marktbaldridge
Member
First off, carrying a receiver around in your pocket is moderately inadvisable. (I believe this is how it all started.) But anyway, if the coax on your receiver is broken, or about to break and you'd like to fix it, this HOWTO is for you.
After opening it up via the four screws on the back, my Fly-Sky 6ch Receiver looked like this:
You can clearly see how the coax is broken right at the spot where it would leave the plastic case. Closer examination showed me that just the outer conductor was broken. This would make it work at close range, but at much more than a hundred yards, you loose signal.
Unfortunately, I didn't have a helper on anything to get a picture of me desoldering it. But the basic technique is to get a small-tipped soldering iron, and touch the wide pad for the outer conductor first and pull it up when the solder melts. Then put your tip on the small pad for the center conductor, and apply light pressure up, and when the solder melts, the coax should pop free.
My coax looked like this. (It's the best picture I could get with my camera considering how extremely tiny it is.)
The next step is to carefully cut the coax past where it is broken. For the next step you must have a good stripping tool. You have to remove the outer layer of insulator without cutting the wires underneath. Cut back about 3mm of the insulation.
When mine was cut, I pulled back the fray, and it looked like this:
Do the same thing for the center conductor and it's insulator. You only need about 1mm of exposed wire on the center conductor.
Then pull back the outer conductor to either side so that it looks like this:
Pre-tin the coax by putting it in a clamp or something, and touching the soldering iron to each of the three bits of wire and adding a teeny bit of solder to each. Let it soak in before removing the iron and moving on to the next wire.
After this, do a similar process to the pads on the circuit board. It's not as critical here, but it's helpful to ensure that the solder on the board, and the solder on your wire are compatible.
Next put the circuit board in a clamp, and touch the tip of the iron to the pad for the center conductor. When the solder is molten, apply the center conductor of the coax, remove the iron, and let it cool. These parts are so tiny that steady hands are a must.
Now lay the coax's outer conductor down against the circuit board, and solder each side. (You may need to add solder.)
When mine was done, it looked like this:
Use a magnifying glass or a microscope to check that there are no shorts on your solder joint. (That is, things connected that shouldn't be connected.)
My USB microscope gave me this blury picture, but it was enough to ensure against shorts:
Put the circuit board back in the case, re-apply the screws, and give it a range test!
After opening it up via the four screws on the back, my Fly-Sky 6ch Receiver looked like this:
You can clearly see how the coax is broken right at the spot where it would leave the plastic case. Closer examination showed me that just the outer conductor was broken. This would make it work at close range, but at much more than a hundred yards, you loose signal.
Unfortunately, I didn't have a helper on anything to get a picture of me desoldering it. But the basic technique is to get a small-tipped soldering iron, and touch the wide pad for the outer conductor first and pull it up when the solder melts. Then put your tip on the small pad for the center conductor, and apply light pressure up, and when the solder melts, the coax should pop free.
My coax looked like this. (It's the best picture I could get with my camera considering how extremely tiny it is.)
The next step is to carefully cut the coax past where it is broken. For the next step you must have a good stripping tool. You have to remove the outer layer of insulator without cutting the wires underneath. Cut back about 3mm of the insulation.
When mine was cut, I pulled back the fray, and it looked like this:
Do the same thing for the center conductor and it's insulator. You only need about 1mm of exposed wire on the center conductor.
Then pull back the outer conductor to either side so that it looks like this:
Pre-tin the coax by putting it in a clamp or something, and touching the soldering iron to each of the three bits of wire and adding a teeny bit of solder to each. Let it soak in before removing the iron and moving on to the next wire.
After this, do a similar process to the pads on the circuit board. It's not as critical here, but it's helpful to ensure that the solder on the board, and the solder on your wire are compatible.
Next put the circuit board in a clamp, and touch the tip of the iron to the pad for the center conductor. When the solder is molten, apply the center conductor of the coax, remove the iron, and let it cool. These parts are so tiny that steady hands are a must.
Now lay the coax's outer conductor down against the circuit board, and solder each side. (You may need to add solder.)
When mine was done, it looked like this:
Use a magnifying glass or a microscope to check that there are no shorts on your solder joint. (That is, things connected that shouldn't be connected.)
My USB microscope gave me this blury picture, but it was enough to ensure against shorts:
Put the circuit board back in the case, re-apply the screws, and give it a range test!
