HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jun 19, 2012, 12:09 PM
Free Falling
markm75's Avatar
Joined Feb 2007
300 Posts
Discussion
72mhz radio transmitters for FPV? + Equipment suggestions for FPV?

I have an an older Futaba T6XA 6 channel radio transmitter and a Twinstar II electric (specs are in the link)..

In the plane I have as of now, a 6 channel micro receiver and a 20C 3200mah 3S battery to handle the 267 watt (30 amp or so i think) output of both engines

Minimum Channels for ?
My first question is, for a Twinstar II which uses really only 4 channels (5 of 6 are consumed in the receiver module).. am I going to find myself running short on receiver channels or transmitter channels, even with using Y cables?

72mhz range?
I've heard good things about the 72mhz range.. but i'm not clear on under ideal conditions, what max range I might expect from the 72mhz transmitter?

To help fill in the void on possible equipment that may fill up receiver ports..

-I'm thinking of a 600mw transmitter/receiver setup.
-I'll have my keychain HD camera as one camera, then another 520 line camera as the remote camera/osd.
*unclear as of now if i would use a secondary battery to power the video tx and osd or piggy it off the flight battery (or a bigger single battery). I'm at 47oz as is wo remote equip.

-OSD still unsure on brand.. i like the stat ability of Eagle Tree, but I like the simple OSD display of something like EzOSD or Cyclops CE. I only care about altitude and speed and the arrow showing the way to home, but do ultimately want to add return to home ability.

I really hate to have to cash out on a new transmitter with more channels, so i'm hoping I can just stick with my T6XA (and maybe just get a receiver with more channels if needed?).

Thanks for any suggestions
markm75 is offline Find More Posts by markm75
Last edited by markm75; Jun 21, 2012 at 11:20 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old Jun 19, 2012, 12:59 PM
Project Tormentor is flying!
United States, WA, White Salmon
Joined Nov 2005
1,976 Posts
That radio/reciever combo should be just fine for your first FPV setup. You'll run out of channels when you want to add pan/tilt (although it looks like you could currently add pan, which is nice) and its nice to have more channels for flaps/lights/other. You will need more channels if you go with a RTH OSD, such as the ET setup. But you could initially start with the Remzibi OSD, which doesn't consume any channels and has speed, arrow home and altitude (No RTH, though).

In the end, I strongly suggest you look into getting the Futaba 9C. Awesome 72mhz radio, easily upgraded to a UHF system, enough channels, good switch layout.
philthyy is offline Find More Posts by philthyy
Reply With Quote
Old Jun 19, 2012, 01:06 PM
NKK for short...
nkkromhof's Avatar
United States, IN, Mitchell
Joined Oct 2010
216 Posts
Quote:
Originally Posted by markm75 View Post
72mhz range?
I've heard good things about the 72mhz range.. but i'm not clear on under ideal conditions, what max range I might expect from the 72mhz transmitter?

Thanks for any suggestions
As for range, I think you'll find that it's not so much the transmitter that makes the difference but rather the sensitivity on the receiver combined with the noise floor in your flying area that determines range .

IBCrazy has gone 5.1 miles on a synthesized dual conversion Corona RX - that doesn't mean that you will be able to go that far as well though.
I believe the consensus is that you shouldn't try to go further than 2 miles on 72Mhz unless you're either A) VERY experienced and know what you're doing or B) Don't mind losing your plane and equipment

Having said that, do the math on a circle with a 2 mile radius and I think you'll find that that's plenty of area to fly around in.

Do yourself a favor and keep your setup simple, before you go adding an OSD, etc. learn the ropes, stay close and get used to flying FPV.
There's nothing worse than having a fully loaded kick @$$ plane and losing it 500ft away from you because you don't know what you're doing.

This is the Corona Synthesized RX I'm talking about, note that it's technically an 8Ch RX I believe, not 9Ch like they say:
http://www.hobbyking.com/hobbyking/s...9Ch_72Mhz.html
nkkromhof is offline Find More Posts by nkkromhof
Reply With Quote
Old Jun 19, 2012, 01:09 PM
Suspended Account
Long Island, New York
Joined Jun 2008
6,428 Posts
Quote:
Originally Posted by markm75 View Post
-OSD still unsure on brand.. i like the stat ability of Eagle Tree, but I like the simple OSD display of something like EzOSD or Cyclops CE. I only care about altitude and speed and the arrow showing the way to home, but do ultimately want to add return to home ability.

Thanks for any suggestions
This thread has a lot of info on OSDs.
http://www.rcgroups.com/forums/showthread.php?t=1063889
Tarro is offline Find More Posts by Tarro
Reply With Quote  (Disabled)
Old Jun 19, 2012, 01:11 PM
NKK for short...
nkkromhof's Avatar
United States, IN, Mitchell
Joined Oct 2010
216 Posts
Forgot to mention:

Your T6XA is a great, reliable radio which should be perfect for your needs as a beginner, don't trade up just yet until you figure out whether you're really going to stick with FPV in the long run.

Please note though, that it doesn't matter how many channels your Rx has, you can never use more than the channels your Tx has - so for the T6XA you'll always max out at 6 channels (plenty for now).
nkkromhof is offline Find More Posts by nkkromhof
Reply With Quote
Old Jun 19, 2012, 01:52 PM
Free Falling
markm75's Avatar
Joined Feb 2007
300 Posts
Quote:
Originally Posted by nkkromhof View Post
Forgot to mention:

Your T6XA is a great, reliable radio which should be perfect for your needs as a beginner, don't trade up just yet until you figure out whether you're really going to stick with FPV in the long run.

Please note though, that it doesn't matter how many channels your Rx has, you can never use more than the channels your Tx has - so for the T6XA you'll always max out at 6 channels (plenty for now).

Thanks for the info guys.. yeah I did actually see a 9C on ebay.. it was going for $250+ on there (compared to mine which still fetches $45-$55).. I'm definitely sticking with the 6xa for now.

*Wouldnt i be able to put say an 8 or 9 channel receiver in the plane and still use the 6xA if all i need are "powered" ports? Or is using a Y adapter here and there going to be ok.. are there certain ports that i should not use a y adapter with, such as the servos etc (chatter and other issues?).

I will definitely start out simple, definitely with a buddy box / spotter and close range.. the idea of all this equipment ending up smashed doesnt appeal to me

But in meantime I really wanted to get some stats to go along with my flights with my keychain HD cam, hence the OSD/GPS thought.. I also didn't want to buy an OSD that i'd ultimately have to replace to later get features like return to home though. I view return to home as essential to avoid losing a plane, but not really on my short list.

Short list would be: Get some flight data going, maybe OSD, but OSD would require sending the stream either to another camera with built in recorder and rca plug or sending it over 5.8ghz for instance and recording the stream on the ground via laptop.

Long term: Add goggles and return to home.

Unclear long term if ill need that secondary battery or just a bigger one though.

*Frankly i'm concerned about the life span/expectancy of the TS2, since its foam.. i'm already seeing some wear on it in parts.. almost considering starting a new EasyStar just for the remote FPV ability.
markm75 is offline Find More Posts by markm75
Reply With Quote
Old Jun 19, 2012, 02:10 PM
NKK for short...
nkkromhof's Avatar
United States, IN, Mitchell
Joined Oct 2010
216 Posts
Quote:
Originally Posted by markm75 View Post
Thanks for the info guys.. yeah I did actually see a 9C on ebay.. it was going for $250+ on there (compared to mine which still fetches $45-$55).. I'm definitely sticking with the 6xa for now.

*Wouldnt i be able to put say an 8 or 9 channel receiver in the plane and still use the 6xA if all i need are "powered" ports?
Yes, you can power stuff off of those ports, you might want to use a separate BEC though, to keep your Rx from browning out

I view return to home as essential to avoid losing a plane
No, having a solid, as simple as possible setup and flying within your capabilities is essential to not losing a plane. RTH is not trivial to set up and not always reliable. RTH won't save your plane if you have a loose connection in your wiring or if you're downwind too far in strong winds.

Short list would be: Get some flight data going, maybe OSD, but OSD would require sending the stream either to another camera with built in recorder and rca plug or sending it over 5.8ghz for instance and recording the stream on the ground via laptop.
A basic OSD such as Remzibi or the Flytron SimpleOSD XL would probably serve you well on a modest budget. For ground recording I bought an Aiptek DVO-V38 which has AV In and will record static for $22.50 shipped. A laptop is cumbersome and most USB Video adapters such as the EasyCap don't always work well or reliably.

Unclear long term if ill need that secondary battery or just a bigger one though.
One battery, but power stuff through a UBEC instead of all of it through the ESC. Two batteries = two failure points.

*Frankly i'm concerned about the life span/expectancy of the TS2, since its foam.. i'm already seeing some wear on it in parts.. almost considering starting a new EasyStar just for the remote FPV ability.
Fly it until you can't fix it anymore, get some Scotch Extreme Packing Tape, the bidirectionally reinforced kind and put a strip on the bottom of the fuse, leading edge of the wing and anywhere else you manage to scrape it up at
My comments in red above
nkkromhof is offline Find More Posts by nkkromhof
Reply With Quote
Old Jun 19, 2012, 04:10 PM
Free Falling
markm75's Avatar
Joined Feb 2007
300 Posts
Quote:
Originally Posted by nkkromhof View Post
My comments in red above
Thanks for those tips.. this is great..

My plane has two ESC's right now, one for each motor..

I'm not following the exact wiring of adding (or did you mean replacing the ESCs) another BEC or UBEC.. I understand the ESC's purpose as i have them now, but not clear on adding the BEC/UBEC...

Adding the BEC prevents an overload on the receiver i take it?

I dont see the Aiptek DVO-V38 listed anywhere for sale.. i take it its small and can take a video input?

What do you do for the OSD + the video, or are you using it strictly as the main and only video..

IE: if you had two RCAs for video, one from an HD cam with video out and one for the OSD (i'm assuming), would u just use an rca splitter into the input and record off that?

On the OSD's you mentioned, does the EZosd fall into the same class of simple to start category..
markm75 is offline Find More Posts by markm75
Reply With Quote
Old Jun 19, 2012, 04:11 PM
Free Falling
markm75's Avatar
Joined Feb 2007
300 Posts
Quote:
Originally Posted by Tarro View Post
This thread has a lot of info on OSDs.
http://www.rcgroups.com/forums/showthread.php?t=1063889
Funny, i know i started that thread ages ago then dropped the ball on the matrix at the time, I wasnt sure how relevant it all still was
markm75 is offline Find More Posts by markm75
Reply With Quote
Old Jun 19, 2012, 04:33 PM
Suspended Account
Long Island, New York
Joined Jun 2008
6,428 Posts
Quote:
Originally Posted by markm75 View Post
Funny, i know i started that thread ages ago then dropped the ball on the matrix at the time, I wasnt sure how relevant it all still was
It is a good thread and deservers to be brought back to life.
Tarro is offline Find More Posts by Tarro
Reply With Quote  (Disabled)
Old Jun 20, 2012, 07:30 AM
NKK for short...
nkkromhof's Avatar
United States, IN, Mitchell
Joined Oct 2010
216 Posts
Quote:
Originally Posted by markm75 View Post
Thanks for those tips.. this is great..

My plane has two ESC's right now, one for each motor..
I'm not following the exact wiring of adding (or did you mean replacing the ESCs) another BEC or UBEC.. I understand the ESC's purpose as i have them now, but not clear on adding the BEC/UBEC...
Adding the BEC prevents an overload on the receiver i take it?
Most low amp ESC's (say 30A and under) will have a BEC in them, it's what supplies 5V-ish to the Receiver and the servos. They're usually spec'ed for 2-3A but in reality they usually deliver less than that (look up linear vs. switching BECs) and a 'brown out' can occur when your servos, RX and whatever else you're powering through your RX draw more Amps than what the BEC can provide or if your motors cause the voltage on your battery pack to sag and your RX can 'brown out' and lose power and reboot (guess what happens )

That's where an external BEC comes in, they're usually spec'ed for more Amps and usually have better performance (again, look at linear vs. switching BECs) and are hooked up directly to your flight battery. For FPV it's generally recommended to use a separate BEC.


I dont see the Aiptek DVO-V38 listed anywhere for sale.. i take it its small and can take a video input?
I got the number wrong, I checked last night and I have a V58: ebay link

What do you do for the OSD + the video, or are you using it strictly as the main and only video..
The Aiptek records the ground feed, so basically everything that you see on your screen/goggles. The OSD is installed in line with your flight camera and its info is overlayed on the camera image.

IE: if you had two RCAs for video, one from an HD cam with video out and one for the OSD (i'm assuming), would u just use an rca splitter into the input and record off that?
See above, an HD cam (like a GoPro) is a standalone device and is not connected to anything else*. For recording on the ground the easiest way is if you have two AV (RCA) outs on your VRx. Your screen/goggles connects to one AV out and your Aiptek or other recording device to the other.
Splitting with a Y causes issues of its own and is usually not recommended. You can however use a powered video splitter like the ones used in cars (to hook up the DVD player to several screens).

* The GoPro CAN be used as your flight camera as well, in that case it would be connected to the OSD, which adds its information to the video image, sends it to the VTx which in turns sends it down to you. The OSD information will not be visible in your HD recording if you're recording on the GoPro as well (to the best of my knowledge).
FWIW - as a beginner I would consider it a Bad Idea (with caps ) to strap a $200 HD camera on your plane when you're still learning and potentially crashing.


On the OSD's you mentioned, does the EZosd fall into the same class of simple to start category..
It's one of easier ones to install yes, just pricier than the other two. It's what I use myself.

Given your relative newness to all of this, I would probably start without an OSD until you're more comfortable with how everything ties together.
Start as simple as possible and add components one at a time - your first few flights you won't need an OSD because you're not going to be flying far away enough from yourself to get lost - or at least you shouldn't
It is critical for your first few flights to fly in an open area that you're familiar with and that has a few distinct landmarks for orientation.
More comments in red
nkkromhof is offline Find More Posts by nkkromhof
Last edited by nkkromhof; Jun 20, 2012 at 07:40 AM.
Reply With Quote
Old Jun 20, 2012, 09:23 AM
Registered User
United States, TX
Joined Oct 2010
331 Posts
I use the 72mhz corona in my mini skywalker. Its about as light as it can get rx wise. I use the 72mhz module that came with my 9C. Ive never
Had a range glitch with it. I stay within 2 miles and doubled its antenna length.
Very good, cheap light weight setup.
Slaphappysamy is offline Find More Posts by Slaphappysamy
Reply With Quote
Old Jun 20, 2012, 09:37 AM
Free Falling
markm75's Avatar
Joined Feb 2007
300 Posts
Quote:
Originally Posted by Slaphappysamy View Post
I use the 72mhz corona in my mini skywalker. Its about as light as it can get rx wise. I use the 72mhz module that came with my 9C. Ive never
Had a range glitch with it. I stay within 2 miles and doubled its antenna length.
Very good, cheap light weight setup.
What kind of wire/material did you use to double the antenna length? I'm assuming you just stripped the end and extended it?
markm75 is offline Find More Posts by markm75
Reply With Quote
Old Jun 20, 2012, 10:23 AM
Registered User
United States, TX
Joined Oct 2010
331 Posts
I use 26awg stradned, teflon insulated wire. Half wave length, soldered to the rx pcb, looped and hotglued in place.
Slaphappysamy is offline Find More Posts by Slaphappysamy
Reply With Quote
Old Jun 20, 2012, 10:38 AM
NKK for short...
nkkromhof's Avatar
United States, IN, Mitchell
Joined Oct 2010
216 Posts
The stock Corona wire is ridiculously thin, don't be tempted to add to it, instead do what Slaphappysamy suggests and use 26AWG all the way. The added weight and strain on the stock wire is going to cause problems I think.
nkkromhof is offline Find More Posts by nkkromhof
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question 7 Channel Radio minimum for Trex 550 v2???? kenbad Electric Heli Talk 10 May 10, 2012 05:16 AM
Discussion Time for a new Radio - need input for FPV and LOS radio kenny_dilger FPV Talk 3 Feb 11, 2012 11:25 PM
Discussion HELP- suggest a Radio for FPV for a newbie garik111 Radios 6 Dec 03, 2011 10:18 AM
Discussion HELP- suggest a Radio for FPV for a newbie garik111 Beginner Training Area (Aircraft-Electric) 4 Dec 01, 2011 09:59 PM