Home
ATV
Committee
Computer
Digipeat
Downloads
For Sale
Help
Information
IP subnets
Links Latest Information
Membership
Modem
Modem Help Desk
Network and BBS
Network Map
NEWS Photo page VHF
Who is the QDG Wireless LAN
Site Index
Spam and Open Relay Blocking System
Antenna Mods
This mod removes the down-converter so the antenna can be used for 2.4 GHz wireless LAN
Another view
Cut open the plastic case along the join, use a small saw and knife
Cut the electronics (down converter) off
You are left with this
This is a view of both sides
Connect the coax cable
The braid is connected to one side of the dipole, the
centre conductor
is connected to the other side.
If you look at the antenna printed circuit board you will see that the small
pad on one side joins one side of the dipole through the board.
Centre conductor to the small pad, braid to the other side of the
board other dipole side.
***********|
|************
| |
|
|
|
|
|
~~~~~
With the coax cable connected
Fitted back in the housing
Now seal the end of the coax with neutral cure silicone sealant
The last step is to re-assemble the housing and seal with neutral cure silicone
Also see http://clown.ecig.com.au/modules.php?name=News&file=article&sid=6
MPAP antenna mods http://www.mpap.net/gallery/Antennas/Mods/index.htm
Hans's Website
http://apache.airnet.com.au/~fastinfo/wireless/PacMon/
This mod uses the antenna to receive Amateur Satellites
Receiving AO40 the cheap way
Many people thing that super high frequencies mean super high equipment costs.
However, Chris VK3CJS has found an economical way of receiving telemetry from
the AMSAT-OSCAR 40 satellite on 2401 MHz. Chris writes as follows:
I have obtained a couple of downconverters (Conifer and Pacific
Monolithics/Hills) which convert 2401 MHz down to 450 MHz. Of course it
would be nice to own a Yaesu FRG 9600 or similar to use as an IF but this luxury
is denied to me.
I have an old scanner which was found on the Maldon tip. It covers 450 MHz
and has a first IF of 21.4 MHz as I believe most scanners have. It was
dead easy to arrange a coupling cap and a bit of coax to connect this to one of my HF receivers. The idea of all this was to use the scanner as a
second converter, to convert the 450 MHz output from the first converter down to
HF.
I tried tapping 21.4 MHz after the filter, but the bandwidth was too narrow for
a good spread with the HF receiver. Happily I found an unused low
impedance link on one of the IF transformers before the filter and this worked
perfectly. As an added precaution I disabled the second local oscillator
crystal in the scanner by cutting the circuit board - there is no point in
having more birdies than necessary.
After a couple of hours of fiddling I was receiving AO40 telemetry with the free
soundcard program from Amsat. PSK and SSTV signals have also been
received. The signals were not very strong, but a bigger homemade dish should work better.
The Conifer downconverter seems to be the better of the two types, having an
extra RF stage. It seems to have two separate front ends fed by a common
local oscillator, so it seems to me that one might be cut off as redundant from the internal IF pre-amp.
It is worth mentioning that the scanner's first local oscillator is ABOVE 450
Hhz, so the HF receiver is inverted (LSB = USB) and one must do mental
arithmetic when tuning around. However this can be overcome somewhat by
the choice of second IF set into the scanner memory. The local oscillators
in the downconverters are accurate and the dish has only to be roughly pointed
in the correct direction in order to hear the middle beacon which has a
distinctive sound and thus is easy to find.
And that was an article by Chris VK3CJS on receiving 2.4 GHz signals from the
AO-40 satellite. If you'd prefer to build a cheap satellite, well we'll
have some ideas on this next week.
VK3CJS
reprinted from APCNEWS
Other Antenna modes
Modifying Confier Antennas for Wireless Networking http://martybugs.net/wireless/conifermods.cgi
NOTICE: always refresh your browser for
each page on this site. Changes
are frequent.
If you are visiting from another site, this is our address http://www.qdg.org.au/