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This mod removes the down-converter so the antenna can be used for 2.4 GHz wireless LAN
Remove F connector and screw
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
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
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.
reprinted from APCNEWS
Other Antenna modes
Modifying Confier Antennas for Wireless Networking http://martybugs.net/wireless/conifermods.cgi
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