Buying cheap new or (slightly) cheaper s/h?

[Engine Doctor]

+ 1 for the DX7 . I'm not generally a Spectrum fan but do have a DX 7 for the Ready to fly small models available. The DX7 will work on DSM2 and DSMX and as already said will "model Match" . Model match is one thing I wish my FF9 had . Its also made by JR and feels a sturdy Tx. . Be careful of fake Spectrum rx on the market .

[Engine Doctor]

+ 1 for the DX7 . I'm not generally a Spectrum fan but do have a DX 7 for the Ready to fly small models available. The DX7 will work on DSM2 and DSMX and as already said will "model Match" . Model match is one thing I wish my FF9 had . Its also made by JR and feels a sturdy Tx. . Be careful of fake Spectrum rx on the market .

[kc]

People seem to have misunderstood the situation - only Spektrum Tx imported into UK before 2015 will work on both DSM2 and DSMX, after that it was illegal to import and Tx only work on DSMX. Not talking about Rx just TX.

So it's irrelevant whether the Rx are Orange or genuine Spektrum. But if the Rx are not DSMX they wont work with post 2015 UK transmitters..

[leccyflyer]

From the posts above it appears that Martin will be informed of the DX7's age by it's previous owner. It's only likely to be an issue if he had some DSM or DSM2 receivers.

I concur with the advice to be careful of fake Spektrum receivers, but any new RX bought in the UK should be okay, with a check to be made before purchasing on their exact mode.

FWIW I have lots of DSM2 receivers, so it's important for me that my transmitter is DSM, DSM2 and DSMX capable. My DX7 is getting on a bit (over 10 years old) and my DX9 is a bit newer.

[Foxfan]

Gents, I think we can safely say the DX7 I'm buying is pre 2015 and will work happily with Orange or Storm Rxs. as well as any genuine s/h Spektrums, but I would probably not bother with the latter as the new Orange, Lemon and Storm Rxs are all good and very inexpensive.

I'll ask the seller to explain Model Match!

Cheers,

Martin

[leccyflyer]

Model Match is dead simple Martin. Let's say you have two models, a Wot-4 (Model #1)and an AcroWot (Model#2). You bind the RX to the TX on a particular model name -the Wot-4 -and that named model memory on the TX (#1:Wpt-4) will only work with that particular rx in the Wot-4.

If you forget to change the model memory and try to fly your Acro-Wot then it simply won;t work, the model won;t respond,, until you select the correct model memory for the Acrowot on the TX menu (#2 Acro-Wot). That way you cannot take off with the wrong model settings (rates, throws, servo reverse) which is a well known model killer..

[Foxfan]

I thought that was the very essence of all computer Txs. Not just the DX7. If not, what are people doing when they select a model on their pootah screens?

Martin

[PatMc]

Does the model memory feature still work with non-Spektrum [Orange, Lemon & Storm] Rx's ?

[Martin_K]

Posted by Foxfan on 28/09/2019 14:06:02:

.... what are people doing when they select a model on their pootah screens?

Martin

leccyflyer has explained what Model Match does but not what it is.

Spektrum radios are manufactured with a unique ID, the GUID (Globally Unique Identification Code). When you bind the RX to a radio with only 1 model memory, like the DX5e, this ID is saved in the RX's memory. Any RX with this same ID will respond to commands from the radio.

For a radio with multiple model memories that supports Model Match, at bind time the radio modifies the hard coded GUID, producing a different ID to be saved by each RX paired with that radio. The radio now has multiple ID's, one for each model.

In all cases every packet in the RF data stream from the radio starts with that radio's (or model's) ID.

More than one RX can be bound to any radio, or model memory.

All these bind related matters are a function of the RX.

As Frank Skilbeck explained above, model memories let you switch models, in the process restoring unique configurations of servos, trim, and mixes for that model. These model memories are a function of the radio.

[gangster]

No Foxfan not many others have model match. It is a great facility. On many other makes it possible to fly on the wrong memory. So if you forget to change the TX memory it is possible to try to fly model x on model y memory. Disastrous if the controls are reversed. On Spektrum that cannot happen nothing moves and then you realise why before you try to fly. It is possible however I believe to st up two receivers to one memory of you really want to. It sounds like you have a bargain I have the dx8of probably similar vintage. Looks and feels well made love it

[Don Fry]

Posted by PatMc on 28/09/2019 14:28:23:

Does the model memory feature still work with non-Spektrum [Orange, Lemon & Storm] Rx's ?

Yes

[Foxfan]

The problem with never having had a programable Tx. I have no idea what it don on screen. So I still can't really see a difference twixt Model Match and what everybody's doing when they select the model they want to fly, which, presumably, has been set up with unique throws, expo, reflex, mixes, etc. I'm hooping the seller can explain it all tomorrow.

Martin

[Martin_K]

Posted by Foxfan on 28/09/2019 14:45:55:

So I still can't really see a difference twixt Model Match and what everybody's doing when they select the model they want to fly

 

Martin

My final attempt;

Model Match - pairing of RX and TX

Model Memory - setup of your aircrafts controls

If you replaced the RX with another of the same type the Model Match would change, requiring a rebind (first bind of new RX) but everyting else in the model memory could stay the same.

Edited By Martin_K on 28/09/2019 15:14:54

[Denis Watkins]

As Martin Says

If you've flown with a programmable system for any amount of time, chances are you've crashed, or you've seen someone crash, because the model selected from memory wasn't the model being flown. Spektrum programmable transmitters are immune to Wrong Model Syndrome thanks to ModelMatch™.

ModelMatch assigns each receiver its own unique code when it's bound to your Spektrum transmitter. If the model you select from memory doesn't share the same receiver code as the model you're trying to fly, the aircraft's controls won't respond until the correct model is selected.

Edited By Denis Watkins on 28/09/2019 15:35:27

[Foxfan]

I've never flown with a programmable system apart from the club's buddy box (also Spektrum) What I can't get straight is

a) why ModelMatch has never been mentioned in any article I've read or in any conversation I've had,

b) if you select say, Piper Cub in your Tx model memory stash, why would you be able to fly anything else, by mistake or otherwise. If you could, why would you bother setting it up by name on the Tx? Most people leave the Rx in the plane so it'll always be the same set up in any given aircraft. Different 'plane, different place on the computer listing, different Rx.

I think this is one of those things that I will need to be shown, rather than have described to me. Not helped by the complete absence of programmable Txs in my life.

Thanks for trying, chaps, but it all sounds the same to me.

Clearly it isn't, but I can't see where it essentially differs.

Martin

[PatMc]

To be pedantic "Model Match" is a misnomer it should really be called "Rx Match".

[Richard Ashworth]

Hi Foxfan

This may help on understanding binding receivers to transmitters.

With Spektrum (and I believe some others) when you bind the receiver it is effectively told to only respond to that transmitter AND only respond if the transmitter is set to the model memory in use when it was bound.

Some systems do or did not have that extra check, they were only set to respond to a specific transmitter no matter which model was selected.

A couple of years ago a colleague using Futaba finished flying an electric model, put it down on the grass in the pits and switched off his transmitter. He forgot to disconnect the plane battery. Twenty minutes later he picked up a second plane, connected its battery and carried to the strip where he ran the motor up prior to takeoff. The live model in the pits also started up and had to be pounced on to prevent an accident. Both receivers were simply listening for a transmission from the owners transmitter.

99.9% of the time we get it right but “modelmatch” or any such double security system makes it “foolproof”.

It also means the transmitter will always have the settings for the model you are flying as nothing will work if you try to use model 1 on any model memory in the tx other than model 1.

[Martin Harris - Moderator]

You take 2 models to the field - say a Piper Cub and a Spitfire.

You turn your Okey Cokey 2000 transmitter on and connect the battery to the Spitfire. It makes the appropriate noises and all the controls wiggle. You take off and it rolls into the ground because the ailerons are reversed. The reason is that in your hurry you've forgotten to select Spitfire and are flying on your Cub program which just happens to have the ailerons arranged with the opposite servo direction.

Model Match was designed (and patented) by Spektrum to eliminate this possibility by registering the receiver's unique identifier to a single program so if you'd made the same mistake, the transmitter would not have bound to the receiver and you'd have scratched your head for a few moments before realising that you had to select the Spitfire.

Of course a proper pre-flight check of the controls would save the model too, but it could be grossly out of trim or over/under responsive. There will be very few long term flyers who can claim they've never at least started to taxy out with the wrong model selected, especially in the early days before you could display a model name and not just a number.

[Foxfan]

Thanks, gents. There was me thinking you all used the computer slavishly to select the right model and that's where my thinking was not in line! I figured that as that's what the whole computer thing is about you would ALWAYS select the right aircraft! Hence my not understanding the difference. Perhaps the over-used word "foolproof" would be very apt in this case?

Thanks again,

Martin