Posts: 4
Threads: 1
Joined: Nov 2020
City: Alexandria
State, Province, Country: Virginia
Greetings All,
This is my first post to this site and I am hoping someone can help me finish my Philco 20 restoration project. I have repacked all the Bakelite blocks, replaced all the resisters, repacked the filter can, fabricated a dial lamp bracket, refinished the cabinet and replaced wiring as needed. The only thing left is this one resister.
My problem is the resister (see photo - grey ) that attaches to terminal 1 of part 25 and terminal 1 of the filter can. Terminal 1 of 25 attaches to terminal 5 of part 24 (transformer).
The resistor has the number 33-3280-1 stamped on it. I have found 33-3280 info which calls for 128 ohms but no wattage. Since these early numbers can be random in nature I am not sure of the resistance or wattage. Since this was probably added later (or different model) it does not appear on any of my schematics. To be honest, my ability to decipher this info using Ohm's Law, is unreliable.
I would appreciate knowing the ohm and wattage for this resister.
Thank you,
Fred
Posts: 15,510
Threads: 544
Joined: Oct 2011
City: Jackson, NJ
This Candohm is not native to the radio.
The part (probably the dead section of the wirewound part) is 1,400 Ohm.
At 18mA per tube (total 36mA) the dissipated power is 1.8W.
You might want to use 5W and up resistor.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
(This post was last modified: 11-23-2020, 06:17 PM by morzh.)
Posts: 101
Threads: 13
Joined: May 2020
City: Clemmons
State, Province, Country: NC
Measure the ohms from the base of where that gray resistor (that someone added) attaches and to the candohm post that goes to ground - scrape deep into the metal at that post and also the base where the gray resistor attaches. What does it say?
Posts: 15,510
Threads: 544
Joined: Oct 2011
City: Jackson, NJ
I am not sure I understood. Are you suggesting I do the scraping and measuring?
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 4
Threads: 1
Joined: Nov 2020
City: Alexandria
State, Province, Country: Virginia
Guys, that was really helpful. I was wondering why I couldn't get a reading (obviously to all but me) that the posts were too corroded. The push-pull transformer had been replaced. It's an "official replacement part" so possibly, there was a problem with the set that affected the last section of the long resister, part 25 (as you suggested). I will check the ohms tomorrow and go with a suitable replacement resistor at 5 watts. Unless you guys have any additional suggestions, I'll leave it at a greatful thanks for your help. Fred
Posts: 15,510
Threads: 544
Joined: Oct 2011
City: Jackson, NJ
Let us know how it turns out.
This very resistor burning out in 20 is a popular thing to happen - my first 20 lowboy had exactly the same (and the only one) section open.
And the output transformer primary open. I guess it goes hand in hand.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 4
Threads: 1
Joined: Nov 2020
City: Alexandria
State, Province, Country: Virginia
All,
I have not forgotten to post my final radio pics BUT I seem to have a new problem. It's a garble problem. I replaced the resistor noted above and (I don't think it's related - tried returning old part - then new part grounded to chassis - finally new part as noted above - no difference) now have a poorer reception with a slight garble. While I believe I have sufficient antenna attached I still get some variation when touching the volume control and get static when the chassis is grounded. I have checked all my solders and "poked" around with a chopstick for change but see nothing out of place. I would appreciate suggestions.
Fred
Posts: 15,510
Threads: 544
Joined: Oct 2011
City: Jackson, NJ
Have you tried to align the set?
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 4
Threads: 1
Joined: Nov 2020
City: Alexandria
State, Province, Country: Virginia
No. I understand that special equipment is needed. Could it be a ground or a better antenna is needed?
Posts: 4,655
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
Not really, a Philco 20 used what was known as TRF circuit, basically the only thing you can do is adjust trimmer/padder condensers for gain, I don't think it even needs a neutralization adjustment since it uses screen grid tubes for RF amplifiers #24s or #35s. I'm not sure how you can get the dial to track on one of these, the factory instructions would probably say.
Regards
Arran
Users browsing this thread: 1 Guest(s)
|
Recent Posts
|
Bakelite crack repair - what is best epoxy?
|
Thanks everyone. I appreciate you sharing your experience and looks like I'll work with the 24 hr two part clear epoxy....de371 — 10:25 PM |
Jackson 665 j2 schematic request
|
Without a schematic its going to be hard tracing the wire wound spool resistors.daveone23 — 05:21 PM |
Jackson 665 j2 schematic request
|
Looking for a schematic for the 665 j2 multimeter.daveone23 — 04:42 PM |
Looking for place to donate unique Philco Philco J-1930 Prototype
|
>>I'll write to the Henry Ford.
I heard, his secretary answers his mail, not he himself.morzh — 12:15 PM |
Philco 48-200 alignment questions
|
Just checked the power cord and I did in fact wire it so the hot side (small prong) goes to the switch.transitony — 11:52 AM |
Looking for place to donate unique Philco Philco J-1930 Prototype
|
Thanks for the suggestions. I'll write to the Henry Ford. That would certainly make sense since by the time this prod...jeibner — 11:49 AM |
Looking for place to donate unique Philco Philco J-1930 Prototype
|
For what it's worth, the Henry Ford Museum and Greenfield Village in Dearborn, Michigan may be an option.
The obvious ...GarySP — 11:39 AM |
Help with Readrite 410 tube tester
|
Mike and I just had a short discussion yesterday about this very subject. So often it's the connections. Ya gotta have t...RodB — 10:08 AM |
Looking for place to donate unique Philco Philco J-1930 Prototype
|
We have a regional museum here in the Twin Cities called The Pavek Museum. They have an extensive collection of communic...RodB — 09:30 AM |
Philco 89B code 123 newbie
|
I did some nosing around and found that the original caps were 4 3/4" long x 1 5/16" in dia. Guess what 1"...Radioroslyn — 09:28 AM |
Who's Online
|
There are currently no members online. |
|
|