Dismantling the EEE PC

Hi all,

This is a post to compliment my post on modding the EEE PC to do awesome things.

I will describe, in detail, the steps required to strip your eee pc 701 down to its bare bones (you have to figure out how to put it back together again yourself).

1 - Remove battery, modem bung, RAM door
Removing the battery is easy. Grap the two slidey locks, push outwards, and pull out the battery. The modem bung is nearly as easy, get a fine screwdriver and carefully pry it out of the connector. Finally unscrew the two screws on the RAM door, save these and remove the door.

2 - Remove the keyboard
Turn the laptop over, so it is now face up. There are 3 tiny catches at the rear of the laptop, behind the F1, F6 and Break keys. Take a straight screwdriver and push these backwards (towards the monitor), and the keyboard will lift up at the back. Now unclip the ribbon connectors for the keyboard and the mouse (shown below).Lift away the keyboard and keep it somewhere safe.



3 - Removing the outer case Under the keyboard are 9 screws. Remove these with a star screwdriver and save them somewhere safe. Turn the laptop over and unscrew 6 screws from the base.

Note: To keep tiny parts safe I use small boxes, especially for screws. This, combined with counting the number of screws to be removed or re-inserted, virtually eliminates the "parts left over" effect.

When removing the upper case you should note that the audio connectors are surrounded by plastic which is part of the case you are removing. You should put a straight screwdriver behind this and pry it out gently before removing the top completely

Remove the case evenly upwards (try not to lift the front first as the rear parts will catch on the monitor). Part of the metal will be stuck to two of the chips underneath by thermal stickers. Be careful to pry these slowly so as not to damage or unseat the chips.

4 - Removing the motherboard
There are two plastic clips holding the front of the motherboard in, unclip these with a straight screwdriver. You need to remove (in no specific order):

• Speakers connector (top left)
• Webcam connector (top left)
• Fan connetor (top left)
• VGA connector (top right)
• WIFI antenna connectors (x2) (underside, top right)
  

(The third picture above is provided for when you forget which way round the speaker/webcam connectors go)

You should now be able to lift the motherboard out. Place this somewhere SAFE - you kind of need this to run your laptop.

5 - Removing and dismantling the screen
The screen is held to the base by two screws at the base of the screen.

To remove the front bezel of the screen, there are 6 screws. These are hidden under the 4 rubber "feet" at the top of the screen, and 2 hidden under round plastic bits at the bottom. You need to pry these out with a sharp knife and keep them safe. They can be re-attached later with some superglue, though not for a while becuase they will be harder to remove again.

There are small plastic clips around the perimeter of the bezel, which are unclipped by applying gentle pressure. There are also two clips on the inner perimeter (next to the screen, just below the speakers). These can be best accessed by poking a screwdriver from the outside of the bezel, past the speaker and unclipping them.


6 - Congratulations
You have stripped down your EEE PC about as far as you'll ever need to make some mods. I will not provide any more details here. I can be reached by email if you for some reason value my less-than-useful opinions.

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A working 815 transmitter

I have a working 815 transmitter. Unfortunately I had to "glue" a capacitor on to the side of the chassis to do it. Key to getting the final to work into a variety of loads is some sort of antenna tuner. Adding a capacitor into the grounded side of the output link does just that. The added capacitor does output loading . Tune up now amounts dipping the final with C2 and increasing/decreasing the loading with the added output link capacitor. Typical operation is 50 watts input and 35 watts out.

Eventually the loading capacitor will be hidden behind a front panel.

read more "A working 815 transmitter"

QRP (and a little homebrew)

After a couple of days of on and off rain with cool weather here in SE Minnesota, today was sunny and temperature about 70 ... great evening for a picnic and a little QRPing from the park. We chose to go to Florence Park in Stewartville, MN. With my K1 and 67' endfed wire in a tree, 20 mtrs sounded pretty dead. An early CQ did raise K9PWK but QSB was bad and we lost each other before we really had much of a QSO (he gave me a 229). Finally at 6:45 Terry, N4IY, in Borden, IN came back to me. We had a nice QSO. His 4 watts was doing a fine 579 job.

On the homebrew 815 transmitter front I've been trying to get the final coil wound so that the transmitter delivers full output to a 50 ohm load. At this point I'm about to add an outboard antenna tuner to my project list.

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Mobile radio installation guidelines.

GMNA Engineering CentersGeneral Motors Corporation

Radio Telephone / Mobile Radio Installation Guidelines
Certain radio telephones or land mobile radios or the way in which they are installed may adversely affect vehicle operations such as the performance of the engine and driver information, entertainment and electrical charging systems. Expenses incurred to protect the vehicle systems from any adverse effect of any such installation are not the responsibility of General Motors Corporation. The following are general guidelines for installing a radio telephone or land mobile radio in General Motors vehicles. These guidelines are intended to supplement, but not to be used in place of, detailed instructions for such installations which are the sole responsibility of the manufacturer of the involved radio telephone or land mobile radio.


INSTALLATION GUIDELINE(refer to enclosed figures during installation)
1. Transceiver LocationA. Locate transceiver for remote radios on driver's side of trunk as near to the vehicle body side as possible.B. One piece transceivers should be mounted under dash or on transmission hump where they will not interfere with vehicle controls or passenger movement.C. Great care should be taken not to mount any transceivers, microphones, speakers or any other item in the deployment path of a Supplemental Inflatable Restraint or "Air Bag".
2. Antenna InstallationA. Each vehicle model and body style reacts to radio frequency energy differently. When dealing with an unfamiliar vehicle, it is suggested that a magnetic-mount antenna be used to check the proposed antenna location for unwanted effects on the vehicle. Antenna location is a major factor in these effects.B. The antenna should be a permanent-mount type located in the center of the roof or center of the rear deck lid. Glass mounted antennas should be kept as high as possible in the center of the rear window or windshield. If a magnet-mount antenna is used, care should be taken to mount the antenna in the same location as a permanent-mount type. If a disguise-mount antenna is used, great care should be taken to shield any tuning network from vehicle electronics and wiring, or to mount the tuning network in an area completely clear of vehicle electronics and wiring.C. Standard metal mount antennas may be mounted on a vehicle with nonmetallic body panels by two methods. Most nonmetallic skinned vehicles have metal frames underneath. Mounting the antenna near a metal frame section and bonding the antenna mount to the frame with a short metal strap will provide the groundplane connection. Some antenna manufacturers offer "groundplane kits" that consist of self adhesive metal foil that may be attached to the body panel to provide the groundplane for the antenna.D. Some vehicles use glass that contains a thin metallic layer for defrosting or to control solar gain. Glass mount antennas will NOT function when mounted on this type of glass. Consult your GM dealer or owner's manual to determine if this glass is installed on your vehicle.
E. If RF related interactions occur when using a hitch or bumper mount HF antenna on a vehicle that has body on frame construction (ie Pickup, SUV) connect a ground strap from the vehicle frame to the bottom rear of the vehicle body (for station wagon type vehicles), or from the vehicle frame to the bottom rear of the cab (pickup style vehicles).
3. Antenna Cable RoutingA. Always use a high quality coax (at least 95% shield coverage) located away from the Engine Control Module and other electronic modules.B. Care should be taken to maintain as great a distance as possible between any vehicle wiring and the feedline.
4. Antenna TuningA. It is important that the antenna be tuned properly and reflected power be kept to less than 10% (VSWR less than 2:1).
5. Radio Wiring and Connection LocationsA. Connecting radio power on General Motors vehicles is model dependent. The installer must decide which one of the following four methods will be appropriate.1.) Connect the positive and negative leads directly to the battery terminals (illustrated in this guideline).2.) Connect the positive lead to the auxiliary power terminal (located at the underhood fuse center or identified by a red plastic cover in the underhood area) and connect the negative lead directly to the negative battery terminal.
3.) Connect the positive lead to the auxiliary power terminal and connect the negative lead to the battery body connection point (identified by a short #10 AWG or larger wire running from the negative battery terminal to the body of the vehicle).4.) Connect the positive and negative leads to the Special Equipment Option (SEO) wiring provided for this purpose.
B. If connections are made directly to the battery terminals, the GM approved methods of connecting auxiliary wiring include the adapter package illustrated in Figure 2, NAPA-Belden replacement battery bolts (part # 728198), or drilling and tapping the hex end of the original battery bolts 10-32 X 3/8" deep. NOTE: It is recommended that a fuse be placed in the transceiver negative lead to prevent possible transceiver damage in the event the battery to engine-block ground lead is inadvertently disconnected.C. For ONE-PIECE TRANSCEIVERS where ignition switch control is desired and no SEO wiring exists, a 12 Volt power contactor must be installed in the transceiver positive lead. The contactor should be located near a proper 12 Volt feed. The coil of the contactor should be connected through an appropriate in-line fuse to an available accessory circuit or ignition circuit not powered during cranking. The contactor coil must return to a proper negative point. Detail "A" illustrates direct connection to the vehicle battery.
D. Any negative lead from a handset or control unit must return to a proper negative connection point. It is preferable that the positive lead for a handset or control unit be connected directly to a proper positive feed. If ignition switch control is desired, the handset or control unit positive lead may be connected through an appropriate in-line fuse to an available accessory circuit or ignition circuit not powered during cranking. It is recommended that the handset or control unit positive and negative leads be appropriately fused separately from the transceiver positive and negative leads.
E. If multiple transceivers or receivers are to be installed in the vehicle, power leads to the trunk or under dash should be connected to covered, insulated terminal strips. All transceivers or receivers may then have their power leads connected to the strips. This makes a neater installation and reduces the number of wires running to the vehicle underhood area.
6. Radio Wire RoutingA. The power leads should be brought through a grommeted hole in the front bulkhead that must be provided by the installer. For trunk-mounted transceivers, the cables should continue on along the driver's side door sills, under the rear seat, and into the trunk through the rear bulkhead. All attempts should be made to maintain as great a distance as possible between radio power leads and vehicle electronic modules and wiring.
B. If the battery is located on the passenger side, radio power leads should cross the vehicle in front of the engine.
7. TroubleshootingA. Should vehicle-radio interaction develop following installation, the source of the problem should be determined prior to further operation of the vehicle. Most interaction problems can be eliminated by following the installation guideline.
B. If any vehicle-radio interaction problems exist after following this guideline, the vehicle should be returned to a GM dealer for examination and resolution of the problem.

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CQ CQ CQ de W0VLZ 2007-05-08 01:30:00

I've powered my new transmitter up on 40 meters.

For use during this test phase I built an adapter to allow the use of B&W 5 pin JVL transmitter coils instead of winding coils on my National coil forms. I'm also temporarily connecting the bias and voltage dropping resistor networks to the back 12 terminal barrier strip. This way I can easily play with the resistor values to get the right voltages.

The transmitter loads up to 40 watts input and 30 watts output with no sign of self oscillation

I've still problems, though. The 815 screen current won't come down. It appears to draw around 60 mA rather than 15. High screen current causes the screen dissipation to be exceeded, maybe damaging the 815. Right now I'm looking for another 815 to compare readings with.

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A mid 30's Three Tube Regen

I aquired another radio last week. This one I "won" through ebay. The pictures posted on ebay showed a fairly ughly set with three mis-matched dials. The layout, though, suggested the "Three Tube Regenerative Receiver of Unusual Performance" by George Grammer and written up in the January 1933 issue of QST.











I bid and the gamble paid off. Underneath the flaking paint front panel and cabinet was a fairly nicely done version of George Grammer's design.







George grammer's original article was more than another construction project. He spent a large part of the article talking about features of good regen receiver design before describing "a practical receiver". This receiver includes a tuned RF stage and general coverage/bandspread tuning. Bandspread tuning is via the drum dial at the left after the detector and RF stage bandset capacitors are set. The receiver showed up in the ARRL handbooks through 1937.

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