New DX8 - great tx but just a question on results of a range test....

[patmacca]

Hi guys,

Please bear with as I'm returning to flying after a few years out. After a lot of toing and froing I decided on a DX8 in the end as I had previously owned a dx6i with no probs. I also purchased a Blade MQX as a trainer (fab little thing!). The firmware is 2.02 I'm waiting on a usb adapter to arive through the post so i can upload the latest firmware.

I've flown several battery packs with the MQX (this is all i have at the mo) with no problems at all however on a 30mtr range check (following all procedures - model on floor and me facing model) before i got to 10mtrs I had the following data on the DX8:

A: 0 L: 0 F:246

B: 0 R: 0 H:1

I take it that F is frame loss? and H is hold? Is this data something to be concerned about given that the mqx is just a micro really (although its on DSMX)? Why no antenna fades but instead frame losses and a hold? Will the 2.05 update sort this? Just looking for some opinions from experienced users and some reassurance. Many thanks - Pat

[MartinW]

I'm not experienced enough to be able to really advise you, especially given that the MQX is a ready built, nothing can be done to alter it, beast (I have one too). I also have a DX8 and have to admit to having been bad and never range tested the MQX on it (maybe I really should!).

BUT...

I did go through all of this with a Mk1 Wot-4 (fixed wing plane) that I converted from IC to battery earlier this year and basically it was a case of ANY Hold's should be investigated and the receiver repositioned until you get no holds. Which in that model I did.

I don't know if 2.0.5 will have much of an impact on it, but I presume there's been other's in between so maybe.

The best thing to do would be to ring Horizon Hobby in the morning and put the question to them. Given both the TX and MQX are new, they'll take either, or both back at their expense if they believe it's anything to be concerned about...

[patmacca]

Many thanks for the reply. I'll contact HH tomorrow and see what they say. It would be interesting to see what results you get if you tried yours as I'm wondering given the fact the MQX is so low to the ground it might be a factor.

[MartinW]

No problem, I'm interested myself now! I'm sure in the DX8 manual it says any 'Hold events' should be investigated and if necessary receivers repositioned, but this is a BNF quad we're talking about. Not much scope for changing anything really

One thing I will say is that you're unlikely to get very far away with the MQx. It can be a bit of a pig to see in terms of orientation. I just bought a set of bright orange blades for mine to replace the white ones, they make quite a difference.

Let us know what HH have to say. They're usually very good if you ring them.

[Zeeflyboy]

It's normal to see frame losses, though in normal operation you'd expect only a few...

Did you do this while stationary or while moving the model? Did you have the dx8 antenna pointing at the model or off to the side at 90 degrees?

Anyway, the mQX has only got an rx with a single, less than optimally positioned antenna. If the antenna is pointed towards the transmitter or is oriented at 90 degrees (eg antenna on mQX is horizontal while antenna on TX is vertical) then you either lose a load of signal from the antenna null or from polarisation losses respectively.

This is fine, because you will still lose sight of the thing before you lose radio contact. 30 paces is considered a pass for even a larger model and should confirm that it will stay in control at LoS distances.

Fades on A and B usually refer to satellites iirc, which the mQX doesnt have.

Personally I'd suggest there is nothing wrong - 30 paces in the reduced power mode is equivalent to far, far, far beyond visual range on an mQX.

[highlightshadow]

A 30m range test is quite a distance for such a small model which will probably have a low power receiver
Given the full-power range that would equate too, plus the receiver is more able to receiver when its in the air rather than losing a fair amount of signal on the floor i wouldn't worry too much ... the chances of losing signal before losing vision on a mQX is very unlikely.

Are you range testing with the antenna sticking straight out or at an angle.... it DOES make a difference especially on the ground because of the way the signal radiates from the sides of the antenna pole not the tip (from what i understand anyway)

[Zeeflyboy]

Highlight, there's no such thing as a low power receiver... It could be less sensitive but I've never seen any data to suggest that.

Completely correct btw, the radiation patten from a whip antenna is pretty much a doughnut shape - the null (or hole in the doughnut if you will) is directly above and below the antenna's tip and base.

[highlightshadow]

Fair enough, just that the mqx receiver is a DSM2 one .... whereas i've seen some other (typically newer DSMX) receivers advertised as 'full range' receivers ... so implied that others were possibly shorter ranged / reduced power

Just a thought thats all

[MartinW]

That's not entirely true. There are park flyer, microlight (6110) and full range (600) in the Spektrum world. I very much doubt it has a full range in it due to the size of the model but the product page doesn't say and I'm working so don't have time to dig out the manual right now.

Will be interesting to see what HH have said. Frame losses I can understand (some) but there shouldn't be Holds.

[bulnose]

ok m8, here is my experience with the dx8..

Had 2 planes loose signal in our field exactly the same spot, they fell out of the sky..

Flew the logo 600se, went into failsafe quite far out, came back into signal and got it back, phew!!!

Started to get worried at this point, one thing i had been doing was flying witht the txx ariel in default poition, ie straight up..

Sooo.. i turned it 90 degrees to the side, had 2 more flights on the logo no problems..

Got home and looked in vbar log... The last 2 flights didnt even loose packets or swop sats..

The previous flights to those and all the ones befotre showed loss of packets and the nasty one where all inputs were lost..

So the moral of the story is never fly your dx8 witht the ariel straight out..

Hope this helps

[highlightshadow]

Echos my experience with dx8

[Zeeflyboy]

The park flyer/ full range is usually distinguished by having diversity in the form of either satellites or more than one antenna.

Regardless, a receiver cannot be high power or low power. It is (disregarding telemetry) a passive item that doesn't transmit. It simply can't be low power as there is nothing to change the power of... You could have a higher or lower power transmitter, but not receiver.

It can be less or more sensitive, but again while its possible I've seen no indication spektrum uses different sensitivity chips.

[MartinW]

It does actually say that in the manual but in fairness it's tucked away on page 36 under safety dos and donts. It really should be more prominent than that as most people don't read that far!

EDIT: Direction of the antenna that is!

[bulnose]

did someone caall the manual police ?

[jimmyhorns]

I've flown several battery packs with the MQX (this is all i have at the mo) with no problems at all however on a 30mtr range check (following all procedures - model on floor and me facing model) before i got to 10mtrs I had the following data on the DX8:

A: 0 L: 0 F:246

B: 0 R: 0 H:1

How are you getting this data?.. I didnt think the MQX had telemetry or flight log?..

If it doesnt then the DX8 wont know what the signal level is at the receiver.