Rf shield pcb mount nc,outdoor survival handbook pdf viewer,best outdoor survival watch - Step 1

I will present here a small report on my efforts to remove the RX filters from a TI calypso based phone. Well, they get in the way when you want to receive the uplink frequencies of the GSM band, attenuating the signal by around 30dB.
Before getting to the filters removal and replacement, we first need to get access to them. If you've already taken appart the phone and shield, just can just skip this section entirely. For this, I wrapped the bottom of the phone with plastic and painter's tape to protect the main area from metal dust and shards.
Then using a dremel with a cutting disk, I just grinded all the corners until the metal is almost gone. Once it's almost all cut, you can just pry the top off, and then clean the inside with dust remover spray to make sure there are no metal shards or dust left on the PCB. With the top side removed, it becomes easier to remove the sides, by unsoldering them one solder point at a time.
Finally, before proceeding further, it's a good idea to check the phone still works (with OsmocomBB for instance). The proper solution is to replace the filter by another component that does the unbalanced to balanced conversion only : a balun.
The remaining problem, that I overlooked on my first try, is that what's actually implemented on the phone doesn't match the schematics.
The good news is that Mouser and Digikey stock those and you can buy them in small quantity easily. I didn't have those exact values, so I used 10 pF (for the DCS path) and 20 pF (for the EGSM path). To put the components back, just apply a very small amount of solder paste to each pads except the filters input pads (the vertically centered ones).
So in a last attempt to make the phone do something, I tried something a little unorthodox (actually proposed by h0rizon on IRC :). EMI screening covers (shielding cans) for PCBs were developed to shield only certain parts of electronic equipment from electromagnetic radiation at the source, rather than all components in the entire housing. Whether its for a small number of prototypes, or large production runs, we can manufacture the precision components you require. Our standard PCB shielding cans are closed completely with the exception of the bottom of course.
For large production runs above 10,000 pieces it is possible to deliver the 1500 series PCB shielding cans on tape or on reel. To get a quotation for Clip-on PCB shielding system within 24 hours fill in the form below.
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The illustrations here are for a Motorola C123, but the same would apply to a lot of other calypso phones since most of them are based around the same reference design.
A lot of further work is needed to actually use the phone like that (if it's even possible), but this is outside the scope of this document.
There is two torkx screws in the battery compartement at the bottom, then unclip the plastic case gently with a flat screwdriver or blade, and finally remove two more screws at the top of the PCB. Once this is done, we also need to get the screen out of the way or it will melt when we heat up the area.
You can also gently bend them forward and backward repeatedely until all the solder points give out. You should also check you didn't make any solder bridges or any kind of damages when removing the sides.
Hopefully, I managed to found some that have almost the same pinout and size as the original filters: TDK HHM1523C1 (for EGSM band) and HHM1526 (for DCS band). So just use your hot air rework station to heat up the area and pick each component one by one with small tweezers. For this just use small amount of solder paste to 'stick' the capacitor in place and heat up with a fine solder iron tip.
As you can see, I had to recover from my damaged pads by putting one of the output capacitor a little weirdly, but it all worked out. Instead of doing a proper unbalanced to balanced signal convesion, I just connected one of the RITA balanced line to the ground using a DC blocking cap. If you have two neighboring sources of interference you can also place two PCB shielding cans right next to each other, making the shieldings into one large can. To prevent short-circuiting, it is posible to make a recess area's in the PCB shielding can. If the source of radiation or inteference produces much heat, it would be wise to make ventilation holes in the shielding can.. If you are afraid that vibrations or movements will set the PCB shielding can free from the RF shielding clips, then you can fix the PCB shielding can with a spud.
If you are afraid that vibrations or movements will set the PCB shielding can free from the RF shielding clips, then you can also place a piece of soft compressable foam between the PCB and the housing of the device. However, we can make many alterations to our PCB shielding cans to meet your specifications, such as: holes in any desired diameter for the passage of cables, higher angles on the PCB shield, allowing the can to be soldered directly onto the PCB (no need for mounting clips or pins anymore) or a self-adhesive removable top cover.
Solder direct onto PCB "Solder land" (Also, see our 1510 series Fixed PCB shielding cans, the same as the 1500 series Clip -on PCB shielding cans, but with teeth in order to glue the can onto the PCB.
Some other calypso phone have a clip-on shield which is easier to remove but those are harder to get a hold of. To do this, just unclip it from the PCB, it's held by two plastic clips and four metal ones on its side. Clipping it back and then using a small wire inside the small hole across the platic and pcb to tighten them together works great.
As you can see, the filter does more than just filters the signal, it also converts the unbalanced 50 ohm input from the antenna itself to a 100 ohm balanced signal going to the RITA chipset.


Since there is no capacitors in reality, there is no DC isolation between the filter and the RITA. You can see on the right that I ripped out two pads and the small traces joining them (on the low frequency path, the pads joining inductor output to filter input).
Note that it's way easier to do if you put the PCB vertically on its side, so that gravity helps you keep the capacitor in place during the work.
To do this, you will need holes on the right places in the design of your PCB and your PCB shielding can. For electric discharge, you can use a EMI gasket or an electrically conductive foam as well.
The option for alterations apply to general features as well: it is possible to produce our PCB shielding cans in virtually any type, shape or size. For more informations on the various models, you can always refer to the "Supported Phone Hardware" list on the OsmocomBB project homepage: here. Clean the glue with isopropyl alcohol so that it doesn't burn and then heat up the soldered zone with a hot air gun while gently pulling on the flex PCB.
The original filters have one vertically centered input pin while the baluns have two pins on the upper and lower border.
If you do rip some stuff, don't panic and just try to figure some way to deal with it (see below).
But you can check that both ground pins are well soldered to the ground and that the NC and input pin are indeed unconnected for now.
For DCS1800 you need to add a capacitor of your own, but for EGSM, there is a capacitor in the input SAW matching that does the trick so you only need a wire. The RITA outputs are DC-biased to some internal voltage, but the balun is gonna be biased to GND. This isn't much of a problem because the balun pins are small enough that if you solder the balun in place of the filter, the input and NC pins will not touch the input solder pad. To make this work, we need to make sure the balun has proper DC blocking on both input and output. It's then possible to connect the input properly where it needs to be using a small capacitor acting as a RF bridge.
For the input, it's already handled because we use a capacitor to connect the input pin as mentionned before. For the output, we need to remove the inductances and replace them by some capacitors of our own.



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