The official G9 help thread

[sarakisof]

Thanks from here too - I've been looking for this type for a long time..

You would think that hookup wire would be among the easiest things to source - but I find the exact opposite irl...

Jakob E.

Found out the cable I got is this type you were discussing in an old thread back then. Pre bond.
It was screaming quality from distance.
Super excited I found out how it's called.

Talking about wiring from PT & filter caps to PCB, what option should be the best?
Western union splice/double heat shrink tag strip, terminal/screw block, wirenuts or other?

Knowing that :

• My PT's leads are common copper stranded for HV (PVC ins.) & "two strand" twisted solid (fiber kind of ins.) for 15V windings
• I'll use that quality pre bond double ins 22 awg wire
• Don't own a proper ferrule crimping tool & never liked the idea.
Old good 60/40 Fluitin & Magnastat lover.
The wires will be soldered straight to PCB. I'll remove the PCB terminal blocks I had used when I first built it back then.

Pros/cons

• was about to use western union splice but then I realized PT leads are stranded & two twisted solids.
• tag strip/eyelet/turret is what I'm using right now but the tag strip board I'd used was sourced from eBay (those cheapo yellow phenolic ones) & noticed tarnishing on eyelets.
It's pretty hard to source new quality ones here. More easy to find "true" old eyelets etc in fleas / e-waste but I'll have to be patient.
• EU terminal block. If pre bond wires can safely go in there (screw connection) & ferrules are not necessarily needed then I'll go for it.

I've been reading on this since two days. Unable to make a clear decision. Hopefully I'm not planning to open G9 again for a long time so I want to be sure.

Any ideas?

 

[smileypitt]

Hello, I have a problem on the power supply on the G9 .
I'm using a 2*15 first and a 2*12v for the second transformer.
I have 275vac on the out put .
I have 360vDC instead of 245v on HT .
No valve on the board ...
I think that my 783 is dead because of a too high input .

I think i should change the second transformer by a 2*15v . And change the 783 . The caps are 400v so they must be ok.

Do you think i'm right ?
Thanks a lot

 

[gyraf]

Hi Pitt,

Yes, 360V DC is too high - and yup, probably best to use a 2x15 for the second transformer in this case. That said, this should be measured under load, i.e. with tubes heated up and drawing their realistic current.

The TL783 is protected from death by high voltages by the string of 39V zeners and the 1N4007 in reverse (check that you have gotten these right) - I have ever only seen broken TL783's from shorting accidents - and I use a lot of them for similar high voltages

/Jakob E.