Futaba FASST Range Check Variations

[Dumorian]

I've gotten my exercise. I've walked maybe 5 miles doing range checks.

I have a 12Z and a 12FGA. My flying friend has a 10C. I lost 3 models due to lock out or drop out on the 12Z (which led to buying the 12FGA). The receivers in these crashes were all early model 6014 and 608, which have a fairly slow reconnect time.

This became our procedure for testing the radios. We used a simple 4.8v flight pack hooked to the receiver. The receiver was set on a wooden flight bench in the middle of our runway. Nothing behind for maybe 400 to 500 yards. We are very rural, so don't have a lot of other stuff to be concerned with. Basically, the KISS method. As simple as possible.

When range testing the 12Z with a TM14 module, there was an area in the 30 to 35 yard range where it would drop out on a fairly consistent basis. Basically, if you made it past that area on the way out, it would normally drop there on the way back in. Very odd. Our range test dropped completely at around 90 yards.

Next, we tested using the 10C. We bound the same receiver to the radio and started testing. We could not get it to drop out until around 150 yards.

Next, the 12FGA. It performed as if it was the 10C. The drop out spots were pretty much identical, out in the 150 yard range.

We repeated the above tests over many days under many conditions, each with the same results. I was even trying it at various voltages on my batteries to see if one area of voltage or lower voltages made any difference. I could find none.

So, I sent my 12Z back to Futaba. I explained in depth my situation. I told them that I was asked by a Futaba rep to have them do a field test on the unit. I received a 'no problem found' note upon return, but another of those something replaced for customer satisfaction responses. In my case, it was the TM14 that was replaced.

Well, that wasn't the confidence lift I needed. So, I began simple range testing again. I have not been able to get it to drop out in the 30-35 yard range (note, this is within the specs of the manual as a 'good' setup to fly, although nearer the lower acceptable range). I still want to do some more testing to be certain I can no longer get it to drop out here. However, it still drops out at around 90 yards.

Can anyone tell me if the 12Z under exactly the same circumstances should drop out at 90 yards when a 12FGA and a 10C both drop out under the same conditions at 150 yards? Is the range test mode on a 12Z perhaps at a lower power than these other radios? The 12FGA uses the same TM-14 module which to me further muddies the waters.

The other nagging question is how could there have been like this donut of dead space at this 30 -35 yard range with my replaced TM14? I don't get that.

And my final questions. If the 12Z drops out at 90 yards while the 12FGA and 10C drop out at 150 yards under range check mode, does this mean that the range in regular mode is around 30% greater for the 12FGA and 10C than the 12Z? This would mean more expensive radio = less range? I don't expect it to have more range, but I would think it should at least be equal? And if the 12Z is doing this, are all 12Zs this way. Then the next logical question is are the 14MZs operating the same as the 12Zs?

I'm pretty sure my 12Z acted this way from the very start. I started with two 6014s and a 607 purchased with the radio. That explains the timeframe of the receivers. I followed that with a couple of 617s and a 608. I haven't flown the 607 in a while, but the 617 was supposed to just be a reordering of channels. I notice that the 617s link to the TX very fast. The multichannel receivers take a few seconds. Each of my three crashes took only a few seconds... likely less time than it takes for one of these receivers to connect. I notice my 6008 binds about as quickly as my 617s, much faster than the 608s and the early model 6014s. As I flew primarily in 7 channel mode, I'm thinking I had this issue all along, but those receivers relinked so fast that I likely wrote it off to some gust of wind. As I moved into larger models, requiring more channels, it hurt a lot. Three quarter scale models totaled.

I now have about 70 hours on my FGA without a glitch. I have started just today exercising the 12Z again. It had about 80 hours on it prior to today. I'm still scared to fly anything nice on that radio. I do however absolutely love the radio. It 'feels' so nice. Programming is totally simple and I sure would like to 'feel' like it is now operating as it should. So, I'm flying around one model with a 617 at the moment and plan to put a 6014 in a $89 electric (now that is whacked out!) to test in the sky until I feel OK about it.... or lose my $89!

Any feedback on range test distances would be fantastic.

[GalenB]

Since I too have a 12z / TM-14 I am interested in this discussion... I would look at the TM-14 more than the 12z when touble shooting this issue... All of the RF stuff is in the module so only the module should affect the signal strength and the range... Are you using the same TM-14 in your 12FGA?

[Dumorian]

	Quote: Originally Posted by GalenB
	Since I too have a 12z / TM-14 I am interested in this discussion... I would look at the TM-14 more than the 12z when touble shooting this issue... All of the RF stuff is in the module so only the module should affect the signal strength and the range... Are you using the same TM-14 in your 12FGA?

I wish I had. I asked Futaba if I could try my TM-14 from my 12FGA and they said send it all back and don't do that. Likely just a safe response. If I had done this, I could have tested the two modules in the same radio on the same day and all of that. Then I would have felt better about all of this. I don't really understand electronics, and I didn't want to take a chance that maybe something in the 12Z had damaged the module. If I had swapped them, I could have had two bad modules and been grounded.

What bugs me the most is first this magical donut of drop out. I could get it to reproduce this at any time and actually, it was doing this from the day the radio was new. Again, that module was swapped out at Futaba 'For customer satisfaction'. And how can I find a problem just walking about for less than one minute in a particular range and them not find any problem?

By the book, all of my models have passed the official Futaba range test of from 30 - 50 paces. Well, first, what's a pace. Most define it as about 2.5 feet. And why 30 -50 paces. Shouldn't it be good to some minimum no matter what. Well, I was seeing issues between 30 and 35 yards, which is greater than 30 paces. Never an issue at less than 30 yards. So, the models passed the range test.

I'm not trying to bash here. I have the two 12 channel radios and I don't really know how many modules without spending some time counting them up. I feel like it is at least 15 and less the 20. I'm invested in this and I really do love my 12Z. I just don't like the results and know this was not normal.

What you say about all the transmitter stuff being from the TM14 module does help me feel a lot better about the radio. I only worried that perhaps the radio somehow wasn't providing the power needed to the TM14.

I would like some official response on the range test modes. I've asked, no answer. Range testing is supposedly at reduced power. What reduces the power? Is this like lower voltage sent by the radio or is this perhaps another circuit within the TM14? If it is reduced power created by the radio, why does the range check always drop out at a shorter distance on the 12Z than the 12FG and 10C? Is this because the battery voltage is lower? And if so, does this mean full range is less as well since the 12Z can never operate at 9.6V like the 12FG? Or is the power sent to the module consistent for all radios and perhaps regulated to something less than the output from a spent 7.2v LiIon battery?

Sorry for the long posts. I've been thinking about this whole thing a LOT and trying to consider every possibility. It has left me with a lot of questions. The whole response from Futaba of "No Problem Found" drives me nuts. I think this must just be legaleze for we fixed it but can't tell you or you might sue.... or maybe we really didn't find a problem. Who knows? All I know is I was about to jump ship until I got the 12FG which has been completely flawless. Further proof that my setups have been right. I can't say the FG has not crashes, but they weren't its fault.

[Dumorian]

So I started thinking back to day one. When I bought my 12Z, I ordered a second 6014 and a 607. This was apparently the last of the 607s from the Towers stock as a week or so later none were to be had. The first model I set up was a little Seagul Extra... something like a 38" wing or so... A very light model. It gave me fits. I figured it was my setup. Brand new radio. It couldn't be the radio! So, I fiddled with antenna placement and could have had some errors with that. Or so I thought. I experienced about three crashes with this model, but each seemed to give me control just before touch down so that I could at least pull some up elevator.. already input, so it never went in hard. Nothing broken. When I flew this model, it was so light that every little blip of wind threw it about. Well, now I'm wondering how much of this was really the wind.

So, I just went out to my workshop and did some more testing. I don't have a buddy to run a stop watch on this so I'm just guessing times a bit. I notice that the 607 takes over one second, I would guess like 1.5 seconds to link. I tested a few 617s, and they all seem to link in under one second. 1.5 seconds is a long time in the air... enough time to get into enough trouble to crash. Less than one second... it seemed like about 0.5 seconds... is not enough time the way I fly to get me out of shape enough to crash.

I had just started flying in March of 08 and bought the 12Z in June of 08. I had one 6014 in a Cularis glider. I had another in a Sr. Telemaster. The 608 was fairly new when it went into a Yak 54 74. I notice that the time to link these three early model receivers is quite long... perhaps a few seconds. If the Cularis had dropped out, well, it could have done this many times and I would never have known as there is just so little input. And then there is the wind way up there in the sky which is much different from down low. The Sr. Telemaster was a real challenge for me. I finally started to fly it more late summer. It dropped out over some trees and went into those trees in just a couple of seconds. That 6014 went into a quarter scale Katana. Second flight it nosed it just a few seconds after takeoff. The Yak was a brand new Extreme Flight with no parts in common with either of the two previous models. It went in on the return leg after takeoff. Talk about sickening.... It was then that I took my eyes off of that one 6014 receiver and started looking at my radio... which continued to fly the 617s without any glitch that I could detect. I did ground the radio after this third crash and got a 12FGA which I have flown up until Sunday.

I notice my 6008 links about as quickly as it gets power. I have a new 6014 coming. I'm hoping it will link equally as fast. At least if I have a drop out, maybe I'll have a quick recovery?

At this point I think I'll be very careful to keep these old receivers around so that I have something to test my radio with. The quick relinks are hard to even see. It can happen in the blink of an eye and be missed by an observer at the model during range checks. These longer link times are obvious to spot. I am however still mystified by why I was getting drop outs at generally 32 or 33 yards and then out beyond that a solid link to 90 yards. In from that, solid... unless I managed to get into eprom failure.

[Dumorian]

I'm still left with questions and concerns. I have not gotten an answer to my question of why does the 12Z range check to 90 yards while the 12FG and 10C test to 150 yards. The next test will be swapping the TM-14s between the 12Z and 12FG to see if there is any change.

I don't know how these things work. Is there a separate circuit in the TM module that sends out a reduced power level or is this done by the radio itself? Or perhaps some combination of the two. Obviously the power comes from the radio, or the battery in the radio.

So now I'm trying to think of a place in the area here where we might be able to get on a mountain with three radios and try to see if they all perform to about the same distance in full power mode. I certainly don't own any testing equipment for this. Although looking at my PC and seeing the signal strength of my wireless connection makes me wonder why there isn't such a device or report function in our receivers. Crud... for that matter cheap cell phones tell you something.

Basically I'm now wondering if the 12Z has less than 2/3rds the range of the 12FG or 10C in range test mode, could this also be true for full power mode?

[King Snake]

Were you doing a power down range check or a full power range check?

[Dumorian]

These were in 'Range Test' mode.

Details:
A big open field of about 30 acres.
No one else around (no radios)
About 1/3 mile to closest power lines
About 3 miles to closest cell tower
No underground lines of any sort

We used a single receiver on a 4.8v NiMH battery pack sitting on a wooden flight bench. Clear to about 1/4 mile behind (no reflective surface). The receiver was bound to each radio for testing. Only the radios were changed. The receiver antenna were placed in a side on 90 degree orientation. The radios were held to our sides while walking with the antenna in a side on orientation to the receiver.

After this initial test, we then changed receivers and repeated the testing, just to make sure this was not something about this one receiver. We did a total of (2) R6014FS, (1) R608 and (1) R617.

Model range testing with installed systems have yielded about the exact same results.

[DougV]

Hi Dumorian,

This is how I'll be troubleshooting this issue:

1. Open the TM-14 module and make sure the antenna is connected/seated properly to the RF board.

2. Swap the modules from the 12Z to the 12FG and re-test.

3. Reload the firmware on the 12Z.

Hope this helps,
Doug.

[exeter_acres]

I'm lost...they both pass range check...

go fly.

[gareth.ky]

Its possible the dropouts at 30 yards are due to the Tx being in just the right spot to be in the cone of silence for one of the receiver antennas.

Try raising/lowering the Tx when that happens to see in the signal comes back. Also try rotating the airplane.

Also make sure you are not pointing the Tx antenna at the model. It should point straight up, perpendicular to the model.

[King Snake]

It is very possible that, when in range check mode, that the 12Z cuts the power to a different level than the 12FG. I would expect changing the module will yield no change in results.

I have performed full power range checks with both of these TX's and got tired of walking after 2 miles. When my buddy put the model in a van, when I was over 2 miles away, it was still getting full signal.

I think your good.