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 (http://www.kiwibiker.co.nz/forums/member.php/2153-notme) you want :bleh: 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 (http://www.kiwibiker.co.nz/forums/member.php/2153-notme) you want :bleh: 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-radios/ubiquiti-nanostation5-ns5-802.11a-250mw-outdoor-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 :facepalm:), 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....

[Hans]

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....

Already have one of those....

[Hans]

More dronage for you....

[pete376403]

wow. I though hexacopter and octocopter were pretty cool, but that could be a whole lot of fun

[Hans]

Not bad for causing UFO sightings around the Hutt. This one flies itself, click on a map and off it goes...

[pete376403]

do you have the machine gun option? If so, I have a small job for you.

[Hans]

do you have the machine gun option? If so, I have a small job for you.

No, but I can deposit stuff with about 1m accuracy... :innocent:

[bogan]

Not bad for causing UFO sightings around the Hutt. This one flies itself, click on a map and off it goes...

Thats pretty cool, how many flights/distance/crashes has it done so far?

Uni project, comercial application, or just for fun?

[Hans]

Thats pretty cool, how many flights/distance/crashes has it done so far?

Uni project, comercial application, or just for fun? 500+ flights, 2 serious crashes. Basically started as a hobby (something to keep the brain busy while working a mundane job), now it's slowly morphing into a commercial thing.

Specs:

15 minute flight time (+/- 2 minutes)
500g payload (can be airdropped or laid down)

Automated flight:

-hold position and/or altitude (GPS+sonar+barometer)
-fly way points
-return to launch point and autoland
and a shitload of less usable stuff

It also has telemetry and control via a laptop-based ground station.

Took about a year to bring to maturity as a system.

Now I'm working on a plane with much better capabilities...

[The Lone Rider]

Can I ask, what are those things used for?

[Hans]

Can I ask, what are those things used for?

You mean multicopters? Just about anything you can imagine, but typically for aerial photography.

[Akzle]

You mean multicopters? Just about anything you can imagine, but typically for aerial photography.

read: perving on the cocky's wife :D

i am SO coming for a dekko.

15 mins is a bit shy/ what Ah are that? you using straight squirrel cage motors?

[Hans]

read: perving on the cocky's wife :D

i am SO coming for a dekko.

15 mins is a bit shy/ what Ah are that? you using straight squirrel cage motors?

Round about 15 minutes on a 4Ah 12v battery. The motors are brushless... It's not bad considering you've got 4 motors to feed and quite a few electronic bits and bobs. It weighs around 2kg too.

[Hans]

Here it is, almost done...

[Akzle]

Here it is, almost done...

dude. you might want a more stable OS than windows... when you've got the warheads strapped to it, the blue screen of death (unhandled exception 0xe000000047) could end up in thermo-nuclear death.

(linux that shit!)

[Hans]

dude. you might want a more stable OS than windows... when you've got the warheads strapped to it, the blue screen of death (unhandled exception 0xe000000047) could end up in thermo-nuclear death.

(linux that shit!)

Meh.

a) Windoze is good enough for NASA - It's good enough for me,

b) Loss of telemetry just means that the aircraft either continues the mission without me watching it, or climbs to a set altitude and returns to the launch point, where it circles until I feel like landing it.

[Ocean1]

A blended wing, nice. What does it weigh, dude?

[Brian d marge]

A blended wing, nice. What does it weigh, dude?haa , same thought !, Ive had a glass or two at lunch , was reading all the lectricity gobblety gook ,then Ii fast forwarded to the end, saw your post ,,,, and shot back to have a look ,
Wow , well done that man ! looks awesome ,
Stephen

[Hans]

A blended wing, nice. What does it weigh, dude?

3.5 to 5.5kg. 3.8 at the moment. Plenty of headroom for more payload after flight testing.

[Ocean1]

3.5 to 5.5kg. 3.8 at the moment. Plenty of headroom for more payload after flight testing.

OK, how much of that is the fusilage? I presume it's Eglass over foam or similar?

Is it a single engined pusher?

[Hans]

It still has some interesting flight characteristics. I'll have to rid it of the tendency to flat spin. At least another 6 months of flight testing.

[Hans]

OK, how much of that is the fusilage? I presume it's Eglass over foam or similar?

Is it a single engined pusher?

Close. EPO foam, with CF spars and glass reinforcing. Only the elevons are glass over a foam core. Single engine pusher, electric. Upwards of 90 minutes endurance.

[Ocean1]

Close. EPO foam, with CF spars and glass reinforcing. Only the elevons are glass over a foam core. Single engine pusher, electric. Upwards of 90 minutes endurance.

OK. I like epo, crashes very well. Bit like me.

How did you shape it, hot wire or did you make moulds?

[Hans]

Ok, so now that I'm off the mobile and on the laptop, I can give you some specs:

Composite (Mainly EPO foam an glass) flying wing, single engine pusher. Fuselage is reinforced with fibreglass, wing has 3 CF spars. Electric brushless motor.

Wingspan: 240cm
AUW: 5.5kg maximum
Current TOW: 3.5 - 3.8kg

Operational endurance: 80 minutes cruising at 25m/s
Ceiling: In the region of 15000ft
Operation radius +/- 40kms

Equipment carried at the moment:

Full autopilot
16MP Camera
640 line video camera mounted on pan-tilt gimbal, operated via joystick or click-to-follow on a map. Live video downlink.
Telemetry at 115Kbps to a range of +/- 50km.

That should about cover most of the basics.

I AM LOOKING FOR SOMEONE TO VOLUNTEER ACCESS TO THEIR LAND CLOSE TO WELLINGTON...see here: http://www.kiwibiker.co.nz/forums/showthread.php/155649-Who-has-a-farm-or-land-in-the-Wairarapa-or-Kapiti?p=1130461634#post1130461634

[Hans]

OK. I like epo, crashes very well. Bit like me.

How did you shape it, hot wire or did you make moulds?

It's a heavily modified off the shelf airframe. So you do a bit of R/C?

[Ocean1]

It's a heavily modified off the shelf airframe. So you do a bit of R/C?

Not since they stopped using balsa and dope.

Wouldn't mind gettine into it when I get some spare time. Scale stuff, possibly. Quite fancy things with fully functional 14cyl sleeve valve radials.

Is there rules about chucking tens of KG around semi-rural airspace?

[Hans]

Not since they stopped using balsa and dope.

Wouldn't mind gettine into it when I get some spare time. Scale stuff, possibly. Quite fancy things with fully functional 14cyl sleeve valve radials.

Is there rules about chucking tens of KG around semi-rural airspace?

I'm sure there is. Not my problem. I'm under 4kg at the moment.

[Ocean1]

It still has some interesting flight characteristics. I'll have to rid it of the tendency to flat spin. At least another 6 months of flight testing.

Can you organise a skinny wee high aspect ratio rudder behind that prop?

[Hans]

Can you organise a skinny wee high aspect ratio rudder behind that prop?

If I needed yaw control, i'd just put drag rudders on the winglets. I know why it flat spins, on swept wings there's a spanwise flow along the leading edges right before the stall. The common way to deal with that is wing fences to disrupt the spanwise flow. That should do it in this case.