[NJARC] Selenium Rectifier replacement

Sat Apr 16 19:23:54 EDT 2016

 Thanks everybody for your suggestions, comments and help.  I'll let you know how things go when I get it finished.  BTW... if you're interested in which radio it is, it's an RCA Model 6-XF-9J with a Gray cabinet.  Everything is original so at least I don't have to retrace someone else's work.  I just hope the IF cans aren't diseased.
I have the Beitman's sheets.  If anyone has a Sams or Riders, I'd appreciate having a copy.

Thanks again.

Joe

This is a photo I found.  My cabinet needs the Novus treatment.

-----Original Message-----
From: William Zukowski <n2yeg at optonline.net>
To: Sal Brisindi <salb203 at aol.com>
Cc: NJARC Reflector <njarc at mailman.qth.net>
Sent: Sat, Apr 16, 2016 2:43 pm
Subject: Re: [NJARC] Selenium Rectifier replacement

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I replaced a selenium rectifier in a TO with a 1N4007 and had to increase the series resistor from 20 ohms to 47.  The series filaments are fed from the rectified DC, and the 1 volt tubes needed the additional resistance get them to the normal 1.3 volts.  So yes the resistor is necessary.

Sent from my iPhone

On Apr 15, 2016, at 17:38, Sal Brisindi via NJARC <njarc at mailman.qth.net> wrote:

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You should put a resistor in series with the silicon diode as the B+ will be higher when replacing the selenium diode.

Sal

From: Matt Reynolds
Sent: ‎4/‎15/‎2016 5:10 PM
To: NJARC Reflector
Subject: Re: [NJARC] Selenium Rectifier replacement

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   I'm probably the least knowledgeable\qualified person on this thread thus far when it comes to radio repair but I was always under the impression the resistor was added to the diode to help account for the differences in how the selenium rectifier works\"acts" in relation to the silicon diode replacement.  It was my understanding the resistor was not added to protect the diode, but the resistor was to protect "the radio" from being "harmed" by the different characteristics of the silicon replacement.  I don't ever think I've heard of fear of the modern part being damaged/burnt out.

Matt

________________________________________
From: NJARC <njarc-bounces at mailman.qth.net> on behalf of Raymond F Chase <raydio862 at verizon.net>
Sent: Friday, April 15, 2016 4:35 PM
To: 'David Sica'; 'Jim Whartenby'; njarc at mailman.qth.net
Subject: Re: [NJARC] Selenium Rectifier replacement

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The predominant failure modes for silicon diodes are: 1. Overheating the
junction by gross current overloads and 2: Exceeding the peak inverse
voltage (PIV) rating.  Silicon diodes with 10 times the expected current
rating and several times the PIV cost pennies so they will be the last to
fail.
Ray

-----Original Message-----
From: NJARC [mailto:njarc-bounces at mailman.qth.net] On Behalf Of David Sica
Sent: Friday, April 15, 2016 4:03 PM
To: Jim Whartenby <antqradio at sbcglobal.net>; njarc at mailman.qth.net
Subject: Re: [NJARC] Selenium Rectifier replacement

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