Ekco AC18 HT Unit - using?

[boater sam]

Sharp on the info there!  Selenium or CuO  does the same job, its likely to be past its best.
Silicon replacement is possibly the best answer, with series resistor to bring voltage back to spec.
4 looks like a box of condensers (as we are back in the 30s, capacitors these days)
7 is a carbon adjustable resistance, like a dropper but carbon with copper/brass contact rings,
(don't know when these were invented!)

[boater sam]

Sorry Lawrence, posts crossed.

[AlanBeckett]

Some Info here - http://www.vintage-radio.net/forum/showt...hp?t=37054

Alan

[Terry]

... Usually now written as 4uF where the u should be a greek "mu" but I'm too lazy to dig out the symbol ...

Tut tut, Jeffrey!

I have little text file which is always open for anything I want and, if the symbol isn't there, I make a point of looking it up and adding it for future use.

The 'mu' symbol is µ and another common one is omega: Ω 

Here's my current list - feel free to copy it for your own use:

¤ § ¶ ± † ‡ © ® ™ ° ² ³ √✔  ⅛ ¼ ⅜ ½ ⅝ ¾ ⅞ ° ⅓ ⅔ × ÷ à ç é ê è ô û ¤ § ¶ ± † ‡ © ® ™ ° ² ³ √✔  ⅛ ¼ ⅜ ½ ⅝ ¾ ⅞ ⅓ ° ⅓ ⅔ × ÷ à ç é ê è ô û µ ρ Ω Ɛ π Π ∑ Φ α β ω λ … ∞ | — ― ‹› Ω ← ↑ → ↓ ↕ │ ∙ ρ Ω Ɛ π Π ∑ Φ α β ω λ … ∞ | — ― ‹› Ω ← ↑ → ↓ ↕ │ ∙

[SurreyNick]

Some Info here - http://www.vintage-radio.net/forum/showt...hp?t=37054

Alan

Yep. Seen that one already Alan. Different model and different component compliment. I have one of these HT units too and it's simpler than the AC18. Internal pic attached of my one before I cleaned it up.
Nick

[AlanBeckett]

It doesn't look 'Simpler' to me, until you work out the Circuit, and Post it, we won't know.

Alan

[Refugee]

I have got an old low voltage power supply with a copper oxide rectifier in it that has been used for all sorts of jobs and had many shorts on its output.
It is still soldiering on to this day.

[Joe]

There's an excellent program for Windows called Keyboard Layout Manager which makes using special characters simple.

http://www.klm32.com/Lite/index.html

I've still got to find out how to do it on linux.

— Joe

[SurreyNick]

It doesn't look 'Simpler' to me, until you work out the Circuit, and Post it, we won't know.

Alan

Fair comment Alan.

I will take the AC18 apart and come back once I have drawn a wiring diagram.

One final question for now. Am I correct in my assumption that component 2 is a choke?

Component List (all values to be determined)
1 = Transformer
2 = ?
3 = CuO Rectifier
4 = Box of papaer filter capacitors
5 = Dry electrolytic capacitor(s) 4+4 mfd / 300 peak volts.
6 = Carbon Adjustable Resistor
7 = Carbon Adjustable Resistor

Nick

[ppppenguin]

Since #2 only has 2 connections it must be a choke. Likely to be connected between the +ve terminals of the pair of 4uF caps. The top image here shows how 2 caps and a choke are normally connected. THis picture shows a valve rectifier rather than your solid state one

http://www.r-type.org/articles/art144a.jpg