Radio Theory Part 5

[@garytaylor7707]

Back in the dark ages I worked in a TV shop while in high school. We had a lot of selenium rectifiers that went to diode heaven. Our go to cure was to just parallel a silicon diode and off we go. Looking back I don't know if we were lucky or failures just tended to be opens vs shorts. Great info. Thanks.

[@DHshreve1]

Great educational videos!

[@dennis525371]

Thank you for your comment. I'm glad you liked it. There is more on the way. Oh, and you can call me Dennis, Mr. Carter makes me feel old even if I am old. LOL. Thank you again, Dennis.

[@tectalabyss]

Hello Mr Carter. Happy to see another video. Thank you for the time and effort you have put in to this series. Very Much appreciated. Thank you again. Bobby

[@ranuts2]

Great info, looking forward to more. The info on the selenium rectifier is really good too. Thank you.

[@ArthurHollingsworth]

Good stuff, Dennis. Keep these coming because I'm learning a few things. Really appreciate it. Also, your new camera looks and sounds great. It was a good investment if you plan to continue making KZbin videos. Thanks again, Art H.

[@tectalabyss]

Hi Dennis. : ) Thank you for the reply. I really liked the rant on the selenium rectifier. People need to know this, and you may have saved someone bad health issues or worse. Take care. Bobby

[@dennis525371]

Thank you, Art. I'm glad you are getting something out of these videos. There is more on the way. Dennis

[@frankreiserm.s.8039]

I would have, for quality, designed this power supply with a step down power transformer and two rectifier tubes for full wave rectification. I know that that would have made the radio heavy, but I like to design quality.

[@peteleoni9665]

We used to make selenium rectifier stew with Oskilator weiners with capacitor wax. it's all we had to eat, my father was a bad Radio tech.

[@Ragitysdad]

Thanks for another great video!!!

[@dean98110]

Dennis can you cite references to the source of your information about the toxicity of selenium dioxide. The information I see on the web including the EPA site indicates that accidental low level exposure is not that dangerous. Chronic exposure over a long period of time is an issue but that is not what we would incur in one rectifier burning. Also can't find any info saying it would burn right through your skin. Thanks.

[@frankreiserm.s.8039]

So often, only a couple of capacitors are used as the filter. That is cheap. If I was a design engineer, I would want to design the highest quality radio that I could. I would use a pi filter using a couple of capacitors and a coil. That is high quality. I would also use a full wave bridge rectifier and not a half wave for the same reason.

[@jimnewman5596]

So that shunt resistor R12 drains off the current at power up, is that the reason the pilot light is very bright at power up for a few seconds.

[@frankreiserm.s.8039]

Your video is great! You mentioned chassis ground. However, the schematic uses the incorrect ground symbol for chassis ground. Frank Frank Reiser Video/Audio Service

[@Landrew0]

Is the selenium in my shampoo dangerous as well?

[@BretFrohwein]

Thanks again.. keep em coming.. :)