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Old Jan 06, 2013, 12:13 PM
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Romania, Dolj, Craiova
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Should not matter, because VTx internally reduce the voltage down to 3.6V, this is the operational voltage of the core VTx. There are reports working fine even from 5V.
If that 7.x Volts power also the camera, then this is the weak link, not VTx.
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Old Jan 06, 2013, 12:40 PM
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Romania, Bucharest
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Quote:
Originally Posted by ridgewalker View Post
Talking about the full size 200mw vtx and 305 vrx...

Found this video on yt and at around 7.9v you can see the picture degradation.
It is the camera that can't handle low voltage. Pixim Seawolf handles a little better the low voltage, it works flawlessly down to 7V.
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Old Jan 06, 2013, 12:57 PM
The lunatic is on the grass
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My camera is a RMRC 420xv and operates fine at 5v,never tried it at lower voltage.
This camera can handle lower voltage than the one in the video so i'm alright powering the vtx (which is powering the camera) on a 1300mah 2s.

And since the vtx reduces the incoming voltage anyways then using a 3s would just result in more voltage being wasted as heat,with nothing more to gain,does that sound correct?
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Old Jan 06, 2013, 01:02 PM
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No heat, the VTx regulator is switching.
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Old Jan 06, 2013, 01:13 PM
The lunatic is on the grass
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Didn't know that the vtx regulator is a switching one,thanks for pointing that out.

So then,using a 3s for powering the vtx is ok ?
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Old Jan 06, 2013, 02:39 PM
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Romania, Bucharest
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Go with 3S, it will be OK. People that use 2S may need less voltage for OSD's like Remzibi. I did the same thing to avoid the dissipated heat of the linear regulator.
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Old Jan 06, 2013, 04:27 PM
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Next time out will use 3s on the vtx.

Have made several flights and only used 2s on the vtx and started getting some static at 850m,antennas Bluebeam cl and a home built spw.
Will see if the 3s makes a difference next time out.
Good to know the 3s is ok and can use a 2s as back up.

Thank you for the help.
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Old Jan 07, 2013, 12:43 AM
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It is normal to get static at 850m in certain positions. I'm very sure you won't notice any difference between 3S or 2S. There is a difference though: at the same capacity the 2S is lighter than 3S . On the other hand, going on 3S gives you the possibility to power video from the engine battery so no supplementary weight at all.
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Old Jan 13, 2013, 03:31 AM
Firepower
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North Brisbane, Australia
Joined Mar 2010
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I have been using the 3.3v Type A 5.8ghz module from Rangevideo with success and now they sell one the same but 5v. I need to but a couple more now.

I guess the 5V will be more versatile and can be used on a 1cell LiPo.

Anyone had any problems with the 5v version?

Here are the two they sell 3.3v and 5v.

3.3v
http://www.rangevideo.com/index.php?...roducts_id=217

5v
http://www.rangevideo.com/index.php?...roducts_id=304
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Old Jan 13, 2013, 04:17 AM
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Romania, Dolj, Craiova
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Even 3.3V version can be used with 1s Lipo, is how I use mine for years.
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Old Jan 13, 2013, 05:00 AM
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Malaysia, Federal Territory of Putrajaya, Putrajaya
Joined Nov 2011
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Quote:
Originally Posted by renatoa View Post
Even 3.3V version can be used with 1s Lipo, is how I use mine for years.
same here i use mine 5.8 got from Foxtech with 1s lipo no problem at all
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Old Jan 13, 2013, 06:11 AM
Firepower
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North Brisbane, Australia
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Thanks renatoa & skellator just was not brave enough to use the on a 1S LiPo on the 3.3v module but from what you say no problems.

Just been attaching the modules to some vero board with double sided tape and soldering an antenna connector to the vero board with wires to the TX to use a SPW. Simple and works great.

So there does not seem to be any problem with the 5v ones and the 5v can be taken from the receiver if BEC/UBEC has enough power.
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Last edited by Firepower; Jan 13, 2013 at 08:28 PM.
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Old Feb 17, 2013, 05:59 PM
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Central Coast, NSW, Australia
Joined Apr 2007
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Hi Guys,

I bought the 5.8ghz 200mw system for my quad about a month or two ago as my introduction to FPV. I am using these spironet antennas from HK.

I don't seem to be getting anyway near the range I expected (1km). At the most in a clear LOS area like the beach I get around 150 - 200meters before the signal starts to degrade. I get the same range if I fly at a sports field as well. From what I have read I should have been able to get at least a few hundred meters with the stock antennas and around 1km with the spironets.

Are the HK spironet antennas no good or is there something else I am missing?

Thanks in advance.
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Old Feb 17, 2013, 07:07 PM
Opt
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New Zealand, Auckland
Joined Oct 2010
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Quote:
Originally Posted by deleted View Post
Hi Guys,

I bought the 5.8ghz 200mw system for my quad about a month or two ago as my introduction to FPV. I am using these spironet antennas from HK.

I don't seem to be getting anyway near the range I expected (1km). At the most in a clear LOS area like the beach I get around 150 - 200meters before the signal starts to degrade. I get the same range if I fly at a sports field as well. From what I have read I should have been able to get at least a few hundred meters with the stock antennas and around 1km with the spironets.

Are the HK spironet antennas no good or is there something else I am missing?

Thanks in advance.
Not sure but same thing happens to me. I get about 5-600m max with 200mW and spironets. Although I am running about 3.7V to the 3.3V vtx to get a bit more power from it.
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Old Feb 17, 2013, 07:14 PM
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Central Coast, NSW, Australia
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Quote:
Originally Posted by Opt View Post
Not sure but same thing happens to me. I get about 5-600m max with 200mW and spironets. Although I am running about 3.7V to the 3.3V vtx to get a bit more power from it.
Sounds like your still getting 3 times the distance I do!

I run the vtx of a 3s 500mah pack s0 12 volts. I didn't realise they could run on as little as 3.7v...I thought it was 7v to 12v input?
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