Ok, I will take some plate voltage readings with my handy dandy Fluke 77.

Thank you. Your opinions are noted.

Why eliminate the 35Z5?

Read "What about B+"
http://www.angelfire.com/electronic/fun ... AA5-1.html

Here's a GREAT simple and low cost ( less than $2 ) circuit that will do the job very well. I've used it often for higher voltages. You can use it as the entire power supply.
Just put a full wave bridge or a single 1n4007 1/2 wave rectifier in front of it to feed it DC.
It is virtually ripple-free:
The supply can also be made adjustable
by replacing R102 with a 500k ohm potentiometer in series with a 75k ohm, 1% resistor.
Do not forget that 75k resistor! it protects the circuit in case you tweak the pot to the extreme low end .. (don't ask me how I know that so well....) lol

http://www.antiquewireless.org/otb/resto0504.htm

Raymond, pick up a bunch of nylon nuts for you tube socket screws. I get them at ACE hardware. Just gives you a little more room around the wire connections without fear of having something short out.
Jerry

Yes, that is a great circuit. I've sent the 3-page project to my printer and I'm going to build it. Thanks! It's exactly what I was looking for. I will take it a step further and design an etched board that will slip over the 35Z5 pins so they can be utilized as tie-points interfacing with the board. Also by using an octal plug, the TIP50 with heat-sink can be plugged into the socket from above chassis. There are all kinds of possibilities here.

Thanks Jerry for the plastic hardware idea. Certainly worth consideration.

My ideas for electroplating the chassis with Nickle were dashed yesterday because the materials I would need to buy are very expensive. I only paid twenty-five bucks for the crack house radio on eBay. So, decided to spray paint the top, front, and back and then leave the inside original metal for grounding purposes.

Now let me tell you about this new metallic aluminum paint I found at K-mart. "Rust-Oleum American Accents" that is touted as being "ultra cover" with 2X coverage. I thought it was a bunch of hype but it is the best spray paint I have ever used and lives up to it's claims. The paint is fast drying too; I'm able to handle with no tack in just a couple of minutes. Incredible!

Below is the chassis after just two coats. There are two irregular areas on the top, one where I had to chisel the speaker bracket off and the other where some rust had eaten into the metal. Thanks to the Navel Jelly and steel wool, all the rust was completely eradicated prior to painting.

I wouldnt put much into their description as the material used. It is black bakelite. The other materials would be Plaskon, which that isn't , or polystyrene, again it isn't that either.
Painted black bakelite.

Your chassis came out great.
The "Ultra cover' probably means that it has more pigment like it used to have. That's a good thing.
Spray paint nowadays seems to be so thinned down.

Another paint I found that works good for chassis is the Hammertone paints. I think they are up to about 4 colors now. They need to add the green and blue.
It is not a wrinkle paint, but does give a 3D effect and looks nice.

Ok then, Bakellite it is and how I will refer to it in the future.

Yes, it seems everything has been reduced in size or altered in some fashion. Orange juice used to be 64 oz. and is now 59 oz but in the same size wax container. Dial bar soap has been cut concave on both sides. Cat food that was formerly a 5 lb. package is now something like 3.75. The 5-cent Milkey Way of the 1960's is now around $1.19 depending on where you buy it. It happens so slowly that people don't seem to be very angry. But the Milkey Way for example, represents a change of 2,280 percent.

The next big challenge will be retrofitting the polypropylene speaker to the chassis on 3/4" spacers. This requires a lot of exacting measurement to get it aligned with the cabinet's speaker outline. Luckily, I have another similar chassis with the old speaker still attached that I can use for reference. I see the dial scale backplate bracket has a couple of holes near the top. I think this time I'll fashion a top speaker bracket extending from the side rather than top. The last time with the 66X1, I ran into trouble with the dial cord and pointer.

Before you get all excited about trying to retro-fit that new 50 watt speaker... you might first want to try it connected by clip leads to another typical AA5 AM radio just to see if you're going like the way it sounds compared to an older original type 4 ohm speaker.

I don't think you are going to find any great improvement over the original.
You can repair the orig if the cone is damaged.

But trying to make mounting hardware for the new speaker may be more trouble that using the original in the end.

Well, the thing has a huge magnet and a dual cone just like the 4" x 6" unit I put into the 66X1. Both the wife and myself notice an increase in the low and high end. The frequency response is 100 Hz to 18K that is more than adequate for AM broadcasting bandwidth. I'm just sick and tired of those old paper cones with tears and holes. You just touch one and your finger goes through it. With these new poly replacements, you can punch the cone forcefully with your finger and nothing happens. They're designed for 25 watt car radio applications but do fine on just the 1 watt output power of the 35L6/50L6. No worries mate.

Holy smokes Batman! The new tube sockets arrived today. They fit perfectly except two at the opposite end where burs need to be filed off the hole. Also, I'm very grateful the heads of my 6-32 hardware are the same height as the socket and don't interfere with tube seating. Once I get the speaker mounted, I'll be able to start running green wire for the filaments. It will be like building a Heathkit with no manual.

Raymond, an exceptional job on that chassis! I tried for a real piece of junk on e-pray for the chance but dang, it went for a lot of money. Keep us posted on progress.

Jerry

Well Jerry, progress has come to a screeching halt. The replacement speakers I bought have a substantially wider basket than the originals and can't be placed exactly where they must go. I would have to notch out the corner of the chassis below the speaker to get clearance. Luckily, Parts Express in Dayton has a very liberal return polity and I was able to send them back. Until I can find something suitable, I'm going to have to make a copy of the rear mounting bracket and attach it to the chassis with 6-32 hardware along with using a brittle, patched up original. Bummer.

This inability to find replacement speakers is beginning to kill my interest in radio restoration. I've decided to continue upgrading the chassis I have on hand but when that's finished, I'm going back to building solid-state projects. But, it's not a total loss. About 17 years ago, I broke my addiction to Ham Radio and have been pretty successful at not wasting money since my rehabilitation. My recent escapade with Vintage Radio was just minor compared to what I've wasted in the past on non-productive hobbies.

Yes, the prices being asked for pieces of junk are outrageous! Then when you add in the cost of shipping and new parts to revitalize an item, it often becomes insane. Fortunately with the help of my wife, she helped me stop buying junk radios on eBay. Be careful!

Copyright 2004 by W3NLB? That seems a bit odd. Look what is available to the public on the Supertex web site:
http://www.supertex.com/pdf/datasheets/LR8.pdf
http://www.st.com/internet/com/TECHNICA ... 000924.pdf

Hope it works out for you ...
please show us the PC board and report on the performance of it.
It works very nicely for me on the bench for a good quick/easy and very smooth HV supply.
So I'm sure you'll have good results but let's hear it when you do.. ok?

Don't give up so easily.
The old speakers can easily be repaired. Even professionally rebuilt and re-coned.
OR... you can do as I do. I buy new five-inch, strong-fiber cones (less than 50 cents or so):

http://www.electronix.com/advanced_sear ... &x=12&y=12

and I replace the old brittle cones with the new ones.
I cut away all the old cone except for a small quarter-sized area around the voice coil area. Then I cut a slightly smaller open area on the new cone and glue it over the old one at the VC area and all around the outer ring of the metal basket. They sound quite good and last.

You should be able to find more pictures and step by step that I've posted on ARF here several times.
Here is one of my past postings and links to the new cone vendor showing sizes and prices. So all you have to do is follow the dots!:
viewtopic.php?f=10&t=64122

Re: Hope it works out for you ...
please show us the PC board and report on the performance of it.

=========================

I ordered the regulator and switching transistor today from Mouser Electronics. I will bread board it first as you have done and connect it to my 66X1 to see how it performs. Designing an etched board will take longer since I have so many unfinished projects going. This high-voltage regulator is very exciting and I might incorporate it into all restoration efforts. Thanks for providing the circuit details.