[RFI] Internet Modem / Router Cable Length and RFI

[Roger (K8RI)]

It could be luck, it could be connected to the purpose of the computers, 
or both.
I do a lot of photography and AVI work, hence, the massive amount of 
storage.

I think the following are important for good relations between computers 
and ham stations.
I've also noted some comments from others who have no problems and they 
too were using fairly high end power supplies..

I do a bit of flight simming as I was a pilot.  Several of the sims are 
very good for IFR practice, have excellent scenery and very realistic 
flight controls and responses.  That takes some powerful processing and 
video cards. In turn the video cards and top end processors require a 
lot of power, so the power supplies I purchase tend toward the top end.  
(200 to 220 watts for the CPU and as much as 300 watts for a single 
video card)

All of this means I often spend as much for individual components ( 
memory/RAM, Video cards, motherboards, cases, and power supplies)  as 
many do for the entire computer as communications do not normally 
require a lot of power. Typical computer use (excluding gaming) takes 
little computing power and that includes streaming video.

  I do go through a lot of components aiming for better performance.  
I've had power supplies quit when I added one more fan that only used 5 
watts.  Hence the present use of 850 watt power supplies with active 
power factor correction.  I'd much rather have lots of excess power than 
not nearly enough

Each computer is powered off its own dedicated UPS which has built in 
filtering for both the power and the network as well as voltage spike 
protection.  I'm moving to "line conditioners" with full time, true sine 
wave generators.  These will run both the rigs and computers.  The power 
to the ham station and computers are dedicated and run parallel from the 
breaker panel to the outlets in the den to eliminate, or minimize 
induced differential voltages.

The cases have conductive air filtering in and out so the cabinets are 
"relatively" RF tight.

I said I have not added any external filtering, but I do purchase 
components with both RF ingress and egress in mind
My biggest fear, other than induced voltage from lightening, is the 
trend (or move) to wall warts. Even those are plugged into the UPS that 
feeds the individual computer.  A wall wart with 6 to 8' of lead wire to 
the load can make for quite an antenna.

The network (modem, router, and switch are also powered from a dedicated 
UPS.

IOW I have resorted to good design practice for the entire station and 
interfacing with the computers.  The power to the den is also according 
to good practice.  In many cases it has taken several years to get 
things done, or modified in the case of house wiring.  Permits are $25 
for each circuit breaker added. Inspections are free.

Most have not been expensive changes to implement, but are often time 
consuming and may require building permits with the required 
inspections.  Fortunately I live in an area where we can do the work 
ourselves even if it has to meet code.   However, the computers, due to 
their intended use have not been cheap.  OTOH as a side effect, those 
requirements may be what has kept me RFI free.  Of course the next piece 
of equipment my shoot down that theory.

Because of induced voltages from lightening, I'd like to go wireless at 
least to the shop. With the servers located next to the router and smart 
switch I may be able to do that.  Before the servers, I had  the 
database spread across the network and when massive transfers may take 4 
or 5 hours on a gigabit network, wireless becomes impossibly slow, 
particularly when I see 10, 12, or more networks  that the router sees 
competing for space.  Now I no longer need that capability.

73

Roger (K8RI)


On 6/4/2015 12:41 PM, Jim Brown wrote:
> On Thu,6/4/2015 3:06 AM, Roger (K8RI) wrote:
>> I'll repeat, I have 2 130'runs of CAT-5 
>
> Hi Roger,
>
> Emissions from equipment can vary widely from one piece of equipment 
> to another. I'd say you're very lucky to have selected equipment that 
> has no emissions. :)  Every piece of wired Ethernet equipment I've 
> owned has birdies around 14,030 and 21,052, and around the bottom end 
> of 10M CW. Broadband noise on 6M and 2M is also common.
>
> 73, Jim K9YC
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