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

48-200 mystery capacitor
#1

I am attempting my first re-capping job on a 1948 Philco 48-200 radio.

I have come across what I think is a melted capacitor (brown tubular item in center of photo). However, (and I am new so I am not sure), I cannot find this on my schematic of the radio, and I do not know what the capactance is for this item. it attaches at pin 6 to the 50L6GT tube and pin 5 of the 14A7 tube. it is in parellel with a resistor but being such a newbie, I don't know what it's resistance is.

If someone could help me out with this, I would appreciate it.

Thank you.

Just added new phot of underside of mystery capacitor.


Attached Files Image(s)
       
#2

(03-05-2012, 07:24 AM)winkydink Wrote:  I am attempting my first re-capping job on a 1948 Philco 48-200 radio.

I have come across what I think is a melted capacitor (brown tubular item in center of photo). However, (and I am new so I am not sure), I cannot find this on my schematic of the radio, and I do not know what the capactance is for this item. it attaches at pin 6 to the 50L6GT tube and pin 5 of the 14A7 tube. it is in parellel with a resistor but being such a newbie, I don't know what it's resistance is.
If someone could help me out with this, I would appreciate it.
Thank you.

Just added new phot of underside of mystery capacitor.

Hi,
The cap. is C202, 220pf, in parallel with the 470K resistor. Pin 6 of the 50L6 is a B- tie point on the tube socket and not an active tube pin. Just use a standard 630V cap. and you'll be fine. Be sure to check all other components. Icon_smile John
#3

(03-05-2012, 11:33 AM)John R Wrote:  
(03-05-2012, 07:24 AM)winkydink Wrote:  I am attempting my first re-capping job on a 1948 Philco 48-200 radio.

I have come across what I think is a melted capacitor (brown tubular item in center of photo). However, (and I am new so I am not sure), I cannot find this on my schematic of the radio, and I do not know what the capactance is for this item. it attaches at pin 6 to the 50L6GT tube and pin 5 of the 14A7 tube. it is in parellel with a resistor but being such a newbie, I don't know what it's resistance is.
If someone could help me out with this, I would appreciate it.
Thank you.

Just added new phot of underside of mystery capacitor.

Hi,
The cap. is C202, 220pf, in parallel with the 470K resistor. Pin 6 of the 50L6 is a B- tie point on the tube socket and not an active tube pin. Just use a standard 630V cap. and you'll be fine. Be sure to check all other components. Icon_smile John


Thanks, That is exactly what my father-in-law told me too. I guess I will need to pick one of these up at Radio Shack.
#4

(03-05-2012, 12:13 PM)winkydink Wrote:  
(03-05-2012, 11:33 AM)John R Wrote:  Hi,
The cap. is C202, 220pf, in parallel with the 470K resistor. Pin 6 of the 50L6 is a B- tie point on the tube socket and not an active tube pin. Just use a standard 630V cap. and you'll be fine. Be sure to check all other components. Icon_smile John


Thanks, That is exactly what my father-in-law told me too. I guess I will need to pick one of these up at Radio Shack.


Well I tried Radio Shack but they only had 100 pf capacitors. I just received a big order of capacitors and resistors from "Just Radios" but did not order this type of cap. Any suggestions from anyone where I can buy just 1 of these caps and not have to pay alot for shipping.

Also a link to the proper capacitor on the vendors page would also be appreciated. I have looked at Antique Electronic supply's web site but could only find ceramic caps at 220 pf, no tubular.

Thanks in advance.
#5

(03-05-2012, 11:33 AM)John R Wrote:  
(03-05-2012, 07:24 AM)winkydink Wrote:  I am attempting my first re-capping job on a 1948 Philco 48-200 radio.

I have come across what I think is a melted capacitor (brown tubular item in center of photo). However, (and I am new so I am not sure), I cannot find this on my schematic of the radio, and I do not know what the capactance is for this item. it attaches at pin 6 to the 50L6GT tube and pin 5 of the 14A7 tube. it is in parellel with a resistor but being such a newbie, I don't know what it's resistance is.
If someone could help me out with this, I would appreciate it.
Thank you.

Just added new phot of underside of mystery capacitor.

Hi,
The cap. is C202, 220pf, in parallel with the 470K resistor. Pin 6 of the 50L6 is a B- tie point on the tube socket and not an active tube pin. Just use a standard 630V cap. and you'll be fine. Be sure to check all other components. Icon_smile John




Hi, agree with John except the resistor in your set R203 reads 430K (yellow=4, orange=3, yellow=4 [43 plus 4 zeros]) not the 470K that the schematic calls for.
#6

Two 100 pf in parallel will probably be good enough. Get 'em tight together.

Next time listen to your other old man.
#7

I'm not sure if those dogbone ceramic capacitors are still manufactured, but as Codefox said, you can use a ceramic disc cap to replace it. Two 100 pF ceramics in parallel should work fine.

Several suppliers of capacitors are listed in the Resources pages of my website. You may not find the exact same type (in this case, "dogbone" ceramics), but you can almost always find a substitute.

http://www.philcoradio.com/resource.htm

--
Ron Ramirez
Ferdinand IN
#8

Hi, agree with John except the resistor in your set R203 reads 430K (yellow=4, orange=3, yellow=4 [43 plus 4 zeros]) not the 470K that the schematic calls for.

I believe that the resistor is 470K. The second band is violet, I think. If you look at the resistor above the capacitor, you will see that it clearly has an orange band. Going by that, I think the resistor below the capacitor is Yellow, violet, yellow.

Steve

M R Radios   C M Tubes
#9

Steve, I'm referring to the resistor which is between the two caps. It clearly has yellow orange yellow which is 430K. The schematic calls for 470K, yellow violet yellow. I don't see a yellow violet yellow cap in the picture. PL
#10

(03-07-2012, 11:53 AM)planigan Wrote:  Steve, I'm referring to the resistor which is between the two caps. It clearly has yellow orange yellow which is 430K. The schematic calls for 470K, yellow violet yellow. I don't see a yellow violet yellow cap in the picture. PL

Im just saying, the second band doesn't look very orange compared to the orange on the resistor just above it.

Steve

M R Radios   C M Tubes
#11

The resistor that is in parallel with the dogbone ceramic 220 pF capacitor is 470K (yellow - violet - yellow).

Look closely. That is a very light violet...almost dark pink...but definitely violet. I've seen old 470K resistors with very light violet bands like this before.

Now if you look above the 220 pF dogbone cap, there is a resistor with an orange band and a silver band; can't make out the other bands. The orange is definitely a different color than the light violet of the 470K resistor.

430K isn't a standard value, and wasn't back then, either...

--
Ron Ramirez
Ferdinand IN
#12

Gentleman, I bow to the numbers. My eyes must be growing weaker that I cant see that as violet. The schematic calls for it to be violet and as pointed out 430K would be a wild duck number. PL
#13

Well I ordered a 220 pf (ceramic) cap today, and hopefully that will do the trick. If not, then I will use the two 100 pf caps in parallel.

thanks all.
#14

Here is another questions for those out in radio land.

It seems to me that in many cases, the radio I am working on, and the schematic don't agree.

(A) For example the schematic may say that a capacitor attaches to pin 2 but on the radio it is pin 3.

(B) The schematic says that the electrolytic caps should be 20 25 30, but the cap in the radio is 10 20 30.

I know in some case for (A) one of the leads may attach to B- so it may be that there are many options for this, and in (B) case, the radio has been repaired so they may have substituted.

My question is, when I encounter a difference between the radio and the schematic which should I use. I don't have enough or ANY real electronic experience to make an educated guess about differences in pin numbers. My gut tells me, to put it back together the way the radio is presently wired.

Any thoughts ?




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 91 Speaker Replacement
The spider is glued on the cone and so is the voice coil. I think you can use a cotton swab dipped in acetone and carefu...RodB — 02:42 PM
Restoring Philco 37-604C
Yes I saw that. If I knew, I'd probably try to arrange for getting it myself. But I have just got one. Which does not m...morzh — 01:44 PM
Philco 38-2 Automatic Tuning
When you push the lever, you are supposed to rotate the disk to the desired station. Then the magnetic tuning will acqu...morzh — 01:42 PM
Philco 38-2 Automatic Tuning
I figure out the muting from another picture that helped. Now I need to know how the automatic tuning works. When I push...dconant — 12:11 PM
Philco 91 Speaker Replacement
How would I go about removing the spider from the cone?dconant — 12:04 PM
Philco 38-2 Automatic Tuning
Hello, I am having trouble getting my automatic tuning to stay unmuted. If I play with the tuning handle I can get it to...dconant — 10:51 AM
Does anyone make photofinish replacements?
Here’s the link to the DIY photofinish section of our site: klondike98 — 09:46 AM
Delco car radio Peko vibrator converstion issues
Hi Richard, Thx for posting the schematic.  As I remember as a kid, these were great performers for the time, likely...MrFixr55 — 08:56 AM
Delco car radio Peko vibrator converstion issues
hello mr Fixr, The Electro  Powersupply that I am powering the radio with has a huge choke plus a 10,000ufd electrolyti...radiorich — 10:58 PM
Delco car radio Peko vibrator converstion issues
How about putting a choke in the power supply? The big cap was likely an attempt to stabilize the DC. Kids who cre...MrFixr55 — 09:19 PM

[-]
Who's Online
There are currently 1277 online users. [Complete List]
» 1 Member(s) | 1276 Guest(s)
Avatar

>