The Jan 2010 issue

[Andy Gates]

David

 

I had twigged about the name hence I expressed it the way I did.

 

It just seems strange that any new system that comes into this arena is the best thing since sliced bread and all the old stuff is rubbish.

 

The 27MHz to 35MHz change was much the same.

2.4GHz does have advantages such as the lack of frequency control required but this does not suddenly mean 35MHz is rubbish or prone to glitching.

Any system can be rubbish if installed badly and 35MHz installed correctly will be fine.

[Tim Mackey]

I have to disagree somewhat here.

Most of what you say is correct, but there is no doubt in my mind that 2.4G is better for electric models. Its true that if good quality equipment is correctly installed and operated it should perform well, but there are at least two models of mine which have definately benefited from 2.4Ghz. - one in particular I often cite....

My ALFA Sabre was fitted with what is arguably some of the best 35Mhz gear I could get - a JETI ESC, a Schulze receiver, and a JR PCM receiver, later replaced with an MPX synth. The tx was a JR PCM9XII. All wiring was routed as best as I could do given the tight layout space etc, and ferrite rings were attached right at the Rx end of the signal leads. Almost every flight was plagued with a small glitching problem - not enough to cause an "accident" but present nonetheless.

I bought into the Spektrum system over 3 years ago - in fact the first 2.4Ghz set in our club - and I believe in the whole region of North Wales. The first model to be converted was the Sabre, and I can honestly say it has never shown the slightest glitch or other trouble since, having been first equipped with the AR7000 Rx, and latterly the AR6100E. Its log now shows over 200 flights, at various venues across the country.

Edited By Timbo - Administrator on 20/12/2009 17:26:26

[Andy Gates]

Timbo

 

I quite agree with your statement but  the machine you are talking about is a very small machine with EDF.

The same arguement could be put forwards to the small foam Lightning model made by a certain company that I will not elude to, in that space is tight and electrics are routed around the reciever.

 

However in the magazine we are talking about an 82" model with no power units close by so interferance should almost be at a nil value anyway.

 

So far the only time I have suffered glitches with 35MHz is when I used a separate BEC of dubious quallity. The glitching was eliminated by the use of a separate battery to power the radio.

 

However I do not want to detract from the superb publication that RCM&E is, and that I have been reading for 30 years or so now.

 

So keep it up guys.

Edited By Andy Gates on 20/12/2009 17:39:15

[Tim Mackey]

Yes I understand the gist of your posting Andy - and in such a large model all may well be OK on 35 Mhz.... it was really your closing statement that prompted me to respond

"Any system can be rubbish if installed badly and 35MHz installed correctly will be fine".

As you rightly say, we are drifting off topic here, but perhaps it would make a lively debate elsewhere on the forum

[Chris Card]

I tend to agree with Andy that when correctly installed 35MHz gear is emminently suitable for use in electric models, mind you I can see that in a magazine review which will be read by a broad cross section of the modelling public, there's no harm in recommending 2.4Gig gear as most suited to electric models.   After all, not everyone has the experience in component placement, use of ferrites, etc. which can help provide problem free operation of electric models on 35MHz.

 

Anyway, finished off my mag today - loved Alex's covering article as this is an aspect of modelling I always struggle with.  I found the article on scale take offs less useful and had to shake my head a little at the author's assertion that almost every model take off should be as scale as possible.  Sorry, scale modelling is one part of this hobby but let's not try to impose on everyone who enjoys sport or competition flying by telling them their take offs should be scale. 

[ken anderson.]

well the thread is now away to a good old 35mhz v 2.4ghz...........aurgument....please send all your ancient no good 35 mhz rx's ect to the needy of the north----i will put them in retirement model's for you all...............................there will be a small charge for me taking them also.........

 

      ken anderson..............thank's to asher's and co.....

[Lee Smalley]

i think Davids comments are just his personal opinion and lets face it you do have a few more glitches on 35meg than you do on 2.4, personally I for a number of years flew a funjet with theJR PCM RX sat almost on top of the ESC and had no real problems, but  there is a big difference in a Funjet and Davids Tigercat.  I for one would not fly such an aircraft (if electric powered) on 35Meg and my stuff was bomb proof !! 

Anyway can i just give big thanks to Andy for his Photos in the Mag they really are top stuff (don't tell him i said that) they even managed to make me look slimmer than i actually am!   And as for the letter suggesting that we doctor some of the photos, well i can tell you no such thing happens, we spend stupid amounts of time waiting for the sun to peek its head out and flying around and around in circles trying to get the right shot and Andy puts himself in some precarious positions to get them shots (don't tell the health and safety police)

 

so to whoever thinks the shots are doctored please come to our patch and watch, you would be amazed at the effort we put it to bring you great piccys!!

[Tim Mackey]

I second that comment about the photos...its well known amongst the various publications, that Mr Ashby is VERY fussy about pictures, and I think the end results show that in print!

[Lee Smalley]

sooo its Mr Ashbys fault is it right me and you outside

[Slopetrashuk]

Oi! Back in yer box Smalley. Honestly you put a guys pic in the rag and it shoots straight to his head! I bet he's selling his autographs on E-Bay by now.....

[Lee Smalley]

 even my mum won't buy one !!

 

[Malcolm Fisher]

My magazine eventually came and I've almost devoured it as usual. As for the sound system in Timbo's article, to my mind this negates one of the so-called advantages of electric power which is supposedly lack of noise. Why then go the the expense of all that electronic gear to generate sound when you could just use a conventional IC engine?

 

That's a personal view, but even so I did enjoy the article along with the rest of the content.

 

Malcolm

[Tim Mackey]

Yes but the IC version still requires all the other faffing about, the slime, the cleaning down, potential deadsticks, and so on. Imagine the cost of fitting a radial IC engine in that camels cowl - especially if you didnt want ugly exhaust boxes sticking out of the side. Apart from that, show me the affordable IC model engine that sounds just like a Merlin V12 or Le Rhone rotary engine, and can sound so realistic at start up and shut down. To top it all, I just like the fact that it has been done, and geeking around with leccy stuff

After all, 'twould be a sorry state of affairs if we all liked the same things - I mean extreme 3D flying profile models dont float my boat, but I respect the skill involved in doing it, and would never "bad mouth"  it, I simply see it as another example of this diverse and fascinating hobby of ours.

Edited By Timbo - Administrator on 21/12/2009 22:53:45

[David Ashby - Moderator]

Posted by Lee Smalley on 21/12/2009 12:53:59:

i think Davids comments are just his personal opinion and lets face it you do have a few more glitches on 35meg than you do on 2.4, personally I for a number of years flew a funjet with theJR PCM RX sat almost on top of the ESC and had no real problems, but  there is a big difference in a Funjet and Davids Tigercat.  I for one would not fly such an aircraft (if electric powered) on 35Meg and my stuff was bomb proof !! 

Anyway can i just give big thanks to Andy for his Photos in the Mag they really are top stuff (don't tell him i said that) they even managed to make me look slimmer than i actually am!   And as for the letter suggesting that we doctor some of the photos, well i can tell you no such thing happens, we spend stupid amounts of time waiting for the sun to peek its head out and flying around and around in circles trying to get the right shot and Andy puts himself in some precarious positions to get them shots (don't tell the health and safety police)

 

so to whoever thinks the shots are doctored please come to our patch and watch, you would be amazed at the effort we put it to bring you great piccys!!

Lee, I keep thinking about this and you've expressed the sentiment nicely. It's not that 35meg can't do the job but having seen so many models glitch themselves around the sky - why risk a nice big model when there's a an alternative that's proven to eradicate the problem in normal models?  All it takes is one glitch when you're low........

[nasa_steve]

hi all

     its funny this debate has come up again given what i've been flying this weekend,eh david??

     we've been test flying a model this weekend but for a change we popped it onto a 35mhz set-up oh my what a difference!!  we experienced quite a few hits to say the least which i'm sure i would not have had on a 2.4 set-up it was quite an eye opener to say the least. it goes to show how used to glitch free flying i've become on 2.4

nasa

[nasa_steve]

hi all

     its funny this debate has come up again given what i've been flying this weekend,eh david??

     we've been test flying a model this weekend but for a change we popped it onto a 35mhz set-up oh my what a difference!!  we experienced quite a few hits to say the least which i'm sure i would not have had on a 2.4 set-up it was quite an eye opener to say the least. it goes to show how used to glitch free flying i've become on 2.4

nasa

[David Ashby - Moderator]

I was thinking of that Steve

[Lee Smalley]

Yes David i agree, i know all about low level glitches!!!

there is absolutely nothing wrong with 35 meg its just that for me the benefits of 2.4 gig more than make up for the cost in re-equipping, just the fact i no longer have to faff around with crystals and sometimes even wait for a fellow flyer to finish before i can go up, is worth it on its own!!!

 

[Erfolg]

Congratulations!

 

For me, that is the best cover shot I have seen in ages.

 

Its got action, the back drop enhances the atmosphere of the flying model, the subject itself is interesting. Finally I am sure it is a technically brilliant picture of the model, in my opinion it looks really good.

 

Very well done

 

As for the content! I do not know, have not bought it as yet. I am pretty sure that it was not in Tesco when buying for Christmas, or I was distracted.

 

Erfolg

[Slopetrashuk]

I can't help feeling that all this talk of 2.4ghz preventing glitching is falling into the same trap as the old problem with PCM masking glitching too.

I know the frequencies are different but by ignoring (or masking) the cause of the glitch in the first place you could potentially open up another can of worms.

PCM used (and probably still is) to be used to mask airframe noise (flying wires, metal to metal etc) interference on 35mHz and it's resultant glitching. However when the noise became 'loud' enough the receiver would momentarily go into failsafe. This raised all sorts of questions about liability. i.e. knowingly flying a model that had a problem with 'noise' but masking that with a system that could eventually force the model to crash.

Most of the 2.4ghz stuff I know of has a failsafe to do just that as well. perhaps the next big problem is just around the corner in our letigious society.

Is nobody prepared to try to fix the issue on the model or are we all content to sit on our laurels and let 2.4ghz take the strain?

I wonder how that would be viewed if pushed to intensive questioning.

Sure 2.4ghz shouldn't be affected by 'noise' from our models, but it will be affected by something. Perhaps we just haven't found out what it is yet.

 

Andy Ellison

[Slopetrashuk]

Well, I seem to have murdered that debate with a tricky question!

[Tim Mackey]

Laurels for me Andy

[Chris Card]

Is nobody prepared to try to fix the issue on the model or are we all content to sit on our laurels and let 2.4ghz take the strain?

I wonder how that would be viewed if pushed to intensive questioning.

Sure 2.4ghz shouldn't be affected by 'noise' from our models, but it will be affected by something. Perhaps we just haven't found out what it is yet

 

To be honest I think 2.4gig technology is still new enough and complex enough that we're all still in the phase of learning the ground rules.  First lesson learned a couple of years ago was regarding the vulnerability which could exist when receiver power supplies were interrupted long enough to force a reboot when those receivers were designed without thought for how long it should take to regain control. 

 

On 35MHz of course we had years and years for "best practice" rules to develop and get disseminated throughout the modelling community.   It wouldn't surprise me if in years to come the common knowledge for best results with 2.4GHz systems which every flyer learns at an early stage will include precautions we don't yet consider, perhaps as a result of increasingly complex systems which will be used at our flying sites in the company of increasingly "loud" background radiation levels in the 2.4 Gig band.

 

Predicting the future by putting a ruler through the past and drawing a straight line is never going to be reliable but one thing's for certain, change will happen, new systems will lead to changes in our operating procedures and as you say Andy, over time people will gain more awareness of the effect on their radio of the operating environment within the model.

[Andy Gates]

As per Slopetrashuk's/Peevie's post above, I agree 2.4 is still in its early days.

 

But there is still a place in this new world for old fashioned thinking and principles.

 

Maybe 2.4 is better at ignoring metal to metal noise, but why not make the installation noise free in the first place?

 

Has anyone out there read the RM Propo book?

 

Very old fashioned I am sure all will agree, but we seem to travel the route that the computer Tx mixing can sort all the evils out for us.

My take is why not sort it all out when building the model in the first place?

 

Take aileron differential as an example.

Easy to offset a servo horn during installation and fit a slightly longer pushrod so why not do it that way?

 

For me and my planes, I do use a 35MHz computer Tx, mainly for model memories.

If my Tx has a problem (dead battery / broken aerial as an example) I can always switch to a standard non computer Tx.

All I will be missing is some expo and the trim settings.

[Garry Pollard]

Andy

Old fashioned is ok in its place. I am old enough to remember cars without heaters , and winters far colder than now, but I wouldnt like to go back down that route. As I say old fashioned is ok in its place.

Garry