Description
TUBE HUNTER VACUUM TUBE GEMS THESE ARE THE SPECIFICS OF THE TUBE/TUBES/PARTS FOR SALE THESE ARE THE TUBE/TUBES/PARTS FOR SALE: MANUFACTURER: RCA PRODUCTION CITY: USA TUBE TYPE: 6AU6A DESIGNATION: TEKTRONIX CHECKED YEAR: 1960S MONTH: VARIES Date code match VARIES SILK SCREEN CONDITION %: 100% MICA: 2 PLATES: GREY GM%: 120%,120% SINGLE/PAIR/QUAD/MULTI: PAIR GETTER: O GETTER DATE CODE VARIES These are a great preamp tubes. Made by RCA and hand checked by Tektronix technicians in the 1960s. These will have varying dates but will be exact gm matches. These tubes must test over 100% and matched to be sold in this auction. I guarantee you will not be disappointed. What does Checked Tube mean? Tektronix was the leader in high MEGAHZ machines. They were doing some really fast switching. Tektronix was building equipment that was on the leading edge of tube technology. They did things that required careful matching of tube characteristics, such as 18 tube distributed vertical amplifiers. Some of their circuits, by virtue of their being flat from DC to 100MHz, or so required tubes that had unusually stable characteristics. They needed the tubes to meet very high standards in some critical circuits. At times only a single manufacturer made tubes that met those standards. Because of these special needs, Tektronix had a department dedicated to testing and matching vacuum tubes. They assigned, special part numbers to these highly tested and selected tubes. These tubes were selected by Tektronix for use in critical sections of precision testing equipment. They were hand selected for GM values and balance (within 2% per section). They also were checked for NOISE. They are the lowest noise tubes you can find for the brand selected. That is what the CHECKED STICKER are all about. Tektronix was very picky about the components that went into their equipment. They made the VERY best test equipment of all time in my opinion. These tubes are an embodiment of that fact. They sound great in my headphone amp, and they will in yours! Normal 0 false false false EN-US X-NONE X-NONE On my tester a B&K 747 tester: Below 55 = BAD 55-66 = ? 65 -100 = Good 100-120+ = NOS *********************************************************************************** IMPORTANT NOTE ON FILLING ORDERS With NOS tubes we will substitute NOS American tubes with NOS American of a different brand to fill an order if we are short the brand listed. If you are brand sensitive let me know BEFORE you order. NOTES ON PHOTO PROPS: THE RCA DOG, PHONOGRAPH, REDDY KILLOWATT, AND OTHER STATUETTES, INCLUDING DEVICES TO MAKE TUBES OR OTHER PARTS STAND UP STRAIGHT, ARE NOT PART OF THE SALE. THIS IS TRUE OF ANY PROPS USED IN PHOTOGRAPHY IN THE LISTING THAT ARE NOT SPECIFICALLY CALLED OUT IN THE LISTING AS ITEMS FOR SALE. NOTES ON PHOTOS FOR SINGLE TUBES: IF YOU ARE BUYING A SINGLE TUBE: FOR THE MOST PART WITH TUBES UNDER 15 DOLLARS WE ARE USING STOCK PHOTOS FOR SINGLES. YOUR MILEAGE MAY VARY. YOU WILL RECEIVE A NEW TUBE. IT WILL TEST NOS. IT MAY OR MAY NOT BE ONE OF THE ONES IN THE PICTURE. WE GET TUBES IN ALL THE TIME. WITH SINGLES OF A LOW VALUE WE ARE NOT PICKY ABOUT DATES AND CONSTRUCTION AND THINGS LIKE THAT. WE ALSO MAY SUBSTITUE A TUBE BY A DIFFERENT MANUFACTOR IF WE ARE LOW ON STOCK OF THAT BRAND SUCH AS AN RCA FOR A GE FOR EXAMPLE, BUT WE WILL NOT SEND A JAPANESE BRAND FOR A USA MADE TUBE, OR A LOWER QUALITY TUBE IN ANY WAY. IF WE ARE SELLING A PAIR, OR A HIGH VALUE SINGLE THEN WE GET SERIOUS ABOUT SUCH THINGS. NOTES ON MATCHING: 1. TRIODES SIMILAR TO 12AX7 ARE DONE ON A TEKTRONIX 576 CURVE TRACER IF I HAVE MATCHED THEM WITH THIS MACHINE I GUARANTEE THAT THESE MATCHED PAIRS WILL BE NOT BE ABLE TO DIFFERENTIATED WITH THE HUMAN EAR IN A PREAMP CIRCUIT. 2. ON OTHER TUBE I USE A CALIBRATED HICKOK 600A TO MATCH TUBES. 3. ON MODERN TUBES, FOR WHICH THE 600A CANNOT PERFORM TESTS, I USE THE CALIBRATED B&K 747B TUBE TESTER. NOTES ON THE BOXES. LISTING WILL GENERALLY HAVE INFORMATION ABOUT ANY BOXES ASSOCIATED WITH THE TUBES FOR SALE. THESE ARE THE OPTIONS: 1. ORIGINAL BOXES IN VARYING CONDITION. THESE BOXES WILL BE THE ORIGINAL BOXES THE TUBES CAME IN AND WILL SHOW AGING IN VARYING DEGREES. THESE TUBES ARE ASSUMED TO BE NEW AND WILL TEST AS NOS. 2. NO BOXES PROVIDED (NONE AVAILABLE USUALLY USED AND SHOULD BE ASSUMED TO BE USED UNLESS OTHERWISE STATED. 3. REPURPOSED BOXES. THESE ARE BOXES OF THE SAME MANUFACTURER. THESE WILL HAVE A LABEL OVER THE TUBE NUMBER THAT REFLECTS THE TUBE BEING SOLD. THESE TUBES SHOULD BE ASSUMED TO BE USED UNLESS OTHERWISE STATED. 4. TUBEHUNTER BOXES. THESE ARE BOXES I HAVE MADE WITH GREAT TIME AND EXPENSE TO PROTECT YOUR VACUUM TUBES AND PROVIDE FOR STORAGE AND EASY IDENTIFICATION. TUBES IN THESE BOXES SHOULD BE ASSUMED TO BE USED UNLESS OTHERWISE STATED. 5. WHITE BOXES. SHOULD BE SELF EXPLANATORY. NOTES ON TESTING OF TUBES: THIS IS DONE ON A NUMBER OF TESTING DEVICES 1. TEKTRONIX CURVE TRACER 2. B&K 747 TUBE TESTER 3. MERCURY 1000 DYNAMIC MUTUAL CONDUCTANCE TESTER 4. HICKOK 600A DYNAMIC MUTUAL CONDUCTANCE TUBE TESTER I test all tubes that I sell in one way or another, or I will state untested. I have a B&K 747 tube tester. This is a mutual conductance tester. It give a percentage value of gm for the tube under test and checks for shorts and grid emissions. I also use a Tektronix curve tracer for testing triodes. I give a number of evaluations for tubes. One evaluation is a screen shot of the tube with a high voltage applied to the plate. This helps the buyer see the linearity of the tube in question at the highest voltage the tube will see in a real circuit. The Curve tracer steps the triode through 10 gate/grid voltages starting with -10 volts and going to 0 volts. The lines show how the tube conducts throughout that range. At 0 volt the tube is at max conduction and is the top line on the display. It is easy at that point to take where that top line intersects the plate voltage, find the milliamp level and compare it to the datasheet. I give those numbers for you in the Item condition box. To further help the buyer I also include the Design values, for gm and ma readings in the table. This can then be compared to other tube sellers using inferior test methods such as Hickok, Amplitrex, and other testers. The Tektronix curve tracer gives values within 3% of the actual value. The very best portable testers only can approach 10% accuracy. 5. Please NOTE: The numbers given for gm are what I see on my tester. I DO NOT guarantee that you will see those numbers on your tester. I only guarantee that these tubes will test good, with no shorts, or gas, on a decent calibrated tester. I dont guarantee or imply anything else. 6. VERY IMPORTANT NOTE!!! Vintage tube testers almost always, due to age, have VERY LOW HEATER VOLTAGES!!! Every tester I have ever bought is below 6 volts when selecting 6.3 volts. They average 5.8 volts. The voltage NEEDS to be 6.3 and 12.6. You can calibrate a vintage tube tester all you want. If the heater voltage is not right, you will NEVER get the right gm value. I have customers complain that their tubes are not the same as what I see on my tester. They say they have a calibrated tube tester. I have 40 tube testers. On all of them I have an outside regulated DC power supply that feeds the tube tester the correct heater voltage. 7. NOTE I dont check each and every tube for noise or tone. This is SUBJECTIVE and it is too time consuming. If you dont like the noise level or the tone we offer a hassle free refund policy. 8. NOTE. TESTING RESULTS SHOW HOW THE TUBE IS PERFORMING NOW. TESTING RESULTS DO NOT SHOW HOW OLD A TUBE IS OR HOW MANY HOURS IT HAS BEEN USED. HOWEVER IF A TUBE TEST NOS YOU CAN BE ASSURED IT WILL LAST A LONG TIME AND IS WORKING VERY WELL. NOTES ON CUSTOMER RELATIONS: I want to see you happy with your purchase. I will never sell a tube that is below standard…… I have sold many tubes here on Ebay, and all my customers have been completely satisfied. I will work with you in good faith if there are any problems, or if you are unsatisfied in any way. I want your business now and in the future, so I assume you are the boss, and I am the employee. All tubes are tested for shorts, continuity, and emissions. I prefer PayPal. NOTES ON RETURNS: 1. NOTE: RETURNS: It is my highest desire that you are completely satisfied with your purchase from me. I will bend over backwards to make sure that you are a happy customer.2. NOTE: We almost always have a replacement available of the same or sometimes even higher quality. Please note that it is our desire TO DO BUSINESS! We never rip anyone off.......EVER. 3. NOTE: If anything you buy from me is less than satisfactory, message me BEFORE you either open a case or hit the “item not as described” button.4. NOTE: Sound quality is tremendously SUBJECTIVE. For tubes returned for noise or sound quality of any kind you pay for the shipping we refund the purchase. We refund the price of the item NOT THE SHIPPING COST. If we sent the wrong tube we will of course pay for return shipping. For any tubes that are DOA we require that you send a us a picture of the shipping box to show us the damage. We test EVERY tube sent out and none should be DOA unless broken in shipping.5. PLEASE NOTE: Tube silkscreen (lettering on the tubes) is VERY fragile. It can be wiped off and destroyed VERY easily. If you wipe off the silkscreen while handling the tube you diminish their value by up to 70%. DO NOT handle the tubes or hold them from the cylinder. ALWAYS hold them from the ENDS. If you are returning tubes and they are not in the same condition cosmetically I cannot give you a full refund. THIS IS VERY IMPORTANT. 6. NOTE: UNLESS YOU MAKE ARRANGEMENTS WITH US BEFORE YOU PURCHASE, YOU MUST PAY FOR ITEMS PURCHASED WITHIN 2 DAYS OR A CASE WILL BE OPENED FOR AN UNPAID ITEM!!! International customers NOTE: 1. Please wait for us to invoice you for the correct amount. If you have purchased more than one item, we must calculate how much the shipping will be. Shipping will be HIGHER due to insurance and shipping methods needed for expensive item totals. If you are buying only one item this will not be an issue. 2. NOTE: Under no circumstances will we state on a US customs a declared value of less than the sale price. This is an honesty issue. We are honest with everyone to the best of our ability to do so. We want you to trust that what we say is true. There cannot be that trust, if we make false statements knowingly to anyone. If your country has tariffs/taxes so high that they cause large numbers of normally honest folks to make false statements, we urge you to work for change of those laws. 3 NOTE: International buyers if you bought more than one item and want combined shipping it will ship in 2 days.4. NOTE: And all the Angels sang because the heavenly music was playing and it was turned all the way up. Listing and template services provided by inkFrog
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(236) : 77.1 €
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