2.4 gig transmitter/receiver

[bwells]

What is the difference on 2.4 gig and 27 am receivers? distance or speed of signal. I know the new thing is 2.4 but why?

[cyberhoops]

So many differences...

1) In general the FM or AM systems have a crystal and transmit and receive on a single channel (frequency). This limits things since there can only be one boat on that channel. For racing any channel conflicts need to be resolved. You can have multiple 2.4Ghz systems in use at the same time without interference.

2) At a higher frequency you have the bandwidth to communicate more information - so some 2.4Ghz systems have telemetry that can come back from the receiver.

3) Interference - AM radios are especially susceptable to noise interference. This is less true for FM modulation and 2.4Ghz has even higher noise resistance.

4) Response - at least in theory the 2.4 Ghz systems have a faster response time, but that probably depends on the exact radios you compare.

5) Antenna length - Although not all that important, since the 2.4Ghz system is at a much higher frequency the antenna length can be much shorter.

6) Cost - AM radios are certainly less expensive.

7) Range - probably not really much of a difference here. You generally have control farther away than you can see and operate the boat.

For boats - at least I have seen some problems with Spektrum DSM and loss of signal, but people running with DSM2 in the club don't seem to have that problem.

[bwells]

Damn good reply and I will need to read it a couple of times to digest it, Thank you

[paulwilliams]

7) Range - probably not really much of a difference here.

FM systems are usually considered to be "line of sight", in other words if you can see the model, you can control it. 2.4GHz can be much less than this. For example, Futaba's 3GR 2.4 set has a stated range (in the manual) of only 80 metres.

Here in the UK there are quite a number of FE boaters who have experienced problems with 2.4, both Futaba and Spektrum, and equally others who have had no problems at all with 2.4. I had enough issues with 2.4 to sell all my 2.4 gear on fleabay and go back to 40MHz FM, which gives me no problems with range.

Paul

[cyberhoops]

Spektrum claims 1000 yards for range - but with the disclaimer of "depending on conditions".

http://www.spektrumrc.com/Articles/A...ID=1423&Page=3

However - I have a feeling that Futaba may be more realistic in the 80 meter limit.

My issues with DSM seem to have been solved when I switched to using the SR3500 receivers.

[ozboater]

personally my spektrum dx 2.0 has been the biggest letdown...

wish i d never bought the thing.... i might ebay it and go for a FM system... my mates uses a JR FM system and can run half way out across the lake here... my cr@p glitches when i m even 50 meters off shore...

[paulwilliams]

The fundamental problem is that the higher the frequency, the more the signal is attenuated in the presence of water vapour or spray - something that is hard to avoid with model powerboats.

Spektrum claims 1000 yards for range - but with the disclaimer of "depending on conditions".

I'd bet that those "conditions" do not allow for running through the roostertail of other boats.

Paul

[AndyKunz]

TI'd bet that those "conditions" do not allow for running through the roostertail of other boats.

That's not a smart place to be if you want to finish the heat.

And 1000 yards is way Beyond Visual Range anyway. I have run my rigger 750' away with my DX3R and SR3100, and that's both the limit of my lake and the limit of visibility, so it really doesn't matter to be much farther.

Andy

[Darin Jordan]

I've been running my DX3R with SR3100 Rxs all season now and haven't had any issues to speak of with glitching or reception. Can't speak for the older stuff, but this one works great...

[ozboater]

maybe my dx2.0 is considered 'older stuff', but it s about a year old and it was purchased new... doesn t seem that old to me... at the time they had a 2 for 1 rx offer - i thought it was a great upgrade and a good deal... in hindsight i wish i d never bought the damn thing... nothing but trouble...

funny thing is that in the swap shop forum spektrum radios seem to ALWAYS be for sale...

[paulwilliams]

I tried, and sold, my FASST system, but I do want to try the Spektrum system to see if this works for me. I have a 3VCS stick set, which Spektrum module set would be good to try out?

Paul

[Flying Scotsman]

I am still sitting on the fence as far as 2.4ghz. I use a Hitec CRX Spectra system with dual conversion RX and have had no problems unless some brain dead twit is on the same frequency. That is the beauty of 2.4ghz. I would change over to 2.4ghz but with many boats way too expensive for me as far as the RX cost. Note Hitec in their infinite wisdom have discontinued the dual conversion crystal controlled RX units

Douggie

[JimClark]

I have the older system a dx3 and never have had any problems even in a all carbon fiber boat. I think most problems are due to improper installation of the receiver and the routing of the antenna.
Jim

[AndyKunz]

I tried, and sold, my FASST system, but I do want to try the Spektrum system to see if this works for me. I have a 3VCS stick set, which Spektrum module set would be good to try out?

Paul

I looked (only a little, inconclusively) to see if it takes a module or not. If it accepts a standard Futaba Air module, then the SPMFUT7 should work fine for you. There's also surface modules which are a different shape.

I started out with a Spektrum 7 module in a Hitec Eclipse 7 for myself and another for my son in his Hitec Optic 6. I've since upgraded to a DX7 (actually, two of them so I can teach my daughter to fly) and gave the Eclipse 7/SPMFUT7 to my big brother. With the low price on the air module system ($110), it's hard to beat.

Take your tx down to your LHS and give it a shot. The only downside to a module system is that you don't have Model Match - that's a real life-saver!

Andy

[ozboater]

I think most problems are due to improper installation of the receiver and the routing of the antenna.
Jim

mine is about and inch down off the top of the transom... 1/2 an inch off the stuffing tube... everything but an inch and a quarter of antenna is exposed... tried everything... must be some kind of interference since there is alot of houses on the lake i run... i m no electronics expert but something weird is up... my friends JR FM stuff runs no problems in his OM21... never seen it glitch... i just want to throw mine in the water, take my cricket bat and go home

[ozboater]

intersting that you mention the FASST system paul... i was gonna sell my spektrum stuff and try it out... now i m not so sure... i might just hit ebay and pick up a used JR FM jobbie... seems to be the key on my local water...

if anyone has some suggestions as to how to solve my spektrum woes - i d be all ears.... i m all out of ideas...

[JimClark]

post some pics of your setup

[ozboater]

cool... thanks jim, i appreciate it... this boat runs great, i m just pulling my hair out with this radio... it ll glitch and the start again only 60 yards out in front of me with a direct line of sight... at first i thought it may have been the sv plastic box hindering the signal somehow... now after reconfiguration, it still does it #@!$%!#%#

arrrgghhhhh

my last resort is to make the antenna dead vertical... it has a slight layback at the moment... thats the final thing that i could do... any suggestions or help to this relative newb would be great... cheers..

anyway, heres some photos...

[bigpapa]

That is you problem the dsm 3000,3001 specktrums will glitch like crazy dsm2 is lots better i had a d3xr and just changed to airtronics mx-3 fhss-2 no proiblems what so ever ,far better than my spektrum so be careful with the dsm expecially if you are around a place that has 2.4ghz wireless internet i will not be good........

[paulwilliams]

intersting that you mention the FASST system paul... i was gonna sell my spektrum stuff and try it out... now i m not so sure...

Like I said, I've had problems, as have Allan at Astec and Phil Jenkins, both of whom, like me, have had boats almost wrecked by FASST failure. Others seem very happy with their FASST systems. One person having problems you could put down to bad luck or incompetence, but three? All experienced modellers capable of reading an instruction manual?

I'm prepared to give 2.4 another chance, this time with Spektrum.

Paul

[JimClark]

When you hold your TX is the antenna vertical? I see a lot of guy's who tilt the radio while driving

[ozboater]

this is where i mainly run... it s a man made 300 acre lake... the shorline is littered with huge homes... i m guessing at leasr every second one has wireless capabilities... prolly more like 85% of the homes... this is the small park where i run...

so i have the older crappy version of DSM ?? great...

[ozboater]

When you hold your TX is the antenna vertical? I see a lot of guy's who tilt the radio while driving

come to think of it i hold it at an angle... she onlyl has a short stubby antenna so could that be my problem ??

[ozboater]

I'm prepared to give 2.4 another chance, this time with Spektrum.

Paul

good luck... i think it may be time to try airtronics...

[bigpapa]

i luv the MX-3 fhss-2 18 model memory, comes with a 4 channel reciever and awsome distance with no glitching....... far better than the spektrum on water that is......

[Flying Scotsman]

mine is about and inch down off the top of the transom... 1/2 an inch off the stuffing tube... everything but an inch and a quarter of antenna is exposed... tried everything... must be some kind of interference since there is alot of houses on the lake i run... i m no electronics expert but something weird is up... my friends JR FM stuff runs no problems in his OM21... never seen it glitch... i just want to throw mine in the water, take my cricket bat and go home

A lot of houses on the lake. Is it possible that telephones operating on 2.4ghz are causing the problems ??

Douggie

[bigpapa]

thats awsome stompin grounds, awsome water it seems, good luck wish i could run there

[bigpapa]

i have the same problems with wireless internet and the MX-3 works awsome no glitching

[bigpapa]

no oz you got the first production dsm they have just improved on the first design

[ozboater]

i didn t think about 2.4 telephones... maybe thats it...

yeah bigpapa, it s an awesome place to run... the parks get a little crowded in summer and the lake is full of full size boats... wakes can be a bit of a problem... in winter time it rules... no one around and zero people / boats on the lake... i havbe it to myself ALL the time..

you get a nice light headwind and the chop makes the boats fly... so much fun... gimmie winter anyway...