Hatty

I have a Futaba Skyport 4 Transmitter with a 7-channel reciever, but I want to know if there is a 4-channel reciever that I could safely substitute it with. I want the 4-channel mainly because of the decreased weight and size. Also, I want it to have the standard servo connectors, not the smaller sized connectors. Any suggestions?

Matt Kirsch

My Feedback: (21)

Very few receivers have the "smaller" servo connectors.

If you're talking about a park flyer, you can't beat the small 4-channel GWS receivers for value.

Bigger planes that need more range, but would benefit from light weight are good candidates for the Hitec HFS-04MG.

Berg receivers are well-regarded for light weight and rock-solid operation.

Time Pilot

I have used both the Berg Stamp 4 and the GWS 4 channel Rx and have been happy with both.

The pilot has been known to glitch once in a while though...

Hatty

But would there be any problem mixing brands? Also, could I use the crystal that I have on my 7-channel for my 4-channel?

Time Pilot

There is this negative & positive shift thing that makes some brands of Tx's and Rx's incompatible.

When you are buying a new reciever, just make sure it is Futaba compatible. I have the exact same transmitter as you do and use it with a GWS Rx and a Berg Rx. Of course, they are on the same channel as my tx.

As far as the crystals are concerned, wisdom here says that you use the crystal that the manufacture recommends for their Rx. The crystals sometimes will work in other brands, but some will say why try to save a few bucks for potential trouble.

My Berg Rx shipped with a GWS crystal though which the manufacture said was okay. Both the Berg and the GWS rx's have worked flawlessly with my Skysport 4.

Matt Kirsch

My Feedback: (21)

Yep. You don't really have to give a crap about the positive/negative shift thing. Nearly all receivers out there are labeled "Futaba/Hitec" or "JR/Airtronics," or have some other fairly obvious way of showing compatibility (e.g. an F or a J, for Futaba or JR).

aeajr

My Feedback: (2)

In general on any forum is is good to state what you are flying so people have a reference point. Is it an 8 ounce GWS tiger moth, a 6 puound pattern plane ora 1.3 meter electric park glider? Weight is always worth saving.

What are you flying?

What kind of range do you need?

What kind of weight are you trying to hit?

Shift:

In general Hitec and Futaba radios are negative shift. JR and Airtronics are positive shift. Other brands are typically one or the othera nd some can do both.

As stated above, just make sure it is negative shift or that it indicates futaba compatible. Hitec also sells negative shift receivers) Most brands sell negative and positive shift receivers so they can sell to the whole market. For example GWS, Htec and I presume Futaba also sell positive shift receivers that would be JR/Airtronics compatible. One is not better than the other, just different. The advice above on crystals is correct.

I have two Futaba radios and I use all Hitec receivers.

Range

The range at which you can reliabley fly is determined primarily by the receiver. For example the current GWS 4 channel receivers have a rated range of about 500 feet. GWS 6 channel, Hitec Feather and many others are 1000 foot range. The Hitec HFS-04MG, micro 555, electron 6, super slim 8 and Supreme 8 are all rated over 1 mile

Weight -

Number of channels is not a good indicator of weight.

The FMADirect Quantum 8 channel is lighter than the six channel Hitec Electron 6 which is lighter than the five channel Hitec Micro 555. The Micro 555 and the Hitec 4 channel HFS-04MG are the same weight. The Feather is less than half the weight of the HFS-04MG and both are four channel.

I would use a Feather, Micro 555, Electron 6 or super slim 8 receiver in my parkflyers depending on number of channels I needed, as well as weight, space and range considerations.

I fly Micro 555s, electron 6s, super slims and supremes in my sailplanes.

I would not fly a feather or a GWS 4 or 6 channel in my sailplanes. Not enough range.

Overall, I like the Electron 6 best for light weigh, small size, long range and apps up to six channels.

Having said all of that:

What are you flying?

What kind of range do you need?

What kind of weight are you trying to hit?

Hatty

Well right now I am flying an electric Hobbico Aero Cruiser until I gather enough money to buy a Headwind B, BLT, or a plane similar to those.

As for the range, I am not sure. I would like to be able to safely fly the AC which requires a fair amount of space to fly. But I am not very good at judging distances so I do not know the farthest out I have flown my plane. I am guessing 1000ft would be around what I would want.

The reciever should be light enough to allow a slow flyer like the Headwind to get off the ground. I am pretyt new to RC flight so I do not know many of the specifics. I just want my new one to be lighter than the one I have now and for it now to fry when I turn everything on.

Also, keeping the cost resonable is always a plus.

Thanks for all the help

aeajr

My Feedback: (2)

If you have a standard 7 or 8 channel futaba receiver that came with your radio, it probably weighs about 1.5 ounces. You can check your manual, or the futaba site.

A micro 555 is about .7 ounces, an electron 6 is about .6 ounces. A feather is about .3 ounces. All would be a lot lighter than what you have.

Distance - Take a walk and estimate how far. This is not an exact thing. Rated at 1000 feet, you could start to reach the limit at 800 feet in an noisy environment or might fly 1500 with not problems in a quiet one.

I use an estimate of 5 feet per pace (one left one right) and measure distances this way all the time. I actually measured my pace when I was about 16 as part of a project. Took about a 50 foot length that I measured with a tape measure. Then I took normal strides and counted how many. 20 steps or 10 paces would be 5 feet per pace. It is probably longer now, but close enough for most things.

Again, it is best to have some estimates otherwise you could exceed the range of your transmitter and lose the plane. Plus it is just good to know what your flying area is. For example, the manual for the Aerobird recommends a 600X600 space as minimum for a starter pilot. So what does that look like? You learn to estimate it at about 2 football by two football fields.

I buy electronics from www.towerhobbies.com or www.servocity.com most of the time. I have also had very good luck buying used stuff and new stuff on e-bay at good prices.

Typically you don't have to worry about overloading the receiver. What you cook would more likely be the electronic speed control if you use one that is too small for the current draw of the motor/prop combo.

Hope this is helpful. BTW, I like the Headwind. Think it is a nice looking slow flyer.

liteflyer

Hi Hatty. I just bought the new Futaba micro 4 channel receiver and it's lite and uses the newer style servo connectors. If you buy this unit, remeber to buy the appropriate "SHORT" crystal as this unit does not use a standard crystal! I have had absolutely no problems with it and it has plenty of range. Keith

Hatty

I have noticed that on some of the Futaba recievers, they say not to go below channel 16 because you could get radio interference. Is this something I really need to worry about or should I just get a new transmitter crystal while I'm at it. This is turning out to be much more expensive than I first thought.

Also, can the Headwind B (and other similar planes) lift the weight of a .7-.8 oz reciever? I have no idea about the performance of these planes.

aeajr

My Feedback: (2)

I have never heard of this concern on low end channels on Futaba. Someone may have experienced that due to a local problem. One of the flying fields near me does not allow channel 21 due to consistant problems on that channel. Don't know the details.

Most Futaba receivers are low range or high range meaning they are only good for a specific set of channels. The Hitecs and most other brands spand the whole 50 channels.

Lighter is alwys better as long as:

the receiver meets your range needs:
Meets your channel count
has the proper shift.
Meets your budget needs

The electron 6 at .6 is pretty light.

The Hitec Micro 555 is .7 oz, but you can take the case off and put some shrink wrap on it and get it down to about .45, I think. That might be a good option for you.

Electron 6 and micro 555 are both dual conversion receivers. They do a higher level of filtering than the single conversion receivers.

In Single conversion receivers you have the Hitec Feather at around .25 with a 1000 foot range and the 4 channel GWS receivers are in the .3 range I think, with 500 foot ranges. They do less filtering so are more prone to glitches, bt if hte RF environment is clean, should not be a problem.

YOu can go to the Bergs or the FMSDirects that have receivers in the .3-.6 range.

Lots of choices. I have Hitec and Futaba radios. I use all Hitec receivers. Have two feathers for my smallest parkflyers.

Matt Kirsch

My Feedback: (21)

You've got to be careful with changing crystals. Changing the transmitter crystal may make things worse, especially if you move more than one or two channels. It's also against FCC regulations. Of course, there aren't any FCC police lurking in the bushes ready to pounce if you touch the crystal in your radio, and they have no way to tell, but you will. Mysterious radio glitches, and people on adjacent channels suddenly having problems are a sure sign that your transmitter went out of tune when you changed its crystal. Heck, you can't even buy Hitec transmitter crystals; you have to send the transmitter in for a crystal change and retune.

Time Pilot

Matt,

In this day and age of modern electronics, something I don't understand is why we are even bothering with crystals anyway. I know they have synthesized Tx & Rx's but at a cost. Marketing ploy? Decades behind in technology? Real costs?

Hatty

OK. I think I am going to go with either the Micro 555 or the Electron 6. The price is about the same and so are its specs, but I am wondering if there is something I don't know about. Does one glitch more than others? Is one more resistant to being damaged during crashes? To me the Electron seems better in every way. What do you think?

aeajr

My Feedback: (2)

They are equally good. Actually for me the difference is that the electron 6 is more rectangular so it is a little longer. The 555 is a little more square. In tight quarters one might fit better than the other. I have one plane that has a 555 because the 6 won't fit.

All things being equal I would get the Electron 6 for the extra channel and the slightly lighter weight.

Hatty

This is kind of an unrelated question, but how do you know if your reciever is sending 4.8 or 6 volts to your servos when you have an ESC with a BEC? I dont want to start a nw thread.

aeajr

My Feedback: (2)

The BEC, battery elimination circut, on most ESCs send about 5 V to your receiver when then sends power and instructions to the servos. It is not really someting you need to be concerned about. This is done so you don't need a separate battery for the electronics, thus the name battery elimination.

If there is a low voltage cutoff, LV, on the ESC, then it will either reduce power to the motor when the motor gets too low, or cut it off completely in order to preserve power for the receiver/servos. This is important to know because if the plane starts to slow down because the ESC is reducing power, you need to recognize it and land the plane.

If you keep flying, the motor might cut out at a bad time, or you may just run the battery down to the point where you lose control of the plane. If you don't have a LV feature than you will just drain the battery down till everything dies.

If you are running lithium batreries you have a different cut off voltage need than if you are running NIMH. If you run lithiums too low, you can ruin them VERY fast.

I extended the answer becasue many flyers confuse the BEC with a low voltage cut-off. They are two different things. Some ESC have both, some have one and some don't have either.

If this is confusing, ask away.

Flypaper 2

Another good reliable micro reciever is the Berg.