I've been reading a lot about selenium rectifiers and about how dangerous they are. Although I've never had one blow up on me, I'd like to try my hand at replacing one. What suitable alternatives are out there that are easy to get from a parts catalogue like Mouser or RadioShack?

Hi Sven

Use a silicon diode such as 1N4004 or better with a series resistor of 47-100 ohms..

A new selenium rectifier had about a 7 volt drop while a silicon diode drops .6-.7 volts. This resistor should be added to make up the difference and prevent turn on surge.

As selenium rectifiers age the voltage drop increases until the radio or TV no longer operates. The selenium rectifier won't really blow up but you will know it if it's shorted. The odor is something you will remember for life!

Norm

: I've been reading a lot about selenium rectifiers and about how dangerous they are. Although I've never had one blow up on me, I'd like to try my hand at replacing one. What suitable alternatives are out there that are easy to get from a parts catalogue like Mouser or RadioShack?

What wattage would you recommend for the silicon diode and the resistor?

By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

Thank you so very much.

By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

Most radios use a single selenium rectifier that can be replaced by one silicon diode. TV's will generally have two in a voltage doubler circuit.

Numbers "1N" just indicate a diode. Numbers after that are just a sequence, lower numbers were assigned first. The 1N4004 diode is rated at 400PIV @ 1 amp. You could buy a higher rated diode but this will replace just about any selenium rectifier in a radio or TV. A 1N4007 is 1000PIV @ 1 amp, also usable. Radio Shack and other parts stores know these numbers.

Not knowing how much current your radio draws, use a 2 watt resistor.

: What wattage would you recommend for the silicon diode and the resistor?

: By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

: Thank you so very much.

: By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

: Most radios use a single selenium rectifier that can be replaced by one silicon diode. TV's will generally have two in a voltage doubler circuit.

: Numbers "1N" just indicate a diode. Numbers after that are just a sequence, lower numbers were assigned first. The 1N4004 diode is rated at 400PIV @ 1 amp. You could buy a higher rated diode but this will replace just about any selenium rectifier in a radio or TV. A 1N4007 is 1000PIV @ 1 amp, also usable. Radio Shack and other parts stores know these numbers.

: Not knowing how much current your radio draws, use a 2 watt resistor.

:
: : What wattage would you recommend for the silicon diode and the resistor?

: : By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

: : Thank you so very much.

: : By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

I have heard that the fumes from an overheated Selenium rectifier are poisonous.

Hi Nigel

I am sure the fumes are poisonous. A shorted selenium rectifier smells so bad you wouldn't want to stay around very long. I've had cases where electrolytics shorted and caused the selenium to smoke and smell. A smell a person will never forget..

If you see Gerry Hale at the swap meet, say Hi. He lives in Washington.

Norm

: : Most radios use a single selenium rectifier that can be replaced by one silicon diode. TV's will generally have two in a voltage doubler circuit.

: : Numbers "1N" just indicate a diode. Numbers after that are just a sequence, lower numbers were assigned first. The 1N4004 diode is rated at 400PIV @ 1 amp. You could buy a higher rated diode but this will replace just about any selenium rectifier in a radio or TV. A 1N4007 is 1000PIV @ 1 amp, also usable. Radio Shack and other parts stores know these numbers.

: : Not knowing how much current your radio draws, use a 2 watt resistor.

:
: :
: : : What wattage would you recommend for the silicon diode and the resistor?

: : : By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

: : : Thank you so very much.

: : : By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

: I have heard that the fumes from an overheated Selenium rectifier are poisonous.

Thanks Norm!!! :-)

Hi fellas,

Just fell into your conversation because of my interest in selenium rectifiers and surge suppressors. You are mistaken about the toxicity of overheated selenium devices. They do stink, for sure, But toxic? No. Not in the amounts you would see in a radio or similar situation. I can fax you a copy of a scientific study report if you don't believe me. Sanford Miller, Inc. still makes selenium stacks. We specialize in reproducing OEM discontinued stacks. Westinghouse, GE, General Instruments, Sarkes, etc... I've heard about enthusiasts who claim that sound reproduction suffers when seleniums are replaced with silicon. I don't know. We only make the stacks. If I can be of help, let me Know. If you can't identify an old selenium by number, you can send it to me for reproduction by reverse engineering. Kurt Catob, Sanford Miller, Inc., 150 Ross Road, Homer City, PA 15748. 800-645-5900,724-479-5090,fax 724-479-5091.
: Hi Nigel

: I am sure the fumes are poisonous. A shorted selenium rectifier smells so bad you wouldn't want to stay around very long. I've had cases where electrolytics shorted and caused the selenium to smoke and smell. A smell a person will never forget..

: If you see Gerry Hale at the swap meet, say Hi. He lives in Washington.

: Norm

: : : Most radios use a single selenium rectifier that can be replaced by one silicon diode. TV's will generally have two in a voltage doubler circuit.

: : : Numbers "1N" just indicate a diode. Numbers after that are just a sequence, lower numbers were assigned first. The 1N4004 diode is rated at 400PIV @ 1 amp. You could buy a higher rated diode but this will replace just about any selenium rectifier in a radio or TV. A 1N4007 is 1000PIV @ 1 amp, also usable. Radio Shack and other parts stores know these numbers.

: : : Not knowing how much current your radio draws, use a 2 watt resistor.

: :
: : :
: : : : What wattage would you recommend for the silicon diode and the resistor?

: : : : By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

: : : : Thank you so very much.

: : : : By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

: : I have heard that the fumes from an overheated Selenium rectifier are poisonous.

Electrolytics and seleniums both can deform in long-term storage or other downtime. Powerup under full voltage and load can precipitate failure. They are not near as harmful as you might think from their stink. You would have to ingest a lot of stink to getr enough to be harmful. Not likely.

: Hi Nigel

: I am sure the fumes are poisonous. A shorted selenium rectifier smells so bad you wouldn't want to stay around very long. I've had cases where electrolytics shorted and caused the selenium to smoke and smell. A smell a person will never forget..

: If you see Gerry Hale at the swap meet, say Hi. He lives in Washington.

: Norm

: : : Most radios use a single selenium rectifier that can be replaced by one silicon diode. TV's will generally have two in a voltage doubler circuit.

: : : Numbers "1N" just indicate a diode. Numbers after that are just a sequence, lower numbers were assigned first. The 1N4004 diode is rated at 400PIV @ 1 amp. You could buy a higher rated diode but this will replace just about any selenium rectifier in a radio or TV. A 1N4007 is 1000PIV @ 1 amp, also usable. Radio Shack and other parts stores know these numbers.

: : : Not knowing how much current your radio draws, use a 2 watt resistor.

: :
: : :
: : : : What wattage would you recommend for the silicon diode and the resistor?

: : : : By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

: : : : Thank you so very much.

: : : : By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

: : I have heard that the fumes from an overheated Selenium rectifier are poisonous.

: Electrolytics and seleniums both can deform in long-term storage or other downtime. Powerup under full voltage and load can precipitate failure. They are not near as harmful as you might think from their stink. You would have to ingest a lot of stink to getr enough to be harmful. Not likely.

: : Hi Nigel

: : I am sure the fumes are poisonous. A shorted selenium rectifier smells so bad you wouldn't want to stay around very long. I've had cases where electrolytics shorted and caused the selenium to smoke and smell. A smell a person will never forget..

: : If you see Gerry Hale at the swap meet, say Hi. He lives in Washington.

: : Norm

: : : : Most radios use a single selenium rectifier that can be replaced by one silicon diode. TV's will generally have two in a voltage doubler circuit.

: : : : Numbers "1N" just indicate a diode. Numbers after that are just a sequence, lower numbers were assigned first. The 1N4004 diode is rated at 400PIV @ 1 amp. You could buy a higher rated diode but this will replace just about any selenium rectifier in a radio or TV. A 1N4007 is 1000PIV @ 1 amp, also usable. Radio Shack and other parts stores know these numbers.

: : : : Not knowing how much current your radio draws, use a 2 watt resistor.

: : :
: : : :
: : : : : What wattage would you recommend for the silicon diode and the resistor?

: : : : : By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

: : : : : Thank you so very much.

: : : : : By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

: : : I have heard that the fumes from an overheated Selenium rectifier are poisonous.

: Electrolytics and seleniums both can deform in long-term storage or other downtime. Powerup under full voltage and load can precipitate failure. They are not near as harmful as you might think from their stink. You would have to ingest a lot of stink to getr enough to be harmful. Not likely.

: : Hi Nigel

: : I am sure the fumes are poisonous. A shorted selenium rectifier smells so bad you wouldn't want to stay around very long. I've had cases where electrolytics shorted and caused the selenium to smoke and smell. A smell a person will never forget..

: : If you see Gerry Hale at the swap meet, say Hi. He lives in Washington.

: : Norm

: : : : Most radios use a single selenium rectifier that can be replaced by one silicon diode. TV's will generally have two in a voltage doubler circuit.

: : : : Numbers "1N" just indicate a diode. Numbers after that are just a sequence, lower numbers were assigned first. The 1N4004 diode is rated at 400PIV @ 1 amp. You could buy a higher rated diode but this will replace just about any selenium rectifier in a radio or TV. A 1N4007 is 1000PIV @ 1 amp, also usable. Radio Shack and other parts stores know these numbers.

: : : : Not knowing how much current your radio draws, use a 2 watt resistor.

: : :
: : : :
: : : : : What wattage would you recommend for the silicon diode and the resistor?

: : : : : By the way, I've never shopped for solid-state components before (excepting resistors), so could you (or someone) please explain to me the 1N4004 number?

: : : : : Thank you so very much.

: : : : : By the way, Do most radios just use one selenium rectifier or do they use a "bridge" and how could you tell? Most of the radios that i've seen have one contact going to a live wire and one contact going to chassis ground. should I assume this to be a single rectifier?

: : : I have heard that the fumes from an overheated Selenium rectifier are poisonous.