Repairing and Restoring Tube Radios - part 3

[Quaaludedude714]

good for you :) QC

[vamtim]

Brilliant videos. I'm in the process of restoring a GEC 5645 it's my first attempt at such a restoration. I have to replace all the waxies and electrolytics just waiting for them in the post. Thanks for posting these videos they're immensely helpful.

[bandet888]

In my other comment I ment rectifier CAPACITORS

[bandet888]

Only the rectifier is responsible for any hum noise. How ever most other capacitors are coupling capacitors. It's important to replace these too especialy the paper ones. What happens is they get leaky a lot and through the voltage off the circuit. What ends up happening is when they through the voltage off the amplifier will become distorted. They wont have a DEAD short (you still get a high voltage reading on 1 side) and will test good on a cap checker. Replace them anyway!

[Teflon65]

Some folks take a digital photo of the chassis and wiring and so on, to aid with their memory. You probably know this, but it seems easier than labeling. Also, why is the hum called a 60 cycle hum? I know that bad electrolytics can cause that hum, and that it can ruin the transformer. I'm just unsure about the nomenclature. No expert here, just watching videos like yours and enjoying them tremendously.

[greasebird]

It looks like you replaced one big Capacitor with two small capacitors in series. Shouldn't they be in parallel?

[force311999]

@greasebird the two caps are of different value the old one has two taps on it so it is like two caps together in one case

[isethaitchison]

question....Does the Farad amount matter??? 

[IstvanN1961]

Why did you use two smaller capaciters to replace one large capaciter?

[force311999]

@IstvanN1961 the large cap has two caps in it

[gbowne1]

I always loved the "Magic Eye" green glowing tubes. Some of your tubes have silver oxided themselves near the base. The nice silvery looking coating on the glass.

[hedwig85]

Great job on this restoration Mike. Some folks not familiar with electronics may believe you are a genius for associating the filter caps with the hum problem. You might want to point out, that the hum is the 50 or 60Hz unfiltered power coming out of the rectifier, riding along with the audio and amplified to the speaker. Going back to your nice diagram, when the filter caps fail, all those DC bumps (ripple) are coming through.

[lastreefalling]

truly lovely, these babies are a joy, yet please please, it's pronounced sh asē| SH not ch.

im such a pedant hahahahaha

[132mikle]

i have a "simfonija" radio from yougoslavia and when i turn it on their is humming noise of i belive 50Hz the tubes are el84,em80,ech81,ecc85,ef89,eab­c80 and ez80 what is wrong?

[ShrCanIt]

Нельзя использовать современные кондеры!

[bandet888]

Even if you don't label the tubes there's still a tube chart inside the cabinate. But sometimes tube numbers can wear out on the tube themselves.

[bandet888]

I once fixwd up a tube radio but there was a capacitor in parallel with the line voltage, (a noise filter not power supply filter) It momentarily shorted, exploded but after it exploded it just got removed from the circuit as it is now open, the radio was still functioning and was tuned to a talk show. After the noise of the capacitor a guy on the talk show happened to say at that time "what was that?" What great timing, LOL. (remember the radio was still working after the capacitor exploded)

[bandet888]

Only the large capacitors in power supply are used as filters, most small paper capacitors are coupling capacitors (blocking DC voltage but passing a signal). but paper capacitors get leaky throwing the voltage off thus causing the circuit not to function correctly. So it's a good idea to replace all paper capacitors (power supply or not)

[rockinrollfan37]

also a good idea to replace the line filter capacitor with a newer safety capacitor

that are designed to fail in a way that won't

burn your house down! line filters on some models are connected in before the power switch and are activated anytime the radio is plugged in always unplug old tube radio's when not in use.

[vlahula]

Just a suggestion: once the damaged part is replaced, the original is seriously affected. With a little more work, the old damaged capacitor can be emptied to save the exterior. Put the new one inside and then replace it. Harder for resistors. But there may be a solution similar to this for any part. Best is to replace with NOS . Great job with the video anyway. I salute ppl. doing this kind of efforts.

[J3sst44]

Hmm, you really should have talked about draining capacitors before working on a tube device. They can store hundreds of volts for ages after a device has been turned off.

Also, when removing tubes, it's best to grip them from the plastic/ceramic base (If they use them), this will avoid snapping any glass.

But overall, good video.

[Madness832]

Nice, but as someone else pointed out, I'd replace all the paper/wax caps, not just the electrolytics.

[nernstequation]

The video was doing pretty well until you got to the replacing of the capacitors, where you went from steps 'A' to 'C' without demonstrating 'B'. Among the questions a viewer would normally be asking while watching:

"Wait, which capacitors, specifically, did you replace?"

"How, exactly, did you remove the old ones and solder the new ones?"

"Can I just remove the caps like that? Will I get zapped?"

"Why did you replace two caps in place of one?" (i.e., multi-unit caps)

[HobieTyourtube]

PERFECT!!----------your procedure was excellent.

Those "old time valve radios "are work horses!--a lttle bit of care-and knowledge-can restore them to-greatness.

That speaker cone looked in excellent shape?

Steve.

[hoke92]

your videos have helped me a lot

im restoring an old rca radiola 17 and a rca radiola 18

do you have any good sites to get parts from?

[joacomio]

How do you calculate the new electrolitic capacitors, i mean the Voltage number in the new electrolitic capacitor? with the max V that gives the rectifier tube?? thanks very much for uploading this videos.

[KC8YOQ]

Can I have the old paper caps you removed?

Where do you get you new caps????

[gamma68]

Since you already have the chassis out of the cabinet, why not go ahead and replace ALL the paper capacitors?

[fwdstuck]

I got a Silvertone wire recorder/phono/radio combo coming in the mail soon that i'm going to recap and restore. Great video!!

[musicman0150]

What a nice sound that radio has with that big speaker. Maybe you can answer some questions for me. Can that type of speaker work with a modern radio and can you connect a modern speaker to this type of radio? If so, how is it done? Also, it looked like the speaker cone had some holes in it, or was it just the lighting?  Where is the danger spot on that type of speaker when the radio is in operation because it amazes me how electricty flows through and there's no electric buzz at all.

[aliendaddy32]

These older radio speakers actually don't have electricity flowing through the speaker cone. They do have a large (and heavy) magnet in behind the paper cone which converts the electrical energy to mechanical energy which vibrates the speaker. These old speakers actually require a very high voltage that would not be compatible with modern electronics without modifications. There was actually a serious buzz on this radio until I replaced the capacitors.

[gbowne1]

@aliendaddy32 you can actually still get the old type caps of new manufacture from Antique Radio supply.

[chbitter]

I done the same thing when I prepared my old tube Radio for optical reasons I always try to place a modern capacitor Inside the casing of an Old Capacitor.

[panstar1]

you don't want to brake any of those tubes ,the

last time I seen them for sale they were $50 and up they were brand new ,it is funny tubes back in the 50's were just a few cents now they are 50 and up ! but I too love those tube radios I was even lucky enough to come across a marcony service manual too bad I don't have any radios to really put it to use !!

[biggestdigger]

Great series!

This is the first time I've heard only replacing the bad capacitors. Most just replace all the old C's.

That lightbulb test in the previous lesson was excellent. Is a 60 watt bulb always correct?

Thanks much.

[aliendaddy32]

No, a 60 watt bulb isn't always correct. It should be about the same power as your radio uses to work properly. Go back to about 3:50 in video #2 for a way to guesstimate what bulb you need.

[force311999]

@biggestdigger he probably did but tests in between of coarse you replace them all he ordered them all and the rest will go bad very soon after using the set after so long

[vinniecorbit]

Your newly capacitorized radio is cristened with Daydream Believer and Love Isn't Always On Time! :O) It's a good idea to spray the pins of your tubes with contact cleaner and insert them a few times in the socket, regardless of how clean they look.

[BillBlaze]

Pretty good. I have been tinkering with restoring tube radios for a few years with mixed results. (Usually just replace the paper caps!) When you get a complete series, you should sell them in DVD form. Let me know when you do!

BillBlaze

[mrgnomeman]

I'm looking forward to seeing part 4

I've past old radios in second hand stores and wondered what is would take to see (hear) these old boys in action once more.

Thanks for these videos.

[Grantiose]

Great series!..I am just starting out in this hobby..a real greenhorn..Your instruction is excellent!......from a fellow Canuck on the West Side!