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

[thundead]

It is already done in 3.5 mate :) use set 2 and that's it :D

Channel spacing on 459MHz is 25kHz.
We cannot get 25kHz multiples, so we must use multipes of 10kHz.

So from a startup frequency of 459.000 we can get, for example,  459.000, 459.050, 459.100, 459.150, 459.200 etc

and for a startup frequency of 459.025, we can get, for example, 459.025, 459.075, 459.125, 459.175, 459.225 etc

http://www.ukrcc.org/459mhz.html

Another code change Mihai?  :D

Nigel.

[papa_lazerous]

if you pick the wrong frequency you can seriously pi$$ off some HAM geeks

Oi, watch who you're calling a Ham geek  ;D

I've been a licenced 'geek' for 30+ years.

Nigel

See what I mean.... such a touchy bunch, just imagine I was broadcasting all over Nigels broadcasts  :o

No offence meant :)

And Splashy, I think 433 for telemetry is limited to a much lower power.  I remember reading it somewhere but cant recall where

[Splashy]

Fair enough, thanks for that.

[Coyote]

I think im missing something with the hopping discussion, I tested without hopping, could not get a lock at 2.4km. The noise floor was high on 433 as it was on 459, but the 433 had no problems at all.

So why are we looking at the channel spacing on 459 when it failed on one single channel ?

I would have thought that channel spacing and hopping really does`nt matter if it cant perform on one static channel

Like I say, maybe I`ve missed something

[Devonian]

I think Mihai was setting channels spacing for 459 at 10kHz but it is 25kHz.

Nothing to do with your tests Ian, just a bit of info mixed inbetween your tests.

Channel spacing may have an influence on things if set too small (10kHz).

One more thing I've noticed.  In the register settings pdf, for power levels,
default for 0x6d at 18 (hex, for full power)
Melih/Mihai set 06xd to 07 (too low a power?)
or am I missing something (quite possible)!!

A quick setting change in the Tx pde, load it to your Tx and run up the spectrum analyzer will prove it - I'm at work but will try it as soon as I get chance.

Attached is Si-AN440 pdf for register settings.
0x6d is on pg3

Nigel.

[Splashy]

I have been doing some playing around using 2 x TX. One running 3.something on 439 Mhz and the other running the standard 459 Mhz (probably 3.5)

Results are below and are as expected.
(I can't post the pic for some reason - so here it is)



Now, this is where it MIGHT get exciting. I created a new TX version last night. It contains the suggestions of a few people including Zitron, is on one channel with no hopping, and uses data from the excel spreadsheet.

[Coyote]

Just in from my first OpenLRS V3.5 flight.

Mixed results, I could only get 3.1km with a 400mw boost, but it was controlling the plane flawlessly

[papa_lazerous]

Just in from my first OpenLRS V3.5 flight.

Mixed results, I could only get 3.1km with a 400mw boost, but it was controlling the plane flawlessly

400mW boost?  the booster I am thinking of starts doing its magic at around 800mW-1000mW

[Dennis Frie]

I have been doing some playing around using 2 x TX. One running 3.something on 439 Mhz and the other running the standard 459 Mhz (probably 3.5)

Results are below and are as expected.
(I can't post the pic for some reason - so here it is)

Now, this is where it MIGHT get exciting. I created a new TX version last night. It contains the suggestions of a few people including Zitron, is on one channel with no hopping, and uses data from the excel spreadsheet.

Very interesting. Anyway possible I can ask you to make a scan with something like 250-400 average to make sure it's the actually peaks we see from the frequency-jumping? Just to be sure

Something like:
Start freq: 440
End freq: 442
Nr avg: 300
Step size: Match the channel-spacing

[Coyote]

Just in from my first OpenLRS V3.5 flight.

Mixed results, I could only get 3.1km with a 400mw boost, but it was controlling the plane flawlessly

400mW boost?  the booster I am thinking of starts doing its magic at around 800mW-1000mW

Yes Im running it at 3.7v ( 0.8watts) but on half power, so 400mw.

Because the tx had booster : 1 it only outputs 50mw but goes through the booster ( switched off ) so no idea what it really was.

I had 2.02v RSSI at 3.2km, but then it went into failsafe without warning

[papa_lazerous]

Just by looking at the datasheet really quick, I would say engaging half power mode( lowers gate from 3.3v to 2.75v at that low of an input voltage on the drain, would mean little or no amplification of the signal.  Infact you are boardline attenuating it.

If you are running the Tx with the booster OFF but passing signal through it I dont know what you end up with or if there would be any damage to the RF amplifier. 

EDIT: this is a copy from the datasheet..

Without the gate voltage (VGG=0V), only a small leakage current flows into the drain and the RF input signal attenuates up to 60 dB.

Where all your tests conducted like this?  This means you had upto 60dB attenuation on 50mW of power!

[Splashy]

Just in from my first OpenLRS V3.5 flight.

Mixed results, I could only get 3.1km with a 400mw boost, but it was controlling the plane flawlessly

400mW boost?  the booster I am thinking of starts doing its magic at around 800mW-1000mW

Yes Im running it at 3.7v ( 0.8watts) but on half power, so 400mw.

Because the tx had booster : 1 it only outputs 50mw but goes through the booster ( switched off ) so no idea what it really was.

I had 2.02v RSSI at 3.2km, but then it went into failsafe without warning

I just did some tests and with the 439 setup with 433 antenna and 459 with 459 antenna. I then changed the antenna on the RX spectrum analyzer to a 459 and the results were much better. I am wondering whether the choice of antenna is set to make a large difference to the range seen .. so far we have been running at 439 with 433 antenna and the results were good, when we changed the 459 the results were bad.

I could send you a set of 459 antenna if you would like. Perhaps then we can remove this from the equation. Just pm me your address if you would like them and I'll post them out tomorrow.

[Coyote]

Just by looking at the datasheet really quick, I would say engaging half power mode( lowers gate from 3.3v to 2.75v at that low of an input voltage on the drain, would mean little or no amplification of the signal.  Infact you are boardline attenuating it.

If you are running the Tx with the booster OFF but passing signal through it I dont know what you end up with or if there would be any damage to the RF amplifier. 

EDIT: this is a copy from the datasheet..

Without the gate voltage (VGG=0V), only a small leakage current flows into the drain and the RF input signal attenuates up to 60 dB.

Where all your tests conducted like this?  This means you had upto 60dB attenuation on 50mW of power!

No previous tests were all done with no booster connected. When half power was selected with 3.7v input my RSSI shot back up to full, so I would say it definitely is boosting fine. 

[Coyote]

Thanks Splashy, if you want to send me them and I will gladly repeat the tests.from the same location so we have more data

[papa_lazerous]

Just by looking at the datasheet really quick, I would say engaging half power mode( lowers gate from 3.3v to 2.75v at that low of an input voltage on the drain, would mean little or no amplification of the signal.  Infact you are boardline attenuating it.

If you are running the Tx with the booster OFF but passing signal through it I dont know what you end up with or if there would be any damage to the RF amplifier. 

EDIT: this is a copy from the datasheet..

Without the gate voltage (VGG=0V), only a small leakage current flows into the drain and the RF input signal attenuates up to 60 dB.

Where all your tests conducted like this?  This means you had upto 60dB attenuation on 50mW of power!

No previous tests were all done with no booster connected. When half power was selected with 3.7v input my RSSI shot back up to full, so I would say it definitely is boosting fine.

Check the data sheet mate, it may have boosted at half power with 3.7 in but nowhere near as high as 400mw and you where definately attenuating with booster off and running through it.