are recapped tube radios safe?
 

I have just done my second recap and I plan on using this radio :) it's an Admial clock radio since it's a clock it will need to be plugged in 24/7. I heat shrinked almost every cap and the radio seems to work well altho it took awhile to "fire up". I do not have a tube tester so I do not know how good the tubes are. So am I safe? Can old radios be left plugged in,or are tube radios just pretty do dads for shelf clutter?

If you recapped the radio and it's now working fine, leaving it plugged in is not problem at all. You mentioned that it took a while to fire up. What do you mean? That it took days/weeks to finish the recap? Or that it took more than 60 seconds or so to turn on? Tubes don't turn right on like solid state, they take a minute or so to warm up. Part of the magic!

How many kitchens do you imagine had one of these on top of the "ice-box" over the last half century? How many have you heard of catching fire? I know this one is older, now, but I wouldn't worry a bit.

I had one in the bookcase headboard of my bed when I was a kid, turned way, way down late at night listening to White Sox games. I may just start looking for one of my own!

The radio section shouldn't see any power when off, only the clock would remain on and that doesn't have any circuitry.

Curious as to why you heat shrinked the capacitors....that COULD retain heat and possibly lead to early failure although that remains to be seen. All tube type devices require a warm up period to get them to function (except for some TVs from the early 70's which kept the picture tube filament slightly powered up)

Anthony

it took weeks to get the parts but the recap only took a few hours. It just took a bit longer then my other tube radios to come on the first time but I didn't count the seconds so I'm not sure hmm I could do a turn on drag race lol

o I just heat shrinked the leads. I had the heat shrink and was trying to be "neat"

OIC, that makes more sense to me! There's something called Liquid Electrical tape that comes in a can with a brush in the cap that is pretty slick for "painting" on exposed leads in tight areas...I use it on old cars with crumbling cloth covered wires for a quick and dirty patch job.

I knew what you meant! :thmbsp:

If you're a natural "neatnik" you'll be great at this!!

As for fire safety, recapped tube radios in cabinets of that size and material should be fine. I don't think bakelite will burn that easily, and resistors overheated are not likely to light anything else on fire. Think of it as any other box that produces 30 watts of heat to be vented.

As for electrical safety, some older radios are not up to modern standards. Some sets that had the chassis directly tied to the line had screws protruding thru the bottom of the cabinet. Or hot volume control shafts that depended on the knob never getting lost for user protection. If the screws are machine type, you should be able to replace them with plastic screws. Sheet metal screws are more difficult. Maybe you can cut a machine screw thread in the sheet metal screw holes, or solder or glue on machine nuts.

They're *really dangerous* !!!! Wrap them all up in plastic and duct tape and send them directly to me. :naughty:

All kidding aside, I used one of these for years. I unplugged it if i went on vacation or something. Unlike modern equipment, when you shut an old radio off, it is really off. The exception is the clock. These telchron clocks are of such a design that if the armature gets stopped, the coil doesnt overheat. I also have never heard of one of these catching on fire. I've seen them pretty old and cooked, even burned out, but no fire. Of course there are plenty of them out there with no clock if it concerns you.

Enjoy it. :thmbsp:

Welp, seeing as how Bakelite has asbestos in it, it may be a little hard to burn! Seriously, be careful if you ever intend to do any sanding or polishing on Bakelite as you shouldn't breathe in any fibers.

Anthony

Well my slow start seems to be worse then I thought :( The first time I plugged it in it wouldn't work so I pulled the tubes and cleaned the connections then it worked! but when I moved it into the bedroom it was dead so I pulled the back off of it and no tube glow. I'm thinking check the solder joints and wiring

Its possible,
But I would check all of your tube connections again.
If they have the heaters connected in series it
will only take a bad connection on one of them to knock out
the entire string.

Didja spray any Deoxit in the tube sockets?

Anthony

I don't have any deox so I used a cleaner for r/c cars (I love this stuff it's safe on plastic) I cleaned the tubes with alcohol. I did find one bad solder joint (not mine :) ! but it's still dead :( no tube glow. Should I try jiggling the tubes while it's on? I am almost thinking it's the power "switch" , I'll check it out with a multimeter whenever I'm not tired

Don't jiggle the tubes while it's on, too much risk of touching something else and gettin your ass shorted out... If it worked after pulling and replacing the tubes, it prolly is just a bad connection there. Do any of the tubes feel at all loose in the sockets? Maybe try a narrow screwdriver down in the pin sockets to tighten up those little grabber contacts.

Are you SURE you got the tubes back in the right sockets?...It's happened to me-I'm not too proud to admit it, either.-Sandy G.

I put them in right I'm lucky the numbers are stamped into the chassis. Everything looks right,good solder joints and I cleaned it well maybe I have a bad tube? I don't have a tester :( are they exspensive? Well I think this one will be a good clock atleast.

Good tube testers are expensive. What you *really* want if you are going to spend any money on a tube tester is "mutual conductance". Also look at the tube sockets, older machines can't test newer tubes. Watch fleabay, eventually bargains come along.

Having said that, *any* tube tester will do what you need here. Heck, you dont even need a tube tester. You can just check the filaments for continuity with your DVM. An RCA tube manual will tell you which pins are the filament. If you don't have one yet, post which tube numbers you have, and I'll post which pins are the filaments.

Good luck. :)

jc

35W4 50C5 12AV6 12BA6 12BE6 I have some other project radios and I think I have most if not all the tubes that the admiral uses :) so I'll change them out 1by1 till something happens. But learning to check tubes with a multimeter would be great!

All those tubes have the heater on pins 3 and 4. The 35W4 also has a tap on its heater on pin 6. Expect to see resistances of a few tens of ohms. Tube pins are numbered such that, when holding the tube with the pin end facing you, starting from the gap clockwise the numbers increase, starting at 1.

I just did some tube swapping eh no luck :( Maybe something got "impact" damage from shipping. For now I am just going to move on to another project. Thanks for the info.