Hello, I have found these 2 symbols in electronic scheme and I can't identify them

Thanks for your help

 

Welcome to AAC.

The bottom symbol is similar to what one sees for neon bulbs:

 

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).

 

I think first symbol is a feedthrough filter.

 

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.

 

They were quite common in the days of VFH/UHF tuners etc,
Max.

 

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.

 

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.

 

Welcome to AAC.

The bottom symbol is similar to what one sees for neon bulbs:
View attachment 209600

Thanks for reply

 

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

But I did not undestand what does mean 10nFx5nF

 

I have never used them, but I think this refers to a 4-terminal SMT feedthrough capacitor, see http://www.x2y.com/techsummary.htm