Original Turnigy Module with a Metal Shield??

[jhsa]

Hi guys I'm just about to desolder the antenna wire on my new turnigy 9x from HK module and when I opened it this is what I found inside. Never seen it before..
Oh, and no hot glue blobs holding the board in place.. It was very easy to remove

João

[Kilrah]

My 2 modules had shields too.

[dvogonen]

My two boards look the same as well. Pretty neat actually. No worse visual production quality than the Futaba stuff I have payed through my nose for.

[jhsa]

well, never seen it, not even in the forums.. I have to agree that they seem to have improved the quality a little

[mmilan]

What does the metal shield do? My 2 new 9xs also have these.

[Spoogy]

I did not have that metal on my 1st. Turnigy9x transmitter. Also the Tx board was not glued anyway in the casing. I just ordered a second transmitter. Lets see if it has that metal plate.

I'm also wondering what does it do? Is it shield against some interference or does it just spread the heat of the components? Looks like that there is somekind of paste under that plate?

[jhsa]

Maybe it just covers their bad soldering so we can't see it..

[kaos]

mine did not have the shield either.
I think they know where these module go to, for some people- nerds/geeks, they need to be protected so they won't get molested.

[jhsa]

[Tommhy]

mine did not have the shield either.
I think they know where these module go to, for some people- nerds/geeks, they need to be protected so they won't get molested.

I think you have reason kaos!

Or maybe is a protection if someone use a 3s Lipo Fully charged and the 7805 mounted on module put out heat as hell! (as mine for example)

[kaos]

This is scary!
I never modded anything before. MY 1st and 2nd Turnigy did not have the metal shield on the module. Then from the 2nd, I started doing some mod to the Tx.
Recently get my 3rd Turnigy for the ERSKY9X board and planned to do major mod on it.
What you know, the module came in with a metal shield. How do they know that

[ShowMaster]

I have several of the older ones and one of the newer modules. I've worked on several for club members lately that also have the metal shield. Without doing a major autopsy I'm guessing,
It could be they had to improve the shielding to prevent spurious emissions that various countries complained about and would not allow their use or importation?
It could be they went to a OEM 2.4g rf deck that's designed that way, or both reasons.
The original module is pretty crude as far as shielding.
Either way this seems to be the new normal rf module shipping so we'll have to accept and work with it.


ShowMaster
Sent from my iPod touch using Tapatalk

[kaos]

I think they have a Skynet watching everyone. Whoever is going to mess around with them, they will put a metal shield on it.

[MostlyHarmless]

RF shielding is never a bad idea.

Keep in mind that at 2.4 GHz, 1/4-l is about 3.125 cm. Extrapolate harmonics from there.

I don't know if this has been mentioned before, but if you intend to modify your 9x by moving the antenna to the RF module, DO NOT cut the cable! Desolder it from the module and connect it back as it was. Changing the length of that cable can detune the transmitter/antenna match and result in reflected power. Reflected power in this case is probably just lost power. But that is lost range, and that is bad enough.


Regards,
Jan

[kaos]

Isn't that only has to do with the tip uncovered by the outer mesh wire?
Should be able to cut the soldered end .

[MostlyHarmless]

Right, making it a little shorter will fix it.

[kaos]

I thought cutting the soldered end is making it a little shorter.

[MostlyHarmless]

The usual "assumption" is that for a "matched" antenna the length of a coax feed line of equal impedance is irrelevant. Most of the time that assumption is right.

[Ozzy]

My first 9x bought two years ago does not have the shield, my new version bought 3 months ago does have the shield.

[ShowMaster]

The usual "assumption" is that for a "matched" antenna the length of a coax feed line of equal impedance is irrelevant. Most of the time that assumption is right.

For this wavelength I don't think the solder end of coax is part of the antenna system but just a transmission line to to get the rf to the tip of the antenna. As you said, if the tip is cut to the proper length it should represent 50 ohms impedance. Assuming this is the case the coax length itself should at the solder end have its length changed and still have the power radiated out the antenna and not be wasted in the coax as SWR power loss.
All fittings added must be zero or low loss and 50 ohms in design to maintain the systems impedance. All added fittings and connections, coax types, can cause a imbalance in the 50 ohm system. This translates to power loss going out the actual antenna (the tip) so be very careful doing any major changes to any antenna and coax feed line system but it can be done.
We only start out on 2.4g with 50/60 milliwatts. 72mhz and other frequencies in the past started with close to 1watt or 1000 milliwatts so we had wiggleroom for a little loss.


ShowMaster
Sent from my iPod touch using Tapatalk

[kaos]

My first 9x bought two years ago does not have the shield, my new version bought 3 months ago does have the shield.

My guess is 3 yrs ago , you were not here. now you are here. so the shield appears.

All fittings added must be zero or low loss and 50 ohms in design to maintain the systems impedance. All added fittings and connections, coax types, can cause a imbalance in the 50 ohm system. This translates to power loss going out the actual antenna (the tip) so be very careful doing any major changes to any antenna and coax feed line system but it can be done.

at the solder end. how much difference when you peel the coaxial just 1 mm and the core compare to 2 mm peeled coaxial and the core?