2. Amateur Radio VA3KV
  3. VA3KV QRP Projects

AT Sprint 2 Project

The ATS 2 is a portable low power HF amateur radio transceiver for back packing. It utilizes small plug-in modules to operate on 4 HF bands using Morse code. This kit was provided by Steve Weber, KD1JV, a few years back and he has more recently released newer versions called the ATS- and ATS-4 (see http://kd1jv.qrpradio.com/) (scroll down on this page to see all the pictures)
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  • The AT Sprint 2 kit was provided by Steve Weber, KD1JV. <br /> Workbench Setup: I ended up just using a toothpick to hold down the surface mount parts. To solder surface mount parts, you have to pre-solder or tin one of the pads on the board where a part will be installed. My method is to hold the part lightly in place with a toothpick over top of it, align it, and reheat the pad to secure the part to the board.

    The AT Sprint 2 kit was provided by Steve Weber, KD1JV.
    Workbench Setup: I ended up just using a toothpick to hold down the surface mount parts. To solder surface mount parts, you have to pre-solder or tin one of the pads on the board where a part will be installed. My method is to hold the part lightly in place with a toothpick over top of it, align it, and reheat the pad to secure the part to the board.

  • The most delicate part is the AD9834, but it turned out to be pretty easy to install. If you have solder bridges, just use solder wick to remove excess solder. The AD9834 is the heart of the AT Sprint II and generates an exact stable frequency anywhere on the band.

    The most delicate part is the AD9834, but it turned out to be pretty easy to install. If you have solder bridges, just use solder wick to remove excess solder. The AD9834 is the heart of the AT Sprint II and generates an exact stable frequency anywhere on the band.

  • This is the completed main board. The time consuming part was yet to come: winding the toroids for the band modules.

    This is the completed main board. The time consuming part was yet to come: winding the toroids for the band modules.

  • Another view of the main board...

    Another view of the main board...

  • These toroids are indeed tiny. I started with the most difficult one, the 80 meter band transformer. The primary winding had 60 turns, but its so small its impossible to verify the turns count. Of course, I lost count and had to take a digital photo of it and blow it up on the computer to a size where I could see the windings and count them. I had to add a couple turns. After that I had to wind the secondary as well. This one coil took me at least an hour to do including tinning the leads.

    These toroids are indeed tiny. I started with the most difficult one, the 80 meter band transformer. The primary winding had 60 turns, but its so small its impossible to verify the turns count. Of course, I lost count and had to take a digital photo of it and blow it up on the computer to a size where I could see the windings and count them. I had to add a couple turns. After that I had to wind the secondary as well. This one coil took me at least an hour to do including tinning the leads.

  • Completed Band Modules (the 30 meter module is installed in the radio)

    Completed Band Modules (the 30 meter module is installed in the radio)

  • I keep a tooth pick taped on the inside of the case as a handy tool to pry off the band module when I want to change bands. Six triple A batteries gives me over 2 watts out. If I use the gell cell, I have a special cable made up, using 3 diodes in series, to lower the gel cell voltage to slightly over 12 volts. This rig is not designed to use a power source greater than 12 volts. Liberal use of tape prevents the battery cases from shorting anything on the main board.

    I keep a tooth pick taped on the inside of the case as a handy tool to pry off the band module when I want to change bands. Six triple A batteries gives me over 2 watts out. If I use the gell cell, I have a special cable made up, using 3 diodes in series, to lower the gel cell voltage to slightly over 12 volts. This rig is not designed to use a power source greater than 12 volts. Liberal use of tape prevents the battery cases from shorting anything on the main board.

  • KD1JV, Steve, did a great job silk screening these little cases. The rig looks good.

    KD1JV, Steve, did a great job silk screening these little cases. The rig looks good.

  • Here is my portable package coming together.

    Here is my portable package coming together.

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