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[Stavros]

Now being new to this wonderfull hobby what is the difference in both systems,is FM better than AM.I see that the AM sets are much cheaper tham AM why? Stavros

[Doc]

Stavros,
AM radio systems are more prone to interference than FM systems (not that FM radios are interference free, they aren't!).  It depends a lot on 'where' the radio system is used.  If in an area where there are lots of interference sources, not too good.  If in an area away from almost everything, should be no problem.
I'm in an area that is considered 'moderate' for interference and have no particular problems with an AM system.  Also not many R/C'ers so that may be a plus too.  If it's a choice between AM or FM, and if price were no problem, I'd have an FM system.  AM systems have been around for much longer than FM systems, so they are a bit cheaper to make.
 - 'Doc

[White Ensign]

Stavros, I am with Doc that the AM-system is more sensitive to interferences, but FM is also not free of them. We had found a wonderfull lake here, beside a railroad. All the lads having AM systems always got trouble, when a train is coming along. The ?could happen if lots of different chrystals are working at the pond as well as radio-stations, radio-towers and electric power poles are close to you. Though in my opinion the FM is the better decision as it gives you a bit more safety. It is cheaper to invest once in this safety, than to smash your model in an accident.

J?rg

[splodger]

My situation is similar to J?rg's, though the trains on his line are probably more punctual, and certainly a lot cleaner. I sail mostly at a lake with a railway running alongside, we seem to get occasional minor interference from the signalling, and there's also a large hospital nearby. Maybe there's some interference from that as well, but I have both AM and FM sets, and I wouldn't say there was any difference at all in the scale of the problem, as both AM and FM seem to be slightly affected to a more or less equal degree. Maybe the manufacturer of the set is a more important factor here, like most things in life, you get more or less what you pay for as far as signal quality and interference rejection are concerned.

[Doc]

AM signals can 'mix' and create something that your R/C system has no idea of how to handle.  FM has a characteristic of only hearing the stronger of two (or more) signals, the weaker one just isn't 'heard', sort of.  Like listening to your car radio.  With AM you can hear two stations at the same time if you're on the fringe of both station's areas.  With FM, it's either one or the other.  Also why aviation radios are AM or SSB, you can hear two or more at the same time (comes in handy at times).  And why FM isn't used, only the stronger of the two talking at once (really dangerous when you have a pilot who doesn't know when to shut up!  Those are pilots who sit ~in~ the plane, not the ones who twiddle sticks with their thumbs.).
Hospitals are one of the worst places in the world for interference!  Huge amount of electrical/electronics stuff in them.  And why two-way radios are sort of frownd on in them.  Causing interference in hospital equipment is a real 'no-no'...
Hows that for something you really didn't need to hear?
 - 'Doc

 

[Daryl]

A couple of years ago I was running a FE boat at Warminster lake. This lake is at the bottom of a steep valley, the sides are concrete with a metal band which runs around the edge at about waterline. To make things worse on the top of the valley ridges are various radio masts. My son and I was using a Acoms AM set which got a tad confused and our boat took off at full speed the wrong way around a bouy and headed towrds the bank after a few turns. All of this happened without any input from the controls. When I retreived what was left of the boat,  the other people who had recovered from laughing told me that was normal with AM sets at that lake but FM is a lot better at filtering out the interfearance which predominates the lake. Acoms sets turned out to be the worst at that lake Futaba seemed the best with Hitec a very close second, now the Acoms set is in a landfill and we have both AM and FM sets which depend on what we are sailing and wherewhich one we use.

Daryl

[anmo]

My lake is similar to splodger's, sounds as if it could even be the same one in fact. The railway is right next to the lake and the hospital about half a mile away. The only interference I've experienced has been limited to occasional minor glitches on the rudder, at any rate that's all I've ever noticed, but I haven't seen any real difference between 27meg AM and 40meg FM, both of which I use regularly. I'm not questioning anything that Doc said, but I still think that set quality is more important than AM/FM or the frequency.

[riggers24]

Ahh, could it be splodger and anmo are one and the same depending at what time the pills have been taken

Riggers[/size]

[John W E]

  ......  ??? ??? ???...or wondering if Splodger could be someone from Westbourne Models??

Aye, aye
John E
BLUEBIRD

[riggers24]

so you think splodger is from westbourne and I think it both of them are the same so are they both real or just a figment of my over enthusiastic mind WHO REALLY KNOWS

[Doc]

anmo,
I sort of agree with you, to a point.  The quality of the system has a great deal to do with what happens in most cases.  That's because there are somethings that the manufacturors can do to help reduce interference, they usually don't really cost all that much depending on when they are done, and it just makes good 'bid-nez' sense. 
The frequency band of use can make a difference in the amount of interference present.  Key word there is 'can', not necessarily 'will'.  It's a sad fact that the 27 Mhz band here in the USA is more prone to interference than other bands (or places?).  The type of modulation used, AM/FM, can also make 'some' difference on 27 Mhz, but not necessarily a huge difference.  [You haven't lived until you've tried to use a 27 Mhz R/C radio system during a CB "shoot out"!]  Do they have those sort of things 'over there'?
The closest thing to 40 Mhz we have over here is the 50 Mhz band which is 'shared' with amateur radio.  The 'older' 49 Mhz band used by some cordless phones, and a commercial broadcast band.  The 50 Mhz thingy is also used by some 'wireless' commecial TV companies for distribution and like the 'cable' systems here, have lots of 'leakage'.  Neither band would be my 'first' choice, but since 40 Mhz isn't 'legal' here, not exactly a biggy.
 - 'Doc

PS - Sometimes I ~need~ to be disagreed with!  :)  I'm at an age where what I say sometimes isn't exactly what I thought I said.  (makes for the best excuse I can think of for being wrong!)

[Gypo]

so you think splodger is from westbourne and I think it both of them are the same so are they both real or just a figment of my over enthusiastic mind WHO REALLY KNOWS

LOOOOl I doubt it and i would know

[splodger]

so you think splodger is from westbourne and I think it both of them are the same so are they both real or just a figment of my over enthusiastic mind WHO REALLY KNOWS

LOOOOl I doubt it and i would know

Only just seen this one, and I'd have to agree, I think they might very well pay me not to work for them. I've been called some nasty things in my time, but that's definitely a first, 'Westbourne employee' indeed, what is this forum coming to?

[Bill D203]

Futaba 2.4Ghz
no more to be said.

[Philipsparker]

If I were a beginner and planning to spend a lot of time in the hobby, I'd go for 2.4ghz rather than AM or FM plus several sets of crystals. I appreciate that the initial cost may appear higher but if compared to the cost of a reasonable sized kit, the extra is minimal. Avoinding frequency clashes at the lakeside plus the extra channels for gizmos is a great dvantage.

Phil