Hickok 750 Mutual Conductance Tube Tester - Calibrated - Voltages Near Perfect

US $190

Kirkland, Arizona, United States
Nov 20th

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Hickok 750 Mutual Conductance Tube Tester - Calibrated - Voltages Near Perfect Hickok 750 Mutual Conductance Tube Tester CALIBRATED All Voltage Specs Near Perfect NOS JAN 83 (RCA) & JAN 5Y3GT (Sylvania) both tested & Balanced (24 Pics in Description) This 750 has an adjustable pot for the signal / plate voltage which makes it a lot easier to calibrate the line, plate, and signal voltage. This is the later version of the Hickok 750 that eliminated the neon SHORTS light and uses the meter to detect shorts/leakage. The 750 was made to replace the 539C & can measure Gm up to 30,000. There are socket savers on the 7 and 9 pin sockets and included are NOS 7 & 9 pin replacement sockets if needed in the future (PIC 19). The DVD includes an owner's manual, domestic & obsolete tube data, comprehensive European tube data, manual and settings for the CA-4 & CA-5 adapters, 2 schematics; one for each version, and front and back covers for the manual that totals 110 pages in all. All Voltages Within SPECS that can be seen in the pictures below. All tests were done with the correct shunt resistor to duplicate 1,000 Ohms/Volt Meter. Picture 3, 4, 5, 6 shows the AC signal voltages, (PIC 4) A, B, & 3k are 2.5 SPEC is 2.5, (PIC 3) 6k is 1.25 SPEC is 1.25, (PIC 5) 15k is .5 SPEC is .5, (PIC 6) 30k is .25 and SPEC is .25. Picture 7 is the plate voltage of 151.5 SPEC is 150 +- 5 Picture 8 is the screen voltage of 133.5 SPEC is 130 +- 5 Picture 9 is the low screen voltage of 57.6 SPEC is 56+- 2 Picture 10 is bias voltage at 100 which is -40.6 SPEC is -40 +- 2 Picture 11 is bias at 22 which is -2.95 SPEC is -3.0 +- .2 Picture 12 shows the filament voltage with the 6L6 tube in the socket at 6.17 which there is no SPEC for, but critical to get accurate test results. Many Hickok testers can be calibrated, but with many Hickok tube testers the heater voltage drops below 6 volts when a tube is in the socket causing in accurate test results, and could indicate other electronic issues. Picture 13 and 14 show a 6L6 calibration tube with Gm of 5475 being tested with the results of 5475. A 6AX7 with Gm of 1400 in Pics 15 and 16 shows tested gm at 1300 and according to the tube data, the 6k range is to be used. Pic 17 shows the low plate voltage at 66.6 and spec is 68 +- 3. It appears some idiot used a screwdriver to try to turn the tube chart and scratched the finish around the dial. It is not gouged and is mostly marks made to the finish. The tube chart turns with ease from end to end. Please look at the pictures and ask any questions. Several Options Available for Shipping! The 750 weighs a little under 21 pounds unpacked AGREEMENT Must read and agree to terms below: Please note and understand that there are no returns on this tester, all sales are final. If you have an issue upon receiving please notify me immediately. I do my best to check the tester for any issues, but it is impossible to check everything and the transistor function was not checked on this tester. This tester is at least 50 years old and should last another 50 if used and maintained properly, but if directions are not followed and someone tries to test a shorted tube e.g., any tube tester, or meter, can be destroyed in a second. I cannot be held responsible for someone's error. I do however guarantee you get exactly what is pictured and as described. You are expected to read the manual and understand what you are reading. You need to familiarize yourself with the tester and how it functions. Please take the time to do this since it could save you a lot of grief such as pressing the Gm button when testing a rectifier. It is an easy mistake to make and why you need to be careful when using this type of equipment. If you read the manual and use the manual while using the tester until you become experienced, you should have very few problems if any. Also, the same tube tested on different and also calibrated testers will usually give different results on each tester. Please do not expect this tester to have the same exact results of a tube tested on another tester. If you expect that this tester will test the exact same Gm because it is also calibrated and all within specs, then are disappointed and want to return it because it tested a tube higher or lower than you expected, do not buy this tester. You are looking to buy something that does not exist and I do not have the time or money to waste on non-issues and unobtainable perfection. We warrantee and represent that the goods are as described in the above listing. We specifically disclaim any implied warranties of title, merchantability, fitness for a particular purpose and non-infringement. Customers should satisfy themselves that any item choice made is suitable for their intended purpose or use. If an item is sold with no returns accepted as its terms then we will not accept returns on that item unless we made an error in the listing. Genuinely faulty goods will be replaced or money refunded, however we must be advised of any faulty goods upon receipt of the item. It is the customers responsibility to pay for and ship the item back to us. If the item is found to be faulty, we will also refund the postage cost. Most of the items we sell are vintage and for this reason returns are not generally offered. Pictures sell! Auctiva Free Image Hosting. Show off your items with Auctiva's Listing Templates Auctiva, THE simple solution for eBay sellers.