DuMont RA-108, how to maintain?

[RetroHacker]

Welcome to the wonderful world of vintage electronics. As jpdylon already pointed out, you don't need to be an electrical engineer to fix up and maintain these vintage electonics, but a basic background in electronics is a big plus. Even if your stuff works at the moment, it will work so much better once the faulty/flakey old capacitors have been replaced. These old things can have a very nice picture and great sound once repaired. To start things off, I would reccomend going to http://www.antiqueradio.org/begin.htm and reading some of the articles, most especially the one about replacing capacitors. If you don't know electronics now, then start reading, you'll find it can be remarkably simple to learn.

Phil's site mainly deals with radios, but he has some TV's as well, read his restoration logs - they're great and are full of useful information. Old TV's and radios are pretty similar from a component standpoint, but radios are much simpler. Start off with a typical 5 tube AM radio set first, and work your way up.

You don't need fancy tools to fix old radios and televisions. Some of the fancy equipment like a tube tester or a signal generator are really nice to have, but far from necessary. You do need some basic tools - the essentials are :

Mulitmeter (cheap Radio Shack model is fine for most things)

Screwdrivers (flat, phillips, couple different sizes, get decent quality tools, I love Sears Craftsmen tools)

Nut drivers, especially 1/4"

Pliers, wire cutters

Soldering iron - I know some people like expensive soldering stations, but I have been using the 30 watt Radio Shack iron for years and it works great for all this stuff with practice. The tips are short lived, but cheap. The iron kinda gets crappy after a year or so of heavy use, but they're only $8.

Solder Sucker - Radio Shack has these, they're about $8, and are a little pump thing to suck up exra solder. Some people never get the hang of it, but I love it. Great tool. Once again, they break after a couple years, but they're cheap and work great until the screw threads holding the top part into the bottom strip out.

Solder - get 60/40 rosin core - make sure it's real solder, not that crap lead free junk, and NEVER use acid core plumbers solder.

Coffee, for late night/early morning/afternoon/mid-day tinkering.


A trip to Radio Shack and Sears can get you all the essential tools for under $60.

Get the schematic for your radio/TV/etc. It is really nice to have when working. Most TV's are covered in Sam's PhotoFacts, but older models can be found in Riders. Your Dumont TV is in Riders volume 10. It's on NostalgiaAir - here's a link to a PDF file of it - http://www.nostalgiaair.org/PagesByM...7/M0004387.pdf

And, there's plenty of resources out there on the net, as well as here. It's a great hobby, with a lot of fun things to learn about. It's pretty easy to get started, and we're here to help. What's your electronic background? Do you know how to solder or read a schematic? If you don't, then you'll have a bit of learning to do before you can get started, but don't worry, it's not too hard, and once you learn how this stuff works, a lot of other stuff makes sense too.

Have fun!

Also, post pictures of your Dumont. We love to see pictures

-Ian

[polaraman]

Welcome!


polaraman

[Chad Hauris]

Just to add to all the good advice already...
I would really recommend a soldering station as it makes soldering a lot easier on a variety of different surfaces. It can sense when more heat is needed and adjust it to keep the tip hot and you can adjust it to solder everything from terminal lugs to a chassis to surface mount components.
Here is the type we use and it has worked great on everything from tube type equipment to very fine circuit board repair.
http://www.cs-sales.net/sl30.html


Replacing bad caps and wiring takes care of most problems especially if the items have some functionality already. Yes you do want to replace these old components because they will continue to degrade and will eventually fail, especially if the device is left on for a long period.

[RetroHacker]

Originally Posted by Chad Hauris

I would really recommend a soldering station ..... Here is the type we use and it has worked great on everything from tube type equipment to very fine circuit board repair. http://www.cs-sales.net/sl30.html

That does look like a nice soldering station. Maybe it is time for me to upgrade - I have never used a "real" soldering station before, I just never had access to one. I just have three or four different irons for different work - a small Radio Shack iron for surface mount chips (15 or 20 watt, I forget), then the good reliable 30 watt Radio Shack iron for most everything else (through hole boards, capacitors, monitor/TV boards, etc) and then a big honking 100 watt Radio Shack soldering gun I bought specifically for stuff that needs to be soldered/unsoldered to the chassis itself, like big electrolytics. When you grow up in a small town where Radio Shack is the closest thing to an electronics store, you make do. I've gotten very, very good at using this equipment, and I even have the requisite homemade soldering station made from scraps of wood and a coiled piece of aluminum wire, with a built in outlet that I made when I was like 14. I've built and repaired some very intricate stuff with those cheap Rat Shack irons. That said, I'm sure that it would have been easier to use the real thing. Maybe one of these days... I'm just so used to the non-controlled, front heavy, inexpensive iron. It is nice that the tips cost about a buck though...

-Ian