quartz crystals
 

Was ham radio gear or color TV the first consumer application of quartz crystals? Either way, the history of their manufacture is interesting.

This 1943 film shows the manufacture starting with natural quartz:
https://www.youtube.com/watch?v=b--FKHCFjOM

This 1962 fikm shows the growth of synthetic quartz at Western electric:
https://www.youtube.com/watch?v=oFH8_uLzano

And this history from 1973 states that synthetic crystals for civilian use were not grown until about 1958:
www.tedlind.net/Dickinson%20Paper.htm
"The government started the development of artificial quartz through a RD (Research & Development) contract to Fort Monmouth. About the same time P. R. Hoffman began to develop the first civilian source in 1958 under the direction of his chief chemist, Warren J. Hunt.(63) During the sixties the synthetic quartz process was steadily improved, until most companies today use at least 50% synthetic quartz in their products."

8 kg crystals - 6 month growth period:
https://www.youtube.com/watch?v=lzHqhNoyx2o

I found old QST magazine advertisements from 1932 for quartz and tourmaline crystals for ham transmitters here. http://www.bliley.net/XTAL/docs/ads.html

That helps explain why the 1943 film was not classified.

In 1932, $4.50 to $14, plus $2.50 for mounting. Inflation from 1932 to 1970 was 2.8 times. I also notice that they frequently don't mention the cut. IIRC, in 1970 or so, AT cut crystals in the single MHz fundamental range were about $1.25 single piece retail, and you could buy single pieces tuned to any custom frequency you wanted to order (not sure now if the price was higher than that for customizing). I can't recall how much TV makers were paying then for color crystals, but it had to be less.

Since the the subject of crystals was brought up, there was something that I have always been wondering, IF a colorburst crystal has to be replaced in a vintage TV, can one go out and get any tiny 3.58 MHz crystal that can be found all over the place? Or will the operating voltages ( 80v – 150v ) and so on be a problem to it?

I'd guess it's OK, but I don't know. Also don't know what the amplitude of the AC waveform is in typical tube sets. Looking at a few schematics, the CTC-5 has a DC blocking cap in series with the crystal. Later RCA chassis have DC across the crystal. The one Zenith schematic on the earlytelevision page has one end of the crystal at -0.5v (grid) and the other end floating DC-wise on a couple of capacitors.

Maybe someone who has done replacements can comment.

By the way, there were at least two different nominal 3.58 crystal tunings used in the industry. RCA and most others used a crystal cut to resonate at the exact color subcarrier with an external 22 pF capacitance. That is, the natural resonance of the crystal was offset so it acted like a large inductor at subcarrier frequency. This inductance resonated with 22 pF, which was supplied by fixed components plus the reactance tube circuit. Zenith, for some reason, came up with a design resonating with 18 pF. So, Zenith crystals were not cut identically to everyone else's. This crystal spec carried through for decades into their solid-state sets. When Zenith supplied a low-cost proc amp to go with their pay-TV headend gear, they re-used their TV IC to recover subcarrier, but it had a transient phase pull-in after vertical sync. That was OK in TVs (hidden in overscan) but did not meet FCC specs. I was called in to redesign the PLL, and determined that a tighter crystal tolerance resonating with 32 pF was needed. I had to call up the retired engineer who had designed the 18 pF circuit back in 1953 to ask if there were any potential gotchas of making the change. He said that 18 pF was just the way the design worked out in the original Zenith prototype, and I could do whatever was necessary.