Grounding the Filament Winding - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 5th June 2006, 09:35 PM   #1
diyAudio Member
 
Join Date: Mar 2006
Location: Michigan
Default Grounding the Filament Winding

Hi everybody, I am getting buzzed from my amp, and I have to clue why, again and again I check, and double check to see that in truth everything is grounded, however everytime i try it i get a shock, so I am starting to wonder if it is not the Filament windind not being grounded. I have a hammond transformer that reads as followsClick the image to open in full size.

On green winding, which one do I put to the ground? any help is greatly apreciated
  Reply With Quote
Old 5th June 2006, 09:43 PM   #2
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
If none of the cathodes in your amp are at high potential, then you can ground the heater CTs.

But if you're getting zapped, it's far more likely that you have a bad earth (safety) ground connection somewhere in your system. That requires immediate attention.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 5th June 2006, 09:47 PM   #3
diyAudio Member
 
jeff mai's Avatar
 
Join Date: Aug 2002
Location: Melbourne
And start using your multimeter to check, not your finger!
  Reply With Quote
Old 5th June 2006, 10:08 PM   #4
diyAudio Member
 
Join Date: Mar 2006
Location: Michigan
Quote:
Originally posted by jeff mai
And start using your multimeter to check, not your finger!

It worked countless times before I buzzed myself, so the first time it got me it was a surprise. but the first time it happend was right after I re-connected a heater, so I thought maybe there as something wrong there.

I am checking countless times with my Multimeter to see if my ground is good, and everywhere I have checked it is good but if seems like thats the problem, I will keep looking untill I find something
  Reply With Quote
Old 5th June 2006, 11:25 PM   #5
Merlinb is offline Merlinb  United Kingdom
diyAudio Member
 
Merlinb's Avatar
 
Join Date: May 2006
Location: Lancashire
You haven't plugged the mains into a different wall socket to the one you usually use, have you?
  Reply With Quote
Old 6th June 2006, 01:53 AM   #6
diyAudio Member
 
cogsncogs's Avatar
 
Join Date: Jul 2003
Location: Wayne, West Virginia
Quote:
however everytime i try it i get a shock
Hi alexmoose, a lot of questions to follow. Just trying to cover all the bases.

When you say you get a shock, what are you touching? The chassis, ground, filament wiring connections? What about your primary connections? Are you sure that neither side of the primary is connected to your chassis ground? Which Hammond transformer are you using? Are you using a 2 or 3 wire power cord? How are your connections to mains (wall) supply?

Quote:
On green winding, which one do I put to the ground?
Green/Yellow.

Wayne
  Reply With Quote
Old 6th June 2006, 02:27 AM   #7
diyAudio Member
 
Join Date: Mar 2006
Location: Michigan
Quote:
Originally posted by Merlinb
You haven't plugged the mains into a different wall socket to the one you usually use, have you?
It's the same Wall socket, but it might be a different socket on the power strip

Quote:
Originally posted by cogsncogs


Hi alexmoose, a lot of questions to follow. Just trying to cover all the bases.

When you say you get a shock, what are you touching? The chassis, ground, filament wiring connections? What about your primary connections? Are you sure that neither side of the primary is connected to your chassis ground? Which Hammond transformer are you using? Are you using a 2 or 3 wire power cord? How are your connections to mains (wall) supply?



Green/Yellow.

Wayne
I get shocked when touching the volume nob, and once I got shocked touching the minijack connect to the two RCA jack inputs, but that doesn't mean I couldn't be getting shocked on the whole Chassis, I suspect that I would be


I am using a 272HX 300-0-300v 200ma 6.3v winding CT 6a, and 5v CT 3? a the the 5v winding is doing nothing however, and is securly insulated

3 Wire, with the third wire grounded to the chassis

what do you mean Primary? one of the taps HV on my Power Tranny? Its possible that one was shorting, but unlikely

How are my connections to the wall supply? Its going through I three-prong power strip, I KNOW that the Chassis is ground too, because I can measure the correct potential between the Plate and the water pipe (my houses ground (I know its against code now))

These are all great ideas, but I never had a problem before, now assuming that I don't want to use my finger, can I then measure a potential between the volume knob and the water pipe?
  Reply With Quote
Old 6th June 2006, 02:32 AM   #8
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Are your chassis, front and rear panels, and potentiometer bodies all firmly connected together?
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 6th June 2006, 02:34 AM   #9
diyAudio Member
 
Join Date: Mar 2006
Location: Michigan
Quote:
Originally posted by SY
Are your chassis, front and rear panels, and potentiometer bodies all firmly connected together?

I think so but I think I may have found the answer


see, I was cleaning the basement, and I disconected the right Channel, I then tested the amp apparently not remembering that it was disconnected and it got me, so is it possible that the right channel not being connected caused a potential to form between the case and the ground?

don't worry, the amp was only on for a few minutes (2-3) with no right channell
  Reply With Quote
Old 6th June 2006, 05:09 PM   #10
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
I think you might need to check that the ground connection on your power strip and the wall outlet are actually good. I would go get one of those outlet testers at home depot or rat shack.

Also use your multimeter and check to see whether you have continuity between the ground prong on your cord to all of the points you previously mentioned in your posts. You should measure well under an ohm taking into account the meter's probe resistance reading. (short probes together to find out, subtract this from total measurement.)

Nothing you have done would account for getting zapped in the way you describe. The other possibility particularly if you have AC or it is still cold and dry in your neck of the woods is esd discharge from you to your amplifier.

Be very careful however as this situation if due to a faulty ground connection could be quite hazardous, possibly fatal under the worst case scenario.

Also don't depend on other components to ground this one through the rca cables, interesting melting things have happened to such cables when fault current flowed through them to a properly grounded device.. Not a pleasant experience...

Be careful!
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How bad is grounding one side of AC filament ? vladn Tubes / Valves 4 27th October 2008 10:51 PM
Raising filament winding above cathode with a EZ81 in the circuit OK? G Tubes / Valves 3 15th May 2008 08:29 PM
Taking a Hammond 369BX filament winding to the limit? G Tubes / Valves 3 15th January 2008 04:25 PM
Grounding Filament CT? Sherman Tubes / Valves 16 8th February 2005 08:15 AM
Help with lowering filament winding voltage. G Tubes / Valves 7 8th September 2003 11:36 PM


New To Site? Need Help?

All times are GMT. The time now is 06:31 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2