Is there any disadvantage to feed a driver and an output tube from the same B+ PSU if the driver and the output tubes are the same DHT connected through an interstage transformer and the PSU has enough current in reserve?
Thank you.
Thank you.
Probably no disadvantage, even if you don't decouple the HT between the stages. However, with more then two stages there is a risk of positive feedback between the 1st and 3rd stages, which can lead to LF instability (motorboating). It's normal practice to decouple the HT for every stage.
kinda unrelated, but I'm assuming you an RC decoupling scheme is typically used. What kind of R and C values should one aim for (assuming there is no need to burn off voltage)?
I seem to remember reading that capacitance in uF x resistance in ohms/1,000,000 should be 0.1 or greater, for good decoupling.
So, from this rule of thumb, if you want a small voltage drop and use e.g. a 470 ohms resistor, the minimum capacitance you need = 1,000,000x 0.1/470 = approx. 220uF.
So, from this rule of thumb, if you want a small voltage drop and use e.g. a 470 ohms resistor, the minimum capacitance you need = 1,000,000x 0.1/470 = approx. 220uF.
- Status
- Not open for further replies.