Replacing selenium rectifier with diode Gearslutz

2014-5-10  Thanks for the information! I'm rebuilding an Altec 525A power supply, and was wondering how to deal with the selenium there (used in the filament supply, and there's a rectifier I can't identify [19PA20] for the B+). Anyway, I was going to replace the selenium in the filament supply with IN4007s, and add a dropping resistor.

Problem with replacing selenium rectifier All About

2019-9-1  Way back when, not really knowing what I was doing where a little knowledge is a dangerous thing, I replace a plate-voltage selenium rectifier that had failed with a silicon rectifier in an old tube TV, without any other changes. The TV then worked but had a bright edge along one side of the CRT display which was the edge of the scan.

Replacing Selenium Rectifiers in TON Trans-Oceanics

Replacing Selenium Rectifiers in TON Trans-Oceanics All the miniature tube Trans-Oceanics, from the G500 to the B600, were equipped with selenium rectifiers instead of the traditional tube rectifier. Selenium rectifiers are notorious for failing gradually over time. Their forward voltage drop increases to the point that the tubes stop working.

Replacing a selenium rectifier Antique Radio Forums

I'm gathering parts for a Silvertone 8020 that I am recapping, and decided to replace the selenium rectifier that is in it. I have read on a few sites that a bridge rectifier can be used, but I'm not sure how that would be possible, since, in the schematic, the rectifier appears as a single diode.<P>If this is the case, what size diode should I use?

Changing selenium rectifier to silicon diode

2. replace selenium rectifier and resistor with a silicon assembly and a switching regulator set to the desired voltage presuming you are only talking an amp or two, this is a small assembly that won't need much heat sinking 3. add reverse biased diodes across the coils as suggested above

Selenium Rectifier Radiomuseum

2005-3-30  On the topic of retaining a selenium rectifier, it probably is a really good idea to replace it with silicon diodes. I am not a chemist but I understand that when a selenium rectifier fails it can release toxic gas, and retaining a selenium rectifier adds unnecessary risk for the power transformer.

Selenium Full-Wave Bridge Rectifier Testing

2013-7-31  Replace Rectifier Meter should read infinity (or a very high reading) The diode is not allowing Voltage to flow through it in this direction, which is normal. The meter is indicating an "open circuit". We expect a good diode to be open in this test, so everything is testing good. Selenium Full-Wave Bridge Rectifier Testing Drawn by Jon Pardue 2007

Life and failures of selenium rectifiers

2016-4-21  Actually, in case of rectifier failure, both the rectifier itself and the power transformer become hot and other secondary voltages are significantly low. Then the failure mechanism must be quite different. Selenium rectifiers were rated for almost infinite continuous service life, over than 60.000 hours, according to this . 1951 GE ad.

Problem with replacing selenium rectifier All About

2019-9-1  Way back when, not really knowing what I was doing where a little knowledge is a dangerous thing, I replace a plate-voltage selenium rectifier that had failed with a silicon rectifier in an old tube TV, without any other changes. The TV then worked but had a bright edge along one side of the CRT display which was the edge of the scan.

Replacing Selenium Rectifiers in TON Trans-Oceanics

Replacing Selenium Rectifiers in TON Trans-Oceanics All the miniature tube Trans-Oceanics, from the G500 to the B600, were equipped with selenium rectifiers instead of the traditional tube rectifier. Selenium rectifiers are notorious for failing gradually over time. Their forward voltage drop increases to the point that the tubes stop working.

Replacing a selenium rectifier Antique Radio Forums

I'm gathering parts for a Silvertone 8020 that I am recapping, and decided to replace the selenium rectifier that is in it. I have read on a few sites that a bridge rectifier can be used, but I'm not sure how that would be possible, since, in the schematic, the rectifier appears as a single diode.<P>If this is the case, what size diode should I use?

Replacing selenium rectifier narkive

I've got a Westinghouse 5 tube AC/DC radio that has a selenium rectifier and I'm guessing I should replace it so I looked through my books and I found a recommendation of a 1N4007 silicon diode. Don't have any onhand so wondering if I can use Radio Shacks PTC205 (catalog # 276-1114)? They're rated at 2.5A, 1000 PIV. Will it work? Thanks.

Changing selenium rectifier to silicon diode

2. replace selenium rectifier and resistor with a silicon assembly and a switching regulator set to the desired voltage presuming you are only talking an amp or two, this is a small assembly that won't need much heat sinking 3. add reverse biased diodes across the coils as suggested above

Correct Way To Replace the Selenium Rectifier on a

2012-10-16  Here is the correct way to replace and install a new IN4007 on a Tweed Amp and removing the Selenium Rectifier. This set of photos shows the Sel Rect. still fastened to the chassis, but the Green Unit itself is not connected in any way. It's just used to hold

Selenium Full-Wave Bridge Rectifier Testing

2013-7-31  Replace Rectifier Meter should read infinity (or a very high reading) The diode is not allowing Voltage to flow through it in this direction, which is normal. The meter is indicating an "open circuit". We expect a good diode to be open in this test, so everything is testing good. Selenium Full-Wave Bridge Rectifier Testing Drawn by Jon Pardue 2007

Selenium rectifiers: failures and restoring tips

There are some good threads on how to replace a selenium rectifier to silicon bridge rectifier,with four snubbing capacitors, and a dropping resistor (possibly with a capacitor instead). The color television of the 1960's owes its presence to the use of the 1N4007 diode.

Old Time Selenium Rectifiers Can someone explain

2005-9-22  Selenium rectifiers are allso semiconductor devices but amorphouse. In old days we used to say taht each plate of rectifier can whithstand about 30V of reverse voltage and that each square centimeter of it's surface can whitstand 100mA of current. You should count number of plates connected in series and calculate area of plate.

Replacing selenium rectifier narkive

I've got a Westinghouse 5 tube AC/DC radio that has a selenium rectifier and I'm guessing I should replace it so I looked through my books and I found a recommendation of a 1N4007 silicon diode. Don't have any onhand so wondering if I can use Radio Shacks PTC205 (catalog # 276-1114)? They're rated at 2.5A, 1000 PIV. Will it work? Thanks.

Gearslutz Replacing selenium rectifier with diode

2014-5-10  Thanks for the information! I'm rebuilding an Altec 525A power supply, and was wondering how to deal with the selenium there (used in the filament supply, and there's a rectifier I can't identify [19PA20] for the B+). Anyway, I was going to replace the selenium in the filament supply with IN4007s, and add a dropping resistor.

HHScott Vacuum Tubes -- Replacing Selenium Bridge

2004-11-5  Reading Room Thermionic Audio Books Last Edited: 31-Jan-2002. Replacing Selenium Bridge Rectifiers. Some vintage H. H. Scott gear typically uses a selenium "stack" bridge rectifier for the preamp's DC filament supply and the negative grid bias supply for the output tubes, sometimes referred as the "C-supply". This is in addition to the full-wave rectifier power supply tube section which

After Class: Working with Selenium Rectifiers,

2012-6-12  Per Wikipedia, "A selenium rectifier is a type of metal rectifier, invented in 1933. They were used to replace vacuum tube rectifiers in power supplies for electronic equipment, and in high current battery charger applications. The photoelectric and rectifying properties of selenium were observed by C. E. Fitts around 1886 but practical

Selenium rectifiers (Barry L. Ornitz)

2017-11-5  Remember that selenium rectifiers have a much greater forward voltage drop with current than do silicon diodes. Thus when you replace a selenium diode with a silicon diode, expect a higher voltage out of your circuit. For most selenium stacks, the DC output is about 2 volts less than the RMS input voltage multiplied by the number of plates.

Tech: Need to replace the selenium rectifier on a '48

bridge rectifier. You will need to identify the AC inputs, and DC outputs for your your original bridge rectifier. Typically the AC leads are offset from the center line and on the same side. The center terminal of the stack is often positive, and the outside terminals that are joined together with a thick jumper are usually common.

Correct Way To Replace the Selenium Rectifier on a

2012-10-16  Here is the correct way to replace and install a new IN4007 on a Tweed Amp and removing the Selenium Rectifier. This set of photos shows the Sel Rect. still fastened to the chassis, but the Green Unit itself is not connected in any way. It's just used to hold

Selenium rectifiers: failures and restoring tips

There are some good threads on how to replace a selenium rectifier to silicon bridge rectifier,with four snubbing capacitors, and a dropping resistor (possibly with a capacitor instead). The color television of the 1960's owes its presence to the use of the 1N4007 diode.

Old Time Selenium Rectifiers Can someone explain

2005-9-22  Selenium rectifiers are allso semiconductor devices but amorphouse. In old days we used to say taht each plate of rectifier can whithstand about 30V of reverse voltage and that each square centimeter of it's surface can whitstand 100mA of current. You should count number of plates connected in series and calculate area of plate.

Restoring a Dynaco ST-70 Tube Amplifier

2007-10-4  You should set the bias when you replace the tubes or when the tubes get older. I was able to bias with the selenium rectifier as is but my bias potentiometer was at one end of its travel. The bias selenium rectifier is the small half inch square component mounted between the 2 10K bias potentiometers as shown.