Sanjay Sir..a million thanks for this radio system..actually i intention was to use this radio unit, in my oncoming submarine project, but i changed my mind once after getting this radio.i dismatelled this radio once fully and cleaned, by all means, retreated the P C B, and it was amazing that to see a high density P C B in a proportional radio system.i laminated the p c b, after re soldering all dry solders, so it will work for again to a 20 years..and too happy to get two receivers and crystals in various frequency.