XPost: rec.radio.amateur.moderated
amateur radio - Hackaday
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Surplus Syringes Make Satisfactory Tuner for Amateur Radio Experimentation
Posted: 14 Aug 2021 10:01 AM PDT
https://hackaday.com/2021/08/14/surplus-syringes-make-satisfactory-tuner-for-amateur-radio-experimentation/
Amateur Radio as a hobby has a long history of encouraging experimentation using whatever one might have on hand. When [Tom Essenpreis] wanted to use
his 14 MHz antenna outside of its designed frequency range, he knew he’d
need an impedance matching circuit. The most common type is an L-Match
circuit which uses a variable capacitor and a variable inductor to adjust
the usable frequency range (resonance) of an antenna. While inefficient in
some specific configurations, they excel at bridging the gap between the 50
ohm impedance of the radio and the unknown impedance of an antenna.
No doubt raiding his junk box for parts, [Tom] hacked together a variable capacitor and inductor using ferrite rods from AM radios, hot glue, magnet wire, copper tape, and some surplus 60ml syringes. You can see that he
ground out the center of the plunger to make room for ferrite rods. Winding
the outside of the syringe with magnet wire, the alignment of the ferrite
can be adjusted via the plunger, changing the characteristics of the
element to tune the circuit. [Tom] reports that he was able to make an
on-air contact using his newly made tuner, and we’re sure he enjoyed
putting his improvised equipment to use.
If Amateur Radio isn’t your thing, then maybe we can entice you with this syringe based rocket, syringe actuated 3D printed drill press, or vacuum syringe powered dragster. Have your own hack to share? By all means, submit
it to the Tip Line!
--- SoupGate-Win32 v1.05
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