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William Waters III - N7IPY

HF-Packer Amp - Remake

The HF Packer Amp kit by Virgil Stamps K5OOR is a small multiband RF Amplifier designed to add a little more ‘punch’ to a QRP radio like the FT-817.  It comes as a kit with all the parts and in the current version is built into a sturdy enclosure.  The original metal enclosure for the earlier models was a little to flimsy for me so I set out to remount the electronics into a more sturdy enclosure and add a few improvements along the way.

My HF-Packer Amplifier is an earlier version with a lightweight Aluminum chassis that has a pop-together upper and lower half, no screws, and a large heat sink on the top.  I wanted it to be a little more sturdy and to remove the jagged heat sink and general make it more finished looking.  
I used an extruded aluminum enclosure (same one I used for the DSTAR Hot Spot project) to mount the amplifier in.  I could not use the original heat sink as it was too thick to fit within the enclosure, so I made my own.  Using some scrap copper sheet, I fabricated a simple heat sink that would allow heat to be dissipated through the entire Chassis and also radiate heat in the air stream of a small chassis mounted fan.  I used heat transfer compound between the lower chassis and the new heat sink.   I inverted the main amplifier stack with the RF transistors now at the bottom of the chassis.  This worked well as there was enough slack in the interconnecting cables to and from the filter board.  What I did:
  • Changed heat sink design and inverted Amplifier stack
  • Added small fan
  • Added a front panel CW/SSB delay switch
  • Added a true On/Off front panel switch with power LED
  • Added fan power control to the Stand-by / Amp On power switch
  • Added an Anderson Power Pole power connector to the back panel

PackerHeatSink.JPG
The Copper Heat Sink in place.  It is made from copper shit, cut and bent to make 2 fins that are in the air flow of the fan.
PackerParts.JPG
The major parts of the Amplifier priot to final wiring and assembly.
PackerFinishedOpen.JPG
The assembled Amp ready for testing.
PackerAndFT817.JPG
Amp & FT-817 in test configuration with dummy load.

A new feature for me on this project was the front panel graphics I used.  I did not want to use stick on letter labels nor did I want to use the old rub on lettering so I tried something new.  I designed the labeling on the computer than transferred it to a one piece label for the front panel.   
To do this project I used a program called Visio and designed the simple graphics then printed them to a transparent label material from 3M I found at the local office supply store.  Prior to applying the new label I panted the front panel part with a flat white paint so the Letters would be white when the label was applied.  While that was drying I spray panted the label with clear enamel paint to protect it.  After it dried I then cut out the holes with my Exact-o knife and carefully applied the stick-on label to the front panel.   Then I trimmed the label and did any touch up with a Black sharpie pen.  The final step was to re-paint the clear enamel making sure as to seal the label edges so it will not peel off. 
Over all the project turned out better than I had planned.

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(C) 2007 - 2014  William Waters   Last Updated February 1, 2014