Need to find an old variable capacitor

  • #1
434
19
hello
i buy allmost all thing needed, for buil you own radio circuits 2013,
but in electronics shop he told me , there are old, you can find it only in old radio
he cant help, those components dont sell anymore,

maybe somebody can help me how to find online those component

VC1: two-gang variable capacitor: 140pF, 60F = 2
VC1: 140pF RF and 60pF oscillator = 2
VC1: variable capacitor twin gang 270pF and 270pF = 2
VCI: TWO SECTION VARIABLE CAPACITOR 140pF ,60pF = 2
 

Answers and Replies

  • #2
berkeman
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hello
i buy allmost all thing needed, for buil you own radio circuits 2013,
but in electronics shop he told me , there are old, you can find it only in old radio
he cant help, those components dont sell anymore,

maybe somebody can help me how to find online those component

VC1: two-gang variable capacitor: 140pF, 60F = 2
VC1: 140pF RF and 60pF oscillator = 2
VC1: variable capacitor twin gang 270pF and 270pF = 2
VCI: TWO SECTION VARIABLE CAPACITOR 140pF ,60pF = 2
If you haven't been able to find the values you need in the dual-gang configuration, have you considered getting a dual-gang capacitor that can be taken apart so you can modify it to the values you need?

https://upload.wikimedia.org/wikipe...le_Capacitor.jpg/220px-Variable_Capacitor.jpg
220px-Variable_Capacitor.jpg
 

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  • #6
berkeman
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Sorry, but i dont see any variable capacitor in that page
That's weird. That's what that whole selection of dual-ganged capacitors is all about!

What do you see at the link?
 
  • #7
434
19
That's weird. That's what that whole selection of dual-ganged capacitors is all about!

What do you see at the link?
sorry dont misonderstand me, i dont know about those variable i know just capactior and trimmers
have a nice wekend.
 
  • #9
davenn
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sorry dont misonderstand me, i dont know about those variable i know just capactior and trimmers
have a nice wekend.

you asked about variable capacitors

you were shown whereto get them and what sort of prices they will cost
what didn't you understand ?


Dave
 
  • #10
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Fwiw the google shopping link returns no hits for me (as in google couldn't find anything).
 
  • #11
berkeman
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Sorry, but i dont see any variable capacitor in that page
Fwiw the google shopping link returns no hits for me (as in google couldn't find anything).
Interesting. I wonder if the search is personalized to me or something. Anyway, just type what I did in the search bar and click on Shopping links. You should get what I see...

dual-gang potentiometer search.jpg
 

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  • #13
phinds
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Fwiw the google shopping link returns no hits for me (as in google couldn't find anything).
Do you mean you clicked on the link provided and didn't see any or do you mean you did your own search and didn't get any?
 
  • #14
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hello thanks to everybody...... i solved i found,
but now i am trying to learn varicap

thnxxxxxxxxxxxxxx
 
  • #15
sophiecentaur
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@michael1978 Did you try eBay? There are many variable capacitors for sale (vintage, mostly). You just need to sort through the ads and contact sellers to see if they have the values you need.
When you are searching for an item, you need to take time and spread your net wide. Why not also look for a vintage radio advertised 'for spares'?
 
  • #16
434
19
@michael1978 Did you try eBay? There are many variable capacitors for sale (vintage, mostly). You just need to sort through the ads and contact sellers to see if they have the values you need.
When you are searching for an item, you need to take time and spread your net wide. Why not also look for a vintage radio advertised 'for spares'?
thank you very much, i solved, but the man in electronics shop he told try to learn varicap, because they are not in use any more.
greetings.
 
  • #17
sophiecentaur
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thank you very much, i solved, but the man in electronics shop he told try to learn varicap, because they are not in use any more.
greetings.
That's his opinion but varicap is a different technology. It all depends what you want to achieve. Starting with a very basic receiver would give you a chance to actually understanding about receivers. There is so much 'hidden' inside modern electronic components. The air spaced variable C is one of the few components that is totally open to view. You can also see all the structures in a simple thermionic valve - but that may be too much trouble to learn about.
 
  • #18
rude man
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This is making me (age 77) all nostalgic! So boring nowadays with transistors replacing those beautiful glowing vacuum tubes, and air-gap dual or 3-gang variable air capacitors rotating merrily back & forth compared to lifeless varactors! I guess all that remains is the antenna loop & speaker - or did the voice-coil speaker also bite the dust?

With tears welling up in my eyes I think of the beautiful Zenith AM radio I bought used in 1958 with a tuned rf stage (3-section variable capacitor!) Dependably picked up a Mexican-based english-speaking station in Boston! I ruined it trying to convert it to short-wave. Follies of youth! I could kill myself even now thinking about that beautiful Zenith. :H Nearly bought one like it on ebay even though I'd never listen to it. Might still look for one again someday.
 
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  • #19
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That's weird. That's what that whole selection of dual-ganged capacitors is all about!

What do you see at the link?
I see this:
cap.png
 

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  • #21
hello
i buy allmost all thing needed, for buil you own radio circuits 2013,
but in electronics shop he told me , there are old, you can find it only in old radio
he cant help, those components dont sell anymore,

maybe somebody can help me how to find online those component

VC1: two-gang variable capacitor: 140pF, 60F = 2
VC1: 140pF RF and 60pF oscillator = 2
VC1: variable capacitor twin gang 270pF and 270pF = 2
VCI: TWO SECTION VARIABLE CAPACITOR 140pF ,60pF = 2

https://www.google.com/search?q=var...nmKTZAhURtlMKHU8KCyEQsAQImwE&biw=1594&bih=848

https://www.aliexpress.com/item/Fud...f7d0OBM8D5Cbtcy14wt1aheCjEf0-WtxoC_T8QAvD_BwE

http://www.surplussales.com/variables/airvariables/AirVar2.html
 
  • #22
358
565
Many old amateur radios were coil-tuned, without any variable cap, like this (note the regeneration):
mrb465_30-500x322.gif

The "L1" inductor is rotating inside the "L2" like this:
image?id=849510600454&t=0&plc=WEB&tkn=*4ubipGS3FeMb-4oaChV1igZrk3A.jpg

- to me, it's even more fun than a variable capacitor . . .
There is a big advantage: You can connect the outdoor antenna via a long coaxial cable, thus avoiding the indoor electromagnetic noises. The cable capacitance then participates in the input LC without reducing the tuning range.
 

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  • #23
rude man
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Many old amateur radios were coil-tuned, without any variable cap, like this (note the regeneration):
View attachment 220290
The "L1" inductor is rotating inside the "L2" like this:
View attachment 220291
- to me, it's even more fun than a variable capacitor . . .
There is a big advantage: You can connect the outdoor antenna via a long coaxial cable, thus avoiding the indoor electromagnetic noises. The cable capacitance then simply works as the input LC capacitance without reducing the tuning range.
Pretty, in fact mind-blowing, but perhaps a bit unwieldy for a table-top radio :smile: . Did or would this kind of tuning work at 550-1600 KHz and without an external antenna?
 
  • #24
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565
would this ... work at 550-1600 KHz?

Yes that circuit was exactly for those frequencies, when without the C2.
. . .
But the tuning coils themselves did not work as antenna, they typically were placed inside the metal box:
odnolampovyi_dvuhkaskadnyi_priemnik_2.jpg
 

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  • #25
335
44
Interesting. I wonder if the search is personalized to me or something. Anyway, just type what I did in the search bar and click on Shopping links. You should get what I see...

Seems to be Google Shopping issue on Firefox Mobile. Works in Chrome and Firefox on my desktop computer. Searching for other things returns many hits on FF mobile tho... weird.
 

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