Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Revisiting my 7S363
#1

Today I pulled the chassis from the Zenith 7S363 console that I "finished" a few months ago. It was an OK player and received the close local stations without too much trouble.
As this was my first attempt, there were quite a few issues I wanted to revisit and plenty of "should haves" and "wish I had knowns."
My major goal is to get the best I can out of this set. I know it's not a crown jewel kind of set, and will never be the black hole of RF that I wish it was but I love the cabinet and it will forever be the first one. Along with my major goal, I am getting basically zero action on the eye tube. I already checked the resistor in the tube socket, and have come up with almost bang on 1 Mohm. My plan is to go back through and check the resistors. Did I mention the should haves or wish I had knowns? After looking at the underside, I realized my old resistor knowledge is far from complete. I have the color codes for the dogbones (I think) with the body, end and dot colors. The problem is that I see some that look like modern-ish colors with bands, but they don't ohm out like I think they should as well as some that are not quite dogbones but don't look like the others.
Does anyone have a link to a primer of the different types of codes and how to read them? I want to do this right and have the set at 100% before I start the hard stuff including a 16B cathedral and my latest acquisition an RCA 9T. Quite frankly, these two scare the crap out of me and I don't want to booger up two highly collectible set that will be the RF black holes that I seek!
#2

http://www.eeweb.com/blog/andrew_carter/...ing-scheme
#3

Look at the sch and go by the values in it. Old resistors won't "ohm out" as they should simply because they mostly were carbon types and have detriorated to become 30-70% above normal value.
#4

Just replace 'em. Nickel apiece, right?
#5

After reading your responses and some more thought, I decided to go the route Codefox suggested. I wrote down a parts list from the schematic, and looked at it. Something didn't seem right to me... Before you guys start laughing, bear in mind that I am in my early 30s and all my knowledge is based on Navy training for modern components.
Looking closely at the list, I realized I didn't have a single value below 1 Megohm!? I thought "That can't be right, why would there be 470 Megohm resistors in this thing?" A little Google-Fu later, and I now know that the annotation of M Ohm in the old schematics is notation for thousand! No wonder everything looked funky to me!
Armed with my new knowledge, I will replace all the resistors in the set. I didn't trust any of the paper caps, why would I trust old carbon resistors.

This brings up a new question. The candohm resistor has one 220 ohm section reading way too high. I have 10W power resistors to make a new one. Is 10W enough dissipation or should I source higher wattage? Is 10W too high?
#6

No...not nickel. I usually use a minimum 1 Watt to keep the size, otherwise leads may not be long enough, and sometimes higher rating is warranted, and this is in tens of cents.
#7

I should think that 10W is plenty.

Personally, I check resistors and replace those outside 20 percent of their stated value.

Bear in mind that you may have to pull one side of your resistor to get a good reading.
#8

If you gotta pull one side free, for a nickel on fractional watt resistors, just put a new one in and be done with it.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Need Help to ID this radio 11 tube Philco
Philco 16 is not intimidating at all. Despite being an 11-tuber. 37-116 is indeed intimidating. 16 has good space unde...morzh — 04:11 PM
48-482 rear panel help
Thanks for the responses Gary and Bob. I'm a little surprised that there's no back panel - although I know older Philco'...keithchip — 04:09 PM
48-482 rear panel help
Gary is correct, there was not a rear panel on the 48-482. I restored one of those and its a great sounding radio that ...klondike98 — 03:24 PM
The list of my radio & TV collection!
A little light positivity in our feed... To nostalgic retro music... With English subtitles My new video on the contin...RadioSvit — 02:14 PM
My Philco 37-116 Restore
Ron and Mike I mentioned a 2 meg resistor not on the schematic. I stumbled on a changes note in Riders that mentioned th...dconant — 12:02 PM
Need Help to ID this radio 11 tube Philco
Here you go: Your the code 125Radioroslyn — 11:12 AM
My Philco 37-116 Restore
Hi Ron, Thanks for the input. I think I'm going to call it good enough. It does seem weird I can usually dial in othe...dconant — 08:01 AM
Need Help to ID this radio 11 tube Philco
Welcome, the radio looks intimating 11 tubes, wish you well.Jimradio — 07:49 AM
462ron
Hi Dan, it’s been 10 years since I restored the electronics on my 37-116 so I’m going on some foggy memories. I remember...462ron — 07:37 AM
Need Help to ID this radio 11 tube Philco
Yes the 16B as morzh pointed out. Specifically its the January 1935 model version of the 16B. There are a couple earli...klondike98 — 11:51 PM

[-]
Who's Online
There are currently 2114 online users. [Complete List]
» 1 Member(s) | 2113 Guest(s)
Avatar

>