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Kermet

3.3 voltage reg for Aw633

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Because they actually have to pay that much for shipping, maybe?

Correct. The DE Vregs only weigh a couple grams and are sent in a small envelope like a postal letter. About $1 to do that.

my 2x TX and 2x RX from Digital Products were $35 freight,

Blame the US Postal system, where international parcel rates have doubled in recent times. I work at DPCAV and I can honestly say we don't try to net any profit on our overall delivery charges (we just aim to cover our costs). Using your order as an example, here is the cost break down. Postage $29.78. Carriage insurance $3.40. Card board container $1.10. Paypal fees for shipping related costs $1.37. Total shipping costs incurred by DPCAV = $35.65 USD (you paid $34.05).

Be sure to LC filter the power from the DE Vreg's. Otherwise you will probably see some faint lines in the image caused by the switching ripple.

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fare enough....

Thomas is it possible to start a sticky with basic essentials to get one complete system started as i didnt know i needed the filter

and could be a problem now.....can you show me a link to the LC filter size needed and material it user's ?

is this usable: https://www.dpcav.com/xcart/product.php?productid=16195&cat=252&page=3

eg,

Tx Airwave 6xx

regulator to suit( switch mode is best Dimension Engineering)

Aerial plug to suit tx

capacitors to suit TX if needed

LC filter for power supply used etc

Rx etc etc

just a idea that's all for the beginner to read, as it can save time when ordering also

Regards

brett

Edited by Kermet

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Since you are building a transmitter, you can certainly build your own LC filter. For a DE Switcher feeding a AWM633TX, try a 47uH-100uH choke in-series with switcher's output. The existing caps on your Tx's board may already be sufficient.

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Cooool,

Got the module working and had a flight today - works great. As mentioned, I used a 5V switching bec powered by the main flight battery, vsn505 5V camera from that, and then a LDO linear 3.3V reg on the module. I put a small piece of tin on the reg as a heatsink (basically a one-fin heatsink). I wouldnt leave it on without any airflow for more than a minute or two, although with the slightest airflow (say 0.5knot), I would say nothing gets over 50degC. I put a switch btw the battery and bec, so I power up plane/check controls etc, then power up vrx, goggles etc, then vtx. I was aiming at a very small/light vtx to put on the wingtip of a 300/400g plane. Weight ended up at 8g including custom dipole coax antenna (thanks mr rccam) :)

I get a little noise in the video with increasing throttle, but not too much. I will prob use a separate battery for larger models, and maybe LC filter for smaller models (if I can make one light enough <_< <_< )

Thanks for all the info guys,

Rob

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Got the module working and had a flight today - works great

Happy endings are awesome.

Now it's our turn to flip things around. How about posting photos and construction details of your project? Someone else will be in your shoes one day. Pay it forward, as they say. :)

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If you're not good at soldering, I would practice until you get it down pat. A blob or cold joint of solder doesn't mean much at 72mhz, but it can often be the the difference between success and failure at these frequencies.

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Sorry, no macro function on camera. Module is mounted on my crash-test plane ;) . The piece of tin is soldered between the regulator output pin (large one) and the cap. This gives enough thermal mass for initial temperature transient (a minute or so before you need to have a slight movement of air). Small pin of reg soldered directly to the module supply pin, ground pin to module ground and input pin directly to 5V supply wire from BEC (separate BEC for camera and vtx). Oh, module is mounted with a gap btw module pcb and wing for airflow

post-3068-125836357749_thumb.jpg

post-3068-125836359521_thumb.jpg

post-3068-125836360799_thumb.jpg

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Ouch, that looks ugly! :wacko:

Oh well, if it works...

Just beware of one thing, the contacts on the module sides (those you directly soldered your stuff to) get stripped easily by movement/vibrations. They're really not meant to hold anything. Make sure the reg is soldered to something else that is robust.

Also, I did that kind of setup once and the antenna solder joint broke pretty much every day. Wouldn't be fun in flight/might burn the TX too.

Edited by Kilrah

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Ouch, that looks ugly! :wacko:

Oh well, if it works...

Just beware of one thing, the contacts on the module sides (those you directly soldered your stuff to) get stripped easily by movement/vibrations. They're really not meant to hold anything. Make sure the reg is soldered to something else that is robust.

Also, I did that kind of setup once and the antenna solder joint broke pretty much every day. Wouldn't be fun in flight/might burn the TX too.

Kilrah, with work like this, I will probably never be let into Switzerland again :lol:

Points taken - I will definitely do things differently next time. However, wrt the antenna, how would you get around having to have an sma connector etc (add lots of weight by the time youve put the mating connector and antenna on)?

Cheers,

Rob

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I'd say a PCB is really is the way to do something with these modules. For the antenna just have a trace that is a couple mm long and leads to a hole to which you solder the antenna. Having a "full" hole holds well, as opposed to the "half" one on the module.

Edited by Kilrah

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I'd say a PCB is really is the way to do something with these modules. For the antenna just have a trace that is a couple mm long and leads to a hole to which you solder the antenna. Having a "full" hole holds well, as opposed to the "half" one on the module.

Right, now with a PCB, I wasnt confident getting thermal contact btw the module pcb and one of my own. I would have used the electric frypan method with solder paste on the main square pins on the module. But what do you use to get thermal contact btw the remainder of the two pcb's and not get any accidental shorts (my pcb would be mainly ground plane) - Oh, and you would want a 2-sided pcb with lots of via's for heat transfer to the outside face, correct?

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I wouldn't try to link the 2 thermally. The TX has enough metal to cool itself. Now for the regulator on your PCB I'd use a little heatsink if needed.

But I wouldn't be using a linear Vreg in the first place, so that would solve the problem ;)

Edited by Kilrah

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