Hello friends,
Considering this 6E5P for example, which has dual cathode+shield pins:
When the cathode is to be connected to a single other node, is using only one of the pins okay or is it better to connect both pins.
I always assumed the dual pin arrangement on each side of the socket is just for wiring convenience but I've often been proven wrong 😎
Thanks for any insights.
Considering this 6E5P for example, which has dual cathode+shield pins:
When the cathode is to be connected to a single other node, is using only one of the pins okay or is it better to connect both pins.
I always assumed the dual pin arrangement on each side of the socket is just for wiring convenience but I've often been proven wrong 😎
Thanks for any insights.
If they're truly just attached to the same point internally? I'd go for one connection.
Two might be better if it's a shield, for ultimate low impedance pathing. Yadaya.
But realistically? It probably is for either wiring convenience of because the pins were available and they might as well hook it up to the shield when it's there yeah?
Two might be better if it's a shield, for ultimate low impedance pathing. Yadaya.
But realistically? It probably is for either wiring convenience of because the pins were available and they might as well hook it up to the shield when it's there yeah?
Very possible, the tube was specified as HF amplifier, which would benefit from good shielding.
Maybe but then there's NC pins 3 and 7 unconnected to the shield...
As this was a soviet military part I suspect the pin arrangement was very application-specific, to allow close-by circuit connections be made on the NC pins instead of an external tag board. That's what I do with NC pins when possible.
I always connecting such pins (4 and 9) together with short wire under the socket.
In Jurassic times, tubes often had multiple pins for important electrodes to reduce inductance internally for high frequencies.
The two cathode connections indicate this is an RF type. The idea is that one cathode connection is for the cathode bias resistor/bypass capacitor while the other one received the ground end of screen and plate bypass capacitors. This keeps the voltage developed across the cathode return from appearing in series with the grid return. This keeps the effective AC resistance of the grid high to prevent loss of gain/selectivity.
Thanks a lot Miles for your reply. As a noob I had to read a bit more about screen and plate bypass.
I thought sceen bypass caps always needed to go to ground. If I understand you correctly this would be such an implementation with screen bypass Cg2 connected to the cathode correct?
I'm not sure what exactly is a plate bypass though. Do you mean a cap from B+/plate node?
Forgive me for this basic question...
I thought sceen bypass caps always needed to go to ground. If I understand you correctly this would be such an implementation with screen bypass Cg2 connected to the cathode correct?
I'm not sure what exactly is a plate bypass though. Do you mean a cap from B+/plate node?
Forgive me for this basic question...