Attila sorry flipped some letters. On Thu, Dec 3, 2015 at 10:06 AM, paul swed <[email protected]> wrote:
> Atilla, > Thanks you have read what I have written and further your experience > aligns with mine for hacking these chips at least into the GHz range. I > suspect it really falls apart in the 2-3 GHz and above region. But I have > built a lot in the 1.296 GHz region so have that experience at least. > Regards > Paul > WB8TSL > > On Thu, Dec 3, 2015 at 5:34 AM, Attila Kinali <[email protected]> wrote: > >> Salut, >> >> On Wed, 2 Dec 2015 18:39:55 -0500 >> paul swed <[email protected]> wrote: >> >> > Just adding that this is home brew so no real boards. At the IF level >> thats >> > both large enough and easy enough to add to a ground plane. So its >> > reasonable to build the basics and add stuff as needed. >> > The LNA front end is cheap so will get that just to try. Have to look at >> > the hot air suggested above to see what that might cost. >> >> The Leister one costs IIRC 300-400EUR. I.e. not the thing you'd buy >> for a single project. There might be cheaper ones though. All you >> need is something that is small enough that you can confortably >> fit into your hand, has a small nozzle and temperature control between >> 200°C and >400°C. >> >> But if you are not building a board anyways, there is an even "simpler" >> way to go: Dead-Bug! :-) >> For 0.5mm QFN/DFN i usually use AWG30 wirewrap wire or 0.08mm^2 tinned >> copper wire. Enamelled wire should work too, but I am generally to lazy to >> tin the tips and make sure that no blobs of enamel residue were left on >> the wire. The way to ensure that you dont get any shorts is to spread the >> wires out, such they gain enough distance. As you will be soldering RF >> chips, >> which have a ground pad in the center that needs to be soldered, i >> recommend >> using solder wick. Use 2 wide strips and solder them first (before any of >> the pads) onto the ground pad, such that they point to opposide >> directions. >> Make sure you do get solder on more of the wick than necessary. After >> you have finished all the pads, solder the wicks to your groundplane at an >> as short distance as possible. >> >> This is of course not optimal, but the inductance of the wick should be >> small enough, thanks to the width and the braiding. And you have the >> advantage >> that you can rework if something doesn't work out. >> >> As for equpiment, you will need a soldering iron with an as fine tip as >> possible >> (0.5mm is absolute maximum, 0.3mm is what you should get, if you can get a >> smaller one, take that one). 0.3mm solder (use leaded, it's easier to >> work with). >> I do not recommend using thinner solder. With those the core gets so tin >> that >> you dont get enough flux. Oh.. and be carefull about stretching the >> solder wire. >> The metal part can be stretched quite easily with such thin wires, but >> the core >> doesn't. So if you get this speckled look, cut of that part with some fine >> side cutting pliers. You will also need at least some kind of optics with >> an >> magnification in the range of 10 to 20 to check the solder joints. It >> would >> be best if you had access to a stereo microscope (with an 10-20 >> magnification) >> but if you have good eyes you can do without and instead using some >> magnifing >> glass (i recommend line tester/weaver's glass) to see whether the joint is >> ok and doesn't have any shorts. >> >> HTH >> >> Attila Kinali >> -- >> It is upon moral qualities that a society is ultimately founded. All >> the prosperity and technological sophistication in the world is of no >> use without that foundation. >> -- Miss Matheson, The Diamond Age, Neil Stephenson >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
