Metropoulos Forum

Hi guys

I'm having some trouble with wiring my 40-18054 PT for 240V, particularly with regard to the 120V pilot light.

The assembly instructions appendix diagram for 240V looks like this:

https://cvws.icloud-content.com/B/AanY3 ... zF2bQ&cd=i

but this is based off the 40-18033:

https://cvws.icloud-content.com/B/AZFbu ... 9Wyh0&cd=i

As I have the 40-18054, its wiring is like this:

https://cvws.icloud-content.com/B/Abffm ... mL6IE&cd=i

https://cvws.icloud-content.com/B/AfBYO ... ShPj4&cd=i

I can't see a way to be able to wire in the 120V lamp.

Any ideas? Help greatly appreciated

David

I am not familiar with the transformers you quote and cannot see the images (gone appears when I click the links)

You have two options:

- get a 6.3vac heater driven lamp (hook up by dedicated pair of wires from V4 or V5.

- use a voltage selector on the back of the amp (like an original uk amp) and wire the 120v amp feed off the 0 and 120v wires (the PT acts like a voltage divider) or like the US amps which use a strip of turret board and you terminate each voltage option on the strip then you take the feed you want from each, i.e. 240v for the PT and 120v for your lamp.

If you look at a Unicord schematic from the early 70s for a JMP50 or a JMP100 you will see how they do it for the US amps.

Thanks for the reply.

Apologies for the lack of images - it looks like my iCloud hosting has a limited viewing time, and if I try to attach an image to the post, I get an error saying the attachment quota for the forum has been reached.

For reference, this is the link to the 40-18054; http://www.classictone.net/40-18054.pdf

It's a complicated primary and not immediately obvious which tap is the 120V.

As you had suggested, I thought of getting a 6.3V fender-style lamp and running it off the heater circuit, but thankfully I received a reply from Magnetic Components which will clarify for anyone who may have similar issues in the future.

The primary connections are as per the above PDF, with the black wire being common and the brown/white lead is the 240V. (To achieve the 240V, you must connect the black/white and brown wires). The black/white wire is the 120V tap, so as well as connecting to the brown wire to achieve 240V at brown/white, you extend the black/white wire to power the 120V lamp.

Again for reference in case anyone is looking, the 240V wiring of the 120V lamp is in the appendix of this PDF (page 29) http://valvestorm.com/sites/default/fil ... T_V2.1.pdf

Thanks again for the advice.

Appreciated.