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Tube sockets for a large number of insertions & extractions

I am surprised that most builders of vacuum tube equipment don’t know about production tube sockets. Production sockets are designed for a very large number of insertions and extractions. The contacts are extremely rugged and can be replaced individually. The … Continue reading

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Eimac VT-127A and VT-327A vacuum tubes

The 127A is the same as the 3-100D2 transmitting triode. Filament is 5 volts @ 10.5 amperes. Max plate ratings: 2000 volts, 210 ma, Pd = 100 watt. If you look closely you can see that the plate is similar … Continue reading

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Westinghouse WL-460 transmitting triode

This is a directly heated (10 volts @ 4.05 amperes) triode with 150 watt plate dissipation. Maximum plate volts is 2500 VDC and max Ib = 200 ma. You won’t see many of these around. Overall height from the pins … Continue reading

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Testing Delta panel mount BNC connectors at high voltage

I got into an interesting conversation via email with a customer about use of BNC connectors to carry high voltage. The HIPOT tester was already out so off I went. The Hi Pot tester used goes to 4000 volts RMS. … Continue reading

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Keithley 610C Electrometer

OK. It’s a little modern for Leeds but the 610C does the impossible: it measures resistance, voltage, charge (in coulombs) and current down to 100 pico-amperes full scale – that’s .0001 billionths of an ampere. A wonderful and versatile instrument. … Continue reading

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General Radio 1422-OD precision variable capacitor

One of my favorite pieces of equipment. Unbelievably well made. It’s fairly big; approx. 23 cm wide, 18 cm tall and 15 cm deep.You can use it as a 0-1.1 pf or o to 11 pf variable depending on which … Continue reading

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Aerovox transmitting mica capacitor

Mica capacitors were invented in 1909 by William Dubilier. He’s the Dubilier in Cornell-Dubilier. Here’s a late 30’s/early-40’s Aerovox .0011 mfd 5000 volt transmitting mica cap. Transmitting mica are different than regular mica caps because they can pass significant RF … Continue reading

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UTC FJ-125 transformer

A gorgeous part in search of a project! There are about a dozen of these, new and in original boxes sitting around the shop. The FJ-125 weighs 10 kg and is just under 18 cm long. It has a single … Continue reading

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Tung Sol’s 7241 & 7242 monster triodes

Both have 100 watt maximum plate dissipation. The 7241 has a maximum DC plate current of 1.2 amperes and the 7242, 0.9 amperes. So you are thinking about OTL (output-transformer-less) circuits, huh? Do not let anyone fool you, both of … Continue reading

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Daven VH-795-G attenuator

This has three decks and can give you attenuation from 0 to 111 db in 0.1 db steps. Unlike the Hewlett Packard and General Radio equivalents each deck has 11 steps. The VH-795-G has 600 ohm input and output impedance. … Continue reading

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