symbols

Irving

Joined Jan 30, 2016
2,759
I concur on the neon, its a variation on the theme. Can also be a gas discharge surge arrester.

The first symbol is most likely a variation on a (RF) resonant filter, most usually a ceramic, crystal or piezoelectric type, as would possibly be found in the IF strip of a miniature radio receiver as an alternative to inductive filters. The symbol usually only has 3 ports, in, out and ground, even though the actual device will often have 4 wires (in/gnd, out/gnd).
 
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Irving

Joined Jan 30, 2016
2,759
I think first symbol is a feedthrough filter.
Kudos, you're right. Quite a rare beast.

I searched for 'capacitor with wire through middle' and got one hit on a 5y old post on EE StackExchange referencing the same symbol.

Strangely I've used such devices in the distant past but don't recall ever seeing that symbol on a schematic.
 

Irving

Joined Jan 30, 2016
2,759
Yes, I recall using them when I was a junior radio engineer designing/building VHF/UHF RF kit for aerospace comms but that was 40-odd years ago and never used them since probably early 1980's. Just don't recall the symbol but must have seen/used it... oh well.
 

dl324

Joined Mar 30, 2015
14,669
I searched for 'capacitor with wire through middle' and got one hit on a 5y old post on EE StackExchange referencing the same symbol.
I used them frequently when I built filters and such (basically anything in a sealed metal box) as an R&D tech.
 

Thread Starter

alitronic

Joined Jun 13, 2020
31
Hello, I have found these 2 symbols in electronic scheme and I can't identify them
View attachment 209598
Thanks for your help
I concur on the neon, its a variation on the theme. Can also be a gas discharge surge arrester.

The first symbol is most likely a variation on a (RF) resonant filter, most usually a ceramic, crystal or piezoelectric type, as would possibly be found in the IF strip of a miniature radio receiver as an alternative to inductive filters. The symbol usually only has 3 ports, in, out and ground, even though the actual device will often have 4 wires (in/gnd, out/gnd).
Thank you for replying. I have found this symbol in a transducer conditioning signal circuit
1592072565627.png
But I did not undestand what does mean 10nFx5nF
 
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