LP-200 Dummy Load / Wattmeter

Transcription

1 LP-200 Dummy Load / Wattmeter Enclosure Retrofit Assembly Instructions March 2009 TelePost Incorporated LP-200 is a trademark of TelePost Inc. Material in this document copyrighted 2009 TelePost Inc. 1

2 Introduction These instructions will gude you through the installation of the LP-200 enclosure. There is really more dissassembly than assembly involved, but it s a straightforward process and should only take about an hour to do. Before starting, you should inventory the parts. Here is a picture of all the parts except the enclosure top, bottom, and six sheet metal screws that hold the top to the bottom. Parts List - Subject to change without notice. Quantity Designation Description 3 SW1,2,3 Right angle tactile switches w/keycaps 1 SW4 Toggle switch and hardware 2 1x8 ribbon cables x ¼ threaded standoffs x 3/8 threaded standoffs x 3/16 machine screws x 3/16 machine screws 1 Enclosure top 1 Enclosure bottom 6 #4 sheet metal screws 4 Rubber feet 2

3 Assembly Pre-assembly overview. Assembly will follow this basic order Removal of power switch. Removal of display connector Installation of new tactile switches (old switches can remain) Installation of new power switch Installation of new display cables The following tools are recommended to complete assembly Adjustable soldering iron 800 degrees maximum Solder Solder wick or solder sucker Needle-nose pliers Wire cutters Small Phillips head screwdriver Small flat screwdriver Alcohol and old toothbrush Electrical tape Step-by-step assembly instructions. It is recommended that you print this manual to allow for easy reference while building, and to allow you to check off the steps as you complete them. Make sure your work area is static-free to avoid damage to the installed parts. It is also advisable to wear an anti-static wrist band and grounded soldering iron. Remove the PCB from the mounting plate. Carefully unsolder and remove the power switch. Carefully unsolder and remove the display connector. I used solder wick to clear the pins of solder. I then gently pried up the connector housing to expose the pins. Take care if you do this to not place your screwdriver blade over a circuit trace. I then pulled the remaining pins one by one. A little heat might be reuired on a pin if it has any residual solder left. Here is a picture of the exposed pins 3

4 Assembly Cont d Using the alcohol and toothbrush, carefully clean away excess flux from the dissassembly procedures. Here is a picture of what the display connector holes should look like after unsoldering and cleaning Install the three right angle tactile switches next to the existing three maller ones. Do not install the keycaps yet. You may have to slightly enlarge the holes where the plastic tabs fit, or file down the plastic tabs so that they fit snugly. DO NOT modify the holes where the metal contacts are soldered. Solder a couple of 1 long wires from to the bottom two pins of the power switch. Solder the other ends of the wires to the middle two holes of the removed switch, as shown 4

5 Assembly Cont d Prepare the two ribbon cables as shown below. You should place a piece of electrical tape over the exposed metal edges where the pins are crimped, because the two cables will be close to each other when installed. For clarity, I used the dark colored wire in each as a reference to determine which side of the cable is up, but this doesn t really matter as long as the two are kept parallel to each other. Solder the cables to the display connector holes so that they are side by side with the taped portions facing each other. It is probably smart to also separate them a little so that they don t touch, as shown 5

6 Assembly Cont d Install the four short standoffs to the underside of the PCB using the 4-40 x 3/16 screws. Leave the screws a little loose so that the board can be adjusted when it s installed. Install the four rubber feet on the bottom of the enclosure. Slide the PCB into the enclosure, and insert the four remaining 4-40 x 3/16 screws on the bottom of the chassis. Once all screws are started, position the board as far back as it will go in the enclosure, and tighten all eight screws. Install the long standoffs on the front of the display, using the 2-56 x 3/16 screws. Mount the display to the front of the enclosure using the remaining four 2-56 x 3/16 screws. Install the ribbon cable connectors on the back of the display as shown Install the power switch, using the lockwasher and nut supplied. Install the four switch keycaps. Before installing the enclosure top, it is necessary to determine the fan direction. The original units had the fan blowing downward, as this provides the most ventilation. With the new enclosure, this will blow a lot of hot air onto whatever sits below the LP-200. You may wish to physically flip the fan to blow upwards. It will reduce cooling efficiency, and decrease the length of time you can transmit at full power, but it will still work with this limitation. Install the enclosure top using the six sheet metal screws. Position the vent slots to the back of the enclosure. 6