Kuba Porta-Color Schematic

[Tom9589]

I came upon a 2009 VK post that had a link to a Kuba Porta-Color schematic. It seems that the link in no longer valid,

I was wondering if the original poster, yagosaga, could post a current link to the Kuba Porta-Color schematic.

[WISCOJIM]

He passed away in 2011.

.

[Tom9589]

Sorry to hear that. It would have been interesting to see how Kuba improved on the GE Porta-Color circuits.

I've owned two Porta Colors and marveled at how well they worked with so few components.

[Electronic M]

ISTR there being a European TV museeum website with a page dedicated to the Kubacolor set...if the site is still up maybe there is a link to the schematic there...
Another thing to try would be dropping the link into the archive.org wayback machine and see if they have it saved in their servers.

[dieseljeep]

Originally Posted by Electronic M

ISTR there being a European TV museeum website with a page dedicated to the Kubacolor set...if the site is still up maybe there is a link to the schematic there...
Another thing to try would be dropping the link into the archive.org wayback machine and see if they have it saved in their servers.

I've seen the schematic of the Kuba set. There is no resemblance to the GE circuit. All European and also a PAL design.
It seems that they bought the cabinet, front bezel, CRT, yoke and convergence assembly, possibly the flyback. I seen no compactrons or US design tubes.

[user181]

Originally Posted by WISCOJIM

He passed away in 2011.



.

Was that the person who had the PortaColor website, or was it someone else?

[WISCOJIM]

Originally Posted by user181

Was that the person who had the PortaColor website, or was it someone else?

Eckhard Etzold
http://bs.cyty.com/menschen/e-etzold/index.htm

http://bs.cyty.com/menschen/e-etzold/archiv/TV/tv.htm

[Tom9589]

I just got through doing a side-by-side comparison between the Kuba schematic and an HC Porta-Color. There is one Compactron in the Kuba set: the 1AD2 high voltage rectifier. There is a lot of similarity in the circuits, even down to the same value of components. The RF, IF and horizontal are very similar. The vertical is somewhat different. Kuba even uses the color oscillator crystal ringing circuit that GE seemed to exclusively use. They even have a screwdriver adjust for tint.

The main difference is the PAL color demod circuit. They still use the diode pair demods that GE uses though.

I would love to see one of the Kuba sets in operation after owning two Porta-Colors.

I suspect that Compactrons were is short supply in Europe so Kuba decided to use equivalent European tubes which accounts for the Kuba set having four more tubes. It also could have been a royalty issue against using the Compactrons. However, considering how much Kuba was already paying GE for all the other components, you would think that GE would have thrown in the Compactrons for free.

One more interesting thing. The power supply choke is tapped. It looks like they may be using it as an auto-transformer to get a little (~ 10V) boost for the +275 V supply. I suspect this may be common practice for a 220VAC TV with a simple half-wave rectifier circuit.

[bgadow]

Was the chassis actually made by Kuba? (European caps & other components?) I can picture some bean-counters doing calculations (on both sides of the pond) to decide whether it was cheaper for GE to build it 100% vs shipping a set less chassis. Nobody could pinch pennies as well as General Electric.

[Tom9589]

Based on the pictures I saw of the chassis, I would definitely say Kuba built the set. The resistors and caps definitely look European. GE used ganged pots for the rear panel adjustment; Kuba used individual pots (and about twice as many as GE).

They showed a view of the flyback and the HV rectifier. The tube had "GE" and "Compactron" on its side.

The metal supporting the CRT definitely looked to be GE. Everything else had the European look to it.

[AlanInSitges]

I have several European-built-American-designed sets in my collection, including a B&W GE (well GEE...long story). During the era we're talking about there were huge import tariffs on imported vacuum tubes and CRTs, and presumably other components, enough to make it worthwhile for them to build a factory and produce some tubes here. Somewhere I've got a photo of a 19" CRT with an American number and a label that says made in Spain by General Eléctrica Española.

I suspect it was especially difficult to make compactrons here, which could explain why they used European types.

[Tom9589]

They might have thought the European tubes were superior in quality to Compactrons.