Lightweight TX

[Wavess 0]

This is the AWM 631TX with 40 mW. Since I changed my 500mW to 100mW easystar´s tx I´m getting more and more range with 35mhz, I was surprised at the french meeting too, some glitches I used to have always at my rc flying club, in france had dissapeared at all. Well this AWM 631, is a really nice tx from Airwave, it goes with 5V, so don´t have to worry to step down to 3.3V like the 633, and with that power I think I could achieve between 2-3 km, more than I want because it´s going to be installed on a 3D Parkflyer.

Final weight of this transmitter is 12g, the lighter tx I´ve ever had.

[Mr.RC-Cam 121]

That looks a lot like the way ThomasS built his AirWave Tx. http://www.rc-cam.com/forum/index.php?showtopic=1836

Airwave's AWM630TX (10mW) and AWM631TX (40mW) modules are perfect for the construction method you are using. For sure, soldering the SMA connector directly to the module ensures proper impedance matching (something that is easily goofed up when using other methods). Plus, this solution is very low cost.

[Wavess 0]

Yes I was inspired on his mounting but without those expensive caps It´s the best way of mounting airwave txs specially when like this is powered by 5v.

[jonforstedavies 0]

Yes I was inspired on his mounting but without those expensive caps It´s the best way of mounting airwave txs specially when like this is powered by 5v.

I have an Intelligent Flight 926 10mW Micro Transmitter which requires a 5v supply. I intend to use a L7805CV 5v Linear Voltage Regulator driven by a 11.1v 3 cell Lipo to get ths 5volts. Is this what you did.

Anyone see any problems with this set up?

Just realised that the two black wires exiting the 926 Tx are not internally connected. I had assumed that these two wires were the common 0v line for the video/audio input and the 0v of the power supply. Has anyone used this Tx and if so how did you wire it up?

Thanks.

Jonathan

Edited June 21, 2008 by jonforstedavies

[Wavess 0]

I have an Intelligent Flight 926 10mW Micro Transmitter which requires a 5v supply. I intend to use a L7805CV 5v Linear Voltage Regulator driven by a 11.1v 3 cell Lipo to get ths 5volts. Is this what you did.

Anyone see any problems with this set up?

Just realised that the two black wires exiting the 926 Tx are not internally connected. I had assumed that these two wires were the common 0v line for the video/audio input and the 0v of the power supply. Has anyone used this Tx and if so how did you wire it up?

Thanks.

Jonathan

Sorry I haven´t seen your reply till today. I wouldn´t use a linear reg for lowering 11.1V to 5V. Too much wasting energy in heat. Would use a swicthing voltage reg, but take care doing a proper filtering. One ready to go dc-dc switching that works very good without any noise is the castle ubec.

I don´t know anything about the 926 TX, sorry

[Kilrah 2]

A 7805 is perfect for a 10mW TX. Even the small 78L05 ones (in smaller TO92 packages) will do fine.

Too much wasting energy in heat.

Of course in percentage you lose a lot, nearly 60%, but with only about 60-80mA on a 10mW TX it's worth the simplicity and lack of possible interference.

I don't know that exact TX, but usually the 2 ground wires are internally connected even if it's not obvious by looking at the circuit.

[Wavess 0]

A 7805 is perfect for a 10mW TX. Even the small 78L05 ones (in smaller TO92 packages) will do fine.

Of course in percentage you lose a lot, nearly 60%, but with only about 60-80mA on a 10mW TX it's worth the simplicity and lack of possible interference.

I don't know that exact TX, but usually the 2 ground wires are internally connected even if it's not obvious by looking at the circuit.

You´re right, I misread the post and thought it was a more powerful TX, a 7805 with that consumption will do fine.

[BlueAngel 0]

Hi,

i want to do the same TX with the AWM630-TX 10mW Module.

In a german forum, they told me that i have to use something like a "Pre-Emphasis" for the video signal.

But on the picture from wavess i don't see anything like that. The video output from the cam is directly connected to the video input from the tx module or not?

thx

Blue

[Doofer 0]

Just a big value electrolytic (470uF), usually.

Is there a reason why just soldering a 1/4 wave whip onto the RF output of an AWM630 wouldn't work (like the small 'stamp' Txs)? Must I use a socket?

[Kilrah 2]

Is there a reason why just soldering a 1/4 wave whip onto the RF output of an AWM630 wouldn't work (like the small 'stamp' Txs)? Must I use a socket?

I did that on a 631 and it worked very well. The only thing is that the pads are a bit fragile and you might break the connection if you apply force on the wire antenna. I had to resolder it a bit too often for my liking.

[Luke 0]

Besides being delicate, are there any complications involved in soldering an antenna directly to the RF output? (SWR issues, tuning etc.)

I'm looking to cut the weight down on a Lawmate 500mw TX, and I'd like to remove the (heavy) SMA connectors, if possible.

~Luke

[Terry 5]

Hmmm, I seem to have answered this on rc groups.

I think there was some good info given too.

Terry

[Luke 0]

Hmmm, I seem to have answered this on rc groups...

Just did some searches, didn't come up with anything?

Have a link, perchance?

~Luke

Edited June 27, 2009 by Luke

[Terry 5]

http://www.rcgroups.com/forums/showthread.php?t=1067243

Terry

[Luke 0]

Thanks!

~Luke