So who knows a bit about electronics?

[Hans]

Heya,

anyone on here know a bit about electronics, especially radio? I might need a bit of help deconflicting a few different transmitters placed in close proximity... Anyone close to Welly would be especially awesome. Beers etc. for a bit of sensible advice...

[The Lone Rider]

What are the devices you are trying to keep from interfering with each other?

[bogan]

Yeh some specifics would be good, are they all on the frequency? Are they burst or continuous transmission? etc...

[Hans]

So the list goes like this:

1 tx @ 1.3Ghz 1500mW continuous
1 tx/rx @ 900Mhz 1000mW continuous
1 rx @ 2.4Ghz
1 rx @ 1.58Ghz

I will be using low pass filters for the 1.3Ghz and 900Mhz and trying to keep the power supplies as separate as possible...

What else do I need to do, apart from not getting snapped using the 1.3gig?

[Hans]

Here's the 900Mhz tx/rx, will try to find spec for the 1.3Ghz...

http://store.rfdesign.com.au/rfd-900-radio-modem/

[Hans]

Yeh some specifics would be good, are they all on the frequency? Are they burst or continuous transmission? etc...

I was hoping you'd show up here.

[bogan]

I was hoping you'd show up here.

Its not me you want, its notme you want But I don't think he's been on here for ages.

Since they are all on different frequencies, I wouldn't expect any major issues, just ensure there is good error checking. Although that is fairly decent output power. Lowering the data rate usually helps too. Height is a huge factor, it might be that the higher you go, the less transmit power you need, which should reduce the error rates of the other gear.

I assume you're fixed into the listed gear? As flexibility in gear choice might make it easier to get better results.

I haven't done too much with RF stuff, some long dist (1kmish) home wireless networking with I think 1/4 watt transmitters, and I've just designed an 868mhz transceiver to hopefully get a few km in rural situations. But in general, electromagnetism is not my strong suit.

Just shove them up on some poles, and see how it goes I reckon.

[Hans]

Its not me you want, its notme you want But I don't think he's been on here for ages.

Since they are all on different frequencies, I wouldn't expect any major issues, just ensure there is good error checking. Although that is fairly decent output power. Lowering the data rate usually helps too. Height is a huge factor, it might be that the higher you go, the less transmit power you need, which should reduce the error rates of the other gear.

I assume you're fixed into the listed gear? As flexibility in gear choice might make it easier to get better results.

I haven't done too much with RF stuff, some long dist (1kmish) home wireless networking with I think 1/4 watt transmitters, and I've just designed an 868mhz transceiver to hopefully get a few km in rural situations. But in general, electromagnetism is not my strong suit.

Just shove them up on some poles, and see how it goes I reckon.

http://www.gowifi.co.nz if you want to play with wi-fi. Pricey but nice.

[bogan]

http://www.gowifi.co.nz if you want to play with wi-fi. Pricey but nice.

Yup, http://www.gowifi.co.nz/wisp-client-...ap/bridge.html we got some of those to set up a network about 1km across palmy. I ended up taking over as my flatmate who bought them was pretty useless (2 or 3 layers of security and he forgot the password/user/ssid details of every one ), nice interface etc, but we never got VOIP to work. Though considering everything else worked perfectly with a bit of tweaking, I think that was probably the fault of the VOIP box itself.

[HenryDorsetCase]

your issue will be antennae won't it? i.e. using the same pole and stuff.

[Hans]

your issue will be antennae won't it? i.e. using the same pole and stuff.

Can you elaborate on that?

[Akzle]

your issue will be antennae won't it? i.e. using the same pole and stuff.

monopole with multiple traps will handle that, but they're all RHF (really high freq). so v. compact antennae, and your best bet would be something like a quad band HSDPA/3G type, if you had only one antenna to buy. jaycar stock em (best price, many people sell antennae) at 5 dB and 8dB and if you're inclined to a yagi, i think they have a 12dB hyper-directional.
that's antennae.
asides from isolated power supply (would recommend lab-supply/inverter, rather than them box transformers or, if you can run it off a DC supply, alternator+car battery) will minimize chance of noise.
belden coax, or quad shield stuff. well grounded. wavelength cableruns etc.

depends where you are.. in town there's a lot of shit flying at those freqs. (.9 & 2.4 esp) out in the cuntry not so much.

software side. windows blows at network traffic, expecially if it starts dropping packets.
check out and tutu with fladigi + flarq.

but.. what's it all for? what's the objective...
you may find a local yachtbuilder-marine type, who will have knowhow, ona ccount of they use the RF modems on superyacts etc...

[Hans]

but.. what's it all for? what's the objective...

Cheers, It all happens to sit on an overgrown model airplane...

The 900Mhz is telemetry and the 1.3Ghz is video downlink...

When I say 900Mhz, I'm only talking about a band rather than a precise frequency, th eprecise frequency sits within the ISM band... And yes, all of this is going to be used well out of town...

[Hans]

Also the power is all from batteries... At least in the air. None of this will be a problem at the ground station.
900Mhz system is diversity with mono and bi antennas on the air side and a patch(or yagi) plus an omni on the ground. 1.3 system has an omni on the air side and a patch on the ground. All ground antennas are tracked. The range requirements are much higher for the 900Mhz system than they are for the 1.3Ghz. Hope that covers most of it.

[Akzle]

Also the power is all from batteries... At least in the air. None of this will be a problem at the ground station.
900Mhz system is diversity with mono and bi antennas on the air side and a patch(or yagi) plus an omni on the ground. 1.3 system has an omni on the air side and a patch on the ground. All ground antennas are tracked. The range requirements are much higher for the 900Mhz system than they are for the 1.3Ghz. Hope that covers most of it.

ahh. well, you'll naturally get longer range on the lower frequency. the mainest thing i can think would be upgrade all your "patch" antennas.
or chuck it all and buy a quadrotor (youtube FPS russia, quadrotor)

now i wanna come see....