thUndeadMod v3.4 - openLRS S**T just got real :)

[raptor_flyer]

Well I have some EPIC news  :o

I did a range test this afternoon with very surprising results. I tested at 459MHz on the new 3.6 software running @100mW using a V2 Tx and a V2 Rx.  On the Tx I had a Diamond SRH-771 antenna (not ideal for 459MHz but ok)  and on the Rx I have a home made dipole tuned to 459MHz.

What was the total length of your "home made dipole tuned to 459MHz" ? I assume 163 mm * 2 = 326 mm ?

How are you planning to mount it on the plane ? Ideally I wanted to use a similiar dipole configuration but can't figure out how to mount it on our twinstar

[papa_lazerous]

Well I have some EPIC news  :o

I did a range test this afternoon with very surprising results. I tested at 459MHz on the new 3.6 software running @100mW using a V2 Tx and a V2 Rx.  On the Tx I had a Diamond SRH-771 antenna (not ideal for 459MHz but ok)  and on the Rx I have a home made dipole tuned to 459MHz.

What was the total length of your "home made dipole tuned to 459MHz" ? I assume 163 mm * 2 = 326 mm ?

How are you planning to mount it on the plane ? Ideally I wanted to use a similiar dipole configuration but can't figure out how to mount it on our twinstar

The antenna I have in my plane is built into the tail of my skywalker, half of it protrudes vertically through the top of the tail and the rest is inside.  I have a RF sensor from flytron that I have hooked so the higher the recieved signal it shows on an LCD.  What I did was make the antenna longer and then trim it down and monitor the signal strength, its very sensitive and works well.  But I am a little OCD about things and 163mm should be fine, the antenna I used for testing with my ghetto test rig was a quicky but accurate dipole that I made purely for range tests, I tuned using the RF sensor by trimming the elements till I got a peak (Yes I did over trim it and start again when doing my first one)  I am going to put that antenna on my quad now

[raptor_flyer]

Thanks for the Info.

Unfortunately we have the Video TX aerial mounted on the tail so can't put the OpenLRS antenna there.

I've been experimenting with so called "Bazooka Dipoles" see http://www.hamuniverse.com/vertbazooka.html

I think they've been mentioned before on this forum. They are fairly easy to make and much easier to mount since you can put them inside a plastic tube. But I have no idea how they perform compared to
classic dipoles like yours ?

[papa_lazerous]

I experimented with making a dipole like that a few weeks ago, but I havent got any tube to put it in so it sat un finished till I get a nice rigid sleeve.  Its easier to make a classic dipole though.  What plane are you trying to fit the antenna on?

[raptor_flyer]

I experimented with making a dipole like that a few weeks ago, but I haven't got any tube to put it in so it sat un finished till I get a nice rigid sleeve.  Its easier to make a classic dipole though.  What plane are you trying to fit the antenna on?

At the moment our FPV Testbed is a Multiplex TwinStar. We have the dipole for the video link mounted in the
tail fin so can't really put the dipole for the radio link there.

Would be interesting to hear if anyone has tested Bazooka verses conventional dipoles ?

If you read the stuff about Bazooka dipoles on the HAM radio sites they should perform better than
a conventional dipole when fed via a coax since they provide similar features to a balun to prevent the
coax from acting as an antenna as well.

I haven't found any reference to them yet in the FPV context though ? 

[papa_lazerous]

maybe you can move your Vtx?  Also why are you using a dipole for your video?  Circular polarisation seems to have taken over as it cures all the multipathing issues.  But forget the buzzword bazooka,  what you linked to is just a dipole antenna!  The difference is that its end fed instead of centre fed.  I do believe there are some advatnages to be had, but its not going to rock your world thats for sure.  As soon as I can find a cheap source of some tubing to slide mine inside of to stop it bending around I will test it and let you know how it compares to a standard dipole,  I dont think we are going to be talking allotof difference.

[thundead]

This will probably be the last firmware release as ppl seem to have been losing interest in this lately (only 2 people actually bothered testing the beta). 


------------------------------------------------------------

Final thUndead Firmware for the openLRS

Changelog:

- v2 RX Pinout reverted back to 3.1 (RSSI on pin 8)
  -RSSI is not rock solid as it was before
- Serial PPM on pin 9
- Hopping algorithm and recovery improved.
- 459 should be nice and reliable (tested 3km on ground)
- 433 should be even better
- Fixed nasty frequency change bug in GUI
- added channel selection dialog in GUI

DISCLAIMER
- Use this fw at your own risk. I cannot be held responsible for plane crashed, exploding rx/tx modules, aliens making contact etc lol.
- big thanks for papa_lazerous and ghost 2212 for bothering to test out the beta.

Background data

- Ground test was carried out on the 459Mhz band
    Was tested up to 3km with some spare rssi left (ground test)
    huge thanks to papa_lazerous for bothering to test this thing.
- rx/tx were stress tested for about 4h without any module lockouts / resets / etc (tx on micro mode in my Faraday microwave oven lol)
- RSSI was rock solid over this 4h period with slight variations (+/- 0.06v max)

so I can say that if this fw is doing weird stuff then you might be doing something wrong. (unless I can reproduce the bug and eat my words :) ) I challenge anyone to prove me wrong hehe.

-----------------------------------
Download
http://openlrs.googlecode.com/files/thUndeadMod3_6FINAL.zip
-----------------------------------

Regards,
Mihai :)

[Coyote]

I`m still interested Mihai, but due to lack of planes I haven`t tested it yet. No one else seemed to be flying / crashing other than me so I want to see someone else take to the air first before I risk another load of money

[thundead]

I appreciate that coyote and I understand no worries :) the thing is i personally dont use the olrs. the 2.4 Frsky is enough for my applications so I've been deving for you guys and want to see if I'm doing it right basically. no point in releasing new firmwares if they get worse.

I`m still interested Mihai, but due to lack of planes I haven`t tested it yet. No one else seemed to be flying / crashing other than me so I want to see someone else take to the air first before I risk another load of money

[papa_lazerous]

Ground tests don't cost money ;) just time and a little petrol (ok that stuff is expensive). My new Vtx arrived today, I broke mine a few weeks ago so wasn't able to fly fpv.  Weather permitting I'll be testing in the air Sunday.  I have absolute confidence in it after testing on the ground

[Coyote]

Ill do a ground test soon enough though, I`m going to make a board up though, apart from it looks better in the tests I can mix n match dead quickly too

On about that, does anyone know how to put a turnigy 9 into a servo test mode, so it continuously moves the servos ?

[papa_lazerous]

Are you running ER-9x?  If so create a new model and servo test is under the templates.  Then goto the mix page and chose the channel the servo is plugged into and add channel 16 to that mix.  It might be ch15 but I'm almost positive it's 16.  If you don't have that template installed I will post after work how to configure from scratch.

[papa_lazerous]

Oh I nearly forgot.... Your making a board up for testing?  What's wrong with the ghetto rig?  All you need is Sellotape and a cardboard box, low tech for the win lol

[Coyote]

Year ER-9X, cool, having a look right now :)

Its just a ply board and velcro, as getto as I can get :)

[papa_lazerous]

Sounds like wanna be ghetto to me, do you have a stroppy adolescent teen that can help you whilst under duress?