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Author Topic: Zinc Negative Resistance Makes 40 Meter CW Transmitter  (Read 204 times)

Offline ChrisSmolinski

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Zinc Negative Resistance Makes 40 Meter CW Transmitter
« on: June 18, 2019, 1312 UTC »
This project pictured above is like a crystal set in reverse - a 40 meter (7.035 mhz) CW transmitter instead of a receiver.

This 50 microwatt (.00005 watt) transmitter could easily be heard from a distance of 5 miles (straight line GPS distance).

The zinc negative resistance device is easily made by putting a piece of galvanized sheet metal into a propane flame until it gets red hot and flares up with a bright white flame and sparks.

http://sparkbangbuzz.com/zinc-40-meter-xmtr/zinc-40-meter-xmtr.htm
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline ThaDood

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Re: Zinc Negative Resistance Makes 40 Meter CW Transmitter
« Reply #1 on: June 18, 2019, 1739 UTC »
WHOA!!!! NICE!!!! I see some nice Part #15 applications here. While we're at it, here's the 20M one, along with an 80M link,    http://sparkbangbuzz.com/zinc-20-meter-xmtr/zinc-20-meter-xmtr.htm
From DC to light, I take a huge spectrum bite!

Offline i_hear_you

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Re: Zinc Negative Resistance Makes 40 Meter CW Transmitter
« Reply #2 on: June 19, 2019, 1533 UTC »
That's pretty cool.  All it's missing is some sort of homemade man-powered battery. While it isn't homemade, a thermoelectric generator could probably be used with a campfire or sunlight scheme for grid-down use with this TX.