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Telemaster Electro Build


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#41 Mr.RC-Cam

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Posted 19 January 2008 - 08:26 PM

First thing to do was to cut a slot in the wing tip for the Video Tx. This particular Tx is an early prototype based on the Airwave AWM612TX RF module. I also mounted the microphone on the wing surface too. The module slips into the cutout and is hidden by a cover. The Tx runs warm, so the cover has an air scoop on it.

You will notice that I use a lot of Toroids on my cables. These are useful for reducing common mode EMI/RFI noise.

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  • tx_wing2.jpg

- Thomas

#42 Mr.RC-Cam

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Posted 19 January 2008 - 08:32 PM

As mentioned earlier, I'm using the Pandora Pan & Tilt mechanism with a KX-131 CCD camera. It is located slightly outboard from the aileron servo (in a location that allowed the wing to balance with the Tx installed on the far opposite wing tip). I installed a 5V linear voltage regulator on Pandora to power the camera. Putting the regulator close to the KX-131 camera ensures that it gets clean power and avoids the voltage drop from the long cable to the battery.

Of course it all began with cutting a hole in the wing that is aligned with the Pan Base Plate's opening. The front of the plate is held by two 4-40 machine nuts (inside the wing is a Pandora Base Plate Backing part with machine screws glued to it). The plate's rear end is held by two #2 sheet metal screws that are sunk into the wing's spar.

That is all there was to it. It will be a couple weeks before I can try it out. But, I don't expect any issues with the remodel job. One thing is for sure, with the camera moved from under the fuselage to under the wing, I no longer have to worry about decapitation on a hard landing. :)


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Attached Thumbnails

  • cam_wing1.jpg
  • cam_wing2.jpg
  • cam_wing3.jpg

- Thomas

#43 Mr.Pibb

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Posted 19 January 2008 - 09:46 PM

As mentioned earlier, I'm using the Pandora Pan & Tilt mechanism with a KX-131 CCD camera. It is located slightly outboard from the aileron servo (in a location that allowed the wing to balance with the Tx installed on the far opposite wing tip). I installed a 5V linear voltage regulator on Pandora to power the camera. Putting the regulator close to the KX-131 camera ensures that it gets clean power and avoids the voltage drop from the long cable to the battery.

Of course it all began with cutting a hole in the wing that is aligned with the Pan Base Plate's opening. The front of the plate is held by two 4-40 machine nuts (inside the wing is a Pandora Base Plate Backing part with machine screws glued to it). The plate's rear end is held by two #2 sheet metal screws that are sunk into the wing's spar.

That is all there was to it. It will be a couple weeks before I can try it out. But, I don't expect any issues with the remodel job. One thing is for sure, with the camera moved from under the fuselage to under the wing, I no longer have to worry about decapitation on a hard landing. :)


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Hey! You pretty much mounted the camera and TX right where I have mine mounted!

I noticed you put a ferrite core on the video TX lines. I was considering doing that, but I was concerned that it could do strange things to the video signal. Any idea what sort of impedance mismatch it may create? I suppose if you don't see any ill effects in the video then it doesn't matter anyway!.

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#44 Mr.RC-Cam

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Posted 20 January 2008 - 12:17 AM

Yes indeed, nearly identical clones. :)

The toroids will have no adverse effect on the video quality. The video signal's content is under 5 MHz, which is substantially below the effective range of the toroids.
- Thomas

#45 JMS

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Posted 21 January 2008 - 11:54 PM

Nice work guys! :D I'm starting to like the idea of the ferrite rings more and more myself. :)

#46 Wavess

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Posted 22 January 2008 - 04:48 AM

Nice work, Iīm thinking were to install my equipment on my telemaster but this option has a disadvantage, thereīs always the side closer to the fuse thatīs blinked by it, I supposse itīs better that the omni has a clear space around it, what do u think about it?
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#47 Mr.RC-Cam

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Posted 22 January 2008 - 10:30 AM

Camera mounting locations are a personal preference sort of thing. Honestly, it doesn't bother me that the fuselage would be in view if I pan far over to one side.

The Telemaster's big size is great for the wing mounted camera. With normal forward facing views, the prop is no longer in front of the camera. Here is an example of a Telemaster with a fixed position wing mounted camera: http://www.dpcav.com...nspire_demo.htm
- Thomas

#48 Wavess

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Posted 22 January 2008 - 02:24 PM

I think I explained bad on my previous post, I didnīt mean the camera position which is the less that bothers me too, I was thinking about the Omni Tx antenna, that it always have 1 side covered by the fuse, example:

If we have the tx on the left half wing and we are flying sideways from left to the right of your field, the tx video antenna itīs placed right behind the fuse, so it would be someway blinded by aircraftīs model. Ideally itīs better that omnis have clear spaces around them without any obstacles. But yes maybe the advantages of this solution are greater than the disadvantages.
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#49 Mr.RC-Cam

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Posted 22 January 2008 - 03:36 PM

Sorry, my misunderstanding. FWIW, I don't expect any noticeable "blind" spots from the Tx's antenna placement. I agree that the electrical junk in the trunk (fuselage) could be in the RF's way for some low altitude RF signal propagation. But I have flown with my A/V Tx and antenna out on the wing before, on a smaller model where I would expect the problem to be more exaggerated, and I never noticed any issues. There are a few other folks with wing mounted Tx's and they are having very good results, plus the R/C Rx's reliable range often improves with the increased distance from the video Tx.

For long range applications this may matter, especially if the fuselage is fully loaded with metal goods. But, honestly, I don't expect it to be a major worry for an installation involving a model like the Telemaster. I guess the best thing would be for you to try it out on yours if the wing mounting method appeals to you.
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#50 Mr.Pibb

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Posted 22 January 2008 - 04:18 PM

Since mine is mounted in basically the exact same spot... :D

I don't really see any blind spots from having the TX on the wing tip. I'm using a 500mW 900MHz video setup.

http://www.vimeo.com/414571

#51 JMS

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Posted 22 January 2008 - 10:03 PM

And indeed it works VERY WELL Tim!!! ;)

#52 Gary Evans

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Posted 23 January 2008 - 05:15 AM

The Telemaster Electro is on sale at Hobby Lobby right now for $129.

#53 Gary Evans

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Posted 06 February 2008 - 05:21 AM

With the long span between the camera and Tx are you using shielded wire for the video signal?

#54 Mr.Pibb

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Posted 06 February 2008 - 05:25 AM

With the long span between the camera and Tx are you using shielded wire for the video signal?


I use shielded wire from a set of light weight audio/video cables I had sitting around.

#55 Gary Evans

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Posted 06 February 2008 - 05:46 AM

Does the shield have to be somehow grounded?

#56 Mr.Pibb

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Posted 06 February 2008 - 08:27 AM

Does the shield have to be somehow grounded?


The shielding in this case is just the ground wire. It's basically coax cable. I'm sure you could go one step further and use two conductor wire with a shield around that. In that case, you would want one side of the shield grounded, I think the camera side.

#57 Kilrah

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Posted 08 February 2008 - 01:19 PM

with a shield around that. In that case, you would want one side of the shield grounded, I think the camera side.

A shield should be grounded on both sides to be effective.

#58 W3FJW-Ron

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Posted 08 February 2008 - 04:28 PM

The shielding in this case is just the ground wire. It's basically coax cable. I'm sure you could go one step further and use two conductor wire with a shield around that. In that case, you would want one side of the shield grounded, I think the camera side.


I'm going to be a devils advocate here. The shield is best grounded at the transmitter and only at the transmitter. Grounding at both ends would give a good setup for ground loops at these frequencies and those we definitly do not want..
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#59 Terry

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Posted 09 February 2008 - 01:31 AM

Grounding at both ends would give a good setup for ground loops at these frequencies and those we definitly do not want..

Maybe, but if the TX and the camera do not share a battery I see no problem.

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#60 Kilrah

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Posted 09 February 2008 - 02:20 AM

If you use the shielding as your system ground I dont see a ground loop... only if you also parallel one of the internal conductors with it.