Another Venturi build

krikey · February 05, 2014, 05:47:15 PM

Very detailed build Tone. I run mine on 2 x 2200 3s throwing a 9x6 prop. Not flown it as much as I'd like but when I do I enjoy it immensely. Mine was the FPV variant which had a shelf on the front for the camera(s) and I ended up using that to add extra weight as thre Lam will throw your CofG back again.

Big_Tone · February 13, 2014, 12:28:43 PM

Build almost finished. Will post some pics soon. Thinking about a maiden on Sunday but there are 10-14 mph winds. Is that doable? Anyone near London want to see a crash? Brucey?

krikey · February 13, 2014, 12:44:02 PM

10-14 mph winds on the vent are fine! I fly my AXN in that and more :)

However, if this is your first wing then get someone to launch it for you so you can concentrate on getting it straight and level quickly.

Brucey · February 13, 2014, 06:31:02 PM

Ah mate, I'd love too, but I'm busy this weekend. Should be free next weekend but take the weather window when you can!
It will be fine in the wind and will help you launch it.

Big_Tone · February 16, 2014, 10:10:34 PM

Tried to maiden. Beautiful day. Something shoddy going on with orange uhf, was losing link intermittently within a few meters so couldn't fly. Could be a problem with my home build turnstile, could be an issue with the tx/rx. Based on this experience and what others say, I think hobbyking orange openlrs unit is quite likely :censored: . Will probably put it on frsky 2.4 to get it flying and maybe get one of the new rlink ones.

Brucey · February 17, 2014, 07:53:41 AM

Unlucky mate, at least you found that out on the ground!

iPeel · February 17, 2014, 08:22:52 AM

Quote from: Big_Tone on February 16, 2014, 10:10:34 PM
Tried to maiden. Beautiful day. Something shoddy going on with orange uhf, was losing link intermittently within a few meters so couldn't fly. Could be a problem with my home build turnstile, could be an issue with the tx/rx. Based on this experience and what others say, I think hobbyking orange openlrs unit is quite likely :censored: . Will probably put it on frsky 2.4 to get it flying and maybe get one of the new rlink ones.

I really think you were being a bit ambitious proving out a new LRS system using a turnstile. If you want to send the OpenLRS TX / RX pair I can test them for you? I know a working 100MW HK OpenLRS system is good for at least 5.5Km and that was at just above tree level on a quad.

Neil.

skyscraper · February 17, 2014, 10:37:48 AM

Quote from: iPeel on February 17, 2014, 08:22:52 AM
Quote from: Big_Tone on February 16, 2014, 10:10:34 PM
Tried to maiden. Beautiful day. Something shoddy going on with orange uhf, was losing link intermittently within a few meters so couldn't fly. Could be a problem with my home build turnstile, could be an issue with the tx/rx. Based on this experience and what others say, I think hobbyking orange openlrs unit is quite likely :censored: . Will probably put it on frsky 2.4 to get it flying and maybe get one of the new rlink ones.

I really think you were being a bit ambitious proving out a new LRS system using a turnstile. If you want to send the OpenLRS TX / RX pair I can test them for you? I know a working 100MW HK OpenLRS system is good for at least 5.5Km and that was at just above tree level on a quad.

Neil.

There is something weird about the HK Orange Open LRS. Some people seem to get good range and others not. With mine I got around 750 m. I shelved it for now

There are various explanations. Here are a couple of thoughts...
1 Interference from other stuff on UHF. Can vary dramatically from place to place. Would be testable by using the frequency scanner function. Should have tried myself but never got round to it!

2 Quality control. If HK are using cheap components then by chance maybe some combinations tune nicer than others. Testable by getting a "good" one and a "bad" one and testing them together. I would be up for that later in the year...

regards
Andy

iPeel · February 17, 2014, 11:07:30 AM

Quote from: skyscraper on February 17, 2014, 10:37:48 AM
There is something weird about the HK Orange Open LRS. Some people seem to get good range and others not. With mine I got around 750 m. I shelved it for now

There are various explanations. Here are a couple of thoughts...
1 Interference from other stuff on UHF. Can vary dramatically from place to place. Would be testable by using the frequency scanner function. Should have tried myself but never got round to it!

2 Quality control. If HK are using cheap components then by chance maybe some combinations tune nicer than others. Testable by getting a "good" one and a "bad" one and testing them together. I would be up for that later in the year...

I agree, which is why I offered to test the TX and RX against known good setups and with known good antennas. One thing's for sure, the HK variants are nowhere near as good as DTF-UHF modules. I'm pretty sure I got terrible results from the HK modules before I added ground planes on both the TX and RX, I know for sure that the TX needs it to operate well. The OrangeRX modules don't have filtration either, where the DTF-UHFs do.

Short of a Yagi, I haven't found anything that beats an MR-75S and a dipole, the turnstile sounds good on a wing, being flat, but having to horizontally polarise your TX antenna means either standing sideways on to your model or using a Moxon / Vee antenna, or a Yagi which is cumbersome. I got some strange nulls with a turnstile and it uses a fair bit of surface area (something a Venturi isn't exactly lacking in I admit), a dipole made with a rigid driven element and flexible ground plane element seems to perform much more reliably.

This video shows at least that low level flight is good out to for a few KM using a basic monopole on both the TX and RX on HK OpenLRS, the module in the back of the 9x is definitely an OrangeRX, not long after that though I switched to DTF-UHF.

http://youtu.be/FBmXo_StMT0

I still have the OrangeRX module so I might stick it back in my 9x and try it out again with a more recent firmware and check what range is possible at a half decent altitude and a better ground plane.

skyscraper · February 17, 2014, 02:31:51 PM

Quote from: iPeel on February 17, 2014, 11:07:30 AM
Quote from: skyscraper on February 17, 2014, 10:37:48 AM
There is something weird about the HK Orange Open LRS. Some people seem to get good range and others not. With mine I got around 750 m. I shelved it for now

There are various explanations. Here are a couple of thoughts...
1 Interference from other stuff on UHF. Can vary dramatically from place to place. Would be testable by using the frequency scanner function. Should have tried myself but never got round to it!

2 Quality control. If HK are using cheap components then by chance maybe some combinations tune nicer than others. Testable by getting a "good" one and a "bad" one and testing them together. I would be up for that later in the year...

I agree, which is why I offered to test the TX and RX against known good setups and with known good antennas. One thing's for sure, the HK variants are nowhere near as good as DTF-UHF modules. I'm pretty sure I got terrible results from the HK modules before I added ground planes on both the TX and RX, I know for sure that the TX needs it to operate well. The OrangeRX modules don't have filtration either, where the DTF-UHFs do.

Short of a Yagi, I haven't found anything that beats an MR-75S and a dipole, the turnstile sounds good on a wing, being flat, but having to horizontally polarise your TX antenna means either standing sideways on to your model or using a Moxon / Vee antenna, or a Yagi which is cumbersome. I got some strange nulls with a turnstile and it uses a fair bit of surface area (something a Venturi isn't exactly lacking in I admit), a dipole made with a rigid driven element and flexible ground plane element seems to perform much more reliably.

This video shows at least that low level flight is good out to for a few KM using a basic monopole on both the TX and RX on HK OpenLRS, the module in the back of the 9x is definitely an OrangeRX, not long after that though I switched to DTF-UHF.

http://youtu.be/FBmXo_StMT0

I still have the OrangeRX module so I might stick it back in my 9x and try it out again with a more recent firmware and check what range is possible at a half decent altitude and a better ground plane.

Dont suppose you are anywhere near Herts or beds area? Would be interesting to see your Orange openlrs working and compare..

regards
Andy

iPeel · February 17, 2014, 03:39:18 PM

Quote from: skyscraper on February 17, 2014, 02:31:51 PM

Dont suppose you are anywhere near Herts or beds area? Would be interesting to see your Orange openlrs working and compare..

Yup', I'm based near Milton Keynes so north Bucks. If you're based near Brucey then we're been threatening to arrange a meet up for a while. Now it's getting calm again it might be worth doing that, but I have to get my tracker back online first as that's on the bench ATM.

Brucey · February 17, 2014, 06:48:33 PM

Yeah we do need to meet up, I just need to moons to align, day off, Mrs at work and good weather! Not asking for much!
It would be good if the three of us get together, skyscraper and I fly together when we get a chance, been a while though.

skyscraper · February 17, 2014, 07:58:18 PM

Quote from: iPeel on February 17, 2014, 03:39:18 PM
Quote from: skyscraper on February 17, 2014, 02:31:51 PM

Dont suppose you are anywhere near Herts or beds area? Would be interesting to see your Orange openlrs working and compare..

Yup', I'm based near Milton Keynes so north Bucks. If you're based near Brucey then we're been threatening to arrange a meet up for a while. Now it's getting calm again it might be worth doing that, but I have to get my tracker back online first as that's on the bench ATM.

Quote from: Brucey on February 17, 2014, 06:48:33 PM
Yeah we do need to meet up, I just need to moons to align, day off, Mrs at work and good weather! Not asking for much!
It would be good if the three of us get together, skyscraper and I fly together when we get a chance, been a while though.

I'm up for it whenever... What about a venue?

regards
Andy

iPeel · February 17, 2014, 08:03:04 PM

Quote from: skyscraper on February 17, 2014, 07:58:18 PM

I'm up for it whenever... What about a venue?

I either fly from the Bury Field in Newport Pagnell or just pitch up beside a field which isn't too accessible.

Some of the places Brucey flies from seem pretty good, how about one of those?

Big_Tone · February 17, 2014, 08:03:48 PM

I did some more testing back at home and I might have been a little quick to blame hobbyking. I left the plane at the front of the house and went two floors up, still with signal. I then went to the back of the house (still two floors up) and got the occasional blip from the tx, which I think might mean lowered signal but I've not looked it up. I therefore think it's either something intermittent or more likely some heavy interference on 459 at the field. I would think the interference would have to be really bad to lose a link 2 meters away? I did a spectrum analyser at home before I chose the chans (currently hopping over about 5 on the high side of 459) and there was not much apart from a tiny blip which I avoided. I would need to take my laptop to the field to conclude and it's battery won't last 10 mins nowadays. There are some big comms towers fairly near the field (the old Croydon airport at purley). I'm not sure what they are but they don't look like mobile phone towers.

Neil, I might well have jumped in too far going for a turnstile! Got excited and jumped a step or two. Thank you very much for your offer to test. If it is interference then the modules might be fine. Only other point to note is that I was using stock rubber ducky on the tx. I have a diamond ant but need an extension to mount it.

I'm thinking of still putting the 2.4 frsky in. This is my first wing and I'm jumping ahead putting something long range in. I might leave the turnstile in place so I can go back to it later. It does freak me out that I could lose signal so close though.

Made some new friends in purley so not a wasted trip!