Epiphone Pacemaker 50T PT short

[Stevem]

Over the decades I have tried a ton of different things and the only thing that works in the end to stop the rust and yet not harm all that silk screening is a good coat of gloss enamel .

Remove the knobs , tape up there shafts and the fuse holder and pilot lamp and do it up!
Be sure to not go so heavy as to get any runs.

3 light coats and then a final heavier one is the way to go, then allow it sit for 3 days or however long is needed until you can’t smell the paint anymore.

[Phil_S]

Anything you do about the rust will involve risk. I wonder how much of what I see is dirt vs. rust? You might try warm water with a drop of dish washing liquid. Don't rub, just dab. Get the soap off with plain water. Try this where is won't show too much.

[angelodp]

I will start with gentle approach and see if anything loosens up.

[maxkracht]

Just call it patina instead of rust, then you don't have to do anything...

[angelodp]

Yes Patina

[angelodp]

That one shows 100 mA for the HV secondary. However, if it worked for a 5F10 Harvard with 2x 6V6GT, then it will work for your 2x 6AQ5. There is a 120VAC primary version 290HAX https://www.hammfg.com/files/parts/pdf/290HAX.pdf you could use if you don't need to operate internationally.

Martin, the Japanese PT fell through, so back to a search. 290HAX dos not have a CT, I do need a PT with CT is that not the case?

Thanks A

[maxkracht]

If you want the tube rectifier you need a CT. could do a hybrid thing without, but you probably want the CT.

[martin manning]

Hammond 290HAX has a center tapped heater winding. The amp schematic on pg 1 does not show a CT, fhe ground reference is made by grounding one side of the heater circuit. If that ground is made through the pilot lamp frame (and not removable), then you would not ground the transformer CT.

[angelodp]

Understood thanks Martin

[Stevem]

I would see if you can open up the ground connection on that pilot lamp socket so you can use a PT who's heater winding has a center tap.
You will have far less 60 hz hum in the audio to be heard.

Even if you end up with one without a center tap you can then make artificial one with two 100 ohm 1 watt resistors

[angelodp]

Ok Steve, will keep that in mind. What do you reckon I need in the way of dropping R for that 290HAX to get it in the ballpark.

10k 5w?

A

[maxkracht]

String of Zeners from HT center tap to ground is probably the easiest. 5w 10-15v Zeners are relatively inexpensive. I have big bag of 1n5348 and 1n5353 in my stash for this reason. You can do it more efficiently with a mosfet, but Zeners are simple.

[angelodp]

What is the dissipation on those Zeners like? A board is best to get them some air?

[maxkracht]

Yep, they get hot. Put on a terminal strip or something and keep away from things that don’t want to be hot.

[martin manning]

I would see if you can open up the ground connection on that pilot lamp socket so you can use a PT who's heater winding has a center tap.
You will have far less 60 hz hum in the audio to be heard.

In some pilot lamp assemblies the socket shell is grounded directly to the frame, so t's impossible to isolate the socket without replacing the whole assembly.
If the heater winding has a CT, that doesn't mean that you have to use it ;^)