Modifications for the ICOM - RogerK

This modification is read 877 times.top of page19-07-1998(R-7000) IC-R7000 scanning improvementWith the scan delay control in "off" position, the scan function resumes immediatly when the signal heard disappears.Consequently, you lost a two-way communication until the next memory scan has occured. On the ICR7100 this feature hasbeen corrected, and the scan function resumes approximately 2 seconds after the signal has disappeared.Here is a simple tip for getting the same resume condition on the ICR7000.On the main unit, there is a signal called "stop" which is available and used by the logic unit. The modification is done by using amonostable multivibrator wired for retriggerable condition on a trailing edge ("stop" signal). The corresponding diagram is drawnbelow.from main unit (+9V/W25) R1: 1 K: R2: 100 K:: (K) Pot: 220 KZener: Cap: 47 uF: tantalum:................................. Zener: 3,9 V: : : :: : : gnd....... : D1: 1N4148: R1 : : : : D2: 1N4148: : 16 15 14 13 12 11 10 9: : IC: CD4528B: gnd (IC): (K): cathode: 1 2 3 4 5 6 7 8: : + :... : : : : :: : Cap : : : : : :: : - : : : gnd : : gnd: : : : : : :: :...: : : : :.....D1..(K).......: : : : : :: gnd : : :.........D2..(K)......:: : : : ::....Pot.......R2......: : : :: : : from main unit: : : (stop OUT / W37 bottom):......................... :from main unit(stop IN / W37 top)All the components are mounted on a small PCB. This PCB is installed behind the S-meter, close to IF board. Power is suppliedthrough link W25. This link is located on main unit near diode D25. The input/output stop signals are picked on the two edges oflink W37 (you have to open it). Top of W37 (close to W9) is the IN signal. Bottom of W37 (close to W11, W12) is the OUT signal.Link W37 is also located on main unit (left vertical PCB). It is not necessary to remove the main unit board. You can solder thewires directly on the components side. Please note that IN/OUT signals are TTL levels, so the DC supply for the IC is about 5volts (through 3,9 V zener diode). Delay can be set between 2,5 and 6,5 seconds by adjusting the potentiometer.This modification is read 868 times.top of page26-03-2000(R-7000) Intermittent display