[Elijah]

I have another project radio, a Zenith Model Y723 that needs a new rectifier or preferably, a diode replacement. I looked on ebay for a NOS selenium rectifier to no avail. Zenith has several listed in their parts list such as a Federal 1101A or a Tarzian 100A but I couldn't' find these. The current rating is .071A.

Anyone know of the proper diode that will work with this set?

[codefox1]

So far as I know finned selenium rectifiers are no longer manufactured except maybe for code compliance for ancient elevator repairs and the like in certain cities, and of course by our dear old government.

Meanwhile elsewhere on Earth, generic 1N4007 should be fine, and costs less than a dime. Of course the silicon replacement will result in a higher B+ voltage which must be ultimately tamed with a resistor, preferable chassis mounted heat dissipated Dale type. Many of us will start out with 100-150 Ohms and measure carefully whilst bringing the recapped and recarbed set to life. Add a fuse.

[Elijah]

There is currently a 22 ohm 1 watt and 1000 ohm 4 watt resistors in series with this rectifier(cathode side). Should I add more and if so, what wattage?

[codefox1]

Please post schematic image or link to give us a better handle on what is going on. Pretty sure that 150 ohm resistor will do.

[Eliot Ness]

Rich Bonkowski, W3HWJ, wrote a pretty good article on replacing selenium rectifiers that was published in the January 2007 AWA Journal:

http://www.w3hwj.com/index_files/RBSelenium2.pdf

[Elijah]

I downloaded the entire Sams from schematicman.com but I can't post the link. I couldn't find one elsewhere to link. I'm wondering if the current 1W 22 ohm and 4W 1000ohm resistors in series would be sufficient. On the schematic, just after the cathode and before the series resistors is a voltage specified of 135v. Right across the 1K resistor are two filter caps of 80 and 40mfd. Maybe this will help though not very sharp. Coming in from the power supply you can see the rectifier and right after that the two dropping resistors mentioned. You'll have to copy and paste in address bar to open.


file:///C:/Users/ColColt/Desktop/Pictures/ScreenHunter_01%20Dec.%2030%2010.31.jpg

For some reason I'm not getting notifications via email of new posts and have to check periodically of new posts even though I'm subscribed to the thread.

[Ron Ramirez]

http://theschematicman.com/downloads.htm

For some reason I'm not getting notifications via email of new posts and have to check periodically of new posts even though I'm subscribed to the thread.

See here for instructions:
http://philcoradio.com/phorum/showthread.php?tid=4390

The setting to receive notifications of new posts is not set by default, you have to set it yourself. I just set it for you, so you should receive these from now on.

[Elijah]

Thank you, sir.