SYLVANIA, Made in USARare 5751 Gold Pin Valve TubeShort Grey Plates, Disc GetterFully Tested on AVO VCM 163Ia 0.85/0.9 - Gm 1.2/1.1100% Book Spec = Ia 1 - Gm 1.2Used, Supplied in White Box

SYLVANIA 5751 Valvola NOS electronic tube valve BOX plate valvole new in box

Very nice quad of scarce Sylvania 5751 gold print tubes. All feature black plates, triple micas, and square getters. Identical 1958 date codes. Matched to about 11% difference across all tubes with excellent balance between the sections in each tube. I ship worldwide directly via USPS and UPS. Buyers from mainland China and Italy: please contact me for shipping cost. Number5751Brand on tubeSylvaniaActual manufacturerSylvaniaCountry of manufactureUSADate codes805 (all)Box typeWhite boxPlate styleBlackGetter styleTop-squareGlass styleClearBase style9-pin miniatureTest results (measured , typical NOS)1300/1350 & 1300/1250 & 1250/1250 & 1200/1200 typical is 1250/1250 Be sure to read my policies below, and contact me before you purchase if you have any questions. I have over 30 years of experience as an electronics engineer, certified electronics technician, and hobbyist, and have been collecting, buying, and selling tubes since the 1980s. Ive been an eBay seller since February of 2000. This is the only seller account I have on eBay and the pictures you see are of the actual tube(s) you’ll receive. Tubes are described, tested, and presented to the best of my ability, subject to the limitations of the equipment that I have available (Hickok 539C and 6000A). Test results are likely to differ between your equipment and mine due to many factors. Tubes are not tested for noise or microphonics. Do you have tubes to sell? Contact me with your inventory!Return Policy Unless otherwise stated in this listing, tubes may be returned within 30 days for a refund. Please keep in mind that while I do allow returns, my purpose here is to sell tubes, not to loan tubes for rolling. Any tube to be returned must: a) still bear my identification stamp. b) be in EXACTLY the same condition in which it arrived to you. Things which may invalidate a return: defaced or smudged print on the glass, bases scratched from retainer springs, cracked or damaged glass, damaged or missing boxes (where original boxes were sent with the tubes), and electrical or physical degradation from improper operation or handling. Returns which do not meet the above criteria may be refused or may be subject to partial refund. Ebays return guidelines prohibit “using or damaging an item and then returning it.” I pay for return shipping on all returns within the USA, regardless of reason. You pay for return shipping if you are located outside of the USA. If the tube arrives to you DOA or significantly not as described (SNAD) I pay for return shipping. I do not pay for return shipping for any other reason. If a tube is returned as DOA or SNAD, but does not test as such upon return, I reserve the right to be reimbursed for any return shipping cost that I paid. International buyers, please note: Import fees and taxes which you pay to your border and/or customs agency are not refundable by me under ANY conditions or for ANY reason, regardless of the reason for your return.Shipping Your tubes will be professionally prepared for shipping using all-new packing materials and will arrive to you in perfect condition. Ive been shipping tubes for many years and know how to get them to you quickly and securely. International orders ship with proper customs documentation and tariff codes to ensure that theyre processed with minimal delay upon arrival in the destination country. DOMESTIC: Unless otherwise noted, free shipping is offered on all tubes purchased with Buy-It-Now. Orders that total $400 or less are generally shipped via the USPS Ground Advantage service, while orders exceeding that value are shipped via USPS Priority Mail. Other services are available at additional cost. If you prefer a shipping method that is not listed, please contact me prior to purchasing. I can usually ship via any USPS, FedEx, or UPS method that is applicable to your ZIP code. If you need expedited shipping (Express, Next Day, etc.) please contact me first to confirm earliest available date of shipment, as cutoff times are generally early in the afternoon. INTERNATIONAL: USPS First Class Mail: This is the least expensive option but the availability of tracking is limited in many cases. Its available worldwide for packages with a value of USD$400 or less. Be aware that First Class Mail has been known to take up to three months to reach some destinations. Customs delays are also more common with First Class. If you select the First Class option I expect that you will be patient and wait three months before requesting a refund for “item not received.” If you require faster delivery please select an option below. USPS Priority Mail: This option is available for shipments with a value less than USD$1000. It typically takes a couple of weeks to reach most destinations. UPS Worldwide Expedited: This option is available worldwide for all shipments, and is required for shipments valued at USD$1000 or more. It is fast and reliable, with end-to-end tracking. I can also usually arrange shipping with other carriers at additional cost. Please inquire before purchasing if you have specific requests. I ship to China and Italy only via UPS Worldwide Expedited, regardless of value. No exceptions. I dont use eBays in-house International Shipping program, as the cost tends to be much higher than shipping directly with a carrier.USPS requires that all addresses be in “Latin” (abcdefg) characters (this means, for example, no Cyrillic (???????) or Chinese (???), etc.). USPS will return to the me any packages which violate this guideline, and the buyer will then be required to correct the address and pay postage again. Ebay places the burden of safe delivery on sellers, so I fully insure all shipments sent outside of the USA, regardless of value. Because I can insure only up to the declared value, ALL SHIPMENTS ARE DECLARED AT ACTUAL VALUE. You might owe significant import fees on higher value shipments once they cross your countrys border – check with your border or customs agency for details. I can ship to a domestic freight forwarder or other third party within the USA, provided their address is on the order at the time you place it. GENERAL: SIGNATURE REQUIREMENT: All orders valued at USD$750 or greater, and ANY order shipped via UPS or FedEx, automatically require a signature release upon delivery. Someone at your delivery address will need to be available at the time of delivery to sign for the package. COMBINED SHIPPING: Im happy to combine shipping on multiple purchases. Those shipping within the US will combine automatically. International orders must be manually combined after the purchase, and any excess shipping will be refunded to your payment source (due to the way eBay buy-it-now items are set up, this is the only way I can combine shipping on more than one item). HANDLING TIME: My handling time is one business day and eBay requires me to ship within that timeframe. I cannot withhold shipment for a later date. If you require shipment on a specific date I can often set up a special listing just for you on that date; please inquire. I usually ship every day of the week, except for Sunday and USPS-observed holidays, and orders often ship same day. Orders placed later in the day usually ship next business day. Orders placed on Friday or Saturday will sometimes not ship until Monday. All orders placed on Sunday or USPS-observed holidays ship the next business day. Expedited and express shipments (FedEx and UPS 2-day & Next Day, etc) must be placed by 12PM Pacific Time in order to ship same day. If you have an urgent delivery need its a good idea to contact me first so I can confirm exact day of shipment. SHIP-TO ADDRESS: Ebay requires that I ship to the address on the order. This protects both you and me. I cannot ship to a different address. If you require shipment to a different address please update your shipping information before making a purchase. R31

5751 - ECC83 - 12AX7 - SYLVANIA USA - 1 PAIR - TOP CONDITION AUF RPG FUNKE W19 GEPRÜFT: 4,0/4,0 - 3,8/3,8mA - GUT AB 1,9mA.

SYLVANIA, Made in USA5751 Valve TubeShort Grey Plates, Triple Mica Construction & Halo GetterFully Tested on AVO VCM 163Ia 0.75/0.8 - Gm 1.1/1100% Book Spec = Ia 1 - Gm 1.2Used, Supplied in White Box

Up for auction is a lot of 9 12AX7 ECC83 5751 7025 tubes. They have been tested on a calibrated TV7. Tested for mutual conductance with a min of 32/32. They test as follows Sylvania 73/70, GE 35/30, GE36/36, Raytheon 39/39, Tung-Sol 45/42, RCA 52/55, Sylvania 65/59, USAF 44/42 and RCA 41/42. I do combine shipping. Due to a divorce I had to open a new account. I was formally known as Harleybabe8574. I have been dealing with tubes for many years.

A matched quartet of the excellent and rare BlackPlate SYLVANIA 5751 made in 1956 in USA. Copper grid posts and tripple mica for lowest microphony. These famous and rare (often called ”holy grail”) SYLVANIA 5751 have been part of the Swedish Army spare parts stock and bought by me direct from the FFV (Förenade Fabriks-Verken, the army spare part holder) in the mid-1990s, when they were decommissioned. They have since then been in my possession and stored in a clean and dry place. For provenance, the last picture shows the 3 layers of labels on top on eachother that I separated from one of the original bulk pac! This shows they have been in storage by FFV all the time before I bough them and were made in 1956 and first tested in 1957 by FFV, then tested again in may 1968 & febr. 1974 and now tested by me for grading and matching, packed & labeled in new white boxes. Test conditions: Ia @ Ua = 250V, Vg -3V S @ Ua = 250V, Ia 1,0mATest results: tube 1: 1,2-1,2; 1,4-1,2tube 2: 1,4-1,25; 1,3-1,3tube 3: 1,4-1,2; 1,2-1,3tube 4: 1,2-1,25; 1,3-1,2 Date & batch printed markings on all is DF/REU VAT & customs free in the EUOther countries may add taxes

This listing is for a precisely matched pair of Sylvania JHS 5751 preamp tubes. Triple mica, heavy duty posts, Fat D getter Tubes are matched at 1650/1700 and 1725/1760 on our Hickok 605A tube tester. Tubes provide a very detailed sound. Motorola labels, matching 2011 date codes. These tubes can be used in any amp that uses 12AX7 tubes. Many prefer these over 12AX7s due to lower noise, quiet background and clean sound. Buyer pays calculated USPS Ground Advantage shipping.Expedited shipping available for additional fee. 30 day returns.

Up for sale : NOS SYLVANIA VINTAGE HIGH QUALITY 5751 GOLD PIN TUBE . THIS TUBE IS ABSOLUTLEY BEAUTIFUL 100% BRAND NEW OLD STOCK WORKING FANTASTIC 100% GUARANTEED YOU GET THE 1 TUBE IN THE PHOTOS .

SYLVANIA, Made in USAJHS 5751 Valve TubeShort Grey Plates, Triple Mica Construction & Halo GetterFully Tested on AVO VCM 163Ia 1.15/1.1 - Gm 1.1/1.2100% Book Spec = Ia 1 - Gm 1.2Used, Supplied in White Box

Condition Is Used Tested Good Tube Tube Passed All Test Tube Tested At 86/84 With A Minimum Being 46/46 And 100/100 Being New Tube Was Tested On A Calibrated Precision 612 Vacuum Tube Tester All Of Our Tubes Are 100% Guaranteed Check Out All Of Our Vintage Listings We Ship Same Or Next Day

This listing is for a precisely matched pair of Sylvania JHS 5751 preamp tubes. Triple mica, heavy duty posts, Fat D getter Tubes are matched at 1650/1700 and 1725/1760 on our Hickok 605A tube tester. Tubes provide a very detailed sound. Motorola labels, matching 2011 date codes. These tubes can be used in any amp that uses 12AX7 tubes. Many prefer these over 12AX7s due to lower noise, quiet background and clean sound. Buyer pays calculated USPS Ground Advantage shipping.Expedited shipping available for additional fee. 30 day returns.

This listing is for a precisely matched pair of Sylvania JHS 5751 preamp tubes. Tubes have triple micas and single O getter. Tubes are matched at 1575/1660 and 1650/1600 on our Hickok 605A tube tester. These tubes are low noise and have a very precise sound. If you like clarity in a 12AX7 you will love the way these sound. These are the Sylvania LG labels. I believe that LG was a Liquid Gold marking campaign for these mil spec tubes. These tubes can be used in any amp that uses 12AX7 tubes. Many prefer these over 12AX7s due to lower noise and clean sound. Buyer pays calculated USPS Ground Advantage shipping.Expedited shipping available for additional fee. 30 day returns.

This listing is for a precisely matched pair of Sylvania JHS 5751 preamp tubes. Tubes have triple micas and single O getter. Tubes are matched at 1575/1660 and 1650/1600 on our Hickok 605A tube tester. These tubes are low noise and have a very precise sound. If you like clarity in a 12AX7 you will love the way these sound. These are the Sylvania LG labels. I believe that LG was a Liquid Gold marking campaign for these mil spec tubes. These tubes can be used in any amp that uses 12AX7 tubes. Many prefer these over 12AX7s due to lower noise and clean sound. Buyer pays calculated USPS Ground Advantage shipping.Expedited shipping available for additional fee. 30 day returns.

Very nice quad of scarce Sylvania 5751 gold print tubes. All feature black plates, triple micas, and square getters. Identical 1958 date codes. Matched to about 11% difference across all tubes with excellent balance between the sections in each tube. I ship worldwide directly via USPS and UPS. Buyers from mainland China and Italy: please contact me for shipping cost. Number5751Brand on tubeSylvaniaActual manufacturerSylvaniaCountry of manufactureUSADate codes805 (all)Box typeWhite boxPlate styleBlackGetter styleTop-squareGlass styleClearBase style9-pin miniatureTest results (measured , typical NOS)1300/1350 & 1300/1250 & 1250/1250 & 1200/1200 typical is 1250/1250 Be sure to read my policies below, and contact me before you purchase if you have any questions. I have over 30 years of experience as an electronics engineer, certified electronics technician, and hobbyist, and have been collecting, buying, and selling tubes since the 1980s. Ive been an eBay seller since February of 2000. This is the only seller account I have on eBay and the pictures you see are of the actual tube(s) you’ll receive. Tubes are described, tested, and presented to the best of my ability, subject to the limitations of the equipment that I have available (Hickok 539C and 6000A). Test results are likely to differ between your equipment and mine due to many factors. Tubes are not tested for noise or microphonics. Do you have tubes to sell? Contact me with your inventory!Return Policy Unless otherwise stated in this listing, tubes may be returned within 30 days for a refund. Please keep in mind that while I do allow returns, my purpose here is to sell tubes, not to loan tubes for rolling. Any tube to be returned must: a) still bear my identification stamp. b) be in EXACTLY the same condition in which it arrived to you. Things which may invalidate a return: defaced or smudged print on the glass, bases scratched from retainer springs, cracked or damaged glass, damaged or missing boxes (where original boxes were sent with the tubes), and electrical or physical degradation from improper operation or handling. Returns which do not meet the above criteria may be refused or may be subject to partial refund. Ebays return guidelines prohibit “using or damaging an item and then returning it.” I pay for return shipping on all returns within the USA, regardless of reason. You pay for return shipping if you are located outside of the USA. If the tube arrives to you DOA or significantly not as described (SNAD) I pay for return shipping. I do not pay for return shipping for any other reason. If a tube is returned as DOA or SNAD, but does not test as such upon return, I reserve the right to be reimbursed for any return shipping cost that I paid. International buyers, please note: Import fees and taxes which you pay to your border and/or customs agency are not refundable by me under ANY conditions or for ANY reason, regardless of the reason for your return.Shipping Your tubes will be professionally prepared for shipping using all-new packing materials and will arrive to you in perfect condition. Ive been shipping tubes for many years and know how to get them to you quickly and securely. International orders ship with proper customs documentation and tariff codes to ensure that theyre processed with minimal delay upon arrival in the destination country. DOMESTIC: Unless otherwise noted, free shipping is offered on all tubes purchased with Buy-It-Now. Orders that total $400 or less are generally shipped via the USPS Ground Advantage service, while orders exceeding that value are shipped via USPS Priority Mail. Other services are available at additional cost. If you prefer a shipping method that is not listed, please contact me prior to purchasing. I can usually ship via any USPS, FedEx, or UPS method that is applicable to your ZIP code. If you need expedited shipping (Express, Next Day, etc.) please contact me first to confirm earliest available date of shipment, as cutoff times are generally early in the afternoon. INTERNATIONAL: USPS First Class Mail: This is the least expensive option but the availability of tracking is limited in many cases. Its available worldwide for packages with a value of USD$400 or less. Be aware that First Class Mail has been known to take up to three months to reach some destinations. Customs delays are also more common with First Class. If you select the First Class option I expect that you will be patient and wait three months before requesting a refund for “item not received.” If you require faster delivery please select an option below. USPS Priority Mail: This option is available for shipments with a value less than USD$1000. It typically takes a couple of weeks to reach most destinations. UPS Worldwide Expedited: This option is available worldwide for all shipments, and is required for shipments valued at USD$1000 or more. It is fast and reliable, with end-to-end tracking. I can also usually arrange shipping with other carriers at additional cost. Please inquire before purchasing if you have specific requests. I ship to China and Italy only via UPS Worldwide Expedited, regardless of value. No exceptions. I dont use eBays in-house International Shipping program, as the cost tends to be much higher than shipping directly with a carrier.USPS requires that all addresses be in “Latin” (abcdefg) characters (this means, for example, no Cyrillic (???????) or Chinese (???), etc.). USPS will return to the me any packages which violate this guideline, and the buyer will then be required to correct the address and pay postage again. Ebay places the burden of safe delivery on sellers, so I fully insure all shipments sent outside of the USA, regardless of value. Because I can insure only up to the declared value, ALL SHIPMENTS ARE DECLARED AT ACTUAL VALUE. You might owe significant import fees on higher value shipments once they cross your countrys border – check with your border or customs agency for details. I can ship to a domestic freight forwarder or other third party within the USA, provided their address is on the order at the time you place it. GENERAL: SIGNATURE REQUIREMENT: All orders valued at USD$750 or greater, and ANY order shipped via UPS or FedEx, automatically require a signature release upon delivery. Someone at your delivery address will need to be available at the time of delivery to sign for the package. COMBINED SHIPPING: Im happy to combine shipping on multiple purchases. Those shipping within the US will combine automatically. International orders must be manually combined after the purchase, and any excess shipping will be refunded to your payment source (due to the way eBay buy-it-now items are set up, this is the only way I can combine shipping on more than one item). HANDLING TIME: My handling time is one business day and eBay requires me to ship within that timeframe. I cannot withhold shipment for a later date. If you require shipment on a specific date I can often set up a special listing just for you on that date; please inquire. I usually ship every day of the week, except for Sunday and USPS-observed holidays, and orders often ship same day. Orders placed later in the day usually ship next business day. Orders placed on Friday or Saturday will sometimes not ship until Monday. All orders placed on Sunday or USPS-observed holidays ship the next business day. Expedited and express shipments (FedEx and UPS 2-day & Next Day, etc) must be placed by 12PM Pacific Time in order to ship same day. If you have an urgent delivery need its a good idea to contact me first so I can confirm exact day of shipment. SHIP-TO ADDRESS: Ebay requires that I ship to the address on the order. This protects both you and me. I cannot ship to a different address. If you require shipment to a different address please update your shipping information before making a purchase. R31

This listing is for a precisely matched pair of Sylvania JHS 5751 preamp tubes. Triple mica, heavy duty posts, Fat D getter Tubes are matched at 1650/1700 and 1725/1760 on our Hickok 605A tube tester. Tubes provide a very detailed sound. Motorola labels, matching 2011 date codes. These tubes can be used in any amp that uses 12AX7 tubes. Many prefer these over 12AX7s due to lower noise, quiet background and clean sound. Buyer pays calculated USPS Ground Advantage shipping.Expedited shipping available for additional fee. 30 day returns.

Sylvania 5751 ECC83 12AX7 green print NOS. Doppel-Triode. Gut geprüft auf Funke W19S: 2,5 mA + 2,3 mA (gut ab 0,8 mA). Zustand siehe Fotos. Die Fotos sind Bestandteil der Artikelbeschreibung.BITTE HINWEISE ZUM VERSAND BEACHTEN (SIEHE UNTEN) Bitte beachten: Der Artikel wird so wie er ist von Privat verkauft. Mit der Abgabe eines Gebotes erklären Sie sich ausdrücklich damit einverstanden, auf die nach neuem EU- Recht geltende Gewährleistung / Garantie bei Gebrauchtwaren zu verzichten. Bieten Sie bitte nicht, wenn Sie mit diesen Regelungen nicht einverstanden sind! Käufer übernimmt die Versandkosten, ebay ich. Angebotene Versandmöglichkeiten: Paket: 12,00 Euro Versand nach Deutschland. Evtl. ist ein Versand in D möglich für 5 Euro (DHL). Kann aber etwas länger dauern!! Paket: 13,00 Euro Die Versandkosten gelten für EU und Schweiz. Paket: 29,00 Euro restliche Länder weltweit 5 Euros en colissimo pour la France

2 x 5751(12ax7) Sylvania Tubes Made in USA Black Plates D or square getter 3-Mica Lettering is smudged/missing Tested on Enhanced Triplett E3444 Laboratory Tester prepared by Paul Hart of Ga. Results = 910/900 micromhos @ .92/ 1.03 mA 1030/750 micromhos @ .88/ .66 mA Bogey(100% or New) = 1200/1200 @ 1.2 & 1.2 mA +/- 10% I do combine S&H The measurements in this listing were taken on a Triplett 3444 modified to test the tube as an amplifier in accordance with RMA/EIA specifications, utilized by all US and most foreign tube manufacturers. This tester applies test conditions for this tube as shown below (including the precise filament voltage) and then measures transconductance (gm) in accordance with the engineering definition of gm. Tubes may also be operated under the test conditions for extended periods to be sure that it is stable. A tube must be tested in this manner to compare its test results with the manufacturer’s original intent or with other tubes of the same type. Most tube testers do not apply the test conditions required or conduct a valid gm test. For more details on the test and our test equipment, please contact us.The test conditions for this listing are__250_V plate, __250_V screen, ___-3___Vbias or Cathode resistance*What were your tubes tested at?

2 tubes 5751 high grade >> ECC83 12AX7tube 1 GE black plates tube 2 Sylvania tubes with Burn-In so more changes in use and constant resultsBoth tubes show same results with 100%

2 x 5751(12ax7) Sylvania Tubes Made in USA Black Plates D Getter 3-Mica Lettering is smudged/missing Tested on Enhanced Triplett E3444 Laboratory Tester prepared by Paul Hart of Ga. 700/840 micromhos @ .80/ 1.00 mA 500/550 micromhos @ .58/ .59 mA Bogey(100%) = 1200/1200 @ 1.2 & 1.2 mA +/- 10% The measurements in this listing were taken on a Triplett 3444 modified to test the tube as an amplifier in accordance with RMA/EIA specifications, utilized by all US and most foreign tube manufacturers. This tester applies test conditions for this tube as shown below (including the precise filament voltage) and then measures transconductance (gm) in accordance with the engineering definition of gm. Tubes may also be operated under the test conditions for extended periods to be sure that it is stable. A tube must be tested in this manner to compare its test results with the manufacturer’s original intent or with other tubes of the same type. Most tube testers do not apply the test conditions required or conduct a valid gm test. For more details on the test and our test equipment, please contact us.The test conditions for this listing are__250_V plate, __250_V screen, ___-3___Vbias or Cathode resistance*What were your tubes tested at? I do combine shipping

This auction is for one strong old stock Sylvania Gold Brand 5751 twin triode vacuum tube as shown. Gold Brand was Sylvanias premium line. This tube has gols-flashed pins and the sturdier triple mica construction. This tube was tested on our Triplett 3444A tester with results of 1100/1200, where 1200 is the expected new value. Tubes are guaranteed for 30 days from the day of receipt. SHIPPING: We combine shipping on multiple items. We have thousands of tube types in stock. Please contact us if you cannot find what you want, so we can list it. Due to too many requests by overseas customers, I have to state in the USA it is illegal to falsify the value on Customs forms, as well as being against eBay rules. Do not buy this item and then ask us to falsify the forms. We always declare the sales price, as required by law. Unlike most casual eBay sellers, we are experts at shipping overseas, and we always use the correct customs commodity codes on shipping forms to minimize duties. Casual sellers often omit the codes, which means Customs officials usually default to a high import duty on those items. If you have asked any seller to falsify the Customs forms in the past, ask yourself this question... Why would you want to buy from a company that demonstrates it is dishonest?

I am selling a lot of my amp tubes I have had in my warehouse for years. Please, after buying this tube, check out my other items for many more tubes. I will always combine shipping to save you money.______________ SylvaniaJAN-JHS-5751True 5751 Tube (12AX7)Triple Mica Black Plates Dated 1956 Angled Square GetterHD Long Life Military Grade Construction.Perfect for that 1950s tone.Tested on one of my Dan Nelson calibrated Hickok TV/7D testers. My testers were last calibrated Nov, 2021.This tube tests Tube #1 tests at 44/53 Approx 89% / 107%the minimum is 32New Old Stock usually tests 48 on my tester. Being offered at a very fair Buy It Now. All my tubes are 100% satisfaction Guaranteed.No shorts or leaksBeing offered at a fair Buy It Now.______________________ ******Shipping Special******* Buy more then one of my tubes and the second, third, and forth set all will ship for free. I will simply pack them all together. You will only pay one shipping charge. This INCLUDES international buyers. All tubes must be purchased at the same time.Shipping will be a flat $4.60 to the USA. I will pack your tubes very well for you. International buyers are welcome here. International shipping will be calculated to your country. International buyers please know that you will be responsible for any duty tax your country may charge and all customs forms will be filled out properly.No shipping to Mainland China. No shipping to Italy or Russian FederationBeing offered at a low Buy It Now.

4 x 5751(12ax7) Sylvania Tubes Made in USA Black Plates D or square getter 3-Mica Lettering is smudged/missing ***These test NOS with test conditions stated, not some crappy Hickok or TV-7 test where you have no idea what you are getting*** Tested on Enhanced Triplett E3444 Laboratory Tester prepared by Paul Hart of Ga. Results = 1390/1260 micromhos @ 1.23/ 1.11 mA 1280/1250 micromhos @ 1.03/ 1.00 mA 1380/1270 micromhos @ 1.15/ 1.02 mA 1350/1220 micromhos @ 1.27/ 1.04 mA Bogey(100% or New) = 1200/1200 @ 1.2 & 1.2 mA +/- 10% I do combine S&H The measurements in this listing were taken on a Triplett 3444 modified to test the tube as an amplifier in accordance with RMA/EIA specifications, utilized by all US and most foreign tube manufacturers. This tester applies test conditions for this tube as shown below (including the precise filament voltage) and then measures transconductance (gm) in accordance with the engineering definition of gm. Tubes may also be operated under the test conditions for extended periods to be sure that it is stable. A tube must be tested in this manner to compare its test results with the manufacturer’s original intent or with other tubes of the same type. Most tube testers do not apply the test conditions required or conduct a valid gm test. For more details on the test and our test equipment, please contact us.The test conditions for this listing are__250_V plate, __250_V screen, ___-3___Vbias or Cathode resistance*What were your tubes tested at?