[RFI] SolarEdge Finds New Source of Solar System RFI

Roger (K8RI) k8ri at rogerhalstead.com
Tue Jun 11 06:47:45 EDT 2019

As I've said before, I've had no problems from CAT-5, and 6 and I 
hundreds of feet of CST-5 underneath my 75/40 meter slopers.  I have had 
induced voltage from lightning strikes though.  My problems with WiFi 
have been its speed, or lack there of when transferring large files and 
directories of up to 500GB, or more, over 130 feet through 4 or 5 walls, 
one of which is Al.  I can mount the shop antenna(s) in a window. 
However, there are usually 4, or 5 WiFi networks in the neighborhood 
which slows all of them to a crawl.

It works fine for connecting a laptop to the network in the house, but 
with images from my full frame D800 at 105 to 110 MB and even the DX 
format at 35 to 50 MB, let alone HD video, I can create some pretty big 
files and directories. At least the video doesn't use memory as fast as 
the high resolution dhots.  I'm currently running between close to 50 TB 
of Network (NAS) storage at home with 5 computers with all the CAT-5, 
but they are far from the quality of what most people purchase already 

At work we went from coax to many miles of CAT-6 and I never noticed any 
increase in noise.  OTOH I only operated HF from the parking lot.  I had 
permission to take in  the 144 / 440 HTs and they worked fine setting 
between the two computers.

73, Roger (K8RI)

On 6/4/2019 1:29 PM, Jim Brown wrote:
> On 6/4/2019 9:18 AM, David Eckhardt wrote:
>> Yes, the capacitor termination keeps us high-frequency types happy 
>> and satisfies the 'one end only' termination for the audio TSP 
>> designers.  I'm an RF type with some experience with audio from my 
>> long ago college days.
> This is NOT a matter of one method being right and another being 
> wrong. They are BOTH right in the situations in which they are 
> applied, because they solve issues with poorly designed, non-compliant 
> legacy equipment, and with equipment spread out over a large area, and 
> in interconnections between elements of systems running from different 
> power sources. There are many examples -- two or three mix consoles 
> bridging the mic lines in a performance facility, one of them being a 
> broadcast truck parked outside.
> Terminating the shield of shielded twisted pair at the input of audio 
> gear is far less of an issue if that input equipment is compliant.
>> Today, modern buildings outfitted with TP for Ethernet are so noisey 
>> that radios, even at FM broadcast frequencies, are unusable.  I have 
>> lot's of 'war stories', but I'll spare those for the time being. In 
>> my experience and regarding only RF up to low UHF, the RF noise 
>> becomes common mode over roughly 10-wavelengths of TP length.  It 
>> radiates like an intentional antenna. 
> Yes.  I've long recommended the use of WiFi for home networking for 
> this reason. In addition to the broadband noise at VHF and above, 
> there are also birdies in the HF ham bands. I've identified some on 
> 30M, and around 14030, 20152, the low end of 10M, and the low end of 
> 6M. The birdies can be attenuated by a few turns around a #31 core at 
> each end of the cable.  Years ago, in Chicago, I had wired Ethernet in 
> the house, and it put out a lot of trash on 2M.
> 73, Jim K9YC
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Roger (K8RI)

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