26-08-2020, 07:51 AM
(This post was last modified: 26-08-2020, 07:56 AM by Mike Watterson.)
Use either a an HT or a potential divider for g2, never a series resistor. The reason why is in the specs and translated documents. The impedances varies too much with g2 current varying from a milliamp down to microamps. Thus the voltage changes to much.
At 50V HT you can tie g2 to HT. At about 80V HT you can vary the 1j24b from almost no gain to maximum gain by varying g2 from 25V to 55V
Layout is very important. Layout with the valves flat, like the Russians did. You also need to cut the leads, but not too short. Never bend close to body, i.e. at untinned portion. Don't use a push in breadboard except for audio work.
Having a screen (tinned steel is fine) with the shield wire, g3 and f- connected to it is important.
At 50V HT you can tie g2 to HT. At about 80V HT you can vary the 1j24b from almost no gain to maximum gain by varying g2 from 25V to 55V
Layout is very important. Layout with the valves flat, like the Russians did. You also need to cut the leads, but not too short. Never bend close to body, i.e. at untinned portion. Don't use a push in breadboard except for audio work.
Having a screen (tinned steel is fine) with the shield wire, g3 and f- connected to it is important.
