Topband: Wireless Internet RFI Issue

Herb Schoenbohm herbs at
Mon Jul 29 15:37:25 EDT 2013

Unfortunately if you have DSL2/2+ the frequencies coincide with the 160 
meter band.  Even if you have straight DSL you can have problems when 
you transmit on 160.  Tom is right about the ferrite not being a 
solution as I have wound the incoming lines on many large coils and 
nothing seemed to worked. I ordered the parts for the DSL filter that is 
on Tom's wonderful site but I also found on line a filter that killed my 
DSL problem cold.  The Westek Z100B1 inserted in the telco in coming 
right at the DSL modem for me was the answer.  It is available on line 
by just putting the model number in your search engine.  Now when a 
quest op is using my stations on the highers bands during a contest 
remotely from the states, my TX on 160 doesn't shut down the Remote Rig 
set up like before by swamping the DSL or making it slow down on data 

This is for transmitting RFI issues on 160 but it may also isolate noise 
from the DSL incoming...if that is an issue apart from switching 
supplies and even routers themselves.

Herb Schoenbohm, KV4FZ

On 7/29/2013 2:11 PM, Tom W8JI wrote:
> That almost always is a switching power supply issue. The normal mode 
> of excitation is differential between the power mains and other 
> cables. My neighbor's system bothered me.
> The BEST solution to this is a lightning protection type outlet strip 
> that (if it does not have them) you add capacitors to. I used a system 
> that had F connectors, eithernet, telco, and power.
> This is thousands of times more effective than throwing beads at it 
> and just hoping common mode impedances are so low the beads do something.
> 73 Tom
>> I recently had an internet wireless antenna/unit installed as our DSL 
>> was
>> painfully slow.
>> Now I notice RFI in the AM broadcast band and into the 160 meter band.
>> There may more
>> RFI issues on other bands however at this point I haven't noticed 
>> anything.
>> I see that Fair-Rate makes a series of "New Low Frequency Suppression 
>> Cable
>> Component
>> ferrites, though I am not sure what I should purchase.
>> It looks like that I should be looking for a "certain impedance" for a
>> particular frequency.
>> Any help would be appreciated.
>> 73 de Brian, KG8CO
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>> 07/29/13
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