Phil Landmeier @shuttersparks@social.cleverlibre.org

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 Modern ceramics are much better but still no match for mica if you need performance at RF, with high voltage, and want stability. Most ceramics drift all over the place with temperature and they exhibit microphonics. There are NP0 ceramics but those are still too drifty for making a VFO. On the other hand, we don't make VFOs anymore, it's all digitally synthesized. lol

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 That makes more sense now that I know the 390 was manufactured by Motorola. A mechanical filter would be odd to find in a VHF FM radio.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 Yep and air variables. Mica caps are still a thing today. Nothing can beat it yet for RF, high power, and stability.

Yeah, the 390. I've never used one. I cut my teeth with a Hammarlund HQ-180 and Viking Ranger transmitter.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 Stewart Warner, eh. Hah. Almost as old as my Bendix MT-11 key.

Mind you, that's 455 kiloCYCLES. We'll have none of that new-fangled Hertz stuff around here.

When I started it was all mmf, no new-fangled picofarads for us.

@coprolite9000 @futurebird 😂

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 @LGsMom

Thanks. Motorola? Must have been for a VHF radio before we started using helical resonators for ultra high-Q stuff. Interesting that it's in a round enclosure.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 @LGsMom That's the kind of busy I like. Carry on!

@Sundae_Gurl Not to mention there are no conservatives in the Republican Party anymore. Republicans are so far into RWNJ territory that today's Democrats are a lot closer to conservatism than they are. It's crazy.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 @LGsMom Hmm, everyone went suddenly quiet. All I hear is snoring. I guess that blog post put everyone to sleep. Lmao.

@coprolite9000 @futurebird Terrible? That's way better than I can do.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 @LGsMom Yep. I remember all those brands, Ken-Rad, Tung-Sol, GE, RCA, Sylvania, Mullard.

In the mid-70s I had a repair business in Los Angeles / Hollywood. I and my partner, Ken Sime, were the primary Hammond Organ and Leslie speaker factory repair guys. We also did Gulbransen organs. Some of the organs I worked on dated from the 1930s, including a couple of Hammond Model A's from 1935, the first ones. Speaker cabinets used dynamic speakers, not permanent magnets. Tubes were obviously 1930s vintage components.

Since this conversation is wandering all over the place, into early electronics, early radio, etc., there's an article I wrote on my ham radio blog that might be of interest. The middle section of the article is a brief background history of radio, thermionic emission, the first tubes, Armstrong's inventions, etc.

https://kw2p.shuttersparks.net/the-radiola-20-a-restoration/

@SrRochardBunson @ClaraListensprechen@universeodon.com @PeeBeeJayBee @Ralph058 @sergio_101 @LGsMom Sorry for giggling. No. Nothing mysterious about piezoelectricity. Some materials have a crystal lattice structure such that mechanical pressure (which changes the shape of the crystal, microscopically) along certain axes of the crystal causes the electric charges to move to a different position. Release the pressure and they move back. And the effect is reciprocal. Apply an electric field, the charges move, and the shape of the crystal changes microscopically.

@SrRochardBunson @ClaraListensprechen@universeodon.com @PeeBeeJayBee @Ralph058 @sergio_101 @LGsMom Lol.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 @LGsMom That's a boxful of money there.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 @LGsMom

Beautiful. Those getters look fine so those might be good as new. They're worth serious money. Keep them safe.

@ClaraListensprechen@universeodon.com @Ralph058 @SrRochardBunson @sergio_101 @LGsMom

A fine collector.