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Old Apr 09, 2012, 04:31 PM
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Switzerland, LU, Buchrain
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Originally Posted by whakahere View Post
Markus since you seems to know much more than a hack like me, what would be the smartest way to get to 3.3volts from s4 to s2 batteries?

Each regulator I look at has a frequency reading. Does that matter to me and if so what should I be looking for? I have seen them range from about 200khz - 2000khz.

While I wanted to use a linear reg I have noticed I am not able to at these voltages. Is it better to get a switching reg from 16 volts down to 3.3v or is it smarter to look for a switching reg that goes to 5volt and then use a linear reg?
The switching frequency basically defines the inductance of the coil needed and for weight and cost reasons the higher the frequency the better for these factors. However, there is a trade off. Higher frequency means more noise, and harmoics, so you have to balance these two factors among eachother.

To use a linear regulator on a 16 volt input to go down to 3.3 is no good idea. In laymans terms, they convert the voltage differnce in heat. That said, the bigger the difference, the hotter the parts gets. Heat means lost energy and you have to deal with it. It also means stress on the parts and shorter livespan. So the second aproach, to go down to say 5v with the DC/DC, then use the linear (low drop in this case) regulator is smart as it at the same time also kills the ripple in most cases.

Markus
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Old Apr 09, 2012, 07:35 PM
RC Farmer
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Some time ago when i build my 200mw with module i used turnigy 5V UBEC... remove the shield, change the voltage divider and re attach the shield. I got nice 3.3V regulator with about 10mV ripple, if i remember correctly.

The unit still works without problems.
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Old Apr 10, 2012, 12:31 PM
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Okay guys today I made a short test with the new placed ESC. As I said I made the connection between ESC - Motor much shorter. I got a video of a short fligth. The quality is not very good I took the picture with my smartphone.

At 18 sec you see that the signal is lost for a moment. At this point I am directly over my receiver. The test starts there and I was going for a short flight till the end of my video range.

Fpv Noise Test (1 min 24 sec)


The range was a bit more than I thougt. Also in my first tests with the old setup I flew these distances. So I was getting always about 700-800m of distance.

The weather was not the best and the video link was not that good as it was on sunny days. But I think thats just because the mini camera was not getting enough light.

When you see as farer a I get the bader the video signal is. At the end of the video it was really hard for me to fly.



So the test failed because I was not getting any aprovements. So the search goes on to find the problem. Next step will be to build a LC Filter to get clean 3,3V to the TX. Anyone got a tutorial to build an easy LC Filter? I dont know much about that.

Thanks for you help
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Old Apr 10, 2012, 12:51 PM
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Switzerland, LU, Buchrain
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Quote:
Originally Posted by Airbuzzler View Post
Okay guys today I made a short test with the new placed ESC. As I said I made the connection between ESC - Motor much shorter. I got a video of a short fligth. The quality is not very good I took the picture with my smartphone.

At 18 sec you see that the signal is lost for a moment. At this point I am directly over my receiver. The test starts there and I was going for a short flight till the end of my video range.

http://www.youtube.com/watch?v=Q0Eq90asOfo

The range was a bit more than I thougt. Also in my first tests with the old setup I flew these distances. So I was getting always about 700-800m of distance.

The weather was not the best and the video link was not that good as it was on sunny days. But I think thats just because the mini camera was not getting enough light.

When you see as farer a I get the bader the video signal is. At the end of the video it was really hard for me to fly.



So the test failed because I was not getting any aprovements. So the search goes on to find the problem. Next step will be to build a LC Filter to get clean 3,3V to the TX. Anyone got a tutorial to build an easy LC Filter? I dont know much about that.

Thanks for you help
IMHO the graininess in your video comes from antennas not being that great. The horizontal lines though seem to be more some sort of noise. The other thing of course is, do you always fly to the very same place? Maybe there is an RF source that generates this? Have you tried to fly in a totally different location?

Markus
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Old Apr 10, 2012, 12:59 PM
Kiwi in Germany
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Germany
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Quote:
Originally Posted by Airbuzzler View Post
So the test failed because I was not getting any aprovements. So the search goes on to find the problem. Next step will be to build a LC Filter to get clean 3,3V to the TX. Anyone got a tutorial to build an easy LC Filter? I dont know much about that.

Thanks for you help
here is how I built mine
http://www.rcgroups.com/forums/showt...441664&page=53
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Old Apr 10, 2012, 01:07 PM
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The other thing of course is, do you always fly to the very same place? Maybe there is an RF source that generates this? Have you tried to fly in a totally different location?
I asked my dad about that and he said that there is a transmitting station from GSM about 500m away. I dont know if there can be interferences from this tower ?

Today I also flew to the direct opposite direction and I lost my signal complety for the first time (was very scary).

If the weather is the same like today I will try to fly from a new place. And I will also try other antennas on a different channel.

Thank you sir, that is exactly what I need !
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Old Apr 13, 2012, 01:11 PM
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Originally Posted by whakahere View Post
How critical are the cap values?

I have some at home but aren't the same value. I have a 1000uF 16V electrolytic cap and a 100uF 16V el.cap...
Regarding the ceramic I have a 104 100V, a 152 and a 1032.

Which combo should i choose?
Why do I have to use a ceramic + an electrolytic cap?
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Old Apr 13, 2012, 06:32 PM
Kiwi in Germany
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not that critical. The number of wraps around the toroid core matters most. In the caps the 1000uF, 100uF and 104 will do the job I believe. I think you could get away with the core and just the 1000uF cap.
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Old Apr 14, 2012, 10:10 AM
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Hey guys,
somethin new from my little project.

I changed a lot and tried the system on different planes. One and two battery setups. I builded the LC Filter. Tried to reduce noise from ESC. Builded 4 pairs of antennas. And nothing really changed my range problem.

I dont really know what else I can do or check to get some more range. Perhaps the easiest step would be to buy a pair of antennas. I think I will do this soon. If you got any tips what I can do just tell me.

I get about 700m of range. Normally I would be pretty satisfied with this range but the problem is that the video quality differs a lot. At 700m its not any fun to fly. Just in 200-300m radius the picture is pretty clear and its a LOT of fun.

I bought a PNP System from Foxtech to check if its my environment thats causing the bad range. But nevertheless I will try to improve my system and get the best quality video out of it.

Thank you all for you help !
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Old Apr 14, 2012, 10:32 AM
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Romania, Dolj, Craiova
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Unfortunately now we are busy to prepare for a big meeting between 27 and 30 April, but later, first weeks of May, if you didn't solved your issues, I can prepare a setup, test it for at least 3km, and deliver to you with the movie as proof.
If still no range you have a perturbing factor in your area.
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Old Apr 14, 2012, 05:38 PM
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Renatoa that would be awesome but I really dont want to steal your time.
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Old Apr 16, 2012, 10:25 PM
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Old Apr 20, 2012, 05:40 PM
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Hi guys! I need your help!

I want to restore toasted foxtech 200mw TX. Please take a look at this picture:



Can anyone tell me the name of the component highlighted in circle

it also misses some components highlighted in rectangular. I guess the are caps?
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Old Apr 21, 2012, 01:50 AM
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Check this thread, maybe helps, seems same trouble:
http://www.rcgroups.com/forums/showthread.php?t=1592710

But yours seems much more damaged. If not succeed to fix it, you still have a chance to extract the core module and use it alone, you find in this thread how.

whakahere, can you post the above link in OP, seems to be a common issue for this VTx.
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Old Apr 21, 2012, 03:46 AM
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SW England
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Quote:
Originally Posted by StormRU View Post
Hi guys! I need your help!

I want to restore toasted foxtech 200mw TX. Please take a look at this picture:



Can anyone tell me the name of the component highlighted in circle

it also misses some components highlighted in rectangular. I guess the are caps?
The part circled is a voltage converter ACT4060
http://www.ebay.com/itm/5-PCS-ACT406...item19cf4ba0b5

The other 2 parts are inductors.
I scavenged same sized parts from an old circuit board and it works fine.

If you don't have the luxury of a hot air de-solder station, then 'flood' all the pins on the 8 pin chip with solder (fill all the pins up so you have 1 big blob of solder on each side of the chip) and use 2 soldering irons to melt the solder and 'lift' the chip from the board. Clean excess solder from the board with braid wick and re-solder the new chip in place.
Same idea on the blown inductors with 2 solder irons with small tips.

HTH

Nigel.
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