Western Electric 247A Vacuum Tube With Old Carton. Quantity: 1
Item History & Price
| Reference Number: Avaluer:51291756 | Brand: Western Electric |
| Type: Vacuum Tube | Model: 247A |
| Country/Region of Manufacture: United States |
Western Electric 247A Vacuum Tube Quantity: 1 Used. This Western Electric 247A tube is definitely used. If you look at the glass envelope, you can see some discoloring. I do not think it is from the getter. I did test this tube with my lab power supply. With 150 volts on the plate, I could cut the tube off with -13.3 VDC. If I reduced the grid voltage the current drawn goes up to 6.75 ma. at 0 volts bias. I am not sure but I suspect that the tube might want to... draw more than 6.75 ma at zero bias. That being said, this tube does have a characteristic curve which is more than you can say about many people who were born in the early 1930's! I am kidding a bit, but the current that it draws at -4.2 VDC is 3.25 ma. The tube specs indicate -4.5 VDC, so it is close to being pretty good. I am not guaranteeing that this tube will be as new by any means. I just did static tests to make sure it is not dead. This tube comes with a rather dilapidated Western Electric tube box. It was stored in a damp environment for many years and the cardboard is a bit mildewed. As you can see from the pictures, the tube itself looks pretty good. There is a red #2 printed on the glass bulb. Not sure what that means, but it can be removed with some paint thinner. I left it as-is. I am not a Western Electric collector, but I do have experience restoring WW2 aircraft radios and some later tactical sets. I hope this tube gets used in a real radio and not re sold or stuck on a shelf. Shipped with USPS Priority Mail. I'll pack it well.
I checked the tube curves for the 247A, and I was right about the current at zero bias. At 150 volts I should see about 8.5 ma with a 100% good tube and this one makes it to about 6.75 ma. Not to bad at all, but definitely not in the new and 100% category.
I checked the tube curves for the 247A, and I was right about the current at zero bias. At 150 volts I should see about 8.5 ma with a 100% good tube and this one makes it to about 6.75 ma. Not to bad at all, but definitely not in the new and 100% category.
