After watching your Sears Suburbanite video a few years ago, I now call selenium diodes 'selenium squeebly zeeblers' every blasted time I see one.

Thanks for the informative video. Just did this repair on my 1960s Canadian Sparton 6 tube AM/FM. Working well with 129 Volts B plus with a 75 ohm resistor.

4007's will work on some radios as a detector but only as a temporary fix. It should be replaced. I remember back when I was a kid building AM radios with 4007's (and other types) because the proper diodes were rare for me to get a hold of. Speaking of selenium rectifiers.. I just restored / rebuilt an old 1960's era variable bench power supply that had 4 of those things to make up a full bridge rectifier. I just replaces them with a modern bridge and gave it a new lease on life.

Thank you Shango066 - I was able to get an old Pilot FM converter to work with my low understanding of how radios work. I got the DC voltage up from about 50 to 110 with a diode, then I changed out the electrolytics, it worked but really poorly. Then I pulled the tubes out, sprayed the sockets and replaced them, now it works OK, gets a lot of stations but sounds farty. I think it needs more caps, but I am on the right track.

So cool to be there when YOU learned something new. Love your videos.

Thanks for the tutorial, I have a couple of radios with bad ones in them. I wish I had a power decade box, I only have a standard low wattage decade box. I'm going to get a bunch of power resistors at different values for doing this.

Replaced the SE rect in my Zenith AM-FM radio with a silicon diode but the voltage fluctuated with the audio when the volume was turned up using a series resistor. Ended up installing two power resistors in a voltage divider config to get a more stable B+ and now the voltage barely changes no matter where the volume is set. Thanks for the video.

Great video! Selenium rectifiers and dial restringing are my pet peeves of repairs. Someday, I'd like to see you do a video of a tube battery/AC radio where the selenium is especially tricky to replace as the series filament voltage is tapped from the selenium rather than directly from the AC line. These can be a headache to calculate the value of the dropping resistor.

That decade box is sweet, I need to get one of those. If the selenium rectifier is really far gone, sometimes I'll bridge a 1N4007 in there long enough to do diagnostics and get workable B+ readings. I've had some that outputted less than 60 volts.

Dam nice job,if it was me I always like old parts tossed,like the selium rectifier,,but it plays great.

Muito bom, gostei. Parabéns pelo vídeo!

Very cool! I just "won" a Philco E670 with a pretty blue selenium wonder. Wanna bet it's good or bad, built in 1957.

EXCELLENT JOB

doing this myself on an old 1-tube record player, and yes the volTage does jump around a bit. Coincidentally, I am using 71 ohms, but will swap that out for a 75 ohm resistor in a higher wattage.

Greetings: Since the B+ voltage varies with the volume setting, I would use the schematic 50 ma value as a starting point and measure ma as you select a resistor. Remember you have the option to use an electrolytic dropping cap whose 60Hz reactance equals whatever resistor you settle on (save a watt, save a penny). I know that you never use dropping caps, but you could learn. It goes between diode cathode and first filter cap +. Cap value is 29.4 mfd at 200v.

Perfect timing...I have to change out a selenium rectifier. ( Fire Department on speed dial!) Question: How do you determine the wattage of the resistor used in series with the diode? Thanks!

Blondie Never Sounded Better!

Thank you!

Using that rectifier as a detector diode will cost you some sensitivity. Strong stations probably won't improve but weak stations should improve. You should look at what diodes are being used in the FM detection circuit. Change to recommended detector diodes.

Could I ask for some advice. There is a lot of confusion regarding the rectifier on old Villers motorcycles and how to replace them with a modern solid state rec. If you google up Villiers 2T engine wiring you will see what I mean but basically there are two ac coils one coil is connected all the time to the rec and the other is only connected throught the lighting switch when the lights are on. So two coils is series black wire common to both coils one red wire one green wire. No problem so far however half way across the coil with the red and black wires there is another yellow wire that goes to the ammeter to the battery. The question is what is this wire for know one seems to know why it was fitted. Its either supplying the ammeter with an AC supply but thats DC to the battery or the coil is getting a 6 volt dc supply. Any ideas dose the old type rec need a dc to work. The bikes were made in 1964.

I personally would not use a 1N4000 series as a detector. The Chinese Silicon Schottky's are probably the the best choice, since Germanium diodes are getting scarce and pricey these days. Then there is the long term reliability and leakage of Ge.

@6:30 - NOOO!!!!! Not that damn Nay nay crap lol

You found the AM detector on the chinese hx108 did not benefit from a Schottky. They had used a BJT NPN base to emitter I think.

If you ever find a Silvertone 3068, I want to see it.

That was hot

Never seen a Power Resistor Decade Box before. I looked them up on ebay. They are all 240-c models, prices range from $245-450. That's one pricey piece of equipment.

I see the camera really likes Blonde

uncle Doug does this too~

Replace that electrolytic on the left on the tube side since you're there.

Why do you need a capacitor in series with the diode? Do I miss something?

Thank....You...For...Sharing.....Beep. :)

Music to re-cap by...bootylicious

Shango can fix anything.

strangely, in all my years I have never encountered a failed selenium rectumfire.

I a old Radio Shack Tube SAF-24 amp that has the same layout as this one with with one red wire going to ground and the other going to the Selenium with a 30ma draw, but when I replace the Selenium with a IN4007 diode the problem is my transformer is overheating now! It is acting like it is a shorted and it is . Any help please

Hell yea, if I could take a current reading and apply Ohm's law I'd be an engineer instead of a hobbyist. (smile)

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