The ISA system was developed by Seimart and Indesit, two (now defunct) Italian TV manufacturers, but i can't find any thechnical description on the web.

An interesting fatc: in the early years of Italian (b/w) television, from the mid 50s to the early 60s, some American manufacturers (Emerson, Philco, Admiral, Dumont, Raytheon, RCA) had TV manufacturing plants in Italy, their Italian sets were an interesting mix of Italian and American parts, styling and technologies.

For eample, 50s Admiral Italian-made sets were 100% identical to the US-built ones (the ones with the knobs in the top corners of the safety glass) but had Italian capacitors and tubes on their chassis

Philco used a 100% American made chassis but the CRT, the speaker and the cabinet were Italian (some even had push through bezels)

Raytheon sets were 100% Italian, Raytheon also set off a small diplomatic crisis between the US and Italy on alleged violations of the Treaty of Friendship when they decided to shut their Italian plant in Palermo in the late 60s and the mayor of Palermo tried to confiscate it

"An interesting fatc: in the early years of Italian (b/w) television, from the mid 50s to the early 60s, some American manufacturers (Emerson, Philco, Admiral, Dumont, Raytheon, RCA) had TV manufacturing plants in Italy, their Italian sets were an interesting mix of Italian and American parts, styling and technologies."

The same thing happened here as well: Admiral, Philco, GE and other American companies had plants here. All gone now, except the Philco plant, that ended in the hands of a Brazilian group. But that one is ALSO in financial trouble today.

Emerson was the last manufacturer to shut its Italian plant in the late 70s (they were building solid state color sets based on a Formenti chassis by then) most other US manufacturers packed up in the mid-late 60s

Anyway, this is an Italian Admiral set that was on Ebay a while ago.

From what i remember reading about the ISA system, it was a PAL variant with improved gain control... details escape me but improvements were marginal over the PAL standard which is why it was abandoned?

I do not think we protectionist is a problem because the market for radio receivers, and various household appliances was also open to American equipment. Here in Europe evaluated the NTSC system that had many flaws and imperfections decided to improve it, opening a technological war between France and Germany. In fact, the PAL and SECAM systems are derived directly from NTSC but not identical because of patents. In Italy in the'70s Indesit ISA developed the system significantly improved at all another, but out of time and impossible to enforce.

sure you are right, but even Dumont, Crosley, Philco, Zenith

Crosley sets were made by Philco, which later became "Philco-Ford" before it was finally sold to Imperial Electronics in the early 70s, the Philco brand survived well into the mid 90s until Imperial finally shut down in about 1996

Zenith sold very few sets in Italy, most if not all were modified PAL Chromacolor hybrid sets, they're very rare now.

in florence were assembled zenith color

You speak of NTSC's many flaws and imperfections. We had already been discussing the phase issues of NTSC and that being one of the primary reasons for the rise of SECAM and PAL. I'm curious about what were the other flaws and imperfections that you are referring to.

David

Sure, apart from the annoying phase change of images, the icon NTSC if you use red or yellow saturated colors can "colarer" on your TV, mingle with other colors or tremolite even if your TV is fully functional.

In Romania we had color television only in 1983 because of Ceauşescu (the first color experiments took place in 1964, in N.T.S.C. and SECAM, but when the Party heard how much SECAM color television costs they order the experimental equypment to be dismentle); they sayed in a book around 1969 or 1975 that in Romania will soon be color tv.

Going to mobile (cellular) telephony, C.D.M.A 2000 is used in Romania, but, belive or not, the signal around here haves lower qualty than G.S.M.

The bastard politicians signed the Geneva Agreement on frequencyes allocation.
So no more F.M. broadcasting on 65-73 M.Hz.

NTSC is not capable of producing a true RGB signal ...because of the weighting of the I and Q signals but both PAL and SECAM contain the full RGB components BUT of course an NTSC style system for 625/25 could be set up to provide true RGB ....but the phase issue was seen as a major problem...

In fact NTSC has superior transmission characteristics for long distance cable/microwave transmission than either SECAM or PAL.

SECAM has problems with studio production ...switching sources etc.

I know the UK had a long investigation into the systems .....the BBC tested 405 line NTSC etc.

Australia was similar with tests of 625 line NTSC before finally settling with PAL.

Of course it is all irrelevant now....digital broadcasting is with us. :(

I had to look up a translation for "colarer" = I think it means "smear" in English; and tremolite" means "flicker"?

If this translation is correct, I must point out that these possible defects are present in all analog color TV systems alike, not only in NTSC, and come from various common causes such as the limited bandwidth of the chroma signals and crosstalk between chroma and luma.

I don't understand this statement at all. I and Q have nothing to do with the correctness of the RGB components. In fact, PAL and SECAM use exactly the same electrical matrix as NTSC - they just modulate the chroma on equal-bandwidth (R-Y) and (B-Y) wothout going to the intermediate non-equal bandwidth I and Q. However, in PAL and SECAM cameras, BEFORE the chroma components are matrixed, modern cameras do have a matrix to form the correct RGB values for the modern phosphors in current picture tubes. NTSC cameras hypothetically have a different matrix to match the original NTSC phosphors, while NTSC receivers are often designed with an (approximate) matrix for modern phosphors that works on the chroma signal only. In practice, modern cameras for NTSC have a matrix that is modified to get pleasing pictures on current studio monitors. This confused situation of some correction at the studio and some in the receiver has never been completely corrected for NTSC, but has been correcterd for high-definition TV.

None of the above has anything at all to do with I/Q modulation.

That's an interesting statement. In what way is NTSC superior for long distance cable and microwave? I would think PAL to be superior due to the phase distortions that could accumulate in multiple-stage video links.

I sort of had to figure out your definitions there. Unfortunately, I have to disagree, any television system can develop these faults because they're frequently due to limitations in the broadcast chain or problems within the receiving set itself. NTSC does not inherently have any more difficulty than any other system with saturation problems.

NTSC has no problems decoding to RGB. There has been over the years some disagreement on implementations of color decoding in NTSC. 3 different revisions if memory serves. The latest one was in the 80's and dealt with modern phosphors on TV sets. Current NTSC broadcast chains should decode correctly for modern TV's.

It might be a true statement, although I haven't read anything that would confirm or deny it. NTSC does tend to be easier to impliment in closed circuit situations. The signaling is simpler, and some of the timings less critical. Since long distance cables, either copper or fiber optic, use FM modulation to transport the signal its feasible that NTSC might be easier to deal with. And using the FM modulation scheme means there are no phase issues, which is the real reason why PAL was developed to begin with. Still I haven't read anything definitive on if that's true or not.

David