157 lines
7.1 KiB
Plaintext
157 lines
7.1 KiB
Plaintext
MiniSport Laptop Hacker - Vol #23. September 1994
|
|
To discourage pecuniary interests, Copyright (c) 1994 Brian Mork
|
|
|
|
>>> ADMIN
|
|
The MLHacker series is formatted to print out on 8.5"x11" sheets
|
|
manually fed into an Epson LQ-850. I print at 8 lpi, which gives 82
|
|
lines per page. Back issues are available from ftp.cs.buffalo.edu in
|
|
the \pub\msdos\ham-radio directory. They are also available in the
|
|
SimTel archives (e.g. oak.oakland.edu//pub/msdos/packet/mlhacker.zip).
|
|
|
|
>>> MOBILE BATTERY POWER
|
|
Last issue, Jim Harvey contributed details of how to wire up a Makita
|
|
power drill's battery pack to the Minisport. In this issue, is part one
|
|
of how he describes making a suitable container for the batter pack,
|
|
without scavenging the handle of the drill!
|
|
|
|
"In the February 1994 issue of WORLDRADIO, Gary Magnum W6WWW described
|
|
the use of a Makita tool battery for powering his HT. There are many
|
|
advantages. A Makita battery has several times the capacity of a large
|
|
HT pack and they can be purchased for $30 to $40. Makita packs come in
|
|
7.2 and 9.6 volt versions and the DC 9700 fast charger (about $50)
|
|
handles both types.
|
|
|
|
"Gary used the broken off handle from a Makita tool to hold his battery.
|
|
I had been contemplating using my two Makita batteries for Ham Radio
|
|
purposes but was unwilling to mutilate my $150 drill to do it. My
|
|
solution was to construct a fiberglass cap containing contacts for the
|
|
business end of the battery. The cap fits snugly and a depleted unit is
|
|
easily changed. One 9.6 volt pack will run the receiver on my ICOM IC-
|
|
02AT for about a day. My goal is a complete portable packet station
|
|
with TNC, Laptop, and HT all energized by power tool batteries.
|
|
|
|
"There are other tool brands featuring removable battery packs which may
|
|
be adapted with a little engineering. CamCorders also use packs that
|
|
may be adapted to portable radio service with a similar contact
|
|
arrangement.
|
|
|
|
"To construct a similar cap, begin by making a contact header that fits
|
|
over the top of the pack. Then cover the header, wires, and 2 - 3
|
|
inches of the battery with a layer of fiberglass. You will end with a
|
|
light, sturdy assembly that is hardly larger than the battery pack
|
|
itself. The whole thing can be tucked into any convenient pocket.
|
|
Before you begin, please note that a fully charged power tool battery
|
|
can deliver over 50 amps into a short circuit. This is enough to melt
|
|
wires and possibly cause a fire. Be VERY careful.
|
|
|
|
"Here's a list of materials you will need:
|
|
|
|
Piece of single sided glass Epoxy PC board material, 1" by 2".
|
|
|
|
Strip of brass for contacts .025 to .035 inch thick, 1/2" wide,
|
|
about 2" long (check hobby shops).
|
|
|
|
Fiberglass cloth and Epoxy resin. I used Bondo brand from an auto
|
|
supply store.
|
|
|
|
Power cable with inline fuse holder and connector for your radio.
|
|
|
|
"Tools:
|
|
|
|
Scissors
|
|
Tin Snips
|
|
Flat file or hand nibbler
|
|
Fine sandpaper
|
|
Thin string
|
|
3 or 5 ounce Dixie cup to mix Epoxy
|
|
Sacrificial small 1/2" or 1" paintbrush for Epoxy
|
|
Rubber gloves for working with Epoxy
|
|
Cheap Condom
|
|
|
|
|
|
"Begin by constructing the contact header assembly. The first step is
|
|
to remove a strip of copper from the center of the PC board with a file,
|
|
hacksaw, or knife. Remove at least 1/16" of copper. Remember these
|
|
battery packs can deliver a huge amount of current so you must be sure
|
|
there is no possibility of a short circuit between the two halves.
|
|
Place the PC board material on top of the battery pack and trace the
|
|
outline on the board. Cut and file the board to match the battery.
|
|
I've found the easiest way to cut glass Epoxy PC board material is with
|
|
large tin snips or a hand nibbling tool. Mark and file two notches in
|
|
the long edges of the board to match the recessed terminals of the
|
|
battery.
|
|
|
|
|
|
Single Sided PC Board Header Cut to Fit Top of Battery
|
|
|
|
Notch for battery contact
|
|
|
|
|
----------- v ----------- --------
|
|
/ |-----| \ |
|
|
/ \ |
|
|
/ \ |
|
|
Insulating cut --> |===================================| 1 inch
|
|
down centerline \ / |
|
|
\ / |
|
|
Round corners \ |-----| / |
|
|
to match battery | ----------- ^ ----------- | -----
|
|
top shape | | |
|
|
| Notch for battery contact |
|
|
| |
|
|
|<<---------- 1 7/8 inches -------->>|
|
|
|
|
|
|
"Next, cut two "T" shaped contacts from the strip of brass. The
|
|
horizontal part of the "T" will be soldered to the PC board header and
|
|
the vertical stem will be bent down 90 degrees to form the actual
|
|
contacts on the battery terminals. File these smooth, then flatten and
|
|
bend as shown below.
|
|
|
|
|
|
|<<------ 1/2 inch ------ >>|
|
|
| |
|
|
______________________________ _____
|
|
Brass | | |
|
|
contact | | 1/4
|
|
before | | in.
|
|
bending | | |
|
|
|________ _bend_line_ _________| ___|_
|
|
| | |
|
|
Trim or file | | |
|
|
both sides | | | | 1/2
|
|
to fit | | in.
|
|
battery | | | | |
|
|
terminals | | |
|
|
| | | | |
|
|
|______________| ___________|_
|
|
|
|
|
| 1 " | | 1 " |
|
|
|< - >|<<-- 1/4"-->> |< - >|
|
|
| 8 | | 8 |
|
|
|
|
|
|
_____________________________
|
|
/ this part soldered /
|
|
/ to header PC board /
|
|
/ /
|
|
/____________________________/
|
|
\ \
|
|
Bend tail of \ this part \
|
|
brass contact \ contacts \
|
|
down 90 degrees \ battery \
|
|
\ \
|
|
\______________\
|
|
|
|
|
|
That's it for this issue. Next issue will finish the construction
|
|
project and then we'll get back to normal. Did you see the July QEX
|
|
article about using the Minisport and an Optoelectronics M1? Next
|
|
issue, I hope to have details about converting the modem port to a
|
|
standard COM2: serial port using the board shown in Photo 2 of that
|
|
article.
|
|
|
|
Please provide feedback! * Direct data 1-509-244-9260
|
|
* ARO Net KA9SNF@ka7fvv.#ewa.wa.usa
|
|
* Internet bmork@opus-ovh.spk.wa.us
|
|
73, Brian * 6006-B Eaker, Fairchild, WA 99011
|