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Old Aug 22, 2011, 05:59 PM
Chris R
United Kingdom
Joined Dec 2009
713 Posts
I also dont use a rudder.
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Old Aug 22, 2011, 10:01 PM
Flying low is expensive.
pdiddyg40's Avatar
United States, CO, Boulder
Joined Jul 2008
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Quote:
Originally Posted by AdamChicago View Post
I'm just about done with my Skywalker rebuild after a crash in June but now I want to power my radio/LR UHF Tx (hitec A9 with Scherrer LR UHF) from a 12volt lead acid battery connected to a Castle Pro BEC, but am not sure if the BEC's output amperage will work with the A9's max input amperage...does anyone know the answer to this?
I'd make my way over to the radio forums and ask there. Maybe you'll get an answer here, but that's a very specific question to ask. I couldn't tell you the draw of my Fut 9C and that's what I fly with. Let alone what someone else flies with I'd kind doubt that a radio would draw a ton of power. If my 2500mah lipo will power my TX for... say... 6 hours (which is on the safe side, but I don't know exactly) then it's only drawing... well not a lot at all

I could be wayyyy off target here, so you should talk to someone that knows their stuff. But that's a good idea
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Old Aug 22, 2011, 10:28 PM
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@AdamChicago: Of course it will work: you need just 1 amp for regular TLRS and 3 amp for high power setting or 10 amp for booster. The hitec TX power use is inconsequential.

But you are over-engineering. You don't need a heavy lead-acid battery.
Just get a cheap 20c 6s lipo. It'll run your transmitter and TLRS for ages. You can buy an "Any to 12v" regulator with 16amp output on ebay for $20. The ones that are in a metal case.
Much more reliable than the Castle.
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Old Aug 23, 2011, 01:10 AM
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UndCon's Avatar
sweden
Joined May 2007
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I use lots of rudder, mainly to keep plane turning level instead of banking so I counteract turning with ailerons.

In an approach prior a sequence for video I can use ailerons/rudder as per normal, but when I fly in the area I want to record I always try to keep camera movements smooth.
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Old Aug 23, 2011, 05:26 AM
SILURIA / UK
Shikra's Avatar
United Kingdom
Joined Jun 2009
2,432 Posts
Another vid for you SkyWalker nuts....

BTW, this place is up for sale - 2 million......
http://www.vimeo.com/28047228

Why is it when you head out all is calm, then as soon as get to the field the wind starts up. meh it P's me off.

I guess the answer is to get up early!!
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Old Aug 23, 2011, 09:07 AM
Whats the wrst that can happn?
AdamChicago's Avatar
Chicago, IL USA
Joined May 2010
2,649 Posts
Thanks for your info, I have been trying a few threads because this is kind of an obscure question....but it is for my SW and this thread has a LOT OF experienced FPVers. Currently my 2500mah lipos only last about 10mins, maybe 15mins powering the A9/Scherrer LR @ 2Ws with a 30ft shielded cable in between and that's why I wanted to move to lead acid so I can just go the whole day without worrying about losing power. I've seen other's ground stations that use lead acid but can't find those specific posts now. I may just bail on the lead acid and go with a 6000mah lipo.

Quote:
Originally Posted by pdiddyg40 View Post
I'd make my way over to the radio forums and ask there. Maybe you'll get an answer here, but that's a very specific question to ask. I couldn't tell you the draw of my Fut 9C and that's what I fly with. Let alone what someone else flies with I'd kind doubt that a radio would draw a ton of power. If my 2500mah lipo will power my TX for... say... 6 hours (which is on the safe side, but I don't know exactly) then it's only drawing... well not a lot at all

I could be wayyyy off target here, so you should talk to someone that knows their stuff. But that's a good idea
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Old Aug 23, 2011, 09:12 AM
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2500mah 3s at 10w is 1 amp
that should last 2 hours
something wrong: look deeper!!
even if the a9 was running it's rf (usually not if you plug in, nor do you want it to) you should still be good..
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Old Aug 23, 2011, 09:38 AM
SILURIA / UK
Shikra's Avatar
United Kingdom
Joined Jun 2009
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Agree, something isn't right!!

I run 2500 with a scherrer like probably many others and it lasts a fair time. Not sure how long excactly, but I had 2 * 1 hour flights without recharge. Certainly capable of more. Not at 2W though...
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Old Aug 23, 2011, 09:58 AM
Whats the wrst that can happn?
AdamChicago's Avatar
Chicago, IL USA
Joined May 2010
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Thanks for the info...actually the lipo is a 2S (7.4v) and I'm using it with the Scherrer LR set at 2Ws

Quote:
Originally Posted by nyc863 View Post
2500mah 3s at 10w is 1 amp
that should last 2 hours
something wrong: look deeper!!
even if the a9 was running it's rf (usually not if you plug in, nor do you want it to) you should still be good..
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Old Aug 23, 2011, 01:10 PM
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Quote:
Originally Posted by AdamChicago View Post
Thanks for the info...actually the lipo is a 2S (7.4v) and I'm using it with the Scherrer LR set at 2Ws
OK, now I understand the problem. i went to the Scherrer site and noticed that he uses an internal switching supply that bumps the voltage to whatever his circuit requires. A 2S battery voltage is just too low for efficient operation, way too much current draw.

I seem to recall that you use a 4s for the Zeph. In that case in the interest of simplicity, I think I'd run the UHF on the same size lipo battery that you have in the Zeph (or Skywalker). That way you don't need to have a lot of oddball stuff that has only one purpose. You could also run the UHF on a lead acid battery if you prefer, but either way I'd mount that battery close to the transmitter and use decent leads, maybe some #18 speaker wire. I would also power the RC radio with its own internal battery.

Cliff

PS - Looks like the UHF can use up to a 6S. You could also wire 2, 3S packs with the same mah ratings in series if that would be more convenient
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Old Aug 23, 2011, 05:17 PM
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Panama City, Fl
Joined Jan 2009
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Quote:
Originally Posted by rcplanes1234 View Post
This is the one I use with a 10x5 prop. On a fully charged, well used 4S battery and a wattmeter, I get 32.4A and 509W. In the air, I never get over 32A, and mid to upper 20s for take off.

I have a few vids on YT under my name for verification.

Joe
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Old Aug 23, 2011, 05:25 PM
RTFM
octane81's Avatar
Antarctica
Joined Oct 2010
1,167 Posts
Another successful LR flight with Skywalker , what an awesome bird !!
Scary landing(w/goggles) , felt like I was about to hit those trees
Skywalker 12.5KM FPV Flight #009 (13 min 8 sec)
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Old Aug 23, 2011, 06:03 PM
Chris R
United Kingdom
Joined Dec 2009
713 Posts
octane81 your MAH is very low for 25km round trip!

Yours 3500mah to do 25km
Me 4000mah to do 20km

Maybe its down to lipo weight and wind speed! or did you fly with crosswind?
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Old Aug 23, 2011, 06:15 PM
RTFM
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Antarctica
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It was almost no wind this day, that might be why.. i dont know.
I just set the throttle to cruise at about 70km/h , 7-8amp drain.
Im carrying a 5000mAh + 2200mAh for video (however it only drained 300mAh for the whole trip)

Quote:
Originally Posted by Cir2kuk View Post
octane81 your MAH is very low for 25km round trip!

Yours 3500mah to do 25km
Me 4000mah to do 20km

Maybe its down to lipo weight and wind speed! or did you fly with crosswind?
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Old Aug 23, 2011, 06:26 PM
Chris R
United Kingdom
Joined Dec 2009
713 Posts
Quote:
Originally Posted by octane81 View Post
It was almost no wind this day, that might be why.. i dont know.
I just set the throttle to cruise at about 70km/h , 7-8amp drain.
Im carrying a 5000mAh + 2200mAh for video (however it only drained 300mAh for the whole trip)
I was flying into 10mph head wind, but that shouldnt matter if you fly back with tail wind helping you!

I carry 4s 6000mah and 3s 2200mah for video.
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