5F6A Choke too low?

[lmolter]

I finally got around to buying the iron for my 5F6A clone, all from Mercury. Although I am pleased with the PT and OT (I got red end bells, but I realized no one will ever see them tucked away in the cabinet. Oh well...). It's the choke that bothers me. I think the inductance is way too low. Not by any fault of the choke, but rather, by what I thought should be the correct value. I was under the impression from reading forum posts and other material that the choke should be 10henries. Unfortunately, the schematic I have does not indicate the inductance value, only the part number: 14684. Mercury has a replacement ToneClone choke (supposedly an exact replacement) that is 2.84 henries. So... given that the filter caps stay the same at 44uf on one side of the choke and 22uf on the other, what is the 3h choke going to do to the ripple attenuation and also to the rectifier sag times? Should I be concerned? Luckily, the choke was not expensive. I could buy a 10h choke and still stay in budget (ha ha). Any thoughts?

Larry

[Wakculloch]

The amount of smoothing from the choke is relative to the size of the inductance in Henrys; ie a 3H choke will give relatively more ripple on the output than a 10H choke.
However, the fact that you have a choke in the power supply will give far superior smoothing than RC filters. Personally i would build with the 3H, as i doubt you will hear any difference.
Sag is a result of DC resistance of the choke which in both cases will be low enough to make almost no difference when compared with the volt drop of the rectifier.
I would go with what you have, but someone may have experience of comparative builds, so may have better advice.

[tubeswell]

I agree with Wakculloch. I think a small choke is probably all you need for the screen supply node onwards. What's probably more important than the rated inductance is the current handling capability. If it can handle the 2 x screens plus the 4 x pre-amp tubes (all up say no more than 40mA???) you should be fine.