RFI
[Top] [All Lists]

Re: [RFI] Keyboard RFI

To: Charlie Gallo <Charlie@TheGallos.com>, rfi@contesting.com
Subject: Re: [RFI] Keyboard RFI
From: Dale <svetanoff@earthlink.net>
Reply-to: Dale <svetanoff@earthlink.net>
Date: Thu, 22 Aug 2013 14:12:36 -0500 (GMT-05:00)
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
Charlie,

While the hash noise must truly be bad news, that 50V on the CATV line could be 
even worse.  Is that 50VDC or 50VAC?  If it is AC, it sounds as if there is 
significant leakage current (or coupling) within a power supply that is 
operating  some part of your CATV systems.  If that potential is on the cable 
coming from the outside world into your house. you need to advise the system 
operator ASAP.  The fcat that you can draw an arc means you have a very 
definite safety hazard present.  If there is 50VDC on the cable, then you still 
have  safety issue, but that would indicate that some power supply voltage has 
been coupled onto the shield of the cable.  That is probably not by design.

73, Dale
WA9ENA 


-----Original Message-----
>From: Charlie Gallo <Charlie@TheGallos.com>
>Sent: Aug 22, 2013 12:03 PM
>To: rfi@contesting.com
>Subject: [RFI] Keyboard RFI
>
>Hi Gang,
>So, got the SW Radio, and have found some interesting RFI sources around the 
>house, have suppressed some, have a tech call in on another (the cable TV line 
>has HORRID noise on it low, and if you lift it off the ground, has about 
>50volts potential to ground (yes, it'll draw an arc!!!))
>
>One odd thing I found - every keyboard around the house (and I have different 
>brands from cheap to Unicomp Model M keyboards) has horrid RFI _IF_ you are 
>close to it (like the hand held within say 6-9 inches)
>
>Any clues to a GOOD keyboard that doesn't broadcast like mad (they are all 
>wired USB keyboards)
>
>-- 
>73 de KG2V - Charles Gallo
>Quality Custom Machine-shop work for the radio amateur (sm)
>
>_______________________________________________
>RFI mailing list
>RFI@contesting.com
>http://lists.contesting.com/mailman/listinfo/rfi

_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi

<Prev in Thread] Current Thread [Next in Thread>