[osanders0311]

All resistors replaced and 1 Aluminum cap to go. I am questionable about something that looks like a resistor and hopefully someone can help figure it out. I am attaching a picture; in the schematic it is around part# 39 which has other resistors in the area. I have an arrow pointing to it on the picture.

[RodB]

It helps to identify what's connected to the mystery part. At the top of the photo there's a white wire connected to a tube socket. What tube is it and which pin? At the bottom is a yellow wire, what is it connected to? These 2 wires are connected to either end of the mystery part.

[osanders0311]

Hello RodB I've tried looking at the schematic to figure out the tube types and still not sure. Hopefully I counted the pins correctly, in my picture the white wire is on tube 7B7 Pin #5 and the yellow goes to another tube 7Y4 (Rectifier) Pin#4. I am attaching a picture of the other end for the yellow cable, I marked it with a black marker. Hopefully this is helpful

[osanders0311]

Hello guys I ordered and received a capacitor from just radios and can't figure out which side is the pos/neg terminal. There is writing on it that says "Neg-Black" and also 1 terminal is knurled. I am attaching pictures of it and hopefully someone can help. PS looking at the writing on the side it's mostly to the knurled terminal. But I don't know which is which.Thanks        

[radiorich]

Hello Osanders,
I even looked that product up on just radio they must have secret design .
I can't find a part number on their site not even on Richey's site Digi-key had just radio selling it on their site and I did find part number but even on the poor data sheet it did not show .

that why I like Nichicon or Chem con from mouser .

maybe some welse knows .

Sincerely Richard

[osanders0311]

Thank you Radiorich unless someone else chimes in I will try and message Just Radios and hopefully they will have an answer.

[osanders0311]

In case anyone else run into the issue I had figuring out Richey caps I received a response from just radios, and the negative terminal is the one with the knurl and the positive is the flat terminal. Or the negative on this cap is the side with the information/2310 stamp on it.    

[osanders0311]

Ok guys, JustRadios has me worried after reading an article about purchasing resistors and I hope that I haven't made a mistake in purchasing from Amazon before finding Just Radios. Long story short, I have replaced all resistors, Caps and safety caps installed. Also connected a polarized power cable which is another story to come.

Today I took a chance and powered the radio up hoping that it didn't blow up etc. The dial lights came on which was good, then the speaker buzz started followed by a little smoke. I immediately unplugged it. Checked it and didn't see anything so tried again and this time I could see a resistor smoking. Now I'm fighting to find it on the schematic but in the meantime, I have re-installed the old resistor.  

I am curious though if the issue was indeed the resistor or possibly a loose wire also connected to it? The speaker wire goes to one end of the resistor in question, and I had temporarily attached it to the lead while testing it and not soldered down. 

After installing the old resistor, I also soldered down the speaker wire and did a test run and the radio powered up with no smoke. Maybe someone can give some advice, I would hate having to replace all the resistors again.    

[RodB]

Hi, what I'm seeing on the schematic is one wire from the output transformer goes to B+ and the other goes to the 7B5 plate terminal. You haven't mentioned the value of the cooked resistor but I'm assuming it is either 220k or 220 ohms. If it's 220K then you have to tell us which end is connected to the 7C6 plate.

[osanders0311]

Hello Rod, 

Honestly I am not sure what you mean by B+ on the schematic, I am still trying to figure it out as I hadn't read one in years. While replacing the resistors I tried following along with the Underside chassis schematic. But and I hope I may have found the issue, it looks like the resistor that burned was 2.2k and not the required 220k. I will try installing the correct one in a few and try double checking the others against the schematic. I am attaching a better picture of the underside as well.
       

[RodB]

Okey dokey, let's get on the wayback machine. Back when radios were running on batteries, they were powered by three DC batteries, A, B, and C. The A is for filament/heater voltage, B is high voltage (typically 22.5 -90 volts) and C is for grid bias. Your radio tubes get these voltages from the power transformer secondary windings. The A voltage is supplied by the 6.3 volt secondary, the high voltage secondary provides the B voltage and C voltage. It is converted to DC by the full wave rectifier tube and filter circuit.

If you look at the 7Y4 in your schematic you'll see the cathode is connected to a choke coil and an electrolytic capacitor. The other side of the choke is a second electrolytic capacitor. This point in the circuit is 180 volts and is your B+ voltage. You can follow this connection up to the output transformer and also to the left to the 220k plate load resistor. Now you can see how B+ is distributed to the plates of the amplifier tubes.

[RodB]

BTW there's a 2.2k resistor from B+ to one of the XXL tubes so you have to identify those resistors before you replace them.

[osanders0311]

"BTW there's a 2.2k resistor from B+ to one of the XXL tubes so you have to identify those resistors before you replace them."

Thank you Rod but unfortunately I have already replaced the resistors, I had seen 2 on the schematic and hopefully traced them correctly. One showed to be #27 and the other #36. I am hoping I replaced the correct one at #27which is the XXL tube near the loop antenna connection. Hopefully I just grabbed the wrong one when replacing the one that burned, I still want to make sure that all replaced are correct. I also found a missed resistor which looks like #30 connected to the 2nd XXL tube near the loop antenna connection. 
       

[osanders0311]

Please correct me if I am wrong, while working on this radio I noticed under the chassis where the bottom of the tubes protrude through the socket a couple had a wire connecting pins. Should this wire be touching the bottom center of the tube? 

I have lifted the ones that were touching.

[osanders0311]

"Your radio tubes get these voltages from the power transformer secondary windings. The A voltage is supplied by the 6.3 volt secondary, the high voltage secondary provides the B voltage and C voltage. It is converted to DC by the full wave rectifier tube and filter circuit."

Rod thank you for explaining this, I have to read it a couple more times to fully understand, I am, guessing the secondary voltages come from the Compensators?

Do I have the best schematic for this radio, I believe I downloaded it from this site but I also have one that shows John F Ryder. I have a printed copy but doesn't show the credits.