PANDORA

PANDORA ENCLOSURE CONCEPT

The project leader for the Pandora Enclosure is Ben Hall [1], KD5BYB.

BACKGROUND

The Pandora name is taken from the old story of Pandora’s Box. One particular telling of the story states that Pandora’s Box was a holding vessel for all of the misfortunes of mankind. However, Pandora opened the box and all the misfortunes came out. However, Pandora was able to close the box quickly, and hope stayed inside. It is hoped that since Pandora has let all the evil out of the box with hope remaining inside, our Pandora’s box will have already had all of “smoke” let out, leaving only hope and goodness inside.

THE PANDORA CONCEPT

The Pandora Enclosure is actually not just a box, but a collection of "building block" like parts that can be utilized in the construction of an enclosure for an HPSDR. Early on, it was determined that each HPSDR user had unique requirements for the enclosure of thier HPSDR. With a "building block" concept, each HPSDR user can chose only the parts they will use from the collection:

An End Panel

This will be an end panel with slots punched out in a fashion similar to what is on the rear of a desktop computer. It will mate to a Commercial Off-The-Shelf (COTS) enclosure. It will also have provisions to allow Close-Out Strips to be attached as well as having provisions to mount the End Panel to a Bottom Plate.

Close-Out Strips

These strips will be of several designs. They will act like the metal brackets on the back of a standard desktop computer card - they'll fit the punched out slot in the End Panel and will have openings that match each HPSDR card. Some strips will be "blank," allowing closing out of unused slots.

A Bottom Plate

The bottom plate will have provisions to accept an Atlas card and provide provisions for mounting the bottom plate to the End Panel, allowing alignment of cards plugged into Atlas with the slots in the End Panel.

DESIGN GUIDELINES

The Pandora design is going to be an attempt to hit a moving target. There are cards currently undergoing design and test as this is being written. Therefore, unfortunately, the Pandora design will somewhat constrain card design. Its hoped that these constraints won’t be too much:

1) Atlas will be the “backplane” card for Pandora.

2) Pandora will accept cards no larger than 100 by 220 mm.

3) Pandora won’t be able to house an amplifier or other card with significant heat dissipation. (Discussions already point to a future power amplifier requiring a power supply in excess of what Atlas can support.)

4) Pandora will try to be as friendly as possible for non-USA HPSDR users. Ideally, this will include selection of a commercial enclosure available outside the USA. If not, the parts will be made as flat as possible for the lowest cost in mailing.

5) Pandora will try and minimize the amount of custom-made parts and focus on what can be obtained off the shelf.

6) Pandora will allow for easy access to the cards contained within with minimal disassembly. It is expected some users will use Pandora to house future HPSDR prototype cards.

7) Pandora will follow the standard HPSDR procedures. It won’t be designed in a vacuum and user input will be sought.

8) Materials chosen will allow for the best possible mix of shielding and easy of modification. Ideally, the outer case will be steel for durability and shielding with the remainder of the parts being aluminum for ease of modification.

9) Of course, it should look nice!

FUTURE CHALLENGES

As Pandora is hitting a moving target, any information on what folks are thinking in the following areas would help:

1) Power consumption / Heat dissipation. So far, with Ozy/Janus, this appears to not be a big deal.

2) Card size. Right now, Ozy/Janus are on the smaller end of the possible sizes for cards. If future cards are going to trend closer to the 220 mm maximum, this would be good to know now.

3) Power supplies. If a pico ITX power supply is used (see www.mini-box.com), very little dedicated space is needed for a power supply. If something larger will be the norm, the enclosure size may have to grow.

CURRENT STATUS

Update, 25 March 2006.

Initial entry to HPSDRwiki. Ordered and received prototype of Ten-Tec BK-959 case. Received PDF and AutoCAD drawings of BK-959 from Ten-Tec. Have drawn up and fabricated cardboard mock-ups of the possible sizes of HPSDR cards ranging from 100 mm by 120 mm all the way to the maximum size of 100 mm by 220 mm. Currently working on End Panel design, have expanded design from 6 slots (which matched Atlas exactly) to as many slots as the End Panel will allow. This allows users to use the "extra" slots for expansion. Have inquired with Ten-Tec as to non-USA distribution possibilities. Working on contacting Buckeye Shapeform as another source of enclosures.

Ben, KD5BYB.