Do capacitors and inductors age?

[raiya_23]

I am working on a 29 year old transceiver, the tuning circuit of which seems to be out of order (the rest is fine). The tuning circuit is made of ceramic capacitors and variable ferrite core inductors. Is it possible that these components have lost their values over time resulting in the failure of the tuning circuit?

 

[Tahmid]

The capacitor for sure did. Take a look here: **broken link removed**

I don't think anything happened to the inductor.

Hope this helps.
Tahmid.

 

[goodboy_pl]

I think all of electronic component suffer from aging. moisture penetrates in devices and after several years it could damage the components specially integrated circuits and other semiconductors. in fact there are special ovens which is used to bake the components in 50 deg for 2-3 days for de-moisturing. quality factor and the value of capacitors will change due to moisture. varnishes which is used to cover the inductor wires also could ***** due to moisture and high working temperature and short some of wires, which will change both value and quality factor of the inductors. for your special case, i think it is better to do some capacitor/inductor tuning before replacing the components, of course it will be a time consuming process.

BEST

 

[pjmelect]

In old equipment like this look out for wax covered capacitors, they are notorious for having high leakage due to moisture ingress.

 

[raiya_23]

Hmmmm how do I heat them...can I microwave the capacitors to bring them back to their normal values? By the way I have been tuning them for the past few weeks but its not working properly

I think all of electronic component suffer from aging. moisture penetrates in devices and after several years it could damage the components specially integrated circuits and other semiconductors. in fact there are special ovens which is used to bake the components in 50 deg for 2-3 days for de-moisturing. quality factor and the value of capacitors will change due to moisture. varnishes which is used to cover the inductor wires also could ***** due to moisture and high working temperature and short some of wires, which will change both value and quality factor of the inductors. for your special case, i think it is better to do some capacitor/inductor tuning before replacing the components, of course it will be a time consuming process.

BEST

 

[rfredel]

Hello raiya_23,

I agrre what all other posters have say.

But in your case my first tip to you: "Don't touch the ceramic capacitors and inductors of resonant circuits".

May experience for more then 40 years says, "Look for bad electrolyt and paper capacitors, resistors and semiconductors or valves." Capacitors lost capacity or making short circuit and resistors make high resistance.

If only one or more tuning ranges are not function look for the selector switch. The connectors will be dirty or oxidized. If you have valves inside, look for the sockets and the connection pins. They also will be oxidized.

Regards

Rainer

 

[raiya_23]

I have cleaned the DIP switches with a contact cleaner and checked their continuity through a multimeter..they are perfectly fine.

Hello raiya_23,

I agrre what all other posters have say.

But in your case my first tip to you: "Don't touch the ceramic capacitors and inductors of resonant circuits".

May experience for more then 40 years says, "Look for bad electrolyt and paper capacitors, resistors and semiconductors or valves." Capacitors lost capacity or making short circuit and resistors make high resistance.

If only one or more tuning ranges are not function look for the selector switch. The connectors will be dirty or oxidized. If you have valves inside, look for the sockets and the connection pins. They also will be oxidized.

Regards

Rainer

 

[tpetar]

I am working on a 29 year old transceiver, the tuning circuit of which seems to be out of order (the rest is fine). The tuning circuit is made of ceramic capacitors and variable ferrite core inductors. Is it possible that these components have lost their values over time resulting in the failure of the tuning circuit?

Inductors with core have thermal aging for sure. This usually occurs at higher temps on longer times.

But that is not case here.



Core Loss Increase Due to Thermal Aging in Iron Powder Cores
**broken link removed**


;-)

 

[picgak]

capacitors ages very faster compared to inductors. By inductor aging I mean there can be aging in the insulation covering the inductor wires and results in breakdown