• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Tubes Numbers

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This may be a very simple question but I want to make sure I'm doing things right before I turn on a radio. My father passed away and one of the few things I have of his is the old tube radio (RCA Radiola 33 - big guy) that he used to listen to sports on. I shipped the radio home and UPS did a fairly good job in packing except they removed the tubes from the radio for shipping. Although I wish they'd have wrapped the tubes separately but they seem intact.

The radio clearly has marked what tubes go into what connections. However the tubes' marking are slightly different.

There were three radiotron bulbs that were clearly marked UX226 (x2) and one marked UY227 which match exactly the numbers on the radio. The other 4 bulbs (all Westinghouse Radiotron) are slightly different shaped (with "nipple" on top). I need two more UX226 and there are two just marked "26" so I assume those are them.

I need a UX171A and there is a tube marked "71A" so assume that is the right one.

Last one needed is UX 2801 and the tube is only marked "80" so again assume this is the right one.

I'm not missing numbers on the last three as those large #'s on on the side of the tubes. But as you see they don't follow the same "short cut" on naming tubes if there was a move to shorten their numbers.

Am I right above in my assumptions? I'll wait until I hear from you on this message line before plugging my machine in.

Thank you in advance

Kevin
 
Kevin,
Your assumptions are correct on the tube numbers. A 227 is a 27 and a 226 is a 26. In the old days the first number indicated the manufacture. Likewise, a 171A is a 71A. And it's very safe to say that the 2801 is a type 80 rectifier. There should be two vertical sections inside.

If the radio hasn't been played in a long time, you might develope a power supply capacitor problem. Be ready to hit the off switch quickly just in case you hear any strange noise or see smoke.
 
Thank you for your responses and especially the warning about overheating. The radio was used by my father regularily up till about 5 years ago in his bed room. He did have and use other radios but I think he liked using this just because it had been in the family a long time. Inside the radio was a 1936-37 annual "private radio receiving license" issed to my grandmother.

I was going to say my father stopped using it when it could navigate the stairs up to his room but actually it might be because, or so I am told, that there are no AM radio stations in Halifax, NS anymore so the radio would not pick up much if any.

I plugged it in and things went okay. All the tubes are lit which I assume is a good sign. One is very hard to tell as the silver coating is still intact so hard to see if it is glowing but it is slightly.

The speaker (Model 100B) also seems to be working as it hums especially when you turn up or down the volume.

But I can't find a station. I'll have to move the radio around for I live in an apartment and maybe the AM frequencies will be stronger. The city where I live still does have AM stations. I just don't have another device that can pick them up so I can be sure they are on air and where to find them.

I'll work more with it tomorrow.

Thank you again.

Kevin
 
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