Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Diagnostic & Test Equipment

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 12-16-2014, 07:00 PM
transmaster transmaster is offline
VideoKarma Member
 
Join Date: Jun 2013
Posts: 87
A Variac, What size? What brand?

I need a Variac. I already am going to pick one with a isolation transformer in deference to the hot chassis Zenith portable I am working on but I am undecided as the the power capacity. The biggest current draw I am likely to use one with would be an HF amp. The Heathkit SB-220 draws about 15 amps set to 120vac mains. But that isn't going to happen much, everything else will be receivers and will much draw much less then 10 amps. Go for broke or get what I will actually use. I have always used the light bulb inline for the first start up procedure in the past I figure time to get fancy.
Reply With Quote
  #2  
Old 12-16-2014, 07:23 PM
Eric H's Avatar
Eric H Eric H is offline
Administrator
 
Join Date: Jun 2002
Location: So. Calif
Posts: 11,565
I have a 5 amp model, it's plenty for any vintage TV set but light duty enough to pop it's breaker if there's a short.

This model here exactly though I paid a lot less. http://www.ebay.com/itm/General-Radi...item259b913249

It does not isolate but I have a separate transformer for that. I do wish it had an ammeter built in but I added an external one.
Reply With Quote
  #3  
Old 12-16-2014, 08:00 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
I'd go for whatever can handle the biggest load I could imagine throwing at it.

Keep in mind heat is what kills them so if you overload one it won't die unless you let it get hot, and keep running it while hot...So you can run one overloaded for a few minutes to hours safely if you watch the temp.
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #4  
Old 12-17-2014, 09:47 AM
dieseljeep dieseljeep is offline
VideoKarma Member
 
Join Date: Jul 2010
Posts: 7,562
Quote:
Originally Posted by Eric H View Post
I have a 5 amp model, it's plenty for any vintage TV set but light duty enough to pop it's breaker if there's a short.

This model here exactly though I paid a lot less. http://www.ebay.com/itm/General-Radi...item259b913249

It does not isolate but I have a separate transformer for that. I do wish it had an ammeter built in but I added an external one.
The General Radio, Superior and Staco are usually the TOTL.
I have several of them, all different sizes. When you do have a bad short, it's not hard to damage the winding surface, that the brush rides on.
Reply With Quote
  #5  
Old 12-17-2014, 12:23 PM
transmaster transmaster is offline
VideoKarma Member
 
Join Date: Jun 2013
Posts: 87
I think I am going for a 20 amp size. That would cover 99% percent of what I need.
Reply With Quote
Audiokarma
  #6  
Old 12-17-2014, 01:19 PM
rca2000's Avatar
rca2000 rca2000 is offline
VideoKarma Member
 
Join Date: Mar 2003
Location: cincinnati,ohio
Posts: 2,090
I use the sencore PR_57. Variable and isolated. It is heavy enough for any vintage TV--but NOT big enough for all plasma tv sets and such Also more than heavy enough for stereo amp work...as LONG as one does not "crank a big amp" too much'...
Reply With Quote
  #7  
Old 12-18-2014, 09:32 AM
dieseljeep dieseljeep is offline
VideoKarma Member
 
Join Date: Jul 2010
Posts: 7,562
Quote:
Originally Posted by transmaster View Post
I think I am going for a 20 amp size. That would cover 99% percent of what I need.
There was one on the E-place. It looked like, at least a 20 amp unit.
They're very expensive, when new. The prices didn't seem too bad.
Reply With Quote
  #8  
Old 02-28-2015, 09:16 PM
Tubejunke's Avatar
Tubejunke Tubejunke is offline
VideoKarma Member
 
Join Date: Apr 2003
Location: Martinsville, VA
Posts: 1,823
I have one of these that I am not using. Pretty much top of the line. I think its a General Radio Variac 20A model, but I may need to correct that when I can get to it. I don't use it because it used weird 3 prong input and output cables which I don't have. It could easily be adapted or perhaps they still make plugs for it. I really don't know.

I would not want the kind of prices I see looking around online, but shipping would be a bear as it is really heavy.
__________________
"Face piles of trials with smiles, for it riles them to believe that you perceive the web they weave, and keep on thinking free"
Reply With Quote
  #9  
Old 02-28-2015, 09:18 PM
Tubejunke's Avatar
Tubejunke Tubejunke is offline
VideoKarma Member
 
Join Date: Apr 2003
Location: Martinsville, VA
Posts: 1,823
Sorry, I meant to post this picture. Not actual, but as close as it gets.
Attached Images
File Type: jpg download.jpg (2.1 KB, 36 views)
__________________
"Face piles of trials with smiles, for it riles them to believe that you perceive the web they weave, and keep on thinking free"
Reply With Quote
Reply


Thread Tools
Display Modes

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

Forum Jump


All times are GMT -5. The time now is 03:27 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.