Optimal reception/transmission

[Jeroen Bartels]

Does anyone know what the optimal length of the RFXcom 'spriet' antenna for both the 433MHz transmitter and receiver?
Ik heb een normaal rijtjeshuis maar heb wat moeite om een goede dekking te krijgen (dik beton??). I have placed the LAN module at various places in the house (as central as possible) and use mainly Kaku.

If that does not help I'm thinking of putting also a transmitter in my USB module which already has a 310MHz receiver in it. Is that a good idea or will I get collisions of the 2 transmitters because there is no handshake between them?"

[Noel]

http://k4far.home.att.net/calc.html

[b_weijenberg]

Jeroen,

The 433.92MHz wire antenna must have a length of 17.5 cm.
You can also connect the RFXCOM 89001 telescopic antenna or the Conrad 190073 - 8A GP antenna.
It is also possible to connect 2 antenna's so that you have an antenna on each floor. To connect 2 antenna you have to connect a 47ohm resistor in series with the inner conductor of the coax cable.

It is NOT possible to have a receiver and a transmitter in an USB interface!

[AshaiRey]

It is also possible to connect 2 antenna's so that you have an antenna on each floor. To connect 2 antenna you have to connect a 47ohm resistor in series with the inner conductor of the coax cable.

I can't visualize how this should be connected. If you add a second antenna to the cable wouldn't that create an open dipole antenna which makes it sensitive to direction?

Since 433mhz is in the range of TV signals would an ordinary TV signal amplifier help here?

[b_weijenberg]

You cannot use an amplifier on the transmitter output!

You can probably use the Conrad 941606 TV antenna splitter. However, the TV antenna splitter has a F-connector and is 75ohm so a little mismatch is present.
Or connect a 70cm 1kW RF power amplifier to the transmitter and you can control all KAKU's of the whole city (until you are visited by the RCD)

[AshaiRey]

connect a 70cm 1kW RF power amplifier

Those times that i did like that are over now.

But no kidding.
What I meant was to use the amplifier on the recieving antenna.
About adding a second antenna to the cable is thought you meant the receiving antenna here.

[b_weijenberg]

Jeroen was talking about a second transmitter.

Yes, a broadband TV antenna amplifier can be used for the receiver if it covers the 434MHz.

[Jeroen Bartels]

Or connect a 70cm 1kW RF power amplifier to the transmitter and you can control all KAKU's of the whole city (until you are visited by the RCD)

Whole city is maybe too much. I would get problems with DJF3 who lives nearby. But the whole street would be nice

I will try a second transmitter-antenna on the next floor and let you know.