Recapped the Avanti and....

[TinCanAlley]

Originally Posted by zeno

OK on cap, I tend to notice those things.

Discharge the cap that you use to sub. If you dont it can be charged
up to 125V when you move it to the 24V & bad things can happen.
In the all tube days we would just ground the neg of the
cap & touch the sections one at a time. Anything solid state
we would hang it in, turn on, see results. Then discharge
& do the next section. Gotta be more careful, transistors
are not forgiving like tubes.

BTW its good you had to readjust after the recap. It shows
you did have bad caps.

If you still have the jail bars after above I have the Sams out & me
& the other cats will try to help you along.....

73 Zeno

Okay, hang in here with me. I just want to make sure this is as simple as I believe it is. I will take a clip-on lead from the ground point of the canister and then a clip-on lead from one of the 400uf legs of the canister. I will then take the other ends of the leads and clip them to a good cap and turn the set on. Is this correct? Also, if I'm reading the schematics correctly, the second 400uf cap is on the other side of the 16ohm filter that the first 400uf connects to. Should I do parallel both at the same time?

[TinCanAlley]

Okay, did some digging and found a couple 300uf 150V -10/+100% caps that measure out to roughly 415uf each. So it looks like I'm in good shape to test. Now all I need is confirmation if I should parallel both of the 400uf caps in the canister independently, or simultaneously.

[zeno]

Originally Posted by TinCanAlley

Okay, hang in here with me. I just want to make sure this is as simple as I believe it is. I will take a clip-on lead from the ground point of the canister and then a clip-on lead from one of the 400uf legs of the canister. I will then take the other ends of the leads and clip them to a good cap and turn the set on. Is this correct? Also, if I'm reading the schematics correctly, the second 400uf cap is on the other side of the 16ohm filter that the first 400uf connects to. Should I do parallel both at the same time?

Negative to ground + to the can section. OK ?
The 16 ohm is a choke, common arangement called a pi filter.
Do one cap at a time. Sometimes subbing either side will
improve it, the bad part is the one that shows most improvement.


73 Zeno

[TinCanAlley]

Originally Posted by zeno

Negative to ground + to the can section. OK ?
The 16 ohm is a choke, common arangement called a pi filter.
Do one cap at a time. Sometimes subbing either side will
improve it, the bad part is the one that shows most improvement.


73 Zeno

Oh yeah, should I put the caps on single or should I series them? If I put one on, it will be a 400uf in parallel with what ever value the can still has. If I series them first, then it will add around 200uf to what ever value the can has left.

Thanks

[Eric H]

Originally Posted by TinCanAlley

Oh yeah, should I put the caps on single or should I series them? If I put one on, it will be a 400uf in parallel with what ever value the can still has. If I series them first, then it will add around 200uf to what ever value the can has left.

Thanks

The old caps should be disconnected completely, besides adding capacitance they can still short out if left in the circuit, and they can also be leaky between sections.

Some of us like to gut the old cap and put the new ones inside for appearances sake.

[TinCanAlley]

Originally Posted by Eric H

The old caps should be disconnected completely, besides adding capacitance they can still short out if left in the circuit, and they can also be leaky between sections.

Some of us like to gut the old cap and put the new ones inside for appearances sake.

At this point I'm just trying to see if the jail bars change based on the addition of the paralleled cap. If it's best to disconnect the lead from the canister, then I think I'll just get all the replacement caps needed to clone the canister, install them on the bottom side of the chassis and leave the can in place for show.

[zeno]

Originally Posted by Eric H

The old caps should be disconnected completely, besides adding capacitance they can still short out if left in the circuit, and they can also be leaky between sections.

Some of us like to gut the old cap and put the new ones inside for appearances sake.

100% correct but we are just doing a quick test to see if the
jail bars go away. Dont unhook the old ones. Since the old
caps are probably near OK otherwise you would have servere
symtoms. We always used a 80 or 100mfd for this test.
Whatever was laying on the bench.
Even if you had a totally open say 200mfd it would make a
huge improvement & you could check the set for other problems
before giving an est.

73 Zeno