Friday, August 8, 2014

Search and Rescue Radio in a box

Arlene is a member of the Incident Support Team (IST) for King County Search and Rescue (KCSAR).  She recently decided to purchase the standard KCSAR radio, which is a Kenwood TK-780.  Initially, she didn't want it permanently installed in her Toyota pickup, so I suggested putting it in a small box.  Apparently, I must really like building radio-in-a-box setups because below you will find photos of  the end result.

Before that here are some of the details that went into making the project.  Total build time approximately 60 minutes, except for the travel time to Harbor Freight where I purchase a small "aluminum" case on sale for just over $11 (always use your coupons!).  It has only an aluminum frame.  The black portions between the frame members are made of a fiberboard that comes very close to a highly compressed cardboard.  Yet, they advertise this as an aluminum case.

Case measures 7 1/2 by 11 1/2 by 4 1/2 outside dimensions.  Inside dimensions are 6 3/4 by 11 by 4 1/8.
Granted this isn't very big, but Arlene's request was to make it small enough to easily carry and store anywhere in her pickup. I believe that was accomplished, because it is in fact "Arlene Approved".

The weight needed to be light and to that end the entire setup weighs a mere 5 pounds, 6.5 ounces.  Optionally, there is enough room to include a direct connected 12 volt 7 AH battery, however this would nearly double the weight since the battery weighs  5 pounds, 4.4 ounces.  Although Arlene tested the "carry" of this option and said this would not be a problem for her, if needed.

A small aluminum bracket was used to raise the radio enough so it could be angled to make the display easily readable and the microphone jack is above the box edge.  The bracket was from an old tower PC, it was a 5 1/4 inch drive bay filler.  This came out of my projects junk box, so it was free.  The bracket is pop-riveted to the bottom of the case.  The radio included a mobile bracket, which was then screwed to the aluminum bracket.  That was the entire construction process.

Radio is attached to the mobile bracket, power and chassis ground cables were routed so can be used with the power accessory plug and chassis ground connection installed in the pickup, respectively.

The setup for in pickup operation is as follows:

  1. Open box, drag out the antenna pigtail, Anderson Powerpole connectors for power and chassis ground
  2. Attach antenna, power and ground wires already in pickup to the matching box items
  3. Turn on pickup and then radio
  4. Listen and talk!
The photos below can be enlarged with a click.  Purchased items were Harbor Freight case, KCSAR radio, Anderson Power Poles and  battery (from earlier project).  Recycled part was the aluminum bracket.

View from handle side, standing on hinged side.

View with box on base.

Opened box with basic setup.

Cables shown are VHF antenna pigtail, fused power lead,
chassis ground and microphone.

Optional battery is inserted to the right of the radio.

Packed for case closure, with optional battery.