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 b
e
> addressed.
>
> 73,
> Ed Hare, W1RFI
> ARRL Laboratory Manager
> 225 Main St
> Newington, CT 06111
> Tel: 860-594-0318
> Email: W1RFI@arrl.org
>
> ________________________________
>
> From: Roger (K8RI) [mailto:k8ri@rogerhalstead.com]
> Sent: Wed 10/6/2010 11:50 PM
> To: rfi@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@arrl.org
>>
>> ________________________________
>>
>> From: K1TTT [mailto:K1TTT@ARRL.NET]
>> Sent: Fri 7/16/2010 7:29 AM
>> To: rfi@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@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@ifwtech.co.uk]
>>> Sent: Friday, July 16, 2010 07:09
>>> To: rfi@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
>>> _______________________________________________
>>> RFI mailing list
>>> RFI@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/rfi
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