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-   -   I got it! I got it! (http://www.videokarma.org/showthread.php?t=114907)

yagosaga 07-18-2007 12:10 PM

Quote:

Originally Posted by tritwi (Post 1252314)
Hi Gianni, the set has a tint control (useless with our Pal system) but no chroma delay line.

I believe this set is fitted with simple PAL circuits. Simple PAL has no delay line but a tint (or hue) control.

- Eckhard

Kiwick 07-18-2007 07:16 PM

Quote:

Originally Posted by bgadow (Post 1253995)
Some of those tubes do not use PVA but instead have the safety glass seperate with a rubber gasket. I have a couple like that, including a 25MC30 Zenith, but have not had them apart to see just how it fits. It may have only been done on the standard models; maybe the anti-glare tubes were bonded?

I'm wondering why American CRTs used separate or PVA bonded safety glass lenses until the late 60s, while most European sets made after 1964 had CRTs with the modern "tensioned rimband" type of integral implosion protection and did away with any kind of safety glass in front of the actual CRT's face...

Maybe the separate or bonded safety glass was a legal requirement in the US back then?

Francesco

Sandy G 07-18-2007 07:58 PM

Think you're right, Francesco. Also dimly remember a health scare going on in the mid-60s about X-rays from color TVs...There was a big yah-yah about it, the "consumer" movement was in its infancy then...

old_tv_nut 07-18-2007 09:47 PM

I don't think there was any particular requirement for safety glass vs. rimband - the tube or tube/faceplate combination just had to meet certain limits on impact strength and dispersion of glass when imploded, I think. It's possible European color tube factories went to rimband directly when first opened, while the U.S. factories had to be adapted to the process.

Gianni 07-19-2007 05:31 AM

Quote:

Originally Posted by yagosaga (Post 1254011)
I believe this set is fitted with simple PAL circuits. Simple PAL has no delay line but a tint (or hue) control.

- Eckhard

Yes.

Somebody, in this forum, affirmed there are no simple PAL TVs from industrial factorys ( not from craftsmen ), apart from Kuba and Telefunken sets with 11SP22 cathode ray tube.

Actually, according to Argeo Deotto, simple PAL was a flop, then following TVs adopted PAL delay; therefore there ARE some simple PAL TVs and Marco's set proveS that.

According to Marco, his PAL Portacolor makes some Hannover bars, more visible on yellow images; but we see two good rasters from his "new" PAL-Zenith, without Hannover bars, only some retrace lineS on the raster from "Cultura moderna" broadcast ( not the young lady ); therefore, supposing both the TVs are connected to the same aerial, pheraps the little one needs some adjustements ( synchro demodulators? ).
I have the schematic and some instructions for the technicians, with regard to the "Telecolor" ( a Telefunken simple PAL TV, pheraps made in Milan, with some writings meaning: "Volume", "Luminosità", "Colore", "1/2" on the VHF/UHF switch knob and Italian VHF channels "A,B,C,D...", and having 11SP22 cathode ray tube; in my opinion it is possible that it resembles Marco's simple PAL Portacolor ):smoke::tresbon:

Quote:

Originally Posted by Sandy G (Post 1254663)
Think you're right, Francesco. Also dimly remember a health scare going on in the mid-60s about X-rays from color TVs...There was a big yah-yah about it, the "consumer" movement was in its infancy then...

1) Yes, in a lot of Italian TVs from 50s there is a safety-glass who increaseS the contrast too; even in some European sets from 70s there is a similar device, a "plastic glass", almost black (!)
My parents had one of these TVs until 1982 ( a Siemens hybrid TV, with push - buttons tuning and four slider potentiometers, one of them for tone adjustement; now it appears only in a lot of photos:dunno:).

2) ...Is there in English any neologism as "consumIST" or sIMILAR?

Gianni 07-19-2007 07:07 AM

...

tritwi 07-19-2007 01:31 PM

2 Attachment(s)
According to what is on the brochure of the set, the tube has a sealed darkened glass on its faceplate. It doesn't seems a bonded type and it has not the classic yellow halo around the hedges. As we in Europe made wide use of push through picture tubes we had the need for tubes having the tube sides completely smooth. American tubes used to be placed inside a mask hiding corners.I heard about x rays issue on older tube type televisions but I think early color tvs all suffered from this kind of emission. Here in Europe there were mainly two kinds of horizontal and eht stages. One used a single horizontal/eht transformer and it also used a similar 6BK4 (PD500)tube to stabilize the hv. The other kind of circuit used separate horizontal and eht tranformers each with its proper driving tubes. This circuitry didn't need to use a high voltage stabilization tube. All this stuff was obviously put inside metal cages and the hv rectifier and ballast tube were commonly labeled with "x-ray" warning.
Gianni, I don't think simple pal was a flop, it was more a variant of NTSC. It is capable of good pictures. The main problem of the simple pal are the so called hannover bars that show up on particular colors such as yellow. Anyway who is
Argeo Deotto?
My Kuba portacolor has exactly the same chassis and picture tube as the Telefunken you mention but aesthetically it's quite similar to the original GE portacolor.

yagosaga 07-19-2007 01:35 PM

Quote:

Originally Posted by Gianni (Post 1255152)
Somebody, in this forum, affirmed there are no simple PAL TVs from industrial factorys ( not from craftsmen ), apart from Kuba and Telefunken sets with 11SP22 cathode ray tube.

SONY for example built simple PAL receivers. Simple PAL with a good antenna input is as well as PAL with delay line. But you have to adjust the PAL hue control before.

- Eckhard

Kiwick 07-22-2007 05:39 AM

Quote:

Originally Posted by Gianni (Post 1255152)
Yes.

in some European sets from 70s there is a similar device, a "plastic glass", almost black (!)

The dark glass or plastic of some 60s and 70s European sets was meant to avoid daylight reflections on the crt's face and improve the contrast, not for implosion safety purposes...

The dark glass was also very hard on the CRT as it had to be run at much higher brightness levels.

Actually, most european sets (both B/W and color) made after 1964 had rimband type integrally protected CRTs, the only exception is the Italian Philco factory, which continued to make sets with unprotected CRTs and separate safety glasses into the early 70s

firenzeprima 08-10-2008 10:50 AM

Quote:

Originally Posted by tritwi (Post 1202939)
Hi everybody! I finally got a genuine Zenith roundie! :banana:
It seems it has been modified to receive the Pal standard (the small unit just at the left of the chassis). I really can't wait to pick it up! From the pictures I seem to read it has a 24MC32 chassis. Is there everyone out there who can give advices and informations about this set? I would really get the best from it !!!
All the best
Marco

Hello!
this zenith color tv set you have bought up and bay? the seller was in northern italy remembrance....
fernando from florence.

firenzeprima 08-10-2008 11:06 AM

Quote:

Originally Posted by Kiwick (Post 1208811)
I bet the chassis of this Zenith was assembled in Italy (or heavily modified here anyway)... because apart from the PAL color system, the set has to work with our 50 hz mains and our 625/50 system

if i'm right, there are probably Italian glass-encased capacitors in place of black beauties and wax caps under the chassis.

Francesco

certainly all color TV set zenith which were sold on the Italian market were assembled in Florence by the company elettronica M. Montagni. boxes arrived with all the components and assemble them to Montagni workers , I remember seeing in years 70 to 80 boxes packed full of components now abandoned stock, but with the flood of the river mugnone went all lost. Curiosity .... many of the workers who worked in assembling the Zenith color TV now working as technicians television in some Italian TV. in attach pic of mr Montagni, tv color Zenith in Montagni office, (1978) and Montagni building
fernando


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