I have perhaps a dozen dead Trimble "Bullet" antennas, allegedly done in
by near-by lightning. Inside looks like the same ceramic patch as the
mobile antennas, with different electronics on the back side of the
"ground plane". The radome is gasketed, and the whole assembly can be
disassembled and reassembled; they have TNC female connectors. $10 plus
shipping, US only. They weigh nothing, so I'll see how cheaply they can
ship.
73,
geo - n4ua
[email protected] wrote:
On 09/05/2010 06:12 PM, Peter Krengel wrote:
Hello,
I just did some experiments using a ceramic patch antenna inside a
small plastic (80 x 30 x 20mm) screw box and experienced much bader
signals at lower elevations.
The plastic is marked as PS (I guess polystyrole ?). Further experiments
covering a GPS with the same kind of box seemed to effect the signals
too. On the other hand covering the patch with a flat pcs of the same
material didnt effect the antenna.
Finding a suitable top for that gps module/patch/.. that is both the
right material and the right shape is hard. Just the right shape is
much easier. So:
I have had good success with vacuum forming such a beast. One particular
glass cup I have in the kitchen is flat top conical, of just the right
size. I put it on top of the ground plane, a 1mm sheet of
clear polycarbonate above that, and with an air pump and heat gun I
pulled the PC down around it. A bit of white paint on the inside, and
it looks really good.
/Kasper Pedersen
Many swedish reference stations have a snow cone made of (iirc) Plexiglass
- Polymetylmetacrylic (PMMA). It should be formable using Kaspers above
method.
http://swepos.lmv.lm.se/stationer/hjo.htm
--
Björn
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
