[JRomero]

This is an spanish Triplex Radio mod. Super 556-A from early 40's.
Triplex Radio was an small post war brand from Madrid, and I think it should have
disappeared in the middle 50's.
This brand used the same cabinet in different models.


My 556-A has ECH3, EF9, EBF2, EL3N and AZ1 tubes.
There is a later version with Rimlock base B8A.

The Radiomuseum one has ECH4 ECH3 EBC3 EL3N AZ1 tubes.
http://www.radiomuseum.org/r/triplex_556a.html
One circuit or other depending the tube's disponibility of the day.
Ah ! I forgot something very important: the vast majority of wiring diagrams
of those small brands have been lost, so you have to use generic schemes often.


There is an AC-DC version too, the model 55.
The same cabinet with 6A7, 78, 75, 25L6G and 25Z6G or CY1:
http://subefotos.com/ver/?ed745e90dfda3a...9660co.jpg
http://subefotos.com/ver/?c2c4ead6fac2d2...344c0o.jpg

My one, before and after.
The power transformer was burned, electrolytics cans and Philips black paper caps with
bad aspect and leaks.
One or two unstuck tube grids, badly damaged varnish, a smudge of something oily on
the top of the cabinet, dial fused bulbs, a sheet of asbestos in the ceiling of the cabinet
and changed by a cork sheet ...
Mi Kodak cam gives too much contrast and warm colors
[Image: http://thumbs.subefotos.com/6013ab5f7025...6dd8do.jpg] [Image: http://thumbs.subefotos.com/9159c31b98e3...65e15o.jpg]

Chassis 1:
[Image: http://thumbs.subefotos.com/88464a543095...7eb9co.jpg] [Image: http://thumbs.subefotos.com/fe69f1c46747...40807o.jpg]


Scale dial and chassis with new power transformer.
look at the HV secondary: 375-0-375 !
So high voltages are common in spanish radios with electrodynamic speakers.
you can not find electrolytic capacitors with suitable voltages, 8uF or 10uF and 550V or 650V,
so you have to put two 22uF 400V in series and help each one with a 220K resistor in parallel to match the
loading and unloading. The aspect of that is ugly.

[Image: http://thumbs.subefotos.com/2541f59684e8...482bfo.jpg][Image: http://thumbs.subefotos.com/9b9d22aadb5c...9e49co.jpg] [Image: http://thumbs.subefotos.com/3b31379076d7...48c39o.jpg]

I'll tray to post one movie if i can, Youtube is very picky about copyright

[morzh]

Juan

I think we have radios with the same secondary voltages.
The large ones. Like 37-116.

As for the serializing capacitors, I do it without resistor. First the resistors do not have to be 200K, they could be over megaohm. They have to conduct current exceeding the leakage so unless the leakag is high ...

Also the resistors are needed only if the skewed voltage could exceed one cap's WV which is rarely the case if you use say 450V rated caps.