Upgraded Antenna

[Bestgear]

Guys

I have been looking around for alternative aerials for my 433 RFXCOM kit.

I read about using UK DAB aerials, so found what appears to be a suitable candidate.

I bought one, installed, and I can certainly say it appears to be an improvement over the simple ground plane antenna that I started with. The antenna is mounted in my loft, where the previous antenna was.

I have not tried it yet on the transmitter, but will do soon.

The aerial is:

http://www.vision-products.co.uk/pdf/V%207-001.pdf

[domloff]

Would be interested in seeing if this helps the transmitter range.

Did you get it from Vision themselves, as I could not see that they had an online shop?

Dom

[Bestgear]

Hi

Nope.. I have an account with Satelite Solutions (solutions group), and just picked one up from them.

There are bound to be a few online for sale.

I supose if I had some time I could do a group buy... but thats hassle!

David

[b_weijenberg]

The older receiver versions use an F-connector with 50ohm coax cable and ground plane.
The current 310 and 433.92 receivers use a 50ohm telescopic antenna with BNC connector. To use another antenna you can use 50ohm RG8 coax cable.

For the 433.92 receiver you can use HAM Radio Amateur 50ohm antennas (434MHz /70cm).
The 433.92 transmitter is certified with the wire antenna. There is a connection on the transmitter PCB for a 50ohm coax antenna (officially not allowed).


IMPORTANT REMARK: the telescopic antenna must be extracted to the maximum length of about 30 cm!
If the antenna is kept as delivered to the length of about 8 cm you will have a bad range.

[MStan]

The older receiver versions use an F-connector with 50ohm coax cable and ground plane.
The current 310 and 433.92 receivers use a 50ohm telescopic antenna with BNC connector. To use another antenna you can use 50ohm RG8 coax cable.

For the 433.92 receiver you can use HAM Radio Amateur 50ohm antennas (434MHz /70cm).
The 433.92 transmitter is certified with the wire antenna. There is a connection on the transmitter PCB for a 50ohm coax antenna (officially not allowed).


IMPORTANT REMARK: the telescopic antenna must be extracted to the maximum length of about 30 cm!
If the antenna is kept as delivered to the length of about 8 cm you will have a bad range.

Why the antenna change?....isn't the ground plane a better ant?...
Can you still order receiver with the ground plane ant?

[b_weijenberg]

The telescopic antenna has the same performance as the groundplane antenna.

[Rotech]

will this work for the w800 (310mhz)???

[Bestgear]

The telescopic antenna has the same performance as the groundplane antenna.

Bert - glad to see you comment!

What in your view, would be a good move to enhance the TX range, obviously in countries that allow such modifications.

David

[b_weijenberg]

David,

Any external antenna will probably increase the range. Use a beam antenna if the range must be extended in only one direction.

Bert

[sooty]

How far do you want to transmit David?

For my transmitter, I may have the standard RFXCOM ground plane with a 70cm HAM antenna attached to it, connected to the LAN interface with a short coax and BNC plug.

This may be mounted almost centrally on the ground floor of my house and it may reach 40 metres + in all directions including outside without any problems.

The problems I have experienced here with RF signals not getting through, particularly on 433 MHz are due to collissions I think rather than signal strength.

I have 2 RFXCOM receivers, so I have monitored this quite a bit in the past. Sometimes the packets just don't get through for some reason even with the second receiver only 1 or 2 metres from the transmitter.

I do know that my dishwasher plays havoc with the RF in the house. If its on, then I am very lucky to get any HomeEasy signals through at all.

Paul..

[Bestgear]

Hi Paul

That may be good advice :-)

I have the antenna up in the loft and the livingroom coverage to HE modules was very patchy before the new antenna...

I am just watching as I go to see if I get any missed signals...

A 70cm whip or whatever might be a very good way to go sue to the extra gain....

David

[sooty]

I played around with a few different antenna configurations for both RX and TX before settling with my current setup. There was a lot of trial and error with the RF in my house because it is all solid brick walls internally.

I am 100% RF now with no X10 or other power line modules and because of this I wanted to be sure I always had control, so I now have 2 RFXCOM LAN interfaces in operation, both with 433 RX and TX. One downstairs and one upstairs. The TX on the upstairs unit has another 70CM whip attached directly to the back of the interface with a 90 degree BNC connector.

HE modules that may be a bit patchy from one tranmsitter generally work fine from the other unit.

The one thing I can't get my head round is the dishwasher issue. During the wash cycle, my HE modules fail to respond 95% of the time. Monitoring with a second RFXCOM receiver shows that the signals, although transmitted, just don't get through. This has no effect of the many Oregon sensors I have and they are all received OK during the pot washing cycle.

Strange?

Paul..

[Bestgear]

868 Antenna?

Guys

The 433 LAN version uses a NA-774 antenna - does anyone know what the 868 BNC version uses?

Thanks

David

[sooty]

I'm not sure that the 868 receiver with interface is shipped with a BNC antenna. I think it just ships with the wire antenna. I'm sure Bert will correct me on this if I'm wrong.

For my 868 receiver, I use this antenna: http://www.rfsolutions.co.uk/acatalo...p_Antenna.html

I have it mounted with a 90 degree BNC connector on the back of the LAN interface.


Paul..

[Bestgear]

Thanks Paul - great link.

I have finally managed to get my hands on a LAN interface, so have the three modules in the one box now.

I could not find anything "like" the 433 antennas, and really did not think a "wire" was a finished solution (jibe in jest Bert, honest!)

Think I will go order one!

David