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 38-4 chassis ith no speaker
#1

Hi all,

I just joined the site an am looking forward to learning a lot about these old Philcos. I had a 38-4 in my cellar when I was 10 years old. It worked great. Just picked up a chassis that needs recapping and a speaker. I changed the power cord and all the tubes light up and I measured the two terminals on the plug for the speaker that are closer together, ( they measure approx. 350V) Can someone tell me how to convert this to a PM speaker? Also, does anyone know the correct illumination lamp that plus into the back of the dial? Alos where to get ot would be good to know too. ((is teh elctromagnet for the speaker also called the Field Coil?) Thanks for your help with these questions. I also have a Philco portable radio that plays great but has a little hum to it. I', using the AC line because I don't think they make the batteris for it anymore.
Dennis
#2

You need to find out what the resistance was of the original the original field coil was and use a resistor or a choke between the B+ ,then you need to find out if you still have audio out put transformer and if it's push pull or not, quite offen the out put transformer was mounted on the speaker.
Need obsolet batterys? build your own, I have several vintage portables , I've got another Portable Philco coming in now, one I have, Philco, has 1 1/2 volt "A" and 90volt "B", I use two "D's" in paralle. and 10 9 volts in series, I also have a Zenith Transoceanic Clipper 7G605[1942] I use 8 "D's" 6 in series two parallel= 9volts and then 10 9volts these radios will play over 50 hours on Dollar Store batterys!
#3

Dennis tiernan Wrote:Hi all,

I just joined the site an am looking forward to learning a lot about these old Philcos. I had a 38-4 in my cellar when I was 10 years old. It worked great. Just picked up a chassis that needs recapping and a speaker. I changed the power cord and all the tubes light up and I measured the two terminals on the plug for the speaker that are closer together, ( they measure approx. 350V) Can someone tell me how to convert this to a PM speaker? Also, does anyone know the correct illumination lamp that plus into the back of the dial? Alos where to get ot would be good to know too. ((is teh elctromagnet for the speaker also called the Field Coil?) Thanks for your help with these questions. I also have a Philco portable radio that plays great but has a little hum to it. I', using the AC line because I don't think they make the batteris for it anymore.
Dennis

A filter choke is the best substitute for a field coil on a speaker, unless it's a smaller set then a wire wound resistor is good enough, there is a way to make a solid sate substitute for a filter choke if you can't find an iron one.
With regards to the portable, if it hums excessively during AC operation, assuming it is a three way portable with a built in AC power supply, then very likely the filter capacitors need to be replaced.
Regards
Arran




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
The list of my radio & TV collection!
Sorry, these are my old videos, so there are no English subtitles yet. RadioSvit — 06:00 AM
The list of my radio & TV collection!
Yes, MrFixr55. I agree with you, this Galicrafters is structurally very similar to the Zenith Transoceanic H500, as well...RadioSvit — 05:58 AM
The list of my radio & TV collection!
Hi Richard. I really like the Hickok, it is very convenient to use. I have another tube tester - the Soviet L1-3. It is ...RadioSvit — 05:27 AM
The list of my radio & TV collection!
Arran. I completely agree with you. I also noticed that the Canadian consoles General Electric, RCA and De Forest Crosle...RadioSvit — 05:11 AM
Electrolytic restuffing/internals
I don’t have a vise so I had to hold it in my hand. Not optimal but covered up by the hvac tape in the end. I have a few...bridkarl — 11:52 PM
Electrolytic restuffing/internals
Bridkarl A question. For a hacksaw the cut looks a little...jagged. Why?morzh — 11:45 PM
The list of my radio & TV collection!
As usual, an interesting post from you, Peter. This seems to be similar to the RCA 3-BX-671 and the Zenith Transoceanic...MrFixr55 — 11:41 PM
The list of my radio & TV collection!
Hello Peter, Thank you for sharing your new video and looks like your weather is nice their too. it was like 25 Cel...radiorich — 11:05 PM
Electrolytic restuffing/internals
hello bridkarl, I will post some better photos ! Sincerely Richardradiorich — 10:14 PM
Electrolytic restuffing/internals
I just taped the two pieces of the cap together, but I can see your method is better. I just held the lead in with solde...bridkarl — 08:18 PM

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

>