Make Air Variable Capacitor

December 16, 2019

Transmitting air variables are becoming scarce and expensive even at hamfests and the kit capacitor from tentec is over 5000. When i found out that i have no variable capacitor in my pile of junkscavenging one from an old radio was not an option.

Variable Capacitor Wikipedia

Py1ahd Alex Alexandre Grimberg Py1ahd

What Makes A Good Variable Capacitor For Crystal Radios

Patrick did just that with his home made capacitor in this case of a few tens of pf and suitable as a low power trimmer capacitor or in a single chip fm radio.

Make air variable capacitor. The base design could be expanded into multi gang capacitors differential capacitors and with some modified stators even butterfly capacitors. Air capacitors are capacitors which use air as their dielectric. This is a viable alternative for medium power projects.

Air variable johnson panel mount. With only 24 plates it had about 4500 pf. Air variable panel mount misc mfg antenna load.

Mica caps for broadcasting. Since most of new radios uses analog tuning. It is very easy to get a very high capacitance and a good highlow capacitance ratio.

Build your own air variable capacitors. How to make your own variable tuning capacitor with a range of 5 pf to 27 pf this multi turn capacitor can be constructed using only six items. Thats a great article using common hardware store goods to build an otherwise hard to find component.

Hammerlund millen bud capacitors. Variable tuning load. Plate coupling bypass.

4l x 3 34 sq body 38 diameter shaft extends 2 14 beyong body on each side. It had a minimum of about 90 pf for a ratio of 501. Heavy duty electrolytic filter.

For those who enjoy building radio projects you may have noticed that variable capacitors are not as available as they once were. Fortunately a variable capacitor is a surprisingly simple device and one you can make yourself if you are of a mind to do so. 21 820 pf uuf at 1kv.

Air variable capacitor from scrap aluminum sheets. Air capacitors can be made in a variable or fixed capacitance form. This compares with only 15 365 pf for commercial variable capacitors of roughly the same size.

Expoxy dipped tantalum chip. The simplest air capacitors are made of two conductive plates separated by an air gap. Extremely loose bearings suggesting a geared or motorized connection.

I was building a crystal set for my son but it came to a halt. And the ones wit.