146: Difference between revisions
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See also [[140]] and [[144]]. | See also [[140]] and [[144]]. | ||
Regarding the 146, [[Phil Crosby]] recalls: | |||
<blockquote> | |||
It was probably a [[Steve Roth]] design, although he may have gotten help from [[Dave Jurgenson]]. | |||
Steve was a wizard. | |||
He designed the goniometer for doing seamless phase adjustment and all of the early video test signal generators. | |||
The first test signal generator was the [[141]] PAL generator. | |||
We had wanted to do test signal generators for a long time, having spent a lot of money for a Riker generator, | |||
which we were told was the top of the line. It was terrible! | |||
The color bars were just hard-switched between the various phase and amplitude sources. | |||
Generating horrible transitions. Other than that, it was a drifty, mechanically horrible piece of crap. | |||
The PAL version of the vectorscope, the [[521]] obviously needed PAL test signals, | |||
particularly linearity staircase and color bars to be calibrated and evaluated. | |||
There was a source. Some Swiss division of RCA said that they could supply us with such a generator in 18 months for about $18,500. | |||
Steve was coming free from the work I'd given him on the [[520]] NTSC vectorscope, | |||
so I asked him if he would be interested in doing a generator for PAL. | |||
I knew it would be tricky because of the subcarrier frequency offset. | |||
Steve also decided to use these newfangled integrated circuits | |||
(RTL, unfortunately, since I had used them in the 520 cuz they were cheaper than TTL Ouch!). | |||
In six months we had working prototypes and I took one to the 1968 NAB show in Chicago. | |||
It made a big hit with the FEs because they had something to demo PAL vectorscopes to systems sellers. | |||
With the groundswell response from the field, in about six months we had product approval. | |||
The 148 followed with Steve's sync separator circuit employing a transistor that is reflexed into common emitter, | |||
common base, and common collector operation at the same time. | |||
As I recall the 146 had the sync separator for its genlock and maybe it went to TTL as well. | |||
Brilliant! | |||
</blockquote> | |||
{{MissingSpecs}} | {{MissingSpecs}} | ||
Revision as of 17:03, 14 August 2022
The Tektronix 146 is an NTSC signal generator.
Regarding the 146, Phil Crosby recalls:
It was probably a Steve Roth design, although he may have gotten help from Dave Jurgenson. Steve was a wizard. He designed the goniometer for doing seamless phase adjustment and all of the early video test signal generators. The first test signal generator was the 141 PAL generator. We had wanted to do test signal generators for a long time, having spent a lot of money for a Riker generator, which we were told was the top of the line. It was terrible! The color bars were just hard-switched between the various phase and amplitude sources. Generating horrible transitions. Other than that, it was a drifty, mechanically horrible piece of crap. The PAL version of the vectorscope, the 521 obviously needed PAL test signals, particularly linearity staircase and color bars to be calibrated and evaluated. There was a source. Some Swiss division of RCA said that they could supply us with such a generator in 18 months for about $18,500. Steve was coming free from the work I'd given him on the 520 NTSC vectorscope, so I asked him if he would be interested in doing a generator for PAL. I knew it would be tricky because of the subcarrier frequency offset. Steve also decided to use these newfangled integrated circuits (RTL, unfortunately, since I had used them in the 520 cuz they were cheaper than TTL Ouch!). In six months we had working prototypes and I took one to the 1968 NAB show in Chicago. It made a big hit with the FEs because they had something to demo PAL vectorscopes to systems sellers. With the groundswell response from the field, in about six months we had product approval. The 148 followed with Steve's sync separator circuit employing a transistor that is reflexed into common emitter, common base, and common collector operation at the same time. As I recall the 146 had the sync separator for its genlock and maybe it went to TTL as well. Brilliant!
Key Specifications
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Pictures
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Output displayed on NTSC monitor
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Output displayed on NTSC monitor
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Output displayed on NTSC monitor
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Output displayed on NTSC monitor
