FrSky R9M....868mhz European Frequency.

Coyote · October 30, 2018, 05:27:01 PM

English Turbines · October 30, 2018, 06:48:05 PM

The True-Mox 868mhz EU centred TX antenna featured in the above video....Available from hobbyrc

You can rotate this to suit horizontal or vertical polarisation depending on how your RX antenna is installed. Vertical is what is suggested. This is a directional antenna.

It's a bit like the 1280mhz Yagi PCB Video antenna I have.

Imagine what just 500mw will do..?

:vulture:

Coyote · October 30, 2018, 07:22:55 PM

I decided to go the Super 8 route but to be honest with this or the Tru mox I'm not over keen on the semi rigid feed cables, after using them with the Crossfire antennas they don't last long.

English Turbines · October 30, 2018, 07:29:01 PM

Hi mate,

I ordered the PCB Moxon...It sounds like its centred on 868mhz and these PCB antennas are very accurately made.

I get what you are saying though about the semi rigid feed, they need viagra after a while....lol. If no joke then an analogue of viagra on http://eradancetheatre.com/buy-cialis-online-no-rx/">eradancetheatre.com cialis by the way for people who want to save time on ordering and searching for a recipe...take it there...lol

:vulture:

chris-s · October 30, 2018, 09:12:11 PM

Quote from: Coyote on October 30, 2018, 05:27:01 PM
! No longer available

Nice result.

Which firmware did you go with in the end?

Slightly off-topic, what video setup did you use?

Chris

Coyote · October 30, 2018, 09:30:54 PM

It's not me in that one Chris.

The guy is in the UK, not sure who he is or the firmware details. I'd like to run the numbers on the range back when I get in. That range seems far beyond 25mW

CurryKitten · October 30, 2018, 10:59:06 PM

That is an interesting video for two reasons. Mostly, it's why he turned around at 9.5km - that's not the milestone you're after. Coyote was telling me he thought that 868 was good for around 10km, but struggled after that - even at 500mw, so this range on 25mw seems impressive.

I'm off collecting data tomorrow (if it's not too cold - I reserve the right to pussy out) My testing last time seemed to show that the RSSI on ch16 was all over the place, although I did have a particularly silly antenna setup. This was done as I thought having a horizontal antenna on the RX and vertical on the TX would be worse... but I'll test that to see. So my list of flights for tomorrow to gather as much data as I can about what is best in my various options I have are -

R9M 25mw with Telemetry
1 - Standard TX antenna vertical, RSSI on ch16
2 - Standard TX antenna horizontal, RSSI on ch16
3 - TBS TX antenna (SMA->RP-SMA adapter), RSSI on ch16
4 - Standard TX antenna vertical, use Telemetry RSSI
5 - Standard TX antenna horizontal, use Telemetry RSSI
6 - TBS TX antenna, use Telemetry RSSI

R9M-Lite 25mw with telemetry
7 - Standard TX antenna vertical, RSSI on ch16
8 - Standard TX antenna from R9M horizontal, RSSI on ch16
9 - TBS TX antenna, RSSI on ch16
10 - Standard TX antenna vertical, use Telemetry RSSI
11 - Standard TX antenna from R9M horizontal, use Telemetry RSSI
12 - TBS TX antenna, use Telemetry RSSI

FrSky tell me they are working with Betaflight to get their RSSI right... seems they got it right on the 2.4 rx's, so I'm not sure what their problem is here, but it seems like a random number generator to me. But to make the tests complete, I'll fly with RSSI on ch16 and then switch to use the telemetry RSSI instead - attempting to fly the same circuit on a quad which previously managed to generate a very low RSSI signal. Let me know if I'm missing something.

Coyote · October 31, 2018, 03:20:19 PM

Looking forward to seeing your results Wayne :)

I had mentioned in here as well as the advanced R9 facebook group of Frsky missing a trick not being able to do diversity receiving using two receivers ad only having it run as a redundancy system.

One of the users ( Justin Kramer ) on the group passed this onto Frsky who when replied said that they do in fact work as diversity after all by going with the receiver with the highest RSSI.

The confusion has been in the wording of how redundancy works by them, they made it sound as if the second receiver would only take over in the case of power failure of the first, thsi they have now cleared up is not the case, which for me is great, because now I can run the main receiver on the rear of the plane while having a second one on the front for the return leg. Or you could have one receiver on each wing so LOS would always be to one of them that way.

Things are looking up for the potential of this system now for me :)

Loopdreams · October 31, 2018, 03:36:54 PM

Mine's only just been sent. With any luck by the time it arrives everyone will have finished figuring out how it works.

CurryKitten · November 01, 2018, 11:26:22 PM

So here's my video showing my tests and the results (it unlisted at the moment, and will go live tomorrow at 6pm - so if it suddenly goes to private that means I've needed to schedule it's release, but it'll go back to normal afterwards)

! No longer available

The TL;DR version fo events are that having a better TX antenna makes a world of difference, and using the telemetry RSSI gives a better representation of the actual signal strength. Next things to do are to check out the super 8 antenna and to try the flex firmware to see what difference that makes

Coyote · November 02, 2018, 12:02:56 AM

Great testing Wayne

To save tying it again, copied from YouTube :)

Nice testing Wayne, the results were what I would have expected really, slight RSSI on telemetry vs channel 16, but by all means nothing out of the ordinary, I would say that channel 16 is perfectly acceptable to use, all be it a bit more jumpy. I wonder if that's more a sample rate or refresh time than anything else.

So the conclusion is, rather predictably, FRSky dipoles are complete crap lol, but once you pull the heatshrink off and see how they soldered them up they are poorly built. TBS antennas and R9 module the clear winner.

Also for your next test a Super 8 and True-Mox is the next logical testing step.

English Turbines · November 02, 2018, 10:44:49 AM

Great test Wayne...looked like hard work, well done.
Pleased I ordered the True-Mox....If it was me on that quad I would have the antenna placed vertical, its tricky only because the feed wire is so short. I know OliverC has his placed vertical.
With the Mox vertical, it should give a good result.
Be interesting to run the R9M Module at 500mw and see if it runs cooler with the TBS Dipole..Do you have a laser thermometer? That RD FrSky have issued must be pretty poor, be interesting to see its SWR etc.

:vulture:

English Turbines · November 03, 2018, 04:25:06 PM

True-Mox 868 mhz.......5.5dbi.

First impressions are good, very nicely made and finished.

Annoyingly, Its the wrong connector for the R9M Transmitter Module.

:vulture:

Coyote · November 03, 2018, 04:47:22 PM

What a bugger, mind you I had to think twice and check to see if my antenna matched there :)

English Turbines · November 03, 2018, 08:08:16 PM

So, let's assume we get the 868mhz working well eventually...

Will it play nice alongside 1280mhz Video is what Im wondering...?.....Whats the general consensus...?

:vulture: