| Up for sale is the following item: | |||||||||
| Article: | Electron tube | ||||||||
| Quantity / Pieces: | 1 | ||||||||
| Manufacturer: | VALVO / PHILIPS | ||||||||
| Type: | ECC83 | ||||||||
| Equal to US Type: | 12AX7 | ||||||||
| Manufactured in: | Copenhagen |
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| General test results: | Tested better than new = excellent electrical values, better than a new tube | ||||||||
| Code on tube: | ΔC mcN | ||||||||
| Specifics / description: | Super
ultra rare! One of the first European ECC83 ever made. The black ΔC mcN
code on the glass bottom between the pins indicates that the tube was
manufactured in March 1954 with Batch 0 (first batch) in the Philips plant in Copenhagen. The tube has long
(17mm) welded (!) plates, copper grid rods, a 45-degree D-foil getter and the old Valvo logo.
The tube has incredible good test values and is totally matched and balanced. I have never seen such a good testing and precise ECC83! Seems back in the early 1950ties they really understood how to make highest qualitiy tubes before rationalization and economic interests were beginning to affect the European tube industry in the 1960ties. This is a real jewel, so please excuse the high price. |
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| Test results emission test: | |||||||||
| Tested with: | |||||||||
| Ua (plate voltage) = 250 Volts | |||||||||
| Ug (grid voltage) = - 2 Volts | |||||||||
| System 1: | Ia (plate current): | 1,4 | Milliamperes (mA) | ||||||
| Equal to: | 118% | Emission | |||||||
| Gas test: | OK | ||||||||
| Shorts tested: | OK | ||||||||
| System 2: | Ia (plate current): | 1,4 | Milliamperes (mA) | ||||||
| Equal to: | 118% | Emission | |||||||
| Gas test: | OK | ||||||||
| Shorts tested: | OK | ||||||||
| The emission value for a new ECC83 tube is: | 1,2 | Milliamperes (mA) = 100% | |||||||
| Gas tests and shorts tests were made with U.S. army tube tester TV-7/U | |||||||||
| Test results mutual transconductance test: | |||||||||
| Mutual transconductance tests were made with U. S. army tube tester TV-7/U | |||||||||
| System 1: | TV-7/U Reading: | 47 | |||||||
| Equal to Gm: | 1.175 | ||||||||
| Measuring / Test Range: | B | ||||||||
| System 2: | TV-7/U Reading: | 47 | |||||||
| Equal to Gm: | 1.175 | ||||||||
| Measuring / Test Range: | B | ||||||||
| Minimum Reading for good for a ECC83 tube on TV-7/U Tube Tester is: | 32 | ||||||||
| Equal to Gm: | 800 | ||||||||
| Measuring / Test Range: | B | ||||||||
| Your satisfaction is very important to me.
I will offer a full take-back with complete refund within 30 days after
delivery if you are not satisfied with the tube! Conditions for a take-back: Tubes must be returned unused (except a short listening test, of course) and completely undamaged. Shipment back to me will be made on buyer’s risk only. Money-back transfer for take-back will only be made via PayPal after the tubes safely arrived back here. Tube is sold as is. Private sale. I cannot offer any guarantee or warranty. Shipping on buyer's risk. I will pack the tube very, very carefully. Shipping with shipment tracking only. Payment: Only in advance via Paypal within 5 days after auction ending. I ship worldwide. Shipping costs accordingly to your destination. Many thanks for your interest. |
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