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.

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

20190119 - SKCC special event

posted Jan 18, 2019, 4:38 PM by Onno Benschop

Charles NK8O shares with us:

Here is the list of standings for the special event.  You can easily see there are folks much more dedicated (fanatical) than I am.   I still need KL7 (Alaska), South America, and Africa for a full sweep of continents, but I have all 10 call areas on 40 & 80 meters.  Hawaii is the best “catch” for me with the state logged 80-15 meters, including WARC bands. 
#nk8o #skcc #dx #cw

20190105 - F-troop discussions

posted Jan 4, 2019, 5:21 PM by Onno Benschop

Many topics were covered during the net.

Ian VK6TWJ reminds us of the SSTV net:
  • Every Tuesday at 20:00 WST on 146.625 MHz, hosted by Glen VK6IQ.

Damien VK6FDEC reminds us that this week is the Scout Jamboree in Talem Bend South Australia. 
  • Look for VK3JAR for Echolink and IRLP connections and frequencies.

Charles NK8O shares with us some band filters / notch filters that can be used during a contest:

Brian VK6FFRA shares with us some information from Bob Rice about antennas:
Two videos by Bob Rice on Viemo.
    1. Portable horizontal multi-band dipole
    2. 7-band semi-vertical trap antenna
Included on these videos are some home-brew construction ideas for
    1. Capacitors using printed circuit boards (Vertical antenna)
    2. Coils (Horizontal) and a
    3. Dip meter using a circuit/BNC connector (Vertical) and an SWR meter. (Featuretech model which is the same one that I have hence the interest).
All are very neat and tidy homebrews!
Printed info on multi-band semi-vertical antenna

John VK6RX points us at a WIA submission to the ACMA about adding functionality to the Foundation License. It includes provisions for:
  • Permit use of digital transmission modes
  • Relax permitted transmission bandwidths
  • Add access to more frequency bands
  • Increase maximum power from 10 W to 50 W pX
  • Relax conditions to enable limited home construction and use of re-purposed transmitting equipment
  • Identify a 6-character callsign range to replace the current 7-character callsigns
The submission is on the WIA website:

There was discussion about horizontal vs. vertical noise. I've explained it previously here:

John VK6RX has just connected the VK6-HUB to the Brandmeister network which means that if you're on DMR you can now participate in F-troop. Details are here:
#vk6twj #nk80 #vk6ffra #vk6rx #wia #sstv #echolink #irlp #fiters #homebrew

20181229 - Bandpass Filter

posted Dec 28, 2018, 4:34 PM by Onno Benschop

Randall VK6WR suggests the following VHF bandpass filter:

20181215 - SDR Radios

posted Dec 14, 2018, 4:41 PM by Onno Benschop

Discussion during the 'net included several suggestions for getting started with SDR:

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