Generic 2.4GHz Recievers

[martin taylor 1]

Does anyone know whether there are any generic receivers which are compatible with the Spektrum DX6i transmitter?

 

ESky seem to do a 2.4ghz receiver, but there is no info on compatibility.

 

Any ideas?

[David Ashby - Moderator]

None I'm aware of Martin, the only compatible receivers in the 2.4GHz world are the DSM2 based items from Spektrum and JR. 

[martin taylor 1]

thanks david

[Tim Mackey]

and of course the mulitiunits fitted to blades etc.

[Brian Parker]

2.4GHZ receivers... some notes and thoughts.

 

The receiver is the most complex part of the 2.4GHz Spread Spectrum system.

 This is due to the almost random coding (pseudo random code-PRN) of the signal. The PRN generator chip within the transmitter will contain several million Logic Gates each with two inputs switching at a multi-MHz rate.

This coding is injected into the transmit signal at a different point within the transmit chain for DSSS or for FHSS and at a sequence known only to the Transmitter and the Receiver, it is then transmitted as a broadband signal.

 At the receiver this needs to be de-spreaded and the required information recovered.

 The receiver also has to extract and add reflected signals if appropriate and reject interfering signals not containing the correct code.

Because of the nature of DSSS the Spektrum receiver is the more complex (advanced?) of the two.

 So cheap quality independent generic receivers covering both Futaba and Spektrum systems is unlikely for some time.

 If an independent manufacturer is capable of developing a receiver (the hard bit) then it is only a short step to a full system.

 Hence the cheaper systems coming onto the market. They almost certainly contain less robust coding but seem to be proving adequate for the average clubman.

[Stephen Trundle]

Hi, just read these posts & Hobbyking do a range of 3 generic rx's for the srektrum tx's. They are around 15$ each!!. I have just bought 2 to try but have not fitted them into a/c yet. They even come with a bind plug. Look under Spektrum in the Tx/rx systems & parts.

Hope that helps.

[Peter Beeney]

   Brian,
           Take a quick butchers at the ‘Cheap 4 channel Rx for Spektrum from Hobby King’ thread by Tim Mackey, 27/ 08/ 2010.
   Maybe the next step will be law suits and court cases. I’m sure these cheap receivers must ultimately affect the sales of Futaba and Spektrum. How long before the import into the States is banned, perhaps?

   Interesting situation!        PB

 

[Stephen Trundle]

Hi,

Took a look at the Tim Mackey post - great. I sorted out what pins did what & polarities  & came out with the same. Hope to get 1 airborne soon.

I agree things may get interesting! - best buy more now while we can!

[David perry 1]

Hobby King are selling receivers of three, four and six channels that are gauranteed to be compatible with Spekky kit.  Timbo has tested them and found them to be good. Several people are using them. I have just ordered one and will post results hereon, but I suspect its a done deal -  the code is broken so the gear will now come "on stream" .

 

They retail for about 15 USD.

 

David 

 

 

[Biggles' Elder Brother - Moderator]

Hobby King are now doing "pirated" 2.4 "Futaba" FAAST Rx;s now. 8 channels for $39. The plot thickens

 

BEB

[Biggestgerbil]

I have purchased an "Orange" (make and colur) 6 channel Rx from e-bay to try out.  It claimes to be 2.4Mhz DSM2 compatible.  It arrived today (next day delivery, although it is more expensive than getting it from Hobby King)  I took it up to my workshop to test.  I have no 6v batteries yet so had to test it on 4.8v  Set it up on the bench first. Binding was first time and quick. (bear in mind that I am new to 2.4Ghz) I taped a bit of 1/4 sq to the servo arm and started walking.  I reached 30 paces and pressed the bind button to do a range test. (JR 3810ADT with Spekky module) My length of 1/4sq waved at me from my workshop door. I waved back. Felling bouyed up by this result I walked a further 10 paces. Still connected.  I went all the way across the yard to where a JCB digger is parked and "hid" the Tx behind the front bucket. STILL CONNECTED.  Now, by way of experiment, I pointed the antenne directly at the Rx. Finally lost signal at about 60 yards.  Turning the antenna horizontal resumed connection fairly quickly.

 

I am now hoping that it will work in a plane.  My Wot4 Mk3 has been earmarked as a test bed.  I have installed it according to Spektrum Rx instructions, although it only has one antenna.  I fitted the Rx so that this points fore & aft thinking that my plane goes up & down the strip in front of me, mostly.  I did another range check with the Rx in the model, fully charged battery and model on the ground tail towards me.  It was ok at 30 paces but fell off rapidly after that. We will see how it performs this weekend (Met Office Permitting) and I will report back.

 

Ioan. 

[Biggestgerbil]

Well, the Met Office was not all that co-operative (must try a live chicken, KFC had no effect)

However, the club had it's September Fun Fly all the same on Sunday.  Quite windy but dry.

 

Did another range check...OK.  Decided to fly.  Well actually, nothing happened.  Perfectly normal flight.  Flew it quite high, higher than I normally would and further out than I normally would, chucked it about a bit, full controll all the time.  How do I know?  The Orange seems not to have QC feature.  It takes about 4-5 secs to reconnect if quickly switched off then on again. (Same for the TX) . I normally fly within 2 - 3 seconds of the ground so if it had gone off I would have noticed.  

 

So happy bunny, for now at least.

 

This was tempered with another member saying that he has bought an identicle one and his, after initially binding OK , lost it's bind upon switching on again and it would not rebind.

 

My opinion is, the quality controll may not be as good as the branded stuff.  The price difference may be that there are more Rx's in the scrap bin at the end of the JR/ Spektrum production line than at the aftermarket 2.4's  JUst a thought.

 

 

Time will tell if the Orange Rx will hold up.  I hope so, it's nice to have options in this life and our sport is no exception.

 

Ioan.

 

[Lee Smalley]

when i have 200£  worth of aircraft in the air (a Cheapie) i will stick with proper spektrum or JR stuff thanks i will pay the extra 30 quid !

[Tim Mackey]

Ioan said

"The Orange seems not to have QC feature.  It takes about 4-5 secs to reconnect if quickly switched off then on again. (Same for the TX) . I normally fly within 2 - 3 seconds of the ground so if it had gone off I would have noticed."

 

Thats not what I found on my testing - QC was instant...faster even than genuine Ar6100s.

 

 

I suspect that you are confusing QC reconnection time with signal loss and reacquisition which is a totally different feature.I draw this assumption from the fact you mention "same for the Tx"

Switching off the Tx and therefore the signal, will result in a delay of several seconds before control is regained ( as with any system ), however this is NOT a brown out.

Brown out is only a symptom of momentary voltage level drop to the rx, and in this case, the Rx does not have to "listen" for the corresponding signal and GUID from the tx, so control is regained instantly the power is returned to the minimum required level.

[Allan Bowker]

Agreed Timbo, I only found this to be true a few weeks ago whilst working on the bench.

[Delta Whiskey]

Roll on a fubbie compatible one - hopefully that will give these 'big' manufacturers food for thought and bring the prices down all round to something reasonable, I mean I would pay £10 - £20 for a genuine Fubbie RX but when you are talking £30 - £40 more, then I'm willing to test out one of these "compatible" ones !

[Biggestgerbil]

Tim...

 

Thanks for that.  I think I have said that this is my first week with 2.4Ghz so I have a bit to learn yet regarding it's little foibles.

 

So far, my only  "regret" is buying the all in one style module/antenna for my 3810ADT.  In

hindsight, I should have got the separate module and antenna and "built it in" with the wire inside the Tx.  This is by far the neatest add-on I have seen from others. 

 

My clubmates say "but it dosen't have model match" but I have never had model match, so what?

 

I had a 388s for years (still have it, for pupil Tx) but  got the 3810 for the digital trims.  I had a PCM9X2 for a while, but it was a bit above my pay grade.

 

I love my (now 2.4Ghz) 3810ADT and even had MacG's do a full service earlier this year and replace the internal battery.  I swear the models flew crisper after.  (No, I don't drink)

I have been modeling since 1955.  My first model was a "Bantam Cock" c/l trainer with, if I remember correctly, a DC "Dart" .5cc motor.  Heady days.

 

I digress,  I love to pass on my experience on to others and now I have reached the 21st century of 2.4 I will continue to do so.  But I cannot begin to match some of the electronic knowledge of other forum members. More power to them.

 

Ioan.

[Biggestgerbil]

Posted by Delta Whiskey on 20/09/2010 14:29:15:

Roll on a fubbie compatible one - hopefully that will give these 'big' manufacturers food for thought and bring the prices down all round to something reasonable, I mean I would pay £10 - £20 for a genuine Fubbie RX but when you are talking £30 - £40 more, then I'm willing to test out one of these "compatible" ones !

 

DW  Hobby King do a Fooltaba  compatible I beleive. 

 

Sorry, I of course meant Futaba.  And please post your findings

 

Ioan

Edited By Ioan Wittmann on 20/09/2010 14:48:21

[John Privett]

Posted by Ioan Wittmann on 20/09/2010 14:46:33:

 

DW  Hobby King do a Fooltaba  compatible I beleive. 

 

Sorry, I of course meant Futaba.  And please post your findings

 

 

Yep - though none in stock at the moment,  here.

[Biggestgerbil]

Posted by John Privett on 20/09/2010 23:05:20:

Posted by Ioan Wittmann on 20/09/2010 14:46:33:

 

DW  Hobby King do a Fooltaba  compatible I beleive. 

 

Sorry, I of course meant Futaba.  And please post your findings

 

 

Yep - though none in stock at the moment,  here.

 

 

Following HK website and reading their user comments, HK seem to be on perminant backorder for most of their stuff.  They probably work the "lust in time" logistic and order a batch when they get a certain number of orders.  But that's just a guess.  Their delivery seems to span from 8 days to 5 months reading their revievs, with some customers tearing out their hair to others heaping  glowing praise.

[kc]

The BMFA says on pages 78 and 79 of their handbook that " you should take care that equip you are using carries a valid CE mark otherwise you become personally liable for the legallity of its operation"  Also " if you have imported equip from outside the EU for your own use then you are personally responsible for its legal operation within the UK.  This is extremely important to you as a user because you may inadvertantly find yourself in serious trouble if you are involved in an accident"

 

Clearly the BMFA are warning people not to import and use non CE marked radio gear .

 

There is another thread about this elesewhere on Modelflying.

[Biggestgerbil]

Posted by kc on 21/09/2010 19:53:11:

The BMFA says on pages 78 and 79 of their handbook that " you should take care that equip you are using carries a valid CE mark otherwise you become personally liable for the legallity of its operation"  Also " if you have imported equip from outside the EU for your own use then you are personally responsible for its legal operation within the UK.  This is extremely important to you as a user because you may inadvertantly find yourself in serious trouble if you are involved in an accident"

 

Clearly the BMFA are warning people not to import and use non CE marked radio gear .

 

There is another thread about this elesewhere on Modelflying.

 

So what happens if one buys a "budget" Rx from a UK supplier?? Is that supplier then responsible for the CE etc??

[kc]

Yes,   to quote BMFA Handbook....."  the onus for making sure that the equip meets EU standards rests not on the manufacturer but on the original importer into the EU.  This applies whether the equip carries a real or bogus CE mark or no CE mark at all "

 

So the BMFA has made it clear the importer must ensure the equip meets EU standards.  Or presumably face the legal consequences if anything goes wrong.

 

It's in our own interests to ensure that only RC equip meeting EU standards is imported and used here.  Bear in mind that most RC 2.4 ghz stuff will have been made to cater for the much larger US market which uses more powerful transmitters.  Unscrupulous importers might bring in RC ( toys etc )  that cause problems with our legal gear.

Edited By kc on 25/09/2010 09:45:59

Edited By kc on 25/09/2010 09:48:32

[Biggestgerbil]

Now I am sure that I am as usual in the wrong place, but my latest "Orange" 6 Ch Rx is CE 'd.

 

It arrived today08/10/10 (Ordered 24/09/10 that's only 14 days )

Photo attached, to prove that it is claiming to be CE legal.

It's like a little fieldmouse.

 

Presumably I am now legal??

 

By the way, This one bound first time and maintained its bind for several on/off cycles.

 

The one I bought on e-bay is also en-planed and working well.  (It crashed yesterday but that was pilot error.)

 

 

Edited By Biggestgerbil on 08/10/2010 17:06:44

Edited By Biggestgerbil on 08/10/2010 17:09:32

[Biggles' Elder Brother - Moderator]

Really hate to dissapoint you BG - but I'm pretty sure that isn't a CE mark - the form and spacing of the letters isn't correct. This is what is known as a "China Export" mark.

 

Suggest you read the last two pages of this thread for the full picture.

 

BEB