Great tube from OLD MIL STOCK , in original box , never used , FROM 80s years, super excellent tube for professional audio application.This tube is considerd one of the best on professional pre-amplifiers field, great accuracy for noise and stability. Selected by TV7 Tube tester Equivalents between tubes should be verifyed on datasheet, 5691 and 6188 have different heating courrent, 6188 and 6SL7 have 0,3A heater5691 has 0,6A heater Choise the pair you need. Hi, someone knows us as gibrilla-it, we have added a new nick to better follow the tube world, our feedbacks are 100%, never neutral or negative feedback. Contact us for information. Our website is www.oldtimeradio.it Greetings A&G

5691 RCA Red Base White Print Matched Pair Tested NOS NIB For sale is one matched pair of 5691 (6SL7) RCA tubes. Dual square getter construction. Military sourced. Real NOS and NIB. Please look at the pictures carefully. One of the best sounding 6SL7 tubes ever produced. • 5691 (6SL7) – RCA Red Base • Black Plate • White Print • Made in USA • Dual Square Getter construction • Copper Rods • Matched Pair • Original Boxes • Real NOS and NIB Both tubes are fully tested on my AVO CT-160 tube tester following the parameters: Ua = 250 V Ug1 = -2.0 V Uf = 6.3 V The (emission) test results are: Tube 14 Ia = 2.2 and 2.0 mA S = 1.8 and 1.6 mA/V Tube 15 Ia = 1.9 and 1.9 mA S = 1.7 and 1.8 mA/V No shorts. No leakage. H//K Isolation is well over 25 Mohms for both tubes. According to the AVO CT-160 data manual for a new tube Ia = 2.3 mA and S = 1.6 mA/V SHIPPING TO EU ONLY! WHAT YOU SEE IS WHAT YOU GET

Wir haben deinradio! Senden Sie uns eine Nachricht Unser Shop Verkäuferprofil Bewertungen Shop speichern Kontakt Mix Konvolut seltene Röhren 7H7 EBC41 EBL21 5691 6N7 EF50 usw. Röhrenradio Bitte entnehmen Sie den genauen Zustand und Lieferumfang den Bildern.Die Röhren wurden stichprobenweise als gut geprüft, wurden aber nicht alle durchgeschaut bzw. durchgeprüft. Wir bieten eine Vielzahl an alten Bastel -und Sammelobjekten an.Bitte beachten Sie, dass aufgrund des Alters keine Garantien auf die technischen Funktionen gegeben werden können.The parts are very old, we dont give any guarantee on the technical function. Zahlung Versand Kombiversand nur bei Artikeln möglich, die am gleichen Tag gekauft werden. (aus einer Auktionsrunde) DIe angepasste Rechnung erhalten Sie dann nach Auktionsende. Aufwendiger Versand (klimaneutral) mit DHL Premium in 2-welliger Kartonage und aufwendiger Polsterung! Versand größtenteils plastikfrei, 80 Prozent des Versandmaterial aus recyceltem Altpapier bzw. Second-Hand Kartonagen. WORLDWIDE SHIPPING ON REQUEST! PLEASE ASK BEFORE YOU BUY! Links Unser Shop Verkäuferprofil Bewertungen Shop speichern Kontakt Newsletter Verpassen Sie keine Angebote mehr! Wir informieren Sie über Angebote und Aktionen bequem per E-Mail. Newsletter abonnieren Kontakt Senden Sie uns eine Nachricht

Aktiv Artikel Kasuga Musen Ka-27Se 2A3 Westinghouse National Elektronik 5691 VACDas Datenblatt dieses Produkts wurde ursprünglich auf Englisch verfasst. Unten finden Sie eine automatische Übersetzung ins Deutsche. Sollten Sie irgendwelche Fragen haben, kontaktieren Sie uns.ZahlungSeien Sie versichert, dass unser Shop eine Vielzahl von Zahlungsmethoden anbietet.Bitte zahlen Sie innerhalb von 5 Tagen nach Auktionsende.Über unsWir sind in Japan ansässig. Überprüfen Sie bei elektrischen Produkten den Hersteller und das Produkt und rechnen Sie die Spannung in das jeweilige Land um. Wir planen den Versand per FedEx oder DHL. Bitte kontaktieren Sie uns, da sich die Versandkosten in einigen Fällen ändern können. Es ist uns eine Freude, Sie glücklich zu machen, indem wir Ihnen unseren empfohlenen Artikel vorschlagen.Wenn Sie Fragen oder Wünsche zu Artikeln haben, wenden Sie sich bitte an uns.Internationale Käufer – Bitte beachten Sie:-Einfuhrzölle, Steuern und Gebühren sind nicht im Artikelpreis oder den Versandkosten enthalten. Diese Gebühren liegen in der Verantwortung des Käufers.- Bitte erkundigen Sie sich vor dem Bieten/Kauf beim Zollamt Ihres Landes, wie hoch diese zusätzlichen Kosten sein werden.-Diese Gebühren werden normalerweise von der liefernden Spedition (Versandfirma) oder bei der Abholung des Artikels erhoben – verwechseln Sie sie nicht mit zusätzlichen Versandkosten.-Wir kennzeichnen Warenwerte nicht unter dem Wert und kennzeichnen Artikel nicht als Geschenke. Die Vorschriften der US-amerikanischen und internationalen Regierung verbieten ein solches Verhalten.]]>Wir sind in Japan ansässig. Überprüfen Sie bei elektrischen Produkten den Hersteller und das Produkt und rechnen Sie die Spannung in das jeweilige Land um. Wir planen den Versand per FedEx oder DHL. Bitte kontaktieren Sie uns, da sich die Versandkosten in einigen Fällen ändern können. -Einfuhrzölle, Steuern und Gebühren sind nicht im Artikelpreis oder den Versandkosten enthalten. Diese Gebühren liegen in der Verantwortung des Käufers. -Diese Gebühren werden normalerweise von der liefernden Spedition (Versandfirma) oder bei der Abholung des Artikels erhoben – verwechseln Sie sie nicht mit zusätzlichen Versandkosten. -Wir kennzeichnen Warenwerte nicht unter dem Wert und kennzeichnen Artikel nicht als Geschenke. Die Vorschriften der US-amerikanischen und internationalen Regierung verbieten e Unit Quantity NA Unit Type NA MPN NA Country Japan Brand No Brand UPC NA Country/Region of Manufacture NA California Prop 65 Warning NA Model NA Type NA

Great tube METAL BASE from OLD stock made on 1956 year , in original box , never used , excellent tube for professional audio application.Selected by TV7 Tube tester PHOTO PRIMARY IS REFERRED AT ONE PAIR AVAILABLE AND IS INDICATIVE.REQUIRE IF INTERESTED PHOTOS ABOUT YOUR PAIR. Hi, someone knows us as gibrilla-it, we have added a new nick to better follow the tube world, our feedbacks are 100%, never neutral or negative feedback. Contact us for information. Our website is www.oldtimeradio.it Greetings A&G

Up for sale is a very nice vintage 1969 NOS GE 5691 / 6SL7 preamp tube. Fully Amplitrex tested in fixed bias manual control mode, robust triple mica construction. Orig GE box. Test results shown in images and included with sale. These are getting to be last of my NOS 5691 collection im selling. Will ship via USPS PRIORITY MAIL, usually same day. Due to the nature of vintage vacuum tubes and tube rollers abusing eBay’s returns policy, this tube is sold AS-IS with no returns accepted. Will guarantee to NOT be DOA and to match any Amplitrex tester using the same settings and test parameters. Thanks for looking!

Up for sale is a very nice vintage NOS GE 5691 / 6SL7 preamp tube. Fully Amplitrex tested in fixed bias manual control mode, balanced triodes, robust triple mica construction. Test results shown in images and included with sale. These are getting to be last of my NOS 5691 collection im selling. Will ship via USPS PRIORITY MAIL, usually same day. Due to the nature of vintage vacuum tubes and tube rollers abusing eBay’s returns policy, this tube is sold AS-IS with no returns accepted. Will guarantee to NOT be DOA and to match any Amplitrex tester using the same settings and test parameters. Thanks for looking!

Up for sale is a very nice vintage NOS RCA 5691 / 6SL7 preamp tube. Fully Amplitrex tested in fixed bias manual control mode NOS, decently balanced triodes with 1956 date code, robust triple mica construction. Orig JAN box is a bit funky and has a pack date of 1958. These are getting to be last of my NOS 5691 collection im selling. Will ship via USPS PRIORITY MAIL, usually same day. Due to the nature of vintage vacuum tubes and tube rollers abusing eBay’s returns policy, this tube is sold AS-IS with no returns accepted. Will guarantee to NOT be DOA and to match any Amplitrex tester using the same settings and test parameters. Thanks for looking!

Nice pair of RCA 5691 black plate Special Red tubes. With date codes from 1948 and 1950, these are among the earlier production runs of this tube. Strong testing and matched to about 12% difference. I ship worldwide directly via USPS and UPS. Buyers from mainland China and Italy: please contact me for shipping cost. Number5691Brand on tubeRCAActual manufacturerRCACountry of manufactureUSADate codes839 & 043Box typeWhite boxesPlate styleBlackGetter styleTop-rectangle x2 Glass styleClear Base styleOctalTest results (measured , typical NOS)1100/1050 & 1200/1100 typical NOS is 1000/1000 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

Two, RCA 5691 tubes, the long life/high reliability 6SL7GT. Red micanol bases, black plates, reinforcing rods. The 5691 is of course the ruggedized, low microphonics, low noise, high reliability, long-life version of the 6SL7GT tube and can be used in applications calling for the 6SL7GT. Tested on a Hickok TV-3 military tester that has been calibrated. Firm bases, excellent silvering. Tubes are matched for dynamic gain and structure- test at 1875-1875, 1750-1750 where pass/fail is 1100 micromho. Tubes have the same exact structure inside and out, having matching codes of 8-39 and 6-22, the 39th week of 1958 and the 22nd week of 1956. Many other lots of tubes for sale this week. Shipping is free within the continental US. Elsewhere- exact postage only, no packing fee.

RCA 5691 NOS Red base Vacuum Tube - Test Strong Amplitrex. GM Measurement: 1400/1700 87%/106%

Up for sale is a very nice vintage NOS GE 5691 / 6SL7 preamp tube. Fully Amplitrex tested in fixed bias manual control mode, balanced triodes, robust triple mica construction. Test results shown in images and included with sale. These are getting to be last of my NOS 5691 collection im selling. Will ship via USPS PRIORITY MAIL, usually same day. Due to the nature of vintage vacuum tubes and tube rollers abusing eBay’s returns policy, this tube is sold AS-IS with no returns accepted. Will guarantee to NOT be DOA and to match any Amplitrex tester using the same settings and test parameters. Thanks for looking! #010

MATCHED PAIR (2) VT-231 JAN SYLVANIA 6SN7GT 5692 MEDIUM ENVELOPE FULLY TESTED 539C. BLACK BAD BOT STYLE PLATES ANCHOR STYLE BOTTOM FOIL DIMPLE GETTER MEDIUM ENVELOPE VERY LIGHT USE WITHIN 6% MATCH 98% LIFE THESE ARE BECOMING SCARCE. GET THEM WHILE YOU STILL CAN All tubes are fully tested for leakage, shorts, gas, life, and mutual conductance. Then they are matched according to brand, properties within the date of production, and mutual conductance. Matches are based on mutual conductance. I use two different, calibrated Hickok 539CS and/or, a Weston model 981 type 3. If they pass the testing, they will be sold with test data for that tube. If the tubes arent matched within 6%, I will acknowledge that in the description. I also offer a money back guarantee. Buyer pays return shipping for local pickups, I advise you to bring the electronics that the tubes are going in, within reason. Guitar amps, small radios, etc. I will allow you to test them on site, but you will be responsible for any product damaged by a faulty electronic. Im an honest seller and I stand by my product. Feel free to message me with questions. GlassBatman81

GE 5691 NOS Red Bottom Vacuum Tube - Test Strong Amplitrex. GM Measurement: 1600/1600 100%/100%

RCA 5691 NOS Red Bottom Vacuum Tube - Test Strong Amplitrex. GM Measurement: 1500/1500 93%/93%

RCA 5691 Vacuum Tube - Test Strong Amplitrex. GM Measurement: 1400/1600 87%/100%

Up for sale is a very nice vintage NOS RCA 5691 / 6SL7 preamp tube. Fully Amplitrex tested in fixed bias manual control mode, robust triple mica construction. Red/brown base looks to be late 50’s early 60’s production. (Later RCA tubes changed to orange lettering). These are getting to be last of my NOS 5691 collection im selling. Will ship via USPS PRIORITY MAIL, usually same day. Will ship in generic white tube box. Due to the nature of vintage vacuum tubes and tube rollers abusing eBay’s returns policy, this tube is sold AS-IS with no returns accepted. Will guarantee to NOT be DOA and to match any Amplitrex tester using the same settings and test parameters. Thanks for looking!

Platinum Matched Pair RCA 5691 NOS Red Bottom Vacuum Tubes Test Strong Amplitrex. NOS: 1600/1600 - 100%/100% GM Measurement: 1600/1700 - 100%/106% 1600/1700 - 100%/106%

Rca A-Rusi-E-5691 Vacuumtube Staubsauger Schlauch Set Mit 2138830Das Datenblatt dieses Produkts wurde ursprünglich auf Englisch verfasst. Unten finden Sie eine automatische Übersetzung ins Deutsche. Sollten Sie irgendwelche Fragen haben, kontaktieren Sie uns.ZahlungSeien Sie versichert, dass unser Shop eine Vielzahl von Zahlungsmethoden anbietet.Bitte zahlen Sie innerhalb von 5 Tagen nach Auktionsende.Über unsWir befinden uns in Japan. Überprüfen Sie für elektrische Produkte den Hersteller und das Produkt und rechnen Sie die Spannung in das jeweilige Land um. Wir planen den Versand per FedEx oder DHL. Bitte kontaktieren Sie uns, da sich die Versandkosten in einigen Fällen ändern können. Es ist uns eine Freude, Sie glücklich zu machen, indem wir Ihnen unseren empfohlenen Artikel vorschlagen.Wenn Sie Fragen oder Wünsche zu Artikeln haben, wenden Sie sich bitte an uns.Internationale Käufer – Bitte beachten Sie:-Einfuhrzölle, Steuern und Gebühren sind nicht im Artikelpreis oder den Versandkosten enthalten. Diese Gebühren liegen in der Verantwortung des Käufers.- Bitte erkundigen Sie sich vor dem Bieten/Kauf beim Zollamt Ihres Landes, wie hoch diese zusätzlichen Kosten sein werden.-Diese Gebühren werden normalerweise von der liefernden Spedition (Versandfirma) oder bei der Abholung des Artikels erhoben – verwechseln Sie sie nicht mit zusätzlichen Versandkosten.-Wir kennzeichnen Warenwerte nicht unter dem Wert und kennzeichnen Artikel nicht als Geschenke. Die Vorschriften der US-amerikanischen und internationalen Regierung verbieten ein solches Verhalten.]]>Wir befinden uns in Japan. Überprüfen Sie für elektrische Produkte den Hersteller und das Produkt und rechnen Sie die Spannung in das jeweilige Land um. Wir planen den Versand per FedEx oder DHL. Bitte kontaktieren Sie uns, da sich die Versandkosten in einigen Fällen ändern können. -Einfuhrzölle, Steuern und Gebühren sind nicht im Artikelpreis oder den Versandkosten enthalten. Diese Gebühren liegen in der Verantwortung des Käufers. -Diese Gebühren werden normalerweise von der liefernden Spedition (Versandfirma) oder bei der Abholung des Artikels erhoben – verwechseln Sie sie nicht mit zusätzlichen Versandkosten. -Wir kennzeichnen Warenwerte nicht unter dem Wert und kennzeichnen Artikel nicht als Geschenke. Die Vorschriften der US-amerikanischen und internationalen Regierung verbieten ein Unit Quantity NA Unit Type NA MPN NA Country Japan Brand No Brand UPC NA Country/Region of Manufacture NA California Prop 65 Warning NA Model NA Type NA

Rca A-Rusi-E-5691 Vacuumtube Aspirateur Tube Set De 2138830Cette fiche produit est originalement écrite en anglais. Veuillez trouver ci dessous une traduction automatique en français. Si vous avez des questions veuillez nous contacter.PaiementSoyez assuré que notre magasin offre une variété de méthodes de paiement.Veuillez payer dans les 5 jours suivant la fin de lenchère.À proposNous sommes situés au Japon. Pour les produits électriques, vérifiez le fabricant et le produit et convertissez-les à la tension de chaque pays. Nous prévoyons dexpédier par FedEx ou DHL. Veuillez nous contacter car les frais dexpédition peuvent être modifiés dans certains cas. Cest avec plaisir que nous vous ferons plaisir en vous proposant notre article recommandé.Si vous avez des questions ou des demandes concernant des articles, nhésitez pas à nous les demander.Acheteurs internationaux - Veuillez noter :-Les droits dimportation, les taxes et les frais ne sont pas inclus dans le prix de larticle ou les frais dexpédition. Ces charges sont sous la responsabilité de lacheteur.-Veuillez vérifier auprès du bureau de douane de votre pays pour déterminer quels seront ces coûts supplémentaires avant denchérir/acheter.-Ces frais sont normalement perçus par la société de livraison de fret (expédition) ou lorsque vous récupérez larticle - ne les confondez pas avec des frais dexpédition supplémentaires.-Nous ne marquons pas les valeurs des marchandises en dessous de la valeur ou ne marquons pas les articles comme - des cadeaux - Les réglementations gouvernementales américaines et internationales interdisent un tel comportement.]]>Nous sommes situés au Japon. Pour les produits électriques, vérifiez le fabricant et le produit et convertissez-les à la tension de chaque pays. Nous prévoyons dexpédier par FedEx ou DHL. Veuillez nous contacter car les frais dexpédition peuvent être modifiés dans certains cas. -Les droits dimportation, les taxes et les frais ne sont pas inclus dans le prix de larticle ou les frais dexpédition. Ces charges sont sous la responsabilité de lacheteur. -Ces frais sont normalement perçus par la société de livraison de fret (expédition) ou lorsque vous récupérez larticle - ne les confondez pas avec des frais dexpédition supplémentaires. -Nous ne marquons pas les valeurs des marchandises en dessous de la valeur ou ne marquons pas les articles comme - des cadeaux - Les réglementations gouv Unit Quantity NA Unit Type NA MPN NA Country Japan Brand No Brand UPC NA Country/Region of Manufacture NA California Prop 65 Warning NA Model NA Type NA

1 x 5691/6SL7gt RCA Tube Made in USA Red base Codes 943 = 1949 Pictures show actual Tested on Enhanced Triplet E3444 Laboratory Tester 1720/1700 micromhos @ 2.4 & 2.5 mA Bogey (100% or New) = 1600/1600 micromhos @ 2.3/2.3 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_Volts plate, __250_Volts screen, ___-2.0___Volts bias or Cathode resistance* What were your tubes tested at? I do combine shipping