| Up for sale is the following item: | |||||||||
| Article: | Electron tube | ||||||||
| Quantity / Pieces: | 2 | ||||||||
| Manufacturer: | VALVO / PHILIPS | ||||||||
| Type: | EL84 | ||||||||
| Equal to US Type: | 6BQ5 | ||||||||
| Manufactured in: | Hamburg / Germany | ||||||||
| General test results: | Tested better than new = excellent electrical values, better than a new tube | ||||||||
| Code on tube 1: | Df rxp / 044 (on top) | ||||||||
| Code on tube 2: | Df rxp / 046 (on top) | ||||||||
| Specifics / description: | Super
ultra rare! One pair of the first EL84 tubes ever made in Europe with same
codes. Code Df rxp on the glass bottom between the pins indicates that both
tubes were made in June 1954 with batch 1 in the Valvo plant in Hamburg /
Germany. Both tubes have identical Df rxp codes and were almost made side by
side which is indicated by the code on the top: 044 and 046. Both tubes have
the very early closed round disc getter (not the closed elliptical getter,
which came later), the old Valvo logo and the white DF rxp code printed
between the pins on the glass bottom. Both tubes are matches with identical mutual transcoductance test values and have very strong emission. This is probably one of the best and earliest EL84 pair with identical codes you will ever find. Sorry for the high price! |
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| Test results emission test: | |||||||||
| Tested with: | |||||||||
| Ua (plate voltage) = 250 Volts | |||||||||
| Ug2 (grid 2 voltage) = 250 Volts | |||||||||
| Ug1 (grid voltage) = - 7,3 Volts | |||||||||
| Tube 1 (Code Df rxp / 044 (on top)): | Ia (plate current): | 60,0 | Milliamperes (mA) | ||||||
| Equal to: | 125% | Emission | |||||||
| Shorts tested: | OK | ||||||||
| Tube 2 (Code Df rxp / 046 (on top)): | Ia (plate current): | 53,0 | Milliamperes (mA) | ||||||
| Equal to: | 110% | Emission | |||||||
| Shorts tested: | OK | ||||||||
| The emission value for a new EL84 tube is: | 48 | Milliamperes (mA) = 100% | |||||||
| 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 | |||||||||
| Tube 1 (Code Df rxp / 044 (on top)): | TV-7/U Reading: | 66 | |||||||
| Equal to Gm: | 3.300 | ||||||||
| Measuring / Test Range: | C | ||||||||
| Tube 2 (Code Df rxp / 046 (on top)): | TV-7/U Reading: | 66 | |||||||
| Equal to Gm: | 3.300 | ||||||||
| Measuring / Test Range: | C | ||||||||
| Minimum Reading for good for a EL84 tube on TV-7/U Tube Tester is: | 50 | ||||||||
| Equal to Gm: | 2500 | ||||||||
| Measuring / Test Range: | C | ||||||||
| 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 tubes! 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. Tubes are sold as they are. Private sale. I cannot offer any guarantee or warranty. Shipping on buyer's risk. I will pack the tubes 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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