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Old January 28th 06, 12:41 AM posted to rec.radio.amateur.antenna
Tam/WB2TT
 
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Default Increase range on 433 Mhz transmitter


"Carsten Hjorth" wrote in message
...

"Tam/WB2TT" skrev i en meddelelse
. ..

"Carsten Hjorth" wrote in message
...
Hello!

I just bought this: http://www.rustindustries.co.uk/remote.htm
The range is only 10-15 meters in free air, only 5-7 meters indoor.
Is it possible to connect a whip type antenna?
I have calculated a length ca 17 cm.
But i cannot see where to connect the antenna.
The transmitter has a loop style antenna, powered by one transistor and
a oscillator of some sort, i have drawn a schematic:
http://media.openbloc.com/1tpwr
I have tried to connect the antenna to the collector, but that gave me
no output at all.

Regards

Carsten Hjorth

You might want to do something with the receiving antenna. My 4xx MHz
garage door opener has about 30 meters range.

Tam/WB2TT


I´m in Denmark and its frezing...
Should i extend the wip antenna on the receiver? Now it´s a 1/4 wave,
should i try full wave?

/Carsten

Full wave won't work, but 5/8 or 3/4 might work better than 1/4. If it does
not have to be non directional, you could use some kind of an antenna that
has some gain, like a 3 element Yagi. You are in the 70 cm ham band; so, any
of the common 430 - 440 Mhz antennas will work, provided you can connect it
to the receiver.

Tam