Neither you nor krw can see any use for me, because you are both too dim to understand most of what I'm saying.
I do wonder what you intended to type instead of "stopped talking to yourself".
"Talking to yourself" is an interesting habit. Doing it out loud can worry other people, but if you confine yourself to the intended audience, there's research that suggests that the habit is useful.
-- Bill Sloman, Sydney
All the commie era TV UHF tuners were on phenolic and performed well.
Best regards, Piotr
All the commie era TV UHF tuners were on phenolic and performed well.
Best regards, Piotr
Whereas the +/-30% variation seems to come from the statistical noise on th e number of atoms in the channel, or the number of photons making it into t he relevant chunk of photoresist. That's set by the laws of physics, rather than the care and attention of the people controlling the assembly of vacu um tubes.
Eventually. You needed modern - essentially solid-state - electronics to ma ke that level of automation practical.
For large volume production. Electron microscopes selling at the rate of a hundred or so units per year didn't get that kind of attention. We did buy enough Analog Devices parts to score a visit from Barry Gilbert once, but h e was covering all the traps in the hope of finding customers for his RF in tegrated circuits, so it probably doesn't count.
-- Bill Sloman, Sydney
UHF is a relatively narrow band of frequencies present as a modulation on a very high frequency. Frequency dependent dispersion is less of a problem i n that application, and there's correspondingly less reason to go for less dispersive substrates and connections (buried stripline is less dispersive than surface microstrip).
-- Bill Sloman, Sydney
With semiconductors that is simply related to process tolerances. You can tolerance it tighter but that only works by either throwing money at the process (mucho Dolares) or selection (weeding out parts). Both very expensive. Sometimes trimming is used but there is no free lunch either.
Tube tolerances are largely determined by mechanical dimensions and assembly precision. They can be remarkably better than semiconductors. When I built my big fat shortwave power amp I pondered having a separate bias adjust for each of the five tubes. Measured it and found the thresholds to be with less than 5%, even between manufacturers. Only one of them was less precise but it was a brand nobody would buy anyhow.
See that Youtube video, they did it mechanically. Transistors had barely been invented and they couldn't do this yet. After seeing that video I had to take my hat off to the people who designed these production machines.
This level of automation made it tough for the transistor. Tubes undercut them in price for many years.
It is actually a low volume production and they know it. They is a huge difference in customer service between companies such as Skyworks and companies like Infineon (where I am still waiting ...). It is why I prefer small companies.
Luckily I wasn't there. Might have slipped my tongue that I don't like Gilbert cells :-)
-- Regards, Joerg http://www.analogconsultants.com/
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.