35Mhz gear

[Piper Cub]

Just been reading the very unfortuante thread about the plane crash on its maiden flight. Very sad (but on a maiden flight I'd have thought the pilot would have done some gentle flying around rather than go into full aerobatic mode).

Anyway, mention of 2.4Ghz and 35Mhz was made with the suggestion that 2.4Ghz with its superior interference rejection is ideally suited to leccie flying. Now I intend to convert to 2.4Ghz when any potential bugs have been ironed out and the sets are the basic bog standard 6 ch affair (yep I've seen Futaba have just brought out a 7 ch 2.4Ghz radio). After all anything that new has some issues with it initially.

So, are there any problems using 35Mhz and leccie? Is there an ideal set up ie opto only esc etc?

As always, advice, info (or insults) gratefully accepted  

[Tim Mackey]

No such thing as ideal...but if you must use 35Mhz and leccy, all I can recommend is to use the best possible gear you can - mpx IPD receivers or schulze for instance,  ESCs.... Jeti / hacker/ kontronic.

Keep all wires as short as possible, keep receivers well away from ESC and motor, keep aerial outside airframe, and NEVER shorten it. Use ferrite rings on all leads into receiver.

OH and yeh....keep fingers crossed

[Bruce Richards]

I have been using 35Mhz with electric models (Small is foam models) and I have had no real problems. I am using  cheap as chips sunip  receivers  and  mostly emax ESCs. I do use a ferrite ring between RX and ESC. My set ups are all below 30A and 3s lipo which may be why I have not seen problems which can occur with high power setups.

Bruce 

[Rafman]

Hi everybody,

This is my first post on the site and thought I would add my experience. I am currently flying a Ripmax Easystreet which uses a brushless set up of an AXI 2814/10 coupled to a Tornado ESC and 3S 2200 LiPo. The Rx is a standard JETI 4 ch (Cheap and cheerful) and is placed in the same bay as the ESC with the aerial inside the fuz and no ferrites fitted anywhere. In two years of running I have not had any problems with interference or glitches using my PCM10 JR Tx. When the set up was brushed I had nothing but glitches due to arcs and sparks from the brushes. Maybe I have been lucky, but I use a similar set up by Hyperion on a spitfire and again no problems encountered. I am in the process of moving over to 2.4 Gig slowly as funds permit.

 Boss

[scott cuppello]

I have used 35mghz obviously on leccy flight with very mixed results....hence now on 2.4ghz.

Recievers are the problem a lot of the time, as so-called "electric flight" recievers should really be re-labelled "cheap, nasty and fairly useless for anything other than little foamie's"......when I have flown large IC conversions, using "standard" 35mghz recievers, Iv'e never had a problem, aside from the odd glitch.

The only exception to the rule in my opinion is EDF, where 35mghz really is not suitable from my experience [unless you are using top draw gear], for peice of mind, 2.4ghz is the only thing to use.

The reason for this is that high power output's and long cable runs simply can't be avoided on EDF, batteries at the front, motor at the back, ESC somewhere inbetween with usually long servo leads....all conspire against 35mghz.

The other reason I switched was because the electric planes I fly keep getting bigger and more powerful, with up to 1300 watts.....I just can't bring myself to trust 35mghz on these models.

[Tim Mackey]

 Quote " the electric planes I fly keep getting bigger and more powerful "

 Hey Scott, does this mean that one day the model will have grown so big that it won't fit in the car anymore ? I reckon its the Lipo-suction....side effect is that it acts as a growth hormone

[scott cuppello]

You know what mate....your not far off the truth!.....but I'm not going to which part!

[JC]

Hi all

What are the ferrite rings mentioned in this thread? I assume they are used as some kind of suppressor. How are they fitted and where?  know a bit about RFI and as I fly only brushed at the moment any advice would be useful.

Regards to all

Jon

[Tim Mackey]

They should be used as close as possible to the receiver itself, on the ESC throttle lead especially, and also any long servo leads. Best to remove the plugs carefully, thread the cable through the ring, and wrap around the ring as many times as possible - at least 3. refit plugs, and bingo.

SOMETIMES helps ...sometimes doesn't

Completely useless and unnecessary with 2.4G

[Tim Mackey]

PS I have bunch of 'em here redundant - if you want them just PM me and they are your's for the price of a stamp or 2

[JohnnyB]

Hi All,

Very interesting. This is actually the first time I've heard about these ferrite rings placed around receiver and long servo leads. Whats the theory behind them then. Any idea's?

John.

[Norman Eyers]

Hi John, When I worked for a relay cable company some years back now, people with cable tv complained of patterning from short wave (ham) transmitters. To stop this we used ferrite rings with aerial lead passed through rings as much as we had room for, then refitted aerial lead plug back in. This worked fine and suppressed this high frequency interference even when the "ham" transmitter was near. Same principle works on speed controller leads keeping ring as near to receiver as you can. Not needed on 2.4 Ghz as operating system is different. Hope this helps.     If any one knows where a supply of small ones can be obtained I need to know. The large ones are heavy and play havoc with the c of g!!

Norman_E

[Tim Mackey]

This might help a little.

suppresion

[Piper Cub]

I only ever fly Futaba dual conversion FM TX and RX. I never mix other brands Rx's with the Tx. I intend to transfer to 2.4Ghz (who isnt?) when time allows and manufacturers can supply demand so have my eye on the Futaba 7ch set coming available now.

[Former Member]

[This posting has been removed]

[Tim Mackey]

The BEST 35mhz results I ever achieved were with a JRPCM9X tr coupled with either a schulze receiver, or MPX IPD. Absolutely no problem in mixing this sort of combo.... as long as you follow the rules on crystal compatibility etc.