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Jeff85
08-15-2005, 10:28 AM
My 15 year old son was flying his Zagi 400 (converted to brushless) with lipos using JR Radio gear 72 mhz channel 38, and about 17 minutes into the flight at about 80' it went straight into the ground FULL THROTTLE!!!
Everyone had gone home except for one Areobird on 27mhz.
He was shot down by something. We packed up and started to go home there was a large picnic going on with 200+ people. As I passed their cars I noticed a small sedan with a large whip antenna (appox. 3 meters), (4-1 meter) antennas on his trunk and personal license plates with his call sign. I stopped and talked with him and he said one of his friends at the picnic were also transmitting on 50 and 52 mhz. He also said, they had the ability to put out 50-100 watts of power.
I suspect they were boosting more power than that!
My question is: Can a HAM radio put out enought power to bleed over frequencies at 100 yards and lock up your servos?
I will post crash shots later.

rcers
08-15-2005, 02:52 PM
Can a HAM radio put out enought power to bleed over frequencies at 100 yards and lock up your servos? Nope not likely.

TV audio is much closer to our 72mHz range and they broadcast at much higher rates that 100w.

Where the servos in erratic operation or locked?

Mike

Hotshot Charlie
08-16-2005, 03:47 AM
Nope, you will not get any interference from a ham transceiver. I am sure they weren't running any more than 50-100 watts, as this is the output of most xceivers. Yes, you can run amps, but most of us hams don't. No need.

Very...... Highly unlikely that the amateur radio ops had anything to do with your problem. Sorry, wish it was that easy.

I am a ham op, for over 20 years. I have run as much as 1kw of power from my home without bothering a single TV set or telephone in my very crowded neighborhood. Amateur (ham) radio is very restrictive on our transmissions and most hams are very concerned and take extra efforts to assure that they aren't interfering with anyone.

Sincerely, WJ5K

debhicks
08-16-2005, 11:08 AM
The zagi has a tendancy to go full throttle into the ground. Ours lost something, we expect the esc, and went full throttle at about 6 feet above ground. Tore it up.

Ham equipment is pretty clean and filtered. CB equipment on the other hand is a problem with the 27 mhz RTR. I also run a cb shop. I have a radio that just keying it up will start up my neighbors 27 mhz truck and put it full throttle in reverse. I quit using my radio at home. I educate those who purchase thr RTR about the danger expecially if they are flying in an industrial area where cb's are in use all the time.

72 mhz would be very difficult to interfer with but CB equipment would be more suspect than ham equipment if it wasn't a malfunction with the actual equipment.

Hope that helps.

EpoweredRc
08-16-2005, 02:18 PM
My 15 year old son was flying his Zagi 400 (converted to brushless) with lipos using JR Radio gear 72 mhz channel 38, and about 17 minutes into the flight at about 80' it went straight into the ground FULL THROTTLE!!!
Everyone had gone home except for one Areobird on 27mhz.
He was shot down by something. We packed up and started to go home there was a large picnic going on with 200+ people. As I passed their cars I noticed a small sedan with a large whip antenna (appox. 3 meters), (4-1 meter) antennas on his trunk and personal license plates with his call sign. I stopped and talked with him and he said one of his friends at the picnic were also transmitting on 50 and 52 mhz. He also said, they had the ability to put out 50-100 watts of power.
I suspect they were boosting more power than that!
My question is: Can a HAM radio put out enought power to bleed over frequencies at 100 yards and lock up your servos?
I will post crash shots later.

Was you useing a single or dual conversion Recevier?

debhicks
08-16-2005, 02:24 PM
I am sorry it wasn't a zagi it was a razor, flying inverted and after I discussed this with my husband, the crash investigator either the esc over volted and quit or the stock servo's stalled and it wouldn't pull up. He was going straight down to do a high speed fly by of the pilots station. The high speed thing worked but the fly by didn't. Made a hole in the sod farms property. :) It's repairable just on the back burner. Even though it hit pretty hard it is remarkably durable.

Don't mind me. I get to talking about some things I shouldn't. Afterall, my husband is my crew chief. :) Some of the perks.

EpoweredRc
08-16-2005, 03:01 PM
I am sorry it wasn't a zagi it was a razor, flying inverted and after I discussed this with my husband, the crash investigator either the esc over volted and quit or the stock servo's stalled and it wouldn't pull up. He was going straight down to do a high speed fly by of the pilots station. The high speed thing worked but the fly by didn't. Made a hole in the sod farms property. :) It's repairable just on the back burner. Even though it hit pretty hard it is remarkably durable.

Don't mind me. I get to talking about some things I shouldn't. Afterall, my husband is my crew chief. :) Some of the perks.

Well glad to see a female on here!My gf likes RC but doesnt fly yet she is learning on the flight sim some..
My fathers GLH done that same thing came across the runway and went straight into the ground,it was a AM and single conversion and got a glith from somewhere,it buried it up to the wing,but didnt do anything except get the motor dirty and broke the prop.

DIALED/CHUCK
10-27-2005, 10:22 PM
Jeff,

I see this thread is kind of old...nevertheless...I have been doing much research on this SAME issue with wings (for the past 5 months now)...

Can you list the setup that was in the wing at the time. Include brands if you remember. I have 6 stories now of wings (7 if you include one of mine) doing something similar and I have found an interesting similarity in all of them)

Servos, RX, ESC, lipos ...

Thanks,

--C

N3CLI
10-28-2005, 03:25 PM
Being a Ham for 40 years I must say Hotshot is right on.

I had a 1000 watt station on six meters and had a few TVI problems but never on 50 watts from the car.

Look elsewear for your problems.

Fred:)

Hotshot Charlie
10-28-2005, 05:24 PM
Nice to meet you N3CLI de WJ5K. I've been a ham for just over 20 years. Got my extra class and the call in 1986. I haven't been very active lately, but I used to spend all my time on CW.

Have a great weekend ! Cheers es vy 73 de WJ5K

hoppy
10-28-2005, 08:19 PM
I think I've heard a couple of you guys calling skip-lannnnn, skip-lannnnn.:) .... ..

Hotshot Charlie
10-28-2005, 09:54 PM
:) Funny Hoppy.... you must know some hams..... you know how we hate to be compared to CB'ers. heheheee :) Have a great weekend !

hoppy
10-28-2005, 10:59 PM
"you know how we hate to be compared to CB'ers. heheh"
C'mon guys, I know you got your ears on and the pedal to the medal..... Admit it, just this morning you said "got a copy on me good buddy?"



Know some hams?? ......yup, see an ugly old one in the mirror every day..LOL
--... ...--

Hotshot Charlie
10-28-2005, 11:52 PM
yup, see an ugly old one in the mirror every day..LOL
Heheheeee Thanks for the grin.... I needed that today ! :-)

Tommyr
10-29-2005, 01:11 AM
"you know how we hate to be compared to CB'ers. heheh"
C'mon guys, I know you got your ears on and the pedal to the medal..... Admit it, just this morning you said "got a copy on me good buddy?"

Know some hams?? ......yup, see an ugly old one in the mirror every day..LOL
--... ...--


Same here! KB2SMS here. Ham since 1994. Never owned a CB by the way.

73!

Tom

rcfoamy
10-30-2005, 06:11 PM
I'm just wanted to find out was it a single or a dual converson RX ?

NCC-1701
10-31-2005, 10:53 PM
I had a similar experience with my old Zagi 400X. I upgraded it to brushless, an Aveox 27/13/3, APC 5.4x4.5 prop (if I remember correctly), CC Phoenix 25, FMA M-5 receiver. I had about 20 or so flights with stock batteries (KR-1700 NiCads) and wanted longer flying time and didn't like how hot the batteries got after the flight.

I decided to upgrade the batteries as well and ordered two of Cheap Battery Packs CBP-1800 8 cell Zagi packs. I was on the third flight with the new batteries and my Zagi started glitching. I immediately cut the throttle and began to set up for an immediate landing. Then, I completely lost it. It went inverted and the throttle made an uncommanded advance to full. It then almost straight nose down and found one of the few patches of pavement my field has. It hit so hard it ejected the battery through the canopy and trashed the receiver. One of the cells from the battery was smoking and it exploded about a minute after the crash!

My post mortem is that I never should have listened to the guy who sold me the motor for a speed control recommendation. I was pulling 28 to 30 amps with that set-up and smoked the BEC on the speed control. I was fine flying with the KR-1700's as they are higher internal resistance cells than the CBP-1800's and the batteries were current limiting and unable to deliver over 23 amps.

Several lessons learned here:

1. ALWAYS validate your planned set-up with a simulation program like Motocalc.

2. ALWAYS verify the power delivery and amp draw of your set-up with an amp meter BEFORE the first flight, even if you've only made a minor change.

3. ALWAYS give yourself some "headroom" when selecting a speed control. If I'd gone with a Phoenix 35, I'd have been fine.

Hope this helps.


Rob

DIALED/CHUCK
10-31-2005, 11:20 PM
NC,

That is what I am talking about with wings especially...I lost 3 wings with that FULL THROTTLE, servos full locked in a roll business. I have the problem dialed (even when pulling 10 amps below an ESC's rating) and can re-create it on the bench time and again. I emailed CC about it and a few other makers...finally after talking with loads of the high performance-types...I was told many NEVER use the on board BEC on any ESC.

I run an external BEC on ALL my wings now no matter what ESC I use...on wings, even with vents, they still get hot as a pistol down in that foam compartment...issue is gone.

--C

Jeff85
11-04-2005, 07:31 AM
Well my son and I finally got the Zagi back up in the air last weekend at Baylands. It flew great!

One of the things we did different was pull out the GWS Rx and replace it with JR Rx. The Transmitter is a JR 6108 PCM. Don't know if that was the souce of the problem but works fine now.

Chuckd;can you provide a link to external BECs?
Thanks

P.S. No HAM operators were there.:p

Geoff_Gino
11-04-2005, 08:20 AM
NC,

That is what I am talking about with wings especially...I lost 3 wings with that FULL THROTTLE, servos full locked in a roll business. I have the problem dialed (even when pulling 10 amps below an ESC's rating) and can re-create it on the bench time and again. I emailed CC about it and a few other makers...finally after talking with loads of the high performance-types...I was told many NEVER use the on board BEC on any ESC.

I run an external BEC on ALL my wings now no matter what ESC I use...on wings, even with vents, they still get hot as a pistol down in that foam compartment...issue is gone.

--C

Hi Chuckd

Please bear with me and the following is a theory of mine and I'll try to keep it short.

I think telling the difference between a hit, loss of Tx signal and glitching is possibly the most difficult thing to prove. I am a radio tech by trade but I have not been active in electronics since 1995.

I am a JR fan but in my travels have collected a couple of Hitech Rx's, but only have the one Tx (All PPM). When setting up a Hitech Rx the throttle and aileron channels are swapped.

Now the theory

1) If you are flying with JR equipment and some one switches on a Hitech Tx on your slot, chances are the plane will go half throttle (stick in the centre position) and roll to the right. This because of the channel swap.

2) I understand a "glitch" to be a servo or 2 having some movement without Tx input and this is mainly due to interference and goes away quickly.

3) If all the connected servo's go haywire it means that there is no input signal - as in Rx switched on with the Tx still off. (Talking PPM here).

Now if I am wrong would some one please correct me as I am currently sitting with a large problem of range loss which is at the moment without explanation.

Only one of my planes is using the BEC and it is an E-flite flat foamy which has a Hitech Rx and strangly enough is the ONLY plane without a problem :confused: :confused: :confused:

Any thoughts will be appreciated
Geoff
Alone in the South African wilderness

DIALED/CHUCK
11-04-2005, 10:05 AM
External b.e.c.'s....there are several I use: UBEC (Hobby Lobby carries), Medusa BEC (best value for quality), and there is a generic one at xushobby.com that is like 11 bucks and works just fine...plus is selectable from 4.8 to 6v with a mini jumper. All have worked magnificently in my endeavors...it is just a matter of how much you want to spend.

And you did the right thing by getting off that GWS indoor rx for a wing.


About the JR/Hitec info...good stuff. Although I can re-create the issue with several different Rx's and two different Tx's (Futaba and Hitec). And I can do it with any ESC 25amps and above now...mind you, it only happens in the flying wings and I am heading to the 'reflection of heat from the foam' theory; overheating the on-board bec on the ESC and therefore causing it to go into thermal overload WAAAY before it's max Amp rating.

When I hook a servo watt-meter up to the circuit...you see the voltage drop siginificantly, causing a loss of sufficient power to the bus on the rx...BAM...a momentary cut out and then the ESC's BEC pops back up and so does the RX...that is when the issue hit...FULL THROTTLE AND BOTH ELEVONS to max range of motion.

I spent a hard two months researching the issue...emails back and forth with ESC manufacturers...ultimately resulting in nothing. It is not that I think they did not care...but rather had other things to worry about at this time.

But again...your info is good to know should I ever have a problem with that kind of App. Thanks for posting that (it is one I will keep a link to)...

Gotta hop...off to work. ...and its FRIDAY!!! :)


--C

Geoff_Gino
11-04-2005, 11:18 AM
Hi again Chuckd

Noted about your "heat" problem and you have obviously done your homework. Wish I could get to the bottom of mine without having to buy new radio equipment.

Heating is not a problem in my case as all my ESC's are up front right next to the "fan"

Geoff

Geoff_Gino
11-07-2005, 05:53 AM
Hi All

Saturday 07:00 :-
Little Extra with JR Slimline
Ultimate Foamy Hitech Rx.

Flew both planes until about 10:30 when it started raining and although I
was not convinced with the report back from the Radio shop I experienced no glitches at all.

Sunday 07:30 :-

Same planes and a brand new JR Slimline Rx.
Little extra range check gave me exactly 10 paces and no more!!! Replaced the Rx for the new one and also only got 10 paces. This with the ESC and motor not connected (Rx flight pack onboard).
Needless to say that even though the weather was perfect I only flew the Ultimate.

Next test:
Friends Tx with my crystal - gave me 15 paces on both my planes.
My Tx friends crystal - His plane gave me a whopping 57 paces WITHOUT a sign of any glitches at all. (using sign language at that distance)

Conclusion:- It appears as though channel 79 is an absolute no no at that club and I am so unsure that I will not even change crystals and will just replace the Tx and Rx's making sure I get well away from 79.

Geoff

hoppy
11-07-2005, 03:40 PM
Are you changing crystals in the radio or the Rx?

Geoff_Gino
11-08-2005, 05:39 AM
Are you changing crystals in the radio or the Rx?

Hi Hoppy

At the moment I am busy pulling my hair out at the roots. Major lack of assistance from my LHS where I have spent in excess of $3000-00 so far.

Being the first with middle to large scale electric (and everyone knows this) my "electric planes" are to blame, even after very carefully explaining that the electrics can only affect the plane when switched on.

All of my planes have flight pack batteries in them and all my tests are being done with ONLY the Rx switched on. At the moment I am only getting 10 paces with the antenna fully collapsed before all, and I mean all of my servo's start jumping as though the Tx is not switched on. At this point lifting the Tx into the air makes the problem go away, but the moment I give any input from the Tx all the servo's start jumping again.

Last night connected a volt meter to a spare channel in the Rx and the voltage stayed a constant 5.02 volts throughout. So that rules out a servo pulling the 5 volt rail down.

Changed Rx and Tx crystals and the problem persists. Will try a new Tx tonight and will use my old crystals as well as new ones on a different slot to see if that will cure my problem.

Geoff

hoppy
11-08-2005, 01:44 PM
Let me rephrase that question-

Are you changing the frequnecy (channel number) of either the TX or RX crystals? I ask because of the all the switching of crystals going on.:)

(If you can't believe that I'm asking this question, please forgive me.... I'm not aware of your depth of knowledge. )

DIALED/CHUCK
11-08-2005, 01:59 PM
Geoff...

I feel your pain. Really, I do....

When i first bought my FUTABA 9C, I was getting glitches and twitches like a madman. Nothing seemed to work....new modules, Xtals, it did not matter. I bought two new antennae (plural for antenna)...and I was ready to sell this thing because everyone was giving me the runaround on getting it fixed.

Out of desparation, I opened the case to look...and there it was...my antenna, though seated all the way on the set screw was not making contact on all sides by about 1/2 a mm...I went to home depot and got a 1mm washer and placed it on the set-screw; bolted on the antenna and went out..... problem solved!

Brother, this thing is going to be a painful journey....TX/RX troubleshooting usually is just that way. But, know that once you DO get it licked...the fun is back.

Again, I feel for you going through this...I remember the frusteration and anger of having an expensive piece of equipment and not being able to get it to work the way you want it to... Stay tough...you're getting closer.

--C

Geoff_Gino
11-08-2005, 02:52 PM
Hi Hoppy, ChuckD

Thanks for your interest in my problem.

ChuckD
Yours sounds like most probable symptom at the moment and first thing I'll be doing when I get home is opening the back of that Tx - "WHY", bust the antenna a short while back and replaced it and guess what, my troubles started and haven't stopped.

Hoppy
My problem has sort of been spread around and also had a lot of PM's to one guy in particular. To fill you in. I have JR equipment and my Rx's (all of them) are acting as though the Tx is switched off when I get to 10 paces with the antenna fully collapsed. I am changing crystals both in the Rx and Tx in an effort to isolate the faulty component. JR do maintain that you can swap channels (slots) with no tuning to either the Tx or Rx. (I personally do NOT agree with this being a radio tech of many years).

Anyway once the faulty component has been found and replaced I will definitely be back on my old slot.

ChuckD watch out, if you are correct I will come over there and kiss you.
:D

Geoff

DIALED/CHUCK
11-08-2005, 04:35 PM
Geoff,

Let's wait till the wife is out of town! LOL!!! :D

For one thing...as I found with all of my issues, no matter how small...later on you will become a beacon to others looking for info. Lets face it....it took a caveman standing on top of a hill during a lightning storm to teach the others that when the flashing lights were in the sky, we'd best hang out in the hole for a while.

Not that you're a caveman...but you get what I mean...experience is the thing.

--C

Geoff_Gino
11-09-2005, 05:36 AM
Hi Hoppy, ChuckD

Who would have known - woke up this morning went straight to the hanger and pulled out the lead for the elevator servo and all my troubles -GONE AWAY :o

Didn't have much time so I will carry on the good work, but I am so sure I have nailed it that I am actually smiling for the first time in weeks.

ChuckD
Luckily for you I could not afford the trip and if you have looked at my profile I am pretty sure you are much relieved :eek:
However I did check the antenna and even re-soldered the connecting tab to make sure.

Will give you guys a great whoopee tomorrow when I have put everything back together.
Thanks for the help and suggestions to all the guys who took the time, especially QbanFlyer. Thanks Bert.

Geoff :D

DIALED/CHUCK
11-09-2005, 05:24 PM
Glad to hear you got it nipped....

Now get out there....


--C

Geoff_Gino
11-10-2005, 05:49 AM
Whoopee

Geoff

airmail wf
01-13-2006, 04:40 AM
This is what these forum are all about. People helping people a world apart in micro seconds. This is where world peace and understanding will come from. Sounds corny but I think this is the great value of the internet. And RC flying.:D You guys are the messengers of goodwill.

DickCorby
01-18-2006, 08:50 PM
I got a Polk Hobby Tracker III Radio for Xmas. (Love My Wife)

It tested out fine in the shop. Setup all my planes and looked like a great Transmitter.

Went to the flying field, took 2 of my more dependable planes, EP Superstar, hightly modified, and my Aero Princess.

Flew the EP Superstar first, great flight, no problems. Then I took the Aero Princess up. 2.5 minutes into the flight, it went nose down, no control and pile drove itself into the mud of the plowed field beyond our flying field. Totaled it, batteries, all gone.

Got back to the bench, and did a full scan of all frequencies, a neat feature of the Tracker III. It found about 10-15 frequencies in use, including mine. And there were only about 3 transmitters on the field.

Sent it in and it turned out to be the RF board had failed. Got the system back, and so far it's performing flawlessly. Their Service was good if anybody asks. Did a scan at the field, and it only found the one Transmitter/Frequence actually in use.

Jeremy Z
01-22-2006, 11:54 AM
Geoff,

If you're going to replace your Tx & Rx anyhow, why not go with a Spektrum DX6 or Spektrum module for Futaba? Unless you fly very large sailplanes, chances are you won't have any range problems.

These are not expensive, and are practically immune to RF problems. (as they have a built-in backup and are always running on two frequencies) Furthermore, since they run on 2.4 GHz, they are also immune to any RF problems being put out by your ESC, motor, etc.

I don't know anything about how frequency bands are controlled in South Africa, but I get the feeling there's no FCC there.

You're on 72 MHz, right? Are you 100% sure that's reserved in South Africa? Are you confident that everyone in the area respects that, or is there an easy way to just screw you up through being inconsiderate?

Another option might be to get a radio with a Spectra module. I've got a Hitec Optic 6, which I really am falling in love with. It was $180 w/Spectra. They go on sale at Hobby-Lobby.com occasionally for $160. While you're at it, buy a few extra receiver crystals that are a good number of channels away from any channel you've heard of people having problems with in your area. Not only will this get you away from the dreaded Channel 79, but it will allow you to troubleshoot the problem you had been having.

If you want to be safe, go with a dual conversion receiver from a maker of good reputation, such as Hitec, Futaba, or Airtronics. BTW, the Optic 6 has selectable shift, so it doesn't matter what kind of receivers you have, as long as the Optic 6 is on the same band. (again, apologies for my ignorance of which bands are used/reserved for RC in South Africa)

For what it's worth, I have never used a separate BEC, but I only fly smaller electrics. (sub 300W)

Jeff85, part of the instructions in my Edge Overlord wing call for the ESC to be mounted OUTSIDE the airfoil, right in the airflow. Even though I'm only using 2 standard GWS servos, it is good to know I have good cooling. I mounted it with the heatsink up, which a lot of people don't do, since it obscures the label. The airflow goes right over the cooling fins, and the ESC is a 25A, when I think the most my motor will pull is around 12-15A. I'd sooner go with a slightly over-rated ESC with a beefier ESC than to jerk around with extra components. Make sure the ESC gets good cooling airflow.

I've heard of problems with single conversion GWS receivers in less than ideal RF conditions, when single conversion JR receivers are highly regarded. (I have one, a micro, but I don't trust it as much as my dual conversion Hitecs. No good reason for that.)

I hope there was at least one useful nugget in there!

For

DickCorby
01-22-2006, 05:25 PM
I've spent a bit more time at the flying field with my new Tracker III and the more I use is the more I love it. My Optic 6 is on the shelf.
Being able to click a switch and change the frequency on the receiver is a big boon. We fly at some fields during the contest season where you must use only odd or even channels only. This will allow me to go to any field and choose the channels less used. Plus if my channel is busy, I have the ability to pick an empty channel and fly.

Being able to scan all freqs will also be great. We had a plane go down at a contest last year, and they found a guy flying at a soccer field a mile away on the same frequency. The Tracker checks your frequency before it even starts transmitting, and if it's busy, wont even turn on the RF board. Protection for both you and the other guy on the Freq.

The computer controlled Synthesizer emits a signal that is as close to dead on center as any transmitter on the market. I was unaware that the major brands transmit on the given frequency, with a plus or minus 5-10 percent on either side of the band. And over time they can detune and get even farther off center causing great reduction in range.

And for $200 its a good deal on a computer radio, with Synthesization, 99 model memory, and lotsa other goodies I'm getting used to. Can't beat it.

Geoff_Gino
01-23-2006, 06:14 AM
Hi JeremyZ

Thanks for the reply. I managed to sort the problem (found a servo was swamping the Rx) but the plane still suffers from major glitches and it is grounded for the moment.

In South Africa our dedicated frequency is 35 Mhz for the air and I think 72 Mhz for the ground guys.

I have ordered a Spektrum DX6 and I am impatiently waiting for it to arrive. It has been shipped and I should have it in a couple of weeks. It will be going into the Little Extra the very moment it arrives.

It would appear as though I will be the first in S.A. with it and beleive me I can't wait - spots are becoming a problem with guys flying in every available open space and I wonder how many planes have been shot down. We hear stories all the time.