I need to remove a surface Diode to expand the transmit freq., D13.
Im looking at it..anyone know best way to remove?
desolder? pull on it tweezers, scrape it w/small flathead?
i design circuit boards for a living, so below is based on actual real-world experience and not internet hearsay...
if you pull on the surface mount diode with tweezers it is very likely you will rip the underlying vias, pads, and/or connecting traces off. (the bond between the part and the solder is often a lot stronger than the bond between the copper pads and the circuit board.)
if you scrape it with a screwdriver it is almost guaranteed that the same thing will happen.
you may get lucky and not damage anything. you may not get lucky and then you have an expensive paperweight.
but in both cases, when you remove the part by strictly mechanical force, you will cause local damage the soldermask -- which covers the bare copper traces on the topside of the circuit board, preventing oxidation and sulfation. the now-exposed bare copper will corrode fairly rapidly, leading to a characteristic white-sulfate look which will spread to inner layers of the circuit board. if this sounds like it's a bad thing to happen it's because it is -- eventually the circuit will corrode open and the radio will fail.
hence, the only right way to do this is with a proper soldering iron -- low power (25-40W) with a small tip, as you don't need much heat to remove an "0402" (0.040" x 0.020") part and you you don't want to damage adjoining circuitry.
that said, as has been discussed on this forum about 87 times, the V8000 when operated out of it's design frequency range (144-148MHz) makes a poor chase radio. the output amplifier's directional coupler and antenna match circuitry is optimized for this standard frequency range -- modification and subsequent operation of the V8000 in the typical "race radio" LMR band (~155-160MHz) will result in premature failure of the RF output amplifier (aka "finals").
when the RF output amplifier goes, you might as well ditch the radio as it will be cost-prohibitive to fix. in any case, i would not operate the V8000 on high power (75w) outside the 144-148MHz band unless you like playing russian roulette. even the mid-power setting is a bad idea.
summary:
companies such as PCI Race Radios sell proper setups for this application, specifically with radios which are not being operated outside of their design specifications. e.g.,
http://www.pciraceradios.com/ProductDetail.jsp?LISTID=5178408624182952449
the V8000 is not a good substitute for a race/chase radio. operated out of it's designed frequency range, it may fail when you most need it. this will prove costly one way or the other.
jim aka the wrooster
(i own 2 V8000's and have installed/fixed many others)
