During the weekly F-troop there are mentions of software, websites and solutions that are worth taking note of. This website attempts to document them.

20190309 - Battery

posted Mar 10, 2019, 9:01 PM by Onno Benschop

Mel VK6BMM shares with us a 1000A jump starter kit which might come in handy for your next portable field day:

20190309 - QRP Labs Linear Kit

posted Mar 8, 2019, 4:52 PM by Onno Benschop   [ updated Mar 8, 2019, 4:57 PM ]

John VK6JB reports that he's built his first Linear Amplifier with great success. He comments that it's probaby a good kit for an intermediate builder.
#vk6jb #qrp #build #kit

20190301 - Battery Life Estimator

posted Feb 28, 2019, 7:26 PM by Onno Benschop

If you've ever gone portable with a bank of batteries with your fingers crossed that "you have enough", here's a calculator that can take away some of the guesswork, the W1PNS / WAØITP / AB8XA Battery Life Estimator:
#fieldday #battery #qrp #dutycucle #charging #vk6flab #portable

20190223 - Homebrew Adventures

posted Feb 23, 2019, 11:45 PM by Onno Benschop

Charles NK8O has been busy. He shares with us the following:
One day, I will run out of money, time, or brains.  One day.

Last week’s project: to get the displays sorted on the 40-30-20 meter Hilltopper radios.  I learned a little more about Arduino programming.  But only a little.  Now I need to figure out what sort of connector I can use to make the display optional, and create an outboard case for the display.  That adds flexibility to the radio for portable ops w/ w/o display.

Today’s project: 20 watt dummy load from QRP labs.  Post any, all, or none.


Charles - NK8O

Display for the Hilltopper-40 with a few added features.

Hilltopper 30 with display and programming cable attached.

20 meter Hilltopper with display and progamming cable.

20 watt dummy load assembly

and completed

And showing that it works as advertised with a 1:1 SWR, showing a 50 ohm load.

#homebrew #nk80 #hilltopper #dummyload #qrp

20190216 - Home brew Adventures

posted Feb 15, 2019, 4:29 PM by Onno Benschop   [ updated Feb 15, 2019, 4:30 PM ]

Charles NK8O shares with us his activities this week:

Four State QRP Hilltopper 20, modified for 30 meters, display added.  Custom offset at 600 Hz instead of 800 Hz.  Several other code additions, including tuning steps of 500 Hz, 100 Hz, and 10 Hz.  Tones notify which step, 3 dits = 500 Hz, 2 = 100 Hz, one = 10 Hz.  Still need to devise a case for this chimera.

40 meter bandpass filter, first of several.  Needs connectors and testing for bandpass edges, in-band and out-of-band attenuation.

HamRadio Workbench Dummy Load, with modified code.  Resistors sufficient for 20 watts, briefly.  Scope was connected to plot actual PEP voltage against ADC output.

Diode output and ADC in the Arduino are far from linear.  This is correct at about 5 watts but not so much at 1 watt or 10 watts.  Maybe a look-up table would be a better solution?

#nk8o #hilltopper#qrp #homebrew

20190209 Gridsquare Locator

posted Feb 8, 2019, 4:45 PM by Onno Benschop

If you need to figure out what "Locator" location you're at, also known as "Gridsquare", or "Maidenhead", you can use several tools:
#nk8o #gridsquare #maidenhead #contesting

20190202 - Optically Isolated Digital Audio Interface

posted Feb 1, 2019, 8:08 PM by Onno Benschop   [ updated Feb 1, 2019, 8:14 PM ]

Charles NK8O shares with us a kit that is available via eBay:
Nothing new about this technology, it consists of two 600 ohm line transformers for audio input and output from your pc to your transceiver, and an opto-coupled push to talk circuit that works off of an RS-232 port on your computer.
  • Transformer coupled audio eliminates ground loops and AC hum on your signal
  • Opto Coupled push to talk circuit also eliminates ground loops and false triggering of your PTT lines.
  • Very small size, only 2 1/16” x 1 3/8” x .625” high, can be incorporated inside of many radios, with only your RS-232 cable coming outside of the radio.
  • Weighs less than 3 ounces
  • High quality FR-4, solder masked, silk screened Printed Circuit Board
  • Compatible with most modern ham radio transceivers.
Shipping is a tad expensive to Australia, $35.05

Same board with some more detail is here:

#audio #interface #digital #isolation #opto #nk8o #ebay

20190126 - Commercial Radio Users Net

posted Jan 25, 2019, 11:19 PM by Onno Benschop

Run every Wednesday at 5.30pm WST on 3640 Upper Side Band so that some of the commercial radios can come on.  

Kim VK6TQ runs a horizontal full wave loop on 80m about 10 meters above the ground and 400 Watts to help the people hear him over their noise floor in Perth.

Kim goes on to say: "We try to have some technical topics and explain things in non technical terms."

Anybody can call in.

Source: Kim VK6TQ

#net #80m #wednesday

20190126 - Brian VK6FBDA (SK)

posted Jan 25, 2019, 5:07 PM by Onno Benschop   [ updated Jan 25, 2019, 8:48 PM ]

Harry VK6YBZ called in to advise that Brian VK6FBDA became a silent key a few days ago. He was diagnosed with leukaemia before Christmas and given 12 months.

Received via email:

Please see attached the funeral notice for Brian Atkins VK6FBDA who passed away two days ago.

I am advised by his wife that any of his ham radio friends will be welcome at the funeral as advised in the attached notice from the West Australian newspaper of today.

Regards Harry VK6YBZ 

#sk #vk6fbda

20190126 - Hole Punch

posted Jan 25, 2019, 5:05 PM by Onno Benschop

If you need to create a D-shaped hole in a chassis for a connector, here are some suggestions:
  • Drill a hole that's smaller and use a half-round file to make the hole the right size.
  • Use a dremel tool, but be prepared to bring band-aids and disinfectant.
  • RS-Components sells Punch and Die combinations
  • Greenlee makes hole punches and they are available via Amazon.
#diy #building

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