>>>
>>>> I'd like to know about your experience!
>>> http://www.ukqrm.org/
>>>
>>> Welcome to HF Hell.
>>>
>>>
>>> --
>>>
>>> 73 from Ian GM3SEK
>>> http://www.ifwtech.co.uk/g3sek
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>>> RFI mailing list
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>>> http://lists.contesting.com/mailman/listinfo/rfi
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