du1vss (D.I.Y.)

It's all about ham radio. Although some of my projects involved transmitters, rf amplifiers and antennas that operate outside the ham bands, these things are solely for educational purpose only and experimentation.

Sunday, December 18, 2016

7MHz VFO using 3.58MHz Ceramic Resonator

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This project is a 7MHz vfo that uses a 3.58MHz ceramic resonator. The oscillator output is fed to a frequency doubler but the output of...

1 comment:

Tuesday, April 5, 2016

QRP RF Voltmeter from your Junk Box

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A useful tool that can be easily crafted out from your junk box is this rf voltmeter. I discovered this circuit online and created a pr...

Sunday, March 20, 2016

40M DSB Transceiver

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The circuit described here is actually a variation of the MDT40 project by VK2DOB, A simple double side band suppressed carrier (D...

7 comments:

Tuesday, December 22, 2015

VHF RF Choke

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Home made VHF rf choke. It has a typical value of 0.3uH made by winding 15 turns of 0.2mm enamel wire over a high value resistor (27K 1/2...

Thursday, September 17, 2015

FM Broadcast 55W Push-Pull RF Amplifier

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This prototype rf amplifier uses two 2SC2640 VHF power transistor wired in push-pull configuration. The 50 ohm impedance of the input...

12 comments:

Friday, September 4, 2015

Quarter Wave Stub Demo

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One of the trick that you can perform to your friend (not a Ham) is this quarter wave stub. Looking at the DC (direct current) point of vi...

1 comment:

Wednesday, August 26, 2015

Telephone Audio Coupler

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This circuit is a simple one, audio signal from the telephone line is sampled by the 600:600 ohm isolation transformer. The combination ...

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About Me

hevirred: Hello, I'm Vir, a ham radio operator with a callsign of DU1VSS. I hope you find this blog useful and interesting. Feel free to send me an email if you have questions about my project. Thank you and 73. hevirred@gmail.com

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