Hello,
I have a need to connect to a device that has 2.4 wireless capability only (no ethernet). We use a 900MHz network. The plan is to add a 2.4 card into an RB433 to reach this unit, and a 900 card to reach our network. I'd rather not spray 2.4 everywhere, so I'm exploring the pitfalls and design options for directly connecting these 2.4 radios. We've all done this in bench testing (get 2 radios near each other without antennas, get a signal, make the tests) but is there a proven way to make this happen on a permanent, reliable basis using a direct cable connection? I'm looking at RF attenuators right now, but I also notice that the TX power is highly tuneable in RouterOS. My options as I see them:
1. small rubber duck on each unit
2. directly cable between connectors, with an attenuator
3. directly cable and adjust TX power to almost nothing

Are there any other ideas? Any long-term issues with this type of setup?
Thanks!
Shaun

1. small rubber duck on each unit
2. directly cable between connectors, with an attenuator
3. directly cable and adjust TX power to almost nothing


1 and 2 are OK and will work great, keep you signal strength to -50ish most cards will tolerate close to -30 or more but you start playing with fire at those signals. 3 will kill your cards you can not adjust your power low enough to not damage the other end. If using "duckies" still turn down you power as far as you can to reduce propagation.

and why not just use ethernet?

Ethernet would be great, except for the first sentence in my post .
I'd much rather use a direct connection and attenuators, so that there's no radiation of 2.4 where there doesn't need to be (there will be a few of these units). That said, any recommendations on an attenuator brand/model?
Thanks for the advice...

I guess you would need 100 db attenuator, 50 ohm, meant for 2.4 GHz or more.

Well, what I could see via Google, it's pretty expensive.

Maybe you would rather like to try make one on your own. for math check: http://www.electronics-tutorials.com/ba ... uators.htm and http://www.odyseus.nildram.co.uk/RFMicr ... nuator.pdf

attach rg58 or common 50 ohm feeder to each unit. At free end of each length of cable connect a 50ohm 1/4 resistor. Cut the leads off tight and make sure that the resistors are carbon composite.

then take 1 feeder, towards the end of it, say 6 inches from end, cut an opening in the sheeth, try and remove some braid. Make kind of a letterbox opening using a scapel, say 1 cm long and 5 mm wide. Having removed the braid or bend it out of the way, cover it again with 1 or 2 layers of pvc tape.

Do exactly the same with the other length of feeder.

Then overlap the 2 feeders so that both letter box openings are on top of one another.

Bind the two feeders together.

Hey presto "leeky feeder" cheepo method.