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Re: [RFI] Query for the group.

To: "jim@audiosystemsgroup.com" <jim@audiosystemsgroup.com>
Subject: Re: [RFI] Query for the group.
From: Charles Gallo <charlie@thegallos.com>
Date: Sat, 25 Jul 2015 18:20:30 -0400
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
Jim, the problem around here with wifi is I can count 14 access points in 
range, so bandwidth is horrible

I've found making my own Ethernet cables, each with a type 31 1/2 inch ID, 
Circa 1/2 long with the 3 or 4 turns I can stuff through works well. My problem 
is living in Queens (part of NYC) wher the houses are all on 40x100 lots, there 
are a metric ton of RFI sources. I can tell when the neighbors are running 
their wash, etc. I can't afford $100s of ferrite for every house within say 500 
feet, and most would tell me to buzz off, so I live with S7 background noise on 
some bands. Killing my own stuff helped, as well as the worst of some of the 
closer neighbors

--  
73 de KG2V
Charlie

> On Jul 25, 2015, at 4:54 PM, Jim Brown <jim@audiosystemsgroup.com> wrote:
> 
>> On Sat,7/25/2015 11:51 AM, Kenneth G. Gordon wrote:
>>> On 25 Jul 2015 at 13:31, Randy Farmer wrote:
>>> 
>>> Ethernet birdies.
>> Ah. Makes sense. Dang.
>> 
>>> You're lucky to have only two.
> 
> Each of those birdies around 14030 are synchronized to the clock on someone's 
> router or switch. If you have neighbors, you'll hear a birdie for each of 
> them. Identify your own by killing power to your router or switch. Ethernet 
> also produces birdies around 21060, on the low end of 10M CW, and the low end 
> of 6M. There are also a few on 30M. These are the ones I've noted because I'm 
> a CW op -- if you work SSB, you may find more. :)
> 
>> Well, actually, I don't KNOW that I have only two. On 40 and 80 there 
>> appears a
>> "wandering" bit ofpretty loud crap that is pretty broad, and wonders up and 
>> down the band at
>> intervals.
> 
>> I haven't tracked that one down yet, but suspect it is some sort of 
>> switching power
>> supply somewhere close by.
> 
> Right -- they are harmonics of Switch-Mode Power Supplies. Everything from 
> wall warts to computers to TVs to battery chargers of all sorts.
> 
> 
>> Well, we have both wired and wireless in our local net. Up to 5 computers, 3 
>> of which are
>> hardwired.
>> 
>> And, at this point, then, there isn't much I can do about them, I would 
>> suppose.
>> 
>> I have added multiple turns of cat 5 through large ferrite "chokes", but 
>> mostly to keep my
>> transmitter out of the hub. That worked.
> 
> Long cables will need a choke at both ends, and you may also need a choke on 
> the power supply cable.
> 
> Consider adding WiFi adapters to your wired computers to eliminate radiation 
> from those cables. I've been using nothing but WiFi in my home and shack 
> (which is in a detached garage), and have all the bandwidth I need -- enough 
> to support streaming audio and video.
> 
> 73, Jim K9YC
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