VK Logger Ham Radio Forum Archive

Some crude transmitter experiments

Transmit a TV picture with a 1N4148 diode (and little else).

Quick & dirty vertical antenna for 6m

Just a reminder that Melbourne QRP by the Bay is coming up next month – Saturday 2 February at 3pm. Melbourne QRP by the Bay is an occasional gathering of homebrewers, QRPers and portable operators. Normally between about 15 and 30 people show up for a very convivial couple of hours. Bring yourself,...

The most recent project. Tested on WSPR, with beacons and SSB DX.

Not the workbench but the ground.

Test was to show that a cheap handheld, some wood, some wire and an LED can work as a lecher line on 70cm and measure frequency to a 2% accuracy.

Why it's sometimes worth staying until the end

Does it work?

Horrendously inefficient but it works

40 & 80m. Details at http://vkqrpclub.org/qrp_new/qrp1_conte ... TwP1MjjzWU

Changing a quartz crystal's frequency with sandpaper



And attacking a ceramic resonator

A transmitter and receiver from Zachtek

A contact with a wire antenna on the ground. It will work but the report won't be good. And only stations with a low noise floor will hear you.

https://www.youtube.com/watch?v=LmJk3hFE8G0

It follows a previous experiment done with WSPR.

https://www.youtube.com/watch?v=Zk1Yg5-xELw

Variable inductor from corflute material - in this case used for a QRP antenna coupler

https://www.youtube.com/watch?v=NyKu0qKVA1I

The Wikipedia quote is likely a relic of 1980s - early 1990s era hobby computer culture (eg bulletin boards, shareware, furtive late night data transfers on phone lines etc). That culture was steeped in technological elitism and flame wars over scarce storage space and bandwidth. Those conditions ho...

Strange sound effects possible with SDRs, wireless microphones and drone machines (the non-flying variety).

https://www.youtube.com/watch?v=N47uxPTGoIc

Using a cheap superregenerative UHF data receiver module and audio amplifier to receive 70cm AM signals on about 434 MHz. https://www.youtube.com/watch?v=7SoXrV6nKBQ 7SoXrV6nKBQ Possible improvements include adding a cavity filter to narrow selectivity (and avoid the heavy activity on 433.92 MHz) an...

Links to articles on Acitron transceivers in AR magazine (available online)

Sept 1968 http://armag.vk6uu.id.au/1968-september-AR.html
July 1971 http://armag.vk6uu.id.au/1971-july-AR.html
Nov 1971 http://armag.vk6uu.id.au/1971-november-AR.html

The effect of adding a 1 transistor Q-multiplier to a crystal set.

https://www.youtube.com/watch?v=4ix5gNrJy2E