Radio Advice

[SweetAccord]

Ha SweetAccord, Im just going to follow you around ose.com it seems like every question im going to ask you post the the same question a day or two before me.

Hehehehe, your funny! If you search a lot of my posts you can find good info too.

Peace~

[SweetAccord]

Well I may be able to get a new Futaba 3PM 2.4 Tx/Rx only for $149.00 (NIB) which is not bad compared to $199.99 that it normally goes for by a price match and a coupon knock down on top of that. I need to see if the funds are there.

[Bill-SOCAL]

I can't even get them for that price (and I'm sponsored by Futaba) so I would jump on that deal in a heartbeat!!

[SweetAccord]

Yeah the deal will be through TowerHobbies. I found a better price locally for $164.99 so -10.00 and then with a coupon code -10.00 makes it a good deal. Guess it's comes to $144.99 not $149.00 Plus Tower is doing a promotion including a Futaba S3004 Standard Ball Bearing Servo with the a 3PM system currently!

[SweetAccord]

Hey Bill,

I see that the 3PM 2.4 requires to use a digital servo is that right or can a standard servo be used or is that only for the HRS mode?

[Bill-SOCAL]

The 3PM has two transmission modes, PPM and HRS

In PPM mode you can use either digital or analog servos. You must also set the failsafe every time you turn on as it does not memorize them. You set the failsafe by pressing the button on the back of the TX. A green light will flash.

In HRS mode you must use digital servos ONLY. The failsafe is set in a menu and is memorized for each model that you set it on.

Schulze 40,160 ESCs will only work in PPM mode as well. They will not arm in HRS mode. The 40.160 is the only ESC I have come across with this behavior.

[SweetAccord]

Kewl! Thank you Bill.

Well the best price I can get is $164.99, no coupon code are accepted on price matching. Still a good deal.

[Bill-SOCAL]

Yes it is. And a very good radio. I like mine a lot.

[Mich. Maniac]

Great thread and Bill shows again his patience with question after question! LOL! Any ways heres one to throw you off. I use a 6EX Futaba and was about to buy a 6EX SS model and for some reason the rx units are discontinued. Whats with that ya think? no substitution is given either. I really would like to keep the 6channel for flying. Any comments would be helpful. Thanks

[Bill-SOCAL]

Futaba discontinued the 6 channel receivers and went to the 7 channel. They are the same size and will work fine with the 6EX transmitter.

There is still one 6 channel, the 616, but it is limited range and meant for park flyer planes only. Either the 607 or the 617 will work fine with the 6EX radio. These two differ only in the channel grouping. The 617 is intended for heli use, especially CCPM helis.

Keep in mind that none of the 4 or 3 channel FASST RXs will work with the 6EX TX. And none of the 6 channel and above RXs will work with the 3 or 4 channel FASST radios.

Here's a good chart with compatibility matrix on it:

http://2.4gigahertz.com/modules/modules-receivers.html

[Mich. Maniac]

WHOA, thank you Bill! I almost made a world of hurt for myself. I use 4ch rx units for my boats and 6ch for Heli's. I will stick to the FM for now. No trouble really as of yet but my local lake is only half mile or less from airport where we fly sooo I really dont wanna have or give someone a bad day.

[Bill-SOCAL]

Not sure I follow you. Regardless of how many channels the radio has surface and aircraft MUST be on different frequency bands with the exception of 2.4 GHz. In the US you can use 27, 50 (with proper license), and 75 MHz for boats and cars. You can use 50 and 72 for planes.

So I am not clear on how you would cause the planes an issue unless your boat is on 72 or you fly your heli at the lake.

At any rate, I would just use the 6EX on 2.4 in both the heli and boats. You would have to use the 2-stick TX for the boat, but that should not be too big of a deal. The 617 and 607 RXs are plenty small even for a T-REX 450 size heli and any boat I can think of.

[SweetAccord]

So Bill do you use digital servos or analog? I understand that the digital draw more current than analog servos but I have yet to test that. Have you seen this to be true if you are using them?

Also, with the Futaba 2.4 FASST system are there any issues with a CC Hydra or a CC BEC right that you are aware of?

Thank you.

[Bill-SOCAL]

I use digitals all the time everywhere, planes, helis, boats. Two reasons (3 really)

1 - generally better centering
2 - much higher holding torque
3 - Allows HRS mode (in boats)

Centering for me is key. I want the rudder, and any control for that matter to return to the same point every time. Holding torque is important. Moving it is one thing, keeping it there all together a different thing. We found this with big planes. A single servo would move the huge rudder, but could not keep it there. So we went to multiple servos. Now we are using fewer stronger digital servos.

I have never seen the added current draw of digital servos as an issue. In theory it is true, in practice it will not really be noticed.

My Castle 120 works fine with the FASST radio in HRS mode.

[SweetAccord]

Got it, thank you.

[SweetAccord]

Interesting info on issues with the Futaba FASST:

http://www.hobbytalk.com/bbs1/showthread.php?t=219133

[Bill-SOCAL]

I only glanced at the thread you linked to. I don't know what to tell you. I read some weird things there. Things that are not even capable of happening as far as I know.

What I know is that FASST is the single most reliable radio I have ever used (42 years of playing with RC things).

Here's my list of things to know/do about using FASST:

1 - ALWAYS get the antenna up and vertical as best you can. Keep it away from wires, metal, etc. as best you can. Resist the temptation to leave it inside the radio box or boat.

2 - ALWAYS use a good quality 5-cell (6 volt) battery. I use 2-cell lithium packs (lithium metal, not Lipo - Fromeco Relion cells) with a 6 volt regulator. Just had the stuff around and it works great for me. But any good 5-cell NiMH pack will work too.

3 - Spray it with CorrsionX first and keep it dry. These things really hate getting wet. If they do get wet the RX shuts down and goes into failsafe or hold depending on how you have it set. If you do dunk it, dry it off, spray it again and you are good to go.

4 - ALWAYS set and use the built in failsafe. I cannot think of a single reason not to do this.

5 - NEVER let the antenna be in a position to get shielded by any carbon fiber. CF will totally absorb the signal. So it is an absolute No-No to EVER have any CF between your TX antenna and the RX antenna.

I follow these "rules" and I have had hundreds of rock solid runs on my fleet with not one single issue ever.

I just scanned the above link some more and I am at a loss to explain the problems these guys say they were having. One issue in cars I know was heat related when they had the RX close to a heat source (like a hot engine) with no air flow, etc. The RX can lose link and get the red LED, BUT if you have set the failsafe as I noted the worst that can happen is it stops you. Sounds to me like some of these fellows were not taking the few seconds it takes to set the failsafe, or set it up wrong, and had some bad results. Some of those cars have lots of CF in them as well and perhpas they were not being careful about that either.

[AndyKunz]

Easy answer to the Futaba heat problem:

http://www.spektrumrc.com/Content/Im...lenge_AD_3.pdf

:D :D :D

Andy

[SweetAccord]

Easy answer to the Futaba heat problem:

http://www.spektrumrc.com/Content/Im...lenge_AD_3.pdf

:D :D :D

Andy

LOL, I wounder if a Futaba can withstand that same situation? I guess my concern is what was being said about the receivers experiencing heat like what was being said on that forum.

"Hi Scott No they a completely different technologies , only similarity is they both operate at 2.4 GHz. We had another Faast system failure at are last points race that's at least 15 !!! ( they don't like hot weather )"

or

"They definitely do not like the Heat, as Bill said out here in AZ & CA they work fine for the 30 lap heat race ,but in the main the heat gets to them and shuts them down."

or

"Yes i had a faliure with my FASST it got hot and i lost my radio while i was runing 2nd cause me to miss geting in to the a-main.I'm going back to my old 3PJ."

or

"Hi All,
After all of the trouble, all of the testing on my own equipment with all honesty, I can say it's the Futaba RECEIVER! It does not matter if it's the R603FF or the R603FS, they will both fault out if used with the 2.4 Fasst system on a 1/4 scale car. It does not matter if it the 3PKS or 3PM! Here are a few items that will set up the failure, some of these will accelerate the process. The 1/4 scale car's inside tempreature, the use of larger and hi torque servos, Servo sxtensions and Y cords, The overall track and the outside air tempreatures and Humidity, The length of use of the servos, Servo or steering binding."

The last statement above pretty well clarified what the issue my have been with these guys. So Bill, your receiver does not get warm after a few runs?

[Bill-SOCAL]

In an electric boat your receiver will not be exposed to the heat like they are in the land vehicles noted above.

Mine have NEVER given me any trouble in either gas or electric boats. Neither has Brian Buaas, or several other boat guys I know of, including a guy who has a couple of gas boat speed records (Tyler Garrard).

[SweetAccord]

Ok, but does the receiver get hot at all? Even Futaba states to mount it in a well ventalated area. "Tip: To keep the receiver cooler use small foam blocks (like standoffs) so that there is an air channel around the receiver."

[Bill-SOCAL]

The mounting guidelines recently put out by Futaba apply mostly to the 6014 and 608 receivers.

Aside from that, my 3 channel receivers do warm up above ambient but not to any significant amount. They certainly do not get anywhere close to what I would call "hot".

At least 4 of them are snug in a foam bed, others are mounted using Velcro on top and below a bit of foam to insulate from vibration, and in the electric boats they are mostly simply attached using velcro with no foam. None of these installations has given me any problems.

[Bill-SOCAL]

FWIW I just connected a 603FS receiver with 2 digital servos and a battery pack. I sat here moving the wheel and trigger and recorded the temps. Here are the results.

Time - Temp
(minutes) - (Deg F)
0 - 82.3
5 - 85.4
10 - 90.5
15 - 90.8
20 - 90.7
25 - 90.7


So after 25 minutes of on time the temperature rose 8.4 degrees. The max was at 15 minutes, but I think that the 0.1 degree variation is really just the instrument drift.

I could not feel the difference with my hands.

Hope that helps.

[SweetAccord]

Interesting, I've never seen or heard of a receiver heating up, but at the same time this is not AM or FM apparently. Technology, gotta love it!

It does help Bill, thank your input and that last piece of info!

[Bill-SOCAL]

There are two reasons these receivers will warm up a bit over ambient:

1) They are best run on 6 volt input. The internal regulator has to dissipate the difference in voltage as heat. And since they are smaller they will warm up a bit.

2) The chipset used for 2.4 runs a bit warmer than the chips used on our older radios.

But, neither is a design flaw or an issue in most applications. Put the RX under a pipe, close to an engine, or leave it baking in the direct sun and you may have a short term issue. The receiver will lose its link, the LED will turn red and the RTX goes into failsafe until it cools down.

I have never had this happen to any of mine, but then again I am careful about not exposing my equipment to any of the above situations.

BTW - people who have reported heat related issues on the 6014 14-channel RX generally report shutdown temps around 150 to 160 degrees F. And the vast majority of those reports were from large aerobatic planes with the RX mounted under the large canopy in the direct sunlight or near the pipe, etc.

Hoenstly I worry far more about water. The FASST RXs don't like any moisture and I am careful about that to a fault. Same deal however, dry them out and they are good to go. And they go into failsafe when wet as well, so that''s a good thing.

[SweetAccord]

I found this and liked what I read:

http://www.rcuniverse.com/forum/m_78...tm.htm#7878234

[Bill-SOCAL]

You can also see similar threads on Jim's RC boat dock. The 3PM FASST has been proven to be a reliable radio in boats.

Bill (AKA Silent-AV8R)

[AndyKunz]

But, neither is a design flaw or an issue in most applications. Put the RX under a pipe, close to an engine, or leave it baking in the direct sun and you may have a short term issue. The receiver will lose its link, the LED will turn red and the RTX goes into failsafe until it cools down.

Hi Bill,

The argument that it IS a design flaw is that it is a major difference between what they have been doing for quite a few years vs. what is now changed with a single brand of receiver. Why is it only a problem with Futaba FAST rx's and not anybody's FM or Spektrum's DSM2? When you fail to maintain backward compatibility with a single component, you open yourself up for a lot of problems.

In my previous job I spent TONS of time ensuring that my new products would not cause problems with older systems. When they didn't (yes, I messed up a time or two) we had recalls.

Most people apply the same standards to all their other consumer goods. Having a rx that you can't leave in the sun is like having a car that won't start in the summer. I could never manage that with my planes or boats - I don't have a shade for my stuff. We enjoy the sunshine!

Here's a great article regarding the issues, done by a pro-Futaba guy, showing data why his system failed.

http://www.aaccmac.org/documents/2.4...tionNotice.pdf

Andy

[Bill-SOCAL]

Well, by your definition HD TV is a design flaw since it is not backwards compatible with analog TV. And I mean the system of transmission, not the TVs themselves.

One might ask how come FASST is not subject to low voltage brownout the way Spektrum is. Would you consider that a flawed design as well? I don't I see it as a result of a radical change in the overall design and something we need to account for when using a new and vastly superior product.

As far as defining the ability to be left in direct sun as something that a design must meet, I don't agree. I cannot leave my 14MZ (or any other TX with a LCD screen) exposed to direct sunlight without having the screen go black on me. I don't see this as a flaw. It simply means that I must not expose it to direct sun.

The greater sensitivity to installation with respect to antenna placement must also be a design flaw then as well. After all, you need to pay special attention to how you isntall it and cannot be as cavalier as we were with 72/75/40 MHz equipment.

So I'm sorry, I cannot accept this as a flaw. It is a simple consequence of a new design. A design that requires a bit a different attention than previous designs.

I have read the article you linked to. If you notice it comes to two basic conclusions:

1) the FASST RXs do generate heat as a result of their design. This is not an issue in most applications and can easily be accounted for in most installations.

2) Servo load seems to have a big influence. Which is again why this issue seems to be most prevalent in large aerobatic planes with a large number of big digital servos that operate under a very heavy current load.

And again, the heat shutdown occurs at temperatures that are extremely high. Most consumer grade electronics are not rated for those types of temps. The temps in the article are in agreement with this. In fact, if I recall correctly, they were even higher than what most people have been seeing.

So, keep the RX under 150 degrees or so and there is no issue. And I cannot for the life of me see how this is a problem to do.

[AndyKunz]

Spektrum recalled the product when they became aware of the brownout problem. They fixed it and it's no longer an issue. Besides, a 3.5V receiver battery is out of spec too.

But an airplane that sits in the sun is a common thing. Always will be, unless we only fly from October to March.

I'm not knocking you, Bill. You have to feel good about the investment you made, just like the guy who documented the weaknesses in the Futaba receiver, so go ahead and refuse to accept the condition as a design flaw.

Meanwhile, I'll fly and drive models that have sat in the sun all day, with a receiver that runs up to 350 degrees using the same 6V rx pack or 5V BEC I've used for years, and is compatible with transmitters from more than one vendor.

Andy

PS - ... and have Model Match so I don't use the wrong model number.