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LP-200Dummy Load / Wattmeter
Enclosure Retrofit Assembly Instructions
March 2009TelePost Incorporated
LP-200 is a trademark of TelePost Inc. Material in this document copyrighted ©2009 TelePost Inc.
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IntroductionThese instructions will gude you through the installation of the LP-200 enclosure. There is really moredissassembly than assembly involved, but it’s a straightforward process and should only take about an hour todo. 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 Description3 SW1,2,3 Right angle tactile switches w/keycaps1 SW4 Toggle switch and hardware2 1x8 ribbon cables4 4-40 x ¼” threaded standoffs4 2-56 x 3/8” threaded standoffs8 4-40 x 3/16” machine screws8 2-56 x 3/16” machine screws1 Enclosure top1 Enclosure bottom6 #4 sheet metal screws4 Rubber feet
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Assembly
Pre-assembly overview.
Assembly will follow this basic order…
Removal of power switch.Removal of display connectorInstallation of new tactile switches (old switches can remain)Installation of new power switchInstallation of new display cables
The following tools are recommended to complete assembly…
Adjustable soldering iron – 800 degrees maximumSolderSolder wick or solder suckerNeedle-nose pliersWire cuttersSmall Phillips head screwdriverSmall flat screwdriverAlcohol and old toothbrushElectrical 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 youcomplete them. Make sure your work area is static-free to avoid damage to the installed parts. It is also advisable to wear an anti-staticwrist band and grounded soldering iron.
q Remove the PCB from the mounting plate.
q Carefully unsolder and remove the power switch.
q Carefully unsolder and remove the display connector. I used solder wick to clear the pins of solder. I then gently pried up theconnector housing to expose the pins. Take care if you do this to not place your screwdriver blade over a circuit trace. I then pulledthe remaining pins one by one. A little heat might be required on a pin if it has any residual solder left. Here is a picture of theexposed pins
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Assembly Cont’dq 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…
q Install the three right angle tactile switches next to the existing three maller ones. Do not install the keycaps yet. You may have toslightly enlarge the holes where the plastic tabs fit, or file down the plastic tabs so that they fit snugly. DO NOT modify the holeswhere the metal contacts are soldered.
q 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 middletwo holes of the removed switch, as shown…
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Assembly Cont’dq 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 ineach 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 toeach other.
q Solder the cables to the display connector holes so that they are side by side with the taped portions facing each other. It isprobably smart to also separate them a little so that they don’t touch, as shown…
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Assembly Cont’dq 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.
q Install the four rubber feet on the bottom of the enclosure.
q 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 screwsare started, position the board as far back as it will go in the enclosure, and tighten all eight screws.
q Install the long standoffs on the front of the display, using the 2-56 x 3/16” screws.
q Mount the display to the front of the enclosure using the remaining four 2-56 x 3/16” screws.
q Install the ribbon cable connectors on the back of the display as shown…
q Install the power switch, using the lockwasher and nut supplied.
q 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, asthis provides the most ventilation. With the new enclosure, this will blow a lot of hot air onto whatever sits below the LP-200. You maywish to physically flip the fan to blow upwards. It will reduce cooling efficiency, and decrease the length of time you can transmit at fullpower, but it will still work with this limitation.
q Install the enclosure top using the six sheet metal screws. Position the vent slots to the back of the enclosure.
