Modifications for the ICOM - RogerK

To be neater you could remove the small 0603 SMT resistor and replace it with a 39k 0603 part.To adjust Scope base-line:Trimpot R966 will adjust the base-line of the Spectrum Scope.Thanks to http://www.qsl.net/vk4cp/ for the modification.This modification is read 1768 times.top of page26-06-2001(IC-756) ACC1 Audio Output IncreaseAuthor: Adam MAURER, VK4CP - vk4cp@bigpond.com.MODIFICATION.NETAccess to the Main Unit is required.The "Line Level" audio output on pin 5 of Rear panel connector ACC1 is very low, with the manual stating 300mV. Normal LineLevel is regarded as about 700mV. Although my MiniDisc Recorder had a gain control for its Analogue I/P it still couldn't make 0VU. Here, by adding two resistors we can increase the gain of the audio appearing on pin 5 of ACC1.●●●●●●●●●Remove the bottom cover.Remove 6 screws holding down Main Unit.Remove screw on rear panel inbetween ALC & Send RCA sockets.Remove heatsinking clip holding transistor to chassis.Remove flat ribbon cable to J3 in far right corner.Carefully pry PBA loose and fold over - see at left.(I actually had to remove RF Unit shield and loosen a shielded cable to allow the Main Unit PBA to fold out).Locate IC-503, a NJM2058 OPAMP in an SMT SOIC14 package.Remove W3 0603 SMT link.Fit an 10k 0603 SMT resistor in W3's place.