variable capacitors

Thread Starter

PRS

Joined Aug 24, 2008
989
Does anyone know where I can find variable capacitors for sale? Mouser and Jameco seem to have quit selling them! :eek:
 

Thread Starter

PRS

Joined Aug 24, 2008
989
Thank you very much. Just what I was looking for. I used to get parts from an old technician at St Vincent de Paul. He'd been doing it for decades. He had barrels full of variable capacitors, tubes, everything else. The store sold them very cheap. When he died all that stuff disappeared.
 

Thread Starter

PRS

Joined Aug 24, 2008
989
Radio tuners and oscillators -- about 100 pF(max) and up to about 365 pF.
 

Thread Starter

PRS

Joined Aug 24, 2008
989
Thanks but I didn't see anything there. Check out KL7AJ's link. See those beautiful aluminum variable capacitors? That's what I want! I used to have lots of them, bought them for peanuts. Now look at them, 10 dollars apiece! Sheesh! ;)
 

PackratKing

Joined Jul 13, 2008
843
In line with this, what is the largest varicap available.........looking .....er....hoping to find one covering 1 - 50 microfarad.

These would be rather large and expensive I would imagine.....??
 
Last edited:

Ron H

Joined Apr 14, 2005
7,012
In line with this, what is the largest varicap available.........looking .....er....hoping fto find one covering 1 - 50 microfarad.

These would be rather large and expensive I would imagine.....??
I Googled "large variable capacitor". I found this on the first page of results.:D
I am dubious. If you get this to work, please post your results here.
 

beenthere

Joined Apr 20, 2004
15,808
I think the construction article I read in a 1920's magazine did pretty well using the foil and cellophane from a pack of Luckies to make the tuning capacitor. It had the coil wound properly on a box (cylinder?) of oat meal.
 

Thread Starter

PRS

Joined Aug 24, 2008
989
You might have to make your own. With a name like PackratKing, I should think you can improvise in experimental fashion with some of the stuff you've got around the shop! ;)
 

Thread Starter

PRS

Joined Aug 24, 2008
989
I had encountered that same article earlier this year, and made hardcopy. The way its set up, the cap isn't very useful -- too fragile, it won't retain its parameters due to evaporation and alignment problems. But it is something to think about. An inventive person might be able to at least put the principle to work.
 

Thread Starter

PRS

Joined Aug 24, 2008
989
That sounds interesting. Lately, I've had the idea of making a variable inductor using a ferrite rod to pass through the tunnel of the winding of an air coil. I thought maybe a crank handle at the end of a screw, kind of like on a lathe, would be a good way of tuning the radio I'm building. A pointer for the radio dial would ride the screw. Just a thought.
 

PackratKing

Joined Jul 13, 2008
843
You might have to make your own. With a name like PackratKing, I should think you can improvise in experimental fashion with some of the stuff you've got around the shop! ;)
You are correct in your assumption.........and you would likely be agast to see some of the stuff I come up with.

.......where I work.... is primarily an HVAC repair shop, repairing any and all equipment to do with oil or gas fired Industrial and residential heating, pumps, motors of all sizes, Industrial and consumer power tools etc. Doesn't matter if it is current - to - obsolete technology, if you can get it in the door, we can usually make it work again.

Our "power supply board" runs high and low voltage 3-phase, 240 split, or humble 120 vac, or dc from 240 volt on down, through a selection of switching controls, that feed an " alligator-clip suicide lead " with which we can power virtually anything.............

an Honest-to-God packrats' paradise !!
 
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