Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

useing a Variac to test radio
#1

How would you use variac to test a radio so as to be safer than putting full voltage to the set. I understand if you make up a tester as I saw where you have light bulbs so if a 30 watt light bulb doesnt light it shows thee is a problewm, etc. But, when useing a variac do you just watch while uping the voltage to see if it smokes, etc? Sounds like by the time it smokes or something you already have ruined something anyway. Can someone explain the steps used so nothing hurts the radio, or am I right in assuming you just wztch it while turnin gup voltage. Thanks for any info on the subject.
#2

Hi All;
Warren, I would not just up the voltage just to see if something smokes..
When, I use my Variac, for the first time on something, I also put in the Dim bulb as well.. Also, I would with each upping check the different voltages, to see if they look like they are in the appropiate ball park of what I would expect.. I start at about 40% and check my filament voltages and B+ voltages, the got to 60% things should have a readable value by then.. then upping 10% at a time untill I get to 100% then by 5% untill It reaches about 115%.. By that time all readings should be in the range of what I would expect from the schematic.. If things look ok by that time and nothing is way off, then I can remove the bulb.. And only use the Variac.. But, If at any time things are not looking right or correct I would immediately shut things OFF.. And Investigate what is wrong..
THANK YOU Marty
#3

Ahhh, that makes sense. Thanks for the reply. I have a variac but didn't want to just up the voltages without some kind of plan on how to check things. Looks like I should build the light thing to check with also. Thanks, again. Warren




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Philco 42-1008 conversion kit
I read about a kit to convert the variable speed changer in the Philco 42-1008 into a single speed unit.  That would rem...alangard — 09:30 PM
HiFi (Chifi) tube amp build - but my own design.
Tim Well...a chassis is metal. Magnetic or not, it does not matter. A transformer has some hum to it. It is natural....morzh — 08:40 PM
Hickok AC51 tube tester
I thought the 83 tube was bad because it looked white but it tests strong. Blue gassy though. I checked the fuse, it was...martinj — 08:37 PM
Shadow Meter Bulb
Ross I am not sure what current limiting effect the incandescent provides. They are two different parts of the sch...morzh — 08:31 PM
12' Philco
Bob Thanks for that photo. I have been looking for it, and I cannot find anythinmg on the web. I forgot it was here...morzh — 08:29 PM
Shadow Meter Bulb
I think after all has been said, I will use the same bulb that is specified for the dial pilot light which is a #55. I ...georgetownjohn — 07:31 PM
12' Philco
There was also this Philco! klondike98 — 07:25 PM
HiFi (Chifi) tube amp build - but my own design.
I expected a challenge and this is just part of it. But, it's also supposed to be fun, entertaining, informative and enj...TV MAN — 07:12 PM
Shadow Meter Bulb
Butting in here with a question. Since the shadow meter is connected directly to the 1st and 2nd I.F.'s wouldn't the met...RossH — 06:43 PM
HiFi (Chifi) tube amp build - but my own design.
Mike, Tim; you are about to enter the twilight zone. Doo doo doo doo, doo doo doo doo This is something alright. I'm go...RodB — 06:26 PM

[-]
Who's Online
There are currently no members online.

>