Posted: 6/17/2008 1:51:46 PM EDT
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Anyone familiar with the Ham Mod Shop? I'm chicken to open up my FT60R to make the MARS mod, but I can't find anything on this web site to make me feel any better about sending him $50 for me. Thanks. |
Its pretty easy to do actually...the resistor is the size of a speck of flyshit...go ahead, live life! :0) It is a rush to pull it off. |
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I've done it twice, and could now do it in my sleep. The only hard part is removing the weird ring nuts on the dials. I had to buy a special tool from lowe's to handle them, sort of scissors with removable pins on the end. Not expensive. If you're careful, and follow the instructions, and keep track of your parts as you disassemble, and stop and ask us for help if you run into trouble, it's VERY easy. As for removing the surface mount resistor or whatever itself, I'm not sure what I ended up using. Either a tiny flathead, or a knife, or tweezers, or fingernail clippers. Any of those will probably work, but you might find one or two easier than the others. If you want, IM me and I'll follow ar-jedi's lead and let you ship the body to me, and I'll fix it up for you. Just cover shipping for me, like $8 or so. |
The good news is that the resistor doesn't have to be functional after you remove it...  I've had good luck with heating one pad with a soldering iron while using a pair of tweezers to break the resistor off the other pad. A carefully-placed Dremel tool cutting wheel would probably also work - As long as the space formerly occupied by the resistor is now an open circuit, you're golden. |
sorry to disagree, but... GACK!!!! both of the approaches above are sure routes to hosing up the board. first, the pad is connected to either a via or a trace; pulling up on one side of the resistor without the solder hot enough to flow on the other side can cause the opposing pad to lift, bringing with it the attached trace and/or the annular ring around the via (which is just a tiny plated through-hole). if any other part of the circuit is hanging off that via, you will be in trouble. second, oftentimes the dense layout of a PCB requires running traces under components. even the body length of an 0402 or 0603 size SMT resistor allows 4/4 (4mil copper width with 4mil spacing) traces underneath. using a Dremel to cut the resistor body is a like using a chain saw to remove a splinter from your hand. you may get the splinter, but the collateral damage will be impressive. besides, resistors are made of partially conductive carbon particles. most resistors used for this type of application (processor configuration) are actually 0 ohm resistors, aka "straps". the last thing you want is particles of that highly conductive carbon composition sprayed all over the internals of the radio. my suggestion for these types of "remove the resistor" or "remove the diode" type mods is to use a fine point soldering iron, heat the solder at one end of the resistor until it flows, and then move the soldering iron to the other end. the solder at the first end will still be molten when the solder at the now hot end flows. the surface tension of the solder will cause the resistor or diode to stick to the soldering iron tip, which you can now pull away from the printed circuit board. this entire process takes 15 seconds, requires very little heat, and there is no danger of any sort in compromising the board's electrical or mechanical integrity. n.b. if there is any desire to be able to un-do the mod in the future, simply take a tweezers and solder the resistor back "standing up" on one of the pads. (the technical term for this type of mounting is a "tombstone"). down the road it is then trivial to heat the pad, tip the resistor over, and solder the other end. another 15 seconds at worst case. i work with extremely dense circuit boards for a living, and in no case would i approach rework of an SMT board with a Dremel of any type. ar-jedi |
keep in mind that the board assembly went through an SMT reflow oven during processing... first, solder paste was applied to the bare board using a stencil, then a pick-n-place machine rapidly set all of the components in place, and finally the entire setup is conveyed through an oven with a carefully controlled time-vs-temperature profile.  unless you are a complete barbarian with a soldering iron, and a 200W one at that, you can't damage the board nor the components due to heating a single component. there is so little thermal mass to an 0402 or 0603 size component (the former is 0.040" x 0.020" -- 40 by 20 thousandths of an inch) and it's associated pads + solder that it takes very little heat to reflow the solder. once the solder is molten, components that small will stick to the soldering iron tip due simply to the surface tension of the solder.
there is *far* more risk damaging the board due to mechanical stress using this method. i tell you this as an experienced circuit designer -- i have reworked my share of SMT boards since the technology was introduced in the mid 1980's and in no case would i attempt to remove a soldered-on component by strictly mechanical means. i have designed boards for cordless phones, cell phones, industrial controllers, and have managed the development of some 30 high speed telecommunications boards. that said, i'm telling you the easiest, most reliable, and safest way to remove a single SMT component is to use a low wattage pencil-type soldering iron. i routinely do this with a Weller Portasol butane-powered soldering iron as well. ar-jedi       |
Have performed component-ectomies on 3 rigs so far, using the one unsoldered pad technique. None of them sustained board damage whatsoever, even though none of the removed components survived the operation!  I would suggest that if you're cutting into the PCB with a Dremel tool, you either need a finer cutting wheel or a new eyeglass prescription... 
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the component-to-solder bond is stronger than the pad-to-FR4-board bond, so by using this "pick" method you will nearly always pull the pads off the board. the net result, again, is that you damage the board and make repair nearly impossible. oftentimes this "shearing of a component" happens during manufacturing and packaging due to poor board assembly handling processes. the worst scenario occurs with via-in-pad designs -- when the component is pulled off the via is obliterated, and any nets that terminate there are gone. also, this dentist's pick method creates an opportunity for corrosion; the copper traces on the PCB are ordinarily covered with soldermask (a thin, clear protective coating) and the pads are tinned. if you physically pull a component off, generally the soldermask is damaged and bare copper trace is exposed. any type of environmental contamination now leads to oxidation and/or sulfation of the the copper trace, turning it non-conductive and giving it a characteristic mushy white look. ar-jedi |
I design/prototype PCB's with these type os small SMD parts. I agree with this post. |
+1000 Desoldering and dremel tool are massive overkill for the job requirements. |
no, not even close.  the blue/yellow/etc "wires" are actually optical fibers. they carry light from the laser/receiver modules to the faceplates of the circuit boards you are looking at. due to the complexity of terminating high power optics, it is not possible to hold the length of the fiber pigtails to exact lengths. hence, small take-up reels are used to accommodate the varying fiber lengths, and prevent damage to the delicate fibers. the underlying drive circuitry is modulating the lasers at around 10.709 GHz, which is a FEC-encoded line rate of 10Gb/s. ar-jedi |
Thanks! |
Do you remember what the tool is called? I just returned from Lowes and didn't see anything like that...although I may have been looking in the wrong place. |
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Guess the Icom and Kenwood boards are more rugged than the Yaesu one! LOL.. I actually had to put one back on an Icom U82. By removing the wrong one, I made it have a 2 meter display. I just peeled the last one off with needle nose pliers. The radio was only $100.00, so if I screwed it up, it was no big deal. The more expensive the radio, the more you will sweat doing it. To remove the ring nut holding the antenna connector, you need a face spanner wrench. I made mine in the tool room shop where I work. A piece of tubing the correct diameter will work too. Use a file to cut down the sides and leave only two tits to engage the notches. Sometimes a pair of lock ring pliers will work if the thread locking compound is not too tough. Althought using a modded ham rig on GMRS, MURS, etc. defies FCC regs, I still have my units modded. The reason being that in a SHTF or PAW, my PC is probably going to be out of commission and there ain't going to be any way to re-program my Part 90/95 radios should there be a need. I have the banks filled up with many freqs I might need, but you never know. Having the modded radio is not against the law, unlike having a modded full-auto capable AR15, which is against the law. Someone might want to comment on whether having a radio that can transmit on law enforcement radio channels is legal? I have heard rumors that some Homeland Defense legislation might have prohibitions relating to non-LEO's carrying such radios. RS |
snap ring pliers? ar-jedi   |
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Okay, picked up a set of split ring pliers at Lowes, got it apart, and... HOLY MOTHER OF GOD THAT RESISTER IS SMALL!!! Seriously, I can barely see the thing. We're talking making sure I destroy/disconnect the head of the correct pin, here. Actually, a pin head would be bigger. "Now, which flea was that, again?" Okay, I'm paying someone else to do it, or taking Mrs. Drang up on her offer to buy one of the MARS modded VX150s on eGay. Or both. While I regret paying $20.00 for the pliers, I imagine they'll come in handy someday--why does so much stuff come in packaging you have to destroy to discover you don't need (can't use) it? (Rhetorical question. OTOH, this stuff is hardly ecologically friendly...)
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Try nail clippers. Just go slow and be careful, and don't squeeze until you're certain what you're squeezing. Use a little magnifying lens if it helps. You can at least try, just don't squeeze anything. Call it a dry run. Those components are very tough, it'll take a concerted effort to actually break them, so don't worry about playing around in there. Just focus on not stressing the board itself. ar was right about the snap ring pliers. |
you are 99% of the way done with the job. removing that resistor is 15 more seconds. do you own a soldering iron? is the tip of said soldering iron sized in the vicinity of a sharpened #2 pencil (the kind you took your "fill in the oval" tests in high school with)? are you capable of enough manual dexterity and stability to put 2 stitches in your friend's hand if he were to suffer a puncture wound while camping? if the answer to all three above is "yes" then we are there. i can walk you through it, and there will be 100% chance of success. ar-jedi |
Listen to this man. I've done 3 FT-60s...it is not that bad. |
www.ar15.com/forums/topic.html?b=10&f=22&t=613925 ar-jedi |