FrSky XHT diy 2.4 ghz RF module

[MJF]

Has anyone tried using one of the newer FrSky XHT modules in the same capacity as we used the older now nonexistent now DHT modules? It looks like they are ACCST compatible.
Any issues?

[stuart mackay]

Works fine, just remember to bind the receiver in Telemetry mode.
Have got a couple of them flying now

[F2B]

Which is great, but in a way, strange.
The XHT seems to have a CE approval, so one would expect the D8 protocol having been rendered inaccessible....
Maybe the UK is not as strict as the continent, and indeed, when flying in some remote place I don't see any problems.
But over here between the densely populated urban areas from the West Netherlands where clubs are in constant legal battle for keeping their grounds, anything shady that could jeopardise their existence is easily frowned upon.
So, what is wisdom?

[Mike_K]

Bruno

I wonder if they have modified the D8 transmitter format. Is there any reason why you could not have LBT with D8? If the next channel to be used was in use, it just wouldn't transmit that packet of data and would wait to go the next "hop frequency". Meanwhile, the receiver would time out on the non-transmitted packet (just another "lost packet") and would listen out on the next-hop frequency. I'm only guessing the above and have no evidence or read anywhere else that this is the case.

I think there are other LBT restrictions such as it must not spend more than 60mS on the hop frequency and there must be at least a 5mS gap before the next transmission, which I think the D8 already meet.

They are being advertised by numerous reputable EU sellers as having D8 ACCST compatibility and are CE marked, so if you buy one, it's the sellers' responsibility to ensure conformance, you don't need worry (unless the instructions give specific guidance on its use). Previously FrSky has had their gear correctly FCC tested and the EU compliance tested by an EU noted test house, I can't imagine this has changed.

Mike

[F2B]

Mike,
that's good food for thought.
At first I was under the impression FrSky would never update their D8 protocol to LBT, in order to make all their customers having to buy new receivers as soon as they would start using the newer D16 LBT TX modules.
From a commercial point of view, a clever move. At least that's how it resonated over here.
I clearly remember that for instance the Taranis, when sold over here, were only available in the "EU" configuration that specifically mentioned "no D8".
And now for the XHT, I see something similar.
Look here: https://www.engelmt.de/mtfrsky-transmit ... ul-xht_lbt
You'll see the D8 mode explicitely mentioned under features and specifications.
Then go to the German page -aimed at the EU domestic market-: https://www.engelmt.de/mtfrsky-fernsteu ... ul-xht_lbt Under 'features', 3rd line, no D8. Under 'Technische Daten', 2nd line, no D8 protocol.
So I think it would be worthwhile, checking whether the version sold under CE/EU restrictions really supports D8, which I'm afraid it very possibly won't.
Or, if it does, would be voiding the CE cover...
I'm still in the dark here.
Again, I'm not as concerned about non-LBT protocols causing any danger in normal flying (if the applicable 'grandfathers rights' would, continuing the use of my DJT/DFT and DHT, I bought before the cut off date, would be rendered illegal on the spot but it isn't)
However, in case of any legal issues (crash, damage, injury) using anything outside a CE could be a very expensive adventure in the end.
But what is it, D8+CE or D8, so no CE? I don't know....

[JohnRogers]

Hello I'm John Rogers and just started putting together a retro single channel system. Learning as I go along

I have an encoder, switch and harness supplied by Phil Green, a transmitter box etc, so the next stage is the RF module. I understand the FrSky XHT unit is good to use but I was wondering on the voltage of the whole set up. I was advised to check the feed between the encoder and the RF module.
I would be grateful for some advice

Thank you John

[Phil_G]

...I was wondering on the voltage of the whole set up

Treat the XHT like any other 2.4g module John, its no different power-wise as they're internally regulated to 3.3 volts.
Use a 2S Lipo, 9v PP3, 7 or 8 NiMh, 3S LiFePo4 etc, I think most of us use a 2S Lipo

I was advised to check the feed between the encoder and the RF module.

Sorry dont follow???? Its just pos neg and PPM same as any other RF module John. Connect it up as per the encoder document, it will be fine!
Cheers
Phil

[JohnRogers]

Thank you Phil, I was advised that a resistor or diode may be necessary in the circuit to keep check on the voltage, i may have misunderstood. Does the encoder work on the full voltage or is it reduced to 3.3 volts ?

Thanks for your help

John

[JohnRogers]

The XHT doesnt need it, and the S/C encoder has a resistor in the PPM line anyway John. Dont worry, just follow the document

Hello Phil - thank you, I am getting up to speed.

One last question when you refer to the document, is that one that comes with the r/f module?

Thanks John

[guzzimeister]

Again, I'm not as concerned about non-LBT protocols causing any danger in normal flying (if the applicable 'grandfathers rights' would, continuing the use of my DJT/DFT and DHT, I bought before the cut off date, would be rendered illegal on the spot but it isn't)
However, in case of any legal issues (crash, damage, injury) using anything outside a CE could be a very expensive adventure in the end.
But what is it, D8+CE or D8, so no CE? I don't know....

I've just bought 2 of the XHT boards, one to do a straightforward Fleet XP/FM conversion and the other to do a full conversion of a Fleet TX to s/c plus all the bells and whistles using Phil Green's board. I can report that they do have D8 capability as they are driving the 3 D8 receivers I got from ebay. They also can transmit D16. Forgive my ignorance but what is the problem with D8?

cheers

Jon