Re: Neon Sign Noise

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Ed,

I posted it since the solutions are similar to what one should do for a
Tesla coil causing interference.

1.	Check the NST case and AC wiring grounding.  Just like a TC, you may
want ground straps going to copper rods.  If they ground through the AC
that may be poor.  Also, if something is arcing to ground...

2.	Be sure all the HV connections are clean and tight.  If there is a tiny
bit of arcing going on somewhere, it will cause dramatic RFI.

3.	AC line filters like DigiKey sells may be useful for the NST AC inputs.
Again, they have to be well grounded with real RF type grounding.

4.	Get a little portable radio and go "hunting" for the exact source.
Hopefully a connection or something is bad.

5.	Get a better phone :-))  Seriously, not all phones are made alike and a
better designed phone may not have the problem.  I bet one of the old
rotary phones will not buzz.  If it does, something is really wrong.

5.5	Be sure the phone and its wiring are grounded (not to the same ground
as the neons :-))

6.	Maybe get the newer electronic NSTs and use the 15/30s for something
else :-)))

7.	Make sure the wiring in the phone outlets is not traveling near the
neons somewhere.  I found I had a phone wire in the ceiling right above my
TC that was connected to an answering machine that "mysteriously" died
after a run...

8.	Put a big coil in the center of the place like Fries in CA and light the
neons with it :-))  They have RFI cages that you may want to consider if
you get desperate.  The third link has EMI info.

http://www.ttr-dot-com/special-projects.html
http://www.ttr-dot-com/Fry-coil.htm
http://www.ttr-dot-com/its_model9.html

Those are my ideas,  Hopefully, of some help to all.

Cheers,

	Terry


At 12:07 PM 1/24/2001 -0500, you wrote:
>Well, I hope Terry will let this pass.  It is not exactly on topic, but does 
>involve neon sign transformers.  Please reply off line to me if you have any 
>ideas.
>
>I recently moved my business (Yamaha golf car dealership) into a new 
>building.  It has really cool neon tubing that runs around the showroom about 
>8 feet up off the floor.  It is broke up into about 4 sections that each have 
>a 12 kv 30 ma neon sign transformer installed in the ceiling for power.  This 
>is the first time I have owned any neon sign transformers that are actually 
>doing what they are designed for.
>
>One section of the neon is right above the parts counter and the neon causes 
>a lot of 60 HZ buzzing in the telephone that is sitting on the counter.  I 
>want to get rid of this annoying buzzing in the phone.  If I shut the neon 
>off, it goes away.  The phone is a standard two line phone with an intercom.  
>I unplugged the ac power supply to the phone and the problem is still there.  
>I tried plugging in the phone line to a different jack located about 40 feet 
>away.  When the phone is brought over to the counter which is about 4 to 5 
>feet below the neon, the problem returns.  As you move the phone, the buzzing 
>intensifies as it gets closer to the neon and goes away when the phone is 
>moved about 10 or 12 feet away on a straight line.  I tried using a 1.5" 
>diameter ferrite core and looping the incoming phone line through it a few 
>times and also tried it on the cord to the handset - neither did anything to 
>reduce the noise.
>
>Anyone have any ideas?
>
>Thanks, Ed Sonderman
>