Replacing those mica wafers requires the hands of a surgeon, due to those hair-thin leads you mentioned. The last time I tried, it ended up sailing across the room, accompanied by a few choice expletives.
Well that was fun getting that working again, well done! Happy Xmas from this side of the pond to you and your family on that side of the pond. Regards - Andrew
I am definitely going to download this video and keep it on my External 2TB HD for future reference seeing as how I am a newbie to this hobby of restoring radios. All the guys I have watched on UA-cam including yourself have been very informative. Thanks and have a Merry Christmas
A well done video. Thanks for all your effort on this radio. I don't have near the experience you have, but I am amazed that the electrolytic capacitors were still good to use after all these years. I was under the impression that these capacitors would have dried out by this time. Regards, Tom
Great video Bryan. I learned a lot and I'm always entertained by your videos. Have yourself and your loved ones a Merry Christmas and a great 2015! Thanks for your videos!
You covered alot of subject areas in that repair. Thank you for your efforts in the sharing of your knowledge! Merry Christmas and a Happy, Healthy New Year!
Wow, what a struggle with this one! I have its brother, same chassis, a GE P736A. Its a little fancier and has a gear reduction tuning dial. It has a microphonic tube also, fixed by wrapping it with a rubber band. They are pretty good for only four tubes.
Excellent video! Back in the 70's I had this radio in red and white. It was very good performer for a set without an RF amplifier stage. Unfortunately, the infamous GE IF can silver migration disease grim reaper reared his ugly head and not being able to obtain a new IF can (no internet then) or knowing how to rebuild, I regretfully tossed the set. A few years ago, I picked up the solid state version on EBay and fixed it but it's not as good of a performer.I'm keeping my eyes out for a tube one like this. They are fairly common. I agree with your view on Raytheon tubes. When they started sourcing them from Japan, the quality went way south. They must have been made by the same company who made Radio Shack Realistic Lifetime tubes! Merry Christmas to you and your family!!
Those old series string radios with 300ma tube heaters wasted 36w on just the tube heaters. The later 150ma heater tubes only needed 18 watts of power, and some clock radios used tubes with 100ma heaters, reducing the heater power to just 12 watts. Of course we also used some power for B+ which typically adds about 6-10 watts to the power drawn. Those 100ma heater tubes required a rather weak audio output power, typically less than 1w, but that's enough for a table top clock radio.
Replace that SEEEEASONAL RECTUM-FIRE with a nice DIE-ODE-EE-EYE-A! (My STUPIDITY, LOL!) In all seriousness, though, Bryan, thanks for explaining how to determine the current drop and correct value and wattage of the resistor(s) by showing us in detail the formulas to do so. It's a refresher course for me, for sure and I'm sure it will be for any other technicians out there!
Hey radiotvphononut. A very Merry Christmas to you & your family. I hope this Christmas becomes a special day for all of you. Thank you! :) Ho! Ho! Ho! :) Merry Christmas to you! :)
Happy Hornyka, Merry Kissmas, Happy New Beers, Happy Obamaquanza, or whatever, don't worry, be happy! Thanks for making all the vids Bryan. Cheers, Don
Those 1 volt tubes acted like solid state transistors in that they warmed up quickly. The reason was the filament was actually the cathode. How neat was that!
Nice radio. Nice repair and a great call not to screw around with the PCB. More stuff ends up in the junkyard by people trying to "fix" something that ain't broke. Just way too much stuff to go wrong.
Do your math the common core method please, this is too easy to understand. I believe I have the solid state version of this radio somewhere. Ill have to find it after I start smoking.
Those battery tubes run in a range between 1.4 to 1.5 volts, at least for the low current ones they started using around 1939 or so, just in case anyone is curious about the 3 volt tube, that was likely a 3V4 which has a tapped filament with two 1.4-1.5 volt sections. The reason for that is that some battery tube radios ran the filaments in series for AC mode, and in parallel for battery mode, with a switch, so they could use a pair of "C" or "D" cells rather then a 7.5 volt battery. When I need to come up with a dropper for battery tubes I tend to make it a little bit on the high side in terms of a standard value resistor, and if it needed a 5.5 Watt resistor I would try to use either a 10 watt or a 15 watt if I had one.
Is that bottom plate of the handle assy made of metal or is it plastic? It's mighty close to the bottom side of the pc board if it is. One other question, even back in the day it seems to me like a 90Vdc battery priced at 5 or 6 bucks would have been a luxury item even for a lake/beach/cabin outing wouldn't it? Happy Christmas there rtvp-nut!
So that static is there due to leaky caps in IF coils? Thanks for this video, I really learned much more from you than they teach me in university. And funny thing - most repair specialists like you, are not math nerds - so I have a chance, because something more fancy than Ohm's law and simple formulas give me headache
Those batteries were even pricey back in the fifties. The B battery was around 15 dollars plus tax. The A battery was about 6 dollars plus tax. We owned one of those style radios back in the fifties and needed a set of batteries to use the radio at Fire Island New York. Fire Island had no electric service back in the fifties. They used kerosene lanterns for lighting and fireplaces for heat and propane gas for stoves and charcoal grills to cook outdoors
I would place a plastic band strap, perhaps two around that power resistor and the filter can capacitor to add support for the power resistor so that it won't wiggle loose a bad solder connection due to the resistor weight onto the pc board solder joint later on in the future? The filter can capacitor can also help heat sink that power resistor as well?
JoeyMars1 IT'S NOT THAT SIMPLE- THE HEAT FROM THE POWER RESISTOR WOULD ACCELERATE DETERIORATION OF THE FILTER CAPACITOR, AND THE RESISTOR WOULD LIKELY OVERHEAT ANYWAY.
I understand this is a rather old video, but a question always comes to mind when I watch the removal of those old Selenium rectifiers, why not replace it with a bridge rectifier instead of a half wave rectifier? Wouldn't that solve some of the voltage issue as 4 diodes would drop each .6 volt and you would come out with a very smoooooth DC rather then the pulsating DC you get with the half wave setup? Just wondering, I am an old fart that plays with the electronics but never studied it in college, back then every one wanted to study computer crap. (I was an old fart when Workers Comp sent me to college in the mid 90's.
These radios would have been great back then if there had been alkaline batteries, especially with the current drain of the A battery (filament drain) . The sound quality was amazing even with these portable radios. There is no reason battery companies could not make batteries for these radios today.
Bryan, try Moyer Electronics, of Pottsville (or Sunbury) Pennsylvania for the flex resistor. Their NOS stock is better than just about anyone in the US. They've bailed me out of many-a-bind!!
...those IF transformers haven't been made for a HECK of a long time- and even if you were lucky enough to find a NOS unit- it would likely be as bad as the IF transformer that you are trying to replace!!!
Replacing those mica wafers requires the hands of a surgeon, due to those hair-thin leads you mentioned. The last time I tried, it ended up sailing across the room, accompanied by a few choice expletives.
Well that was fun getting that working again, well done! Happy Xmas from this side of the pond to you and your family on that side of the pond. Regards - Andrew
I am definitely going to download this video and keep it on my External 2TB HD for future reference seeing as how I am a newbie to this hobby of restoring radios. All the guys I have watched on UA-cam including yourself have been very informative. Thanks and have a Merry Christmas
thanks! I have enjoyed all your videos that I have seen. So many electronic adventures in each project!
Thanks for the taking the trouble to make and post video - very informative as all your videos are. Marry Christmas...
That was fun. Really enjoyed that.
Thanks
Carl
Merry Christmas
Touched on a little bit of everything in this repair, with great results. Merry Christmas.
A well done video.
Thanks for all your effort on this radio. I don't have near the experience you have, but I am amazed that the electrolytic capacitors were still good to use after all these years. I was under the impression that these capacitors would have dried out by this time.
Regards, Tom
Great video Bryan. I learned a lot and I'm always entertained by your videos. Have yourself and your loved ones a Merry Christmas and a great 2015! Thanks for your videos!
Thanks yet again for a terrific and very informative video. I learn a bit more from each of them. Have a Merry Christmas and a Happy New Year.
Great Job. Have a Happy Christmas and a Great new Year.
You covered alot of subject areas in that repair. Thank you for your efforts in the sharing of your knowledge!
Merry Christmas and a Happy, Healthy New Year!
Another great video, as usual I gained a few bits of knowledge, thank you and Merry Christmas to you and yours.
Carl
Merry Christmas Bryan great video.😀
Very instructional, my friend. Superb stuff for our beginning hobbyist folks.
Regards,
John
In depth and exquisitely to the point. Great job. S
44:00 My late father had one just like this
Wow, what a struggle with this one! I have its brother, same chassis, a GE P736A. Its a little fancier and has a gear reduction tuning dial. It has a microphonic tube also, fixed by wrapping it with a rubber band. They are pretty good for only four tubes.
Great video!
Have a Merry Christmas!
Excellent video! Back in the 70's I had this radio in red and white. It was very good performer for a set without an RF amplifier stage. Unfortunately, the infamous GE IF can silver migration disease grim reaper reared his ugly head and not being able to obtain a new IF can (no internet then) or knowing how to rebuild, I regretfully tossed the set. A few years ago, I picked up the solid state version on EBay and fixed it but it's not as good of a performer.I'm keeping my eyes out for a tube one like this. They are fairly common.
I agree with your view on Raytheon tubes. When they started sourcing them from Japan, the quality went way south. They must have been made by the same company who made Radio Shack Realistic Lifetime tubes!
Merry Christmas to you and your family!!
Those old series string radios with 300ma tube heaters wasted 36w on just the tube heaters. The later 150ma heater tubes only needed 18 watts of power, and some clock radios used tubes with 100ma heaters, reducing the heater power to just 12 watts. Of course we also used some power for B+ which typically adds about 6-10 watts to the power drawn. Those 100ma heater tubes required a rather weak audio output power, typically less than 1w, but that's enough for a table top clock radio.
Replace that SEEEEASONAL RECTUM-FIRE with a nice DIE-ODE-EE-EYE-A! (My STUPIDITY, LOL!) In all seriousness, though, Bryan, thanks for explaining how to determine the current drop and correct value and wattage of the resistor(s) by showing us in detail the formulas to do so. It's a refresher course for me, for sure and I'm sure it will be for any other technicians out there!
Hey radiotvphononut. A very Merry Christmas to you & your family. I hope this Christmas becomes a special day for all of you. Thank you! :) Ho! Ho! Ho! :) Merry Christmas to you! :)
Happy Hornyka, Merry Kissmas, Happy New Beers, Happy Obamaquanza, or whatever, don't worry, be happy! Thanks for making all the vids Bryan. Cheers, Don
Those portable radios were so neat for there Era.
Those 1 volt tubes acted like solid state transistors in that they warmed up quickly. The reason was the filament was actually the cathode. How neat was that!
Nice radio. Nice repair and a great call not to screw around with the PCB. More stuff ends up in the junkyard by people trying to "fix" something that ain't broke. Just way too much stuff to go wrong.
Do your math the common core method please, this is too easy to understand. I believe I have the solid state version of this radio somewhere. Ill have to find it after I start smoking.
Those battery tubes run in a range between 1.4 to 1.5 volts, at least for the low current ones they started using around 1939 or so, just in case anyone is curious about the 3 volt tube, that was likely a 3V4 which has a tapped filament with two 1.4-1.5 volt sections. The reason for that is that some battery tube radios ran the filaments in series for AC mode, and in parallel for battery mode, with a switch, so they could use a pair of "C" or "D" cells rather then a 7.5 volt battery.
When I need to come up with a dropper for battery tubes I tend to make it a little bit on the high side in terms of a standard value resistor, and if it needed a 5.5 Watt resistor I would try to use either a 10 watt or a 15 watt if I had one.
Is that bottom plate of the handle assy made of metal or is it plastic? It's mighty close to the bottom side of the pc board if it is. One other question, even back in the day it seems to me like a 90Vdc battery priced at 5 or 6 bucks would have been a luxury item even for a lake/beach/cabin outing wouldn't it? Happy Christmas there rtvp-nut!
So that static is there due to leaky caps in IF coils? Thanks for this video, I really learned much more from you than they teach me in university. And funny thing - most repair specialists like you, are not math nerds - so I have a chance, because something more fancy than Ohm's law and simple formulas give me headache
MrJohhhnnnyyy Actually, the mica capacitors are not "leaking"- they are actually arcing because of bad connections.
Wow! All that work made me tired. :) Great job though, very worth it, great looking radio and very sensitive to boot.
Those batteries were even pricey back in the fifties. The B battery was around 15 dollars plus tax. The A battery was about 6 dollars plus tax. We owned one of those style radios back in the fifties and needed a set of batteries to use the radio at Fire Island New York. Fire Island had no electric service back in the fifties. They used kerosene lanterns for lighting and fireplaces for heat and propane gas for stoves and charcoal grills to cook outdoors
I would place a plastic band strap, perhaps two around that power resistor and the filter can capacitor to add support for the power resistor so that it won't wiggle loose a bad solder connection due to the resistor weight onto the pc board solder joint later on in the future? The filter can capacitor can also help heat sink that power resistor as well?
JoeyMars1 IT'S NOT THAT SIMPLE- THE HEAT FROM THE POWER RESISTOR WOULD ACCELERATE DETERIORATION OF THE FILTER CAPACITOR, AND THE RESISTOR WOULD LIKELY OVERHEAT ANYWAY.
What do you recommend for across the line capacitors and where can they be obtained?
does this use 12ax7 tubes?
Hey radiotvphononut, can you tell me where the "parts house" is in Meridian?
Very interesting video. Thanks.
still amazes me anyone restores radios given there is nothing worth playing on them
glad they did not just get dumped like all the old TVs
I understand this is a rather old video, but a question always comes to mind when I watch the removal of those old Selenium rectifiers, why not replace it with a bridge rectifier instead of a half wave rectifier? Wouldn't that solve some of the voltage issue as 4 diodes would drop each .6 volt and you would come out with a very smoooooth DC rather then the pulsating DC you get with the half wave setup? Just wondering, I am an old fart that plays with the electronics but never studied it in college, back then every one wanted to study computer crap. (I was an old fart when Workers Comp sent me to college in the mid 90's.
a 6.8v zener across the filaments is a very good insurance against tube burnout
Great video! Thanks!
These radios would have been great back then if there had been alkaline batteries, especially with the current drain of the A battery (filament drain) . The sound quality was amazing even with these portable radios. There is no reason battery companies could not make batteries for these radios today.
1:55 With the tubes hanging down from the PC board, I'm surprised the board is still in one piece and the tubes haven't fallen out.
Hay do you have any tubed radio for sell
Nice . . . better than anything NEW ~
7.1 volts is actually not bad, the tube filaments are rated at 1.4 volts and 2.8 volts, so the string in total is actually 7.0 volts.
Metal chassis were bulky but were more sturdy. What's wrong with heavy radios, for HE MEN to carry around.
Why not remove the mica sheets and measure the inductance of the IFT? The required capacitance can then be easily calculated.
SMD capacitors would probably do to replace the silver mica ones.
The trick I learn today was let the radio run a while before putting it back together
I have a copy of the transistor model - all white.
Bryan, try Moyer Electronics, of Pottsville (or Sunbury) Pennsylvania for the flex resistor. Their NOS stock is better than just about anyone in the US. They've bailed me out of many-a-bind!!
Make your own resistor wire by putting some resistors in series
Now you can sell this fine antique radio on epay for 400$, just say it worked the last time you turned it on... AS IS.
Tube Depot has 10 watt resistors at 2200 watt resistors.
I know this is quite late to reply, but I would think some gap-filling super glue could repair cracks in the circuit board.
Can you still buy I f transformers ,or do you have to rebuild them anyone please
...those IF transformers haven't been made for a HECK of a long time- and even if you were lucky enough to find a NOS unit- it would likely be as bad as the IF transformer that you are trying to replace!!!
...even if you COULD find NOS IF transformer, it probably wouldn't be any better than the IF transformer in the radio...
What about a solid state bridge rectifier and a LM7805 5v regulator should get you what is needed 5v is better than 7v.
DAVID GREGORY KERR It wouldn't work...
Voltage & resistance Makes Amperage
It Goes Around In A Circle.
Amperage & VoltageMakesRezistance
I have the transistor radio version of that radio
You Could Run That Radio
Off A Power Inverter
If You Want To Use It Outside.
Nice saved
A 5W Christmas tree bulb is about 2k2 ohms at 50ma.
Edit:
A 120VAC, 5W Christmas tree ...
Jammit Timmaj A light bulb generates a lot of heat-
You Have A Multi Meter. Test The Wattage Of The Rezister. Getting Batterys For A Radio Like thatone would Be Hard.
You'd Need To Use Modern Cells.
...you can't measure watts with a multimeter...
It sounded better on Rush Limbaugh
Happy Christmas
Another formula is: P=I squared x R