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

Philco 39-7 resto
#16

One of the old ones? I use to work on the old ones and had a bunch back in the 70's. '51 split window, '55 convertible 3-'56 sedans 66'Giha....
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#17

Oh, I wish it was an "old" one. I have a 72 standard (so, kind of old). The PO messed with it, and left it in a yard for a couple of years. I "rescued" him (Jack), and then paid too much money to get him running. I ran out of money, and patience, for a crappy running engine so I became my own VW aircooled mechanic. Now, he runs like a top. LOL

Now that it is winter time, and Jack's hibernating, I decided to become a "radio mechanic" ... sheesh... Icon_crazy

I wish I had an older one ... mid 60's ... no real reason other than I like the looks of them.
#18

Okay, back on topic. Icon_biggrin

I am replacing the original cord with a polarized one, as the insulation rotted away. Am I correct in thinking that the hot side goes to the switch, and the neutral to the chassis ground?

Then, once I have that accomplished, I think I should try it out by plugging it in. I have a dim bulb tester. What wattage bulb should I try first?

Thanks!
#19

The polarization doesn't matter on the set as it use a power transformer. This isolate the AC line from the chassis. Don't connect one of the AC leads to the chassis! It doesn't go there, it goes back to the other black lead from the transformer. One of the black leads goes to the switch and the other goes to the AC line.
If your set was an AC/DC set you are correct to connect the neutral to the chassis but it isn't.
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#20

Thanks for the clarification, Terry. Icon_smile

Just had an "Aha... D'oh!" Moment. Icon_surprised Yes, one wire of the plug goes to the switch, and the other to the cap and a different wire from the transformer. Got it now!

Will connect that way, and then .... plug it in ... Icon_biggrin
#21

Moderate success to report.

After replacing the electrolytic capacitor, the line filter capacitor, the power cord, AND resleeving several badly crumbling wire insulation, I decided it was time to plug her in.

I powered up the radio using the dim bulb tester. Starting with a 25 W bulb, then a 40 W, and last a 75 W bulb, none of them lit up. I then plugged it in without the DBT, and no smoke or fire! Yay! Icon_smile

Questions I know have:

1. I heard nothing at all from the speaker.

2. While I saw all tubes "light up" I am not sure they were at full power. How "lit" up should they look, say, compared to a regular light bulb?

3. And, now what to do? Do I begin replacing the other capacitors?


EDIT: Also, when I had the radio plugged directly into power, the dial lamp burned brightly for about a minute or more, and then went out. Icon_confused:
Thanks for the help so far! Icon_smile
#22

I'd poke around and see if I had any HV. Measure from one of the filament pins of the 80 tube to the chassis .Should show a few hundred volts.
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#23

Please pardon my ignorance, but what is HV? And, how would I test?

I know I would be using my meter but, I am not sure how. Remember, I am a complete novice here...

Icon_confused:
#24

Sorry HV stands for High Voltage. It also has an alias known as B+. Respect it it can be shocking. Like fire needing air water and fuel a radio needs certain properties to operate. HV is one of them. In the power supply section of you set that would be the power transformer, the 80 tube and the electrolytic caps. If it is working properly these parts will make about 220volt DC at either of the filament pins of the 80 tube and at the+side of the electrolytic caps to chassis ground. So what you do to measure this voltage is set your meter for DC VOLTS and the range up to 500v if your meter isn't one that has an autoragne feature. The black probe hooks to the chassis and the red probe touches one of the fat pins of the 80 tube. You should see on your meter a few hundred volt. Two important things when you replaced the electrolytic caps the + side must be connected towards + side of the HV line. No +'s connected to the chassis. And watch out for the angry 80 tube. The 80 should have it's filament lit when the set is on. Look at it and see if the part around the the filament is called the plate. It should stay nice and black if it starts to glow a faint red or you see sparks inside it turn the set off you've got a short that will burn out the power transformer. If this is going to happen it will occur in the first few seconds of turn the set on.
Terry
2:38AM wow that's pretty late! Ever read How To Fix You VW For Complete Idiot? By John Muir. Come out in the '70's Great book!!! To bad it's been out of print for a long time.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#25

Thanks, Terry. After I thought about it a bit, I figured HV was for High Voltage, as that is what should be going to the rectifier ... Icon_redface

I will test the HV, and will double check how I hooked up the electrolytic caps. I was aware that they needed to be put in a certain way, but who knows? I may have put them in backwards.

I do have that Muir book, and it is not out of print! It's in it's 37th printing, or something crazy like that. Icon_smile I started with that book, and then on to a Haynes manual, and finally a Bentley. I love the Bentley! Wish there was something like that for my radio. Icon_smile
#26

Should the other tubes remain in when I do this test?

Because I had them all out when I did the test. I put the positive probe in pin 3 and the negative I put on the chassis. My meter was at 500V DC, and the needle hardly budged. Icon_sad

The dial lamp burned brightly the entire time.

Icon_confused:
#27

You should have an equal amount of AC on pins 2 and 3 (plates) of the type 84 rectifier with or without the tube plugged in with respect to ground. If that is so, you should have DC of a couple of hundred volts on pin 4 (cathode ) of the type 84 rectifier with the tube plugged in. Then you can plug in the type 41 audio output tube and measure the plate and screen grid voltages as per the schematic. If there is nothing there the field coil on the speaker may be open. Anyway work through the voltage dividers after that.

http://www.nostalgiaair.org/PagesByModel...013301.pdf
#28

Ok pull out the 80 tube and measure the AC voltage across the two smaller pins/ holes at the 80 socket. Should see about 500vac. Be careful stick the two probes in the socket hole and then turn the set on. Did you disconnect the old electrolytic caps when you put in the new ones? If not do so.
CF
Her set had the power transformer replaced and the rectifier was replaced with an 80.
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#29

Thanks for the replies, guys.

I am not getting much of a reading at all. So, either the transformer has problems, or I have problems. Not ruling out the latter, so I will keep reading and working on it. I don't completely trust my ability with the multimeter, so I will call in a friend this week to give me another lesson. Icon_smile
#30

Just for laughs just measure the ac line going into the set to check your meter setting. Will be gone for a hour Amos n Andy and Jack Benny are on my radio curtiscy of WNAR.
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry




Users browsing this thread: 1 Guest(s)