Hi,
I am considering ruuning 2 rectifiers in parallel. I understand that this will supply more current and should lower the voltage drop across the tube rectifiers, reducing sag. I have seen 2 methods:
1. Ties pin 4 in 1 valve to pin four in 2nd valve, and ties pin 6 in 1st tube to pin 6 in 2nd valve. These leads then attach to the transformer. gz-34 type
2. The second method connects the anodes of each tube, then attaches to transformer leads. It seems like it makes each tube a half wave rectifier.
My question is, which method is more stable and does a better job at sharing the load between the two tubes? How much will this lower the voltage drop across the rectifiers compared to a single tube?
Does this give each tube a longer life, since it sees 1/2 the load and theoretically is not worked as hard. The single rectifier is delivering about 200-210 mA, which close to the tubes maximum rating. I could put in a stronger tube, but that would increase the sag.
I am considering ruuning 2 rectifiers in parallel. I understand that this will supply more current and should lower the voltage drop across the tube rectifiers, reducing sag. I have seen 2 methods:
1. Ties pin 4 in 1 valve to pin four in 2nd valve, and ties pin 6 in 1st tube to pin 6 in 2nd valve. These leads then attach to the transformer. gz-34 type
2. The second method connects the anodes of each tube, then attaches to transformer leads. It seems like it makes each tube a half wave rectifier.
My question is, which method is more stable and does a better job at sharing the load between the two tubes? How much will this lower the voltage drop across the rectifiers compared to a single tube?
Does this give each tube a longer life, since it sees 1/2 the load and theoretically is not worked as hard. The single rectifier is delivering about 200-210 mA, which close to the tubes maximum rating. I could put in a stronger tube, but that would increase the sag.
Normally the practice back in the day was to tie the two plates of one tube together and use it as if it were a half-wave rectifier. Two half wave rectifiers = one full wave.
BUT.... If the power transformer was not built for this configuration originally then it is a bad idea. You would have twice the current load on the 5v. winding, not good.
As to longer tube life, if the working load on a given tube is reduced then it should see in theory a longer life.
Voltage drop is reduced by half for a given load current; two 100 ohm resistors in parallel = 50 ohm. You are effectively paralleling the resistance of the rectifiers.
Be sure to check the datasheets for the tubes you wish to use; some recommend balancing resistors in series with the plates of the rectifiers so that the plates share current equally.
HTH
BUT.... If the power transformer was not built for this configuration originally then it is a bad idea. You would have twice the current load on the 5v. winding, not good.
As to longer tube life, if the working load on a given tube is reduced then it should see in theory a longer life.
Voltage drop is reduced by half for a given load current; two 100 ohm resistors in parallel = 50 ohm. You are effectively paralleling the resistance of the rectifiers.
Be sure to check the datasheets for the tubes you wish to use; some recommend balancing resistors in series with the plates of the rectifiers so that the plates share current equally.
HTH
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