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

Replacing NTC resistor in Philco 52-940
#1

There is a negative temperature coefficient resistor/filament dropping resistor used in the model 52-940 AC/DC set. It's rated at 100 ohms, but I believe this is a resistor that has a cold-hot resistance-also known as " globars". I've read elsewhere that the CL-90 inrush current limiter is the replacement for this. What are the correct replacement options?
#2

Just a suggestion. I have never tried it. If the globar is open replace it with a 100 ohm 10 watt resistor and add a CL-90 in series with the On/off switch. Another possibility is to replace the 35L6 with a 50L6 and do away with the 100 ohm globar and still add a CL-90 in series with the on/off switch to prolong the life of the tube filaments.

I have used a CL-90 in AA5 sets without any original surge resistor protection eg. a Emerson 503. It drops 4-5 volts and increases warm up time to about 30 seconds. In general I usuallly add a CL-90 to all the sets that I restore just to prolong tube life. It's kind of neat to watch the pilot light ramp up to full brightness. Icon_smile Mount the CL-90 so there is as much clearance as possible to other components, particularly electrolytics. CL-90s get hot. That is how they work. Mouser has CL-90s and does not have a minimum order charge.

Kind regards,
Terry
http://home.comcast.net/~suptjud/
"Life is simpler when you plow around the stump."




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
New Philco Repair Bench
I am sure this is the archive, and not the Chuck's site.morzh — 09:50 PM
Made mistake & did not label connection
It's not like we are good friends with that wire and can tell it from other ptetty identical looking wires. Why'n't you...morzh — 09:49 PM
Made mistake & did not label connection
I'm not sure why that wire wasn't covered in the video. I'm pretty sure the 6A8 won't work until that pin is grounded. Y...RodB — 09:47 PM
Made mistake & did not label connection
You'll have to forgive me, I am not sure what you mean.  Can you explain what you are really saying.  If anyone does not...georgetownjohn — 08:05 PM
Made mistake & did not label connection
Those are details better left to the ones who know. Maybe you disconnected the wrong end of the wire.RodB — 06:22 PM
Made mistake & did not label connection
Maybe this is starting to make some sense in my hard head.  Is this why the wire in question was not in the great Ron Ra...georgetownjohn — 04:34 PM
Made mistake & did not label connection
I was correct with the 6A8 pin connection's, 7 and 8 are connected to ground as well as the tube shield (the broken line...RodB — 02:41 PM
Made mistake & did not label connection
What does the dotted line representing that surrounds the tube in the schematic?georgetownjohn — 02:17 PM
Made mistake & did not label connection
Hello John, I have been there either label got lost or was not labeled ! Sincerely Richardradiorich — 02:15 PM
Made mistake & did not label connection
Sorry, it is a Philco 37-640.  Does that help?--Johngeorgetownjohn — 02:14 PM

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

>