Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

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

Philco 118 - Power Transformer Shorted?
#1

This set fails the dim bulb test with the rectifier tube removed. Transformer primary measures 2.3 Ohms. I assume the transformer is shorted, correct?
#2

Possibly but not necessarily. Did you remove all the other tubes also? There are lot of them and all the filaments combined will put a significant load on the transformer. 

What wattage bulb are you using? The power transformer is pretty large and can draw appreciable line current.



Do you have a Variac where you can bring the voltage up slowly and see when the AC line current starts to increase?
#3

Unless it is a short in the wiring to the transformer or between its secondary and the rectifier, I would say yes.
Yes it does matter what wattage you are using for a lamp. I assume you know what to use for the lamp.
Rob
#4

It's a 100W bulb and lights brilliant immediately. I measured several of my large transformers and they all measure at least 5 Ohms. Owner reports "smoke and burning electronics" at last turn on. I called him after I posted this thread.
#5

Bad short somewhere.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Restoration of the Canadian General Electric A-87
Thanks for your help Michael. In fact, this video is only an intermediate result. Later I had to apply another tinting l...RadioSvit — 09:01 AM
Restoration of the Canadian General Electric A-87
Great job on the cabinet. PS. In the US notation, "kenotron" refers to specific type of tubes; we call re...morzh — 08:24 AM
Part numbers to model cross
This document has at least some tables of models and parts used. Example: Choke 32-7572, used in 604 radio. Search f...morzh — 08:19 AM
Restoration of the Canadian General Electric A-87
I also checked all the radio tubes on my Hickok 530 tube tester. The 5Z3 kenotron turned out to be faulty, all the other...RadioSvit — 08:02 AM
Restoration of the Canadian General Electric A-87
Well... While the varnish is drying up, I started repairing the chassis... Of course I started by replacing the pa...RadioSvit — 07:12 AM
Philco Model 38-7: what caps & resistors do fail typically?
Hello Martin, Welcome aboard our little community what great Model 38-7 Sincerely Richardradiorich — 12:30 AM
Philco Model 38-7: what caps & resistors do fail typically?
Welcome to the Phorum Martin. I count about 9 paper caps, the 3 electrolytic caps and 2-Y2 safety caps to replace th...RodB — 09:44 PM
Part numbers to model cross
Jim, We have this index put together by Dale Cook but I don't think that is quite what you are looking for. The Parts...klondike98 — 09:37 PM
Philco Model 38-7: what caps & resistors do fail typically?
Yep the dim bulb test is OK but I'd definitely replace all those electrolytics before I did it. Since those #47 conden...klondike98 — 09:18 PM
Philco 42-345 Restoration/Repair
The resistor is a 2.2 Meg, it was the last one I hadn't replaced. The broadcast is coming in after replacing it.osanders0311 — 09:09 PM

[-]
Who's Online
There are currently 1136 online users. [Complete List]
» 1 Member(s) | 1135 Guest(s)
Avatar

>