With theI found it difficult to drive the transmitter to full output with a dynamic microphone element. I have written about ICOM radios and microphones on another page. Since I made my first comparisons, I have made a closer look at the S Meter. The meter readings are not the result of analog signals changing, they are the result of a numeric computation. The meter itself, which reports several different qualities, is driven from a microprocessor. The S meter on the seems to follow syllables in words, and the dits and dahs of CW.įinally, there appears to be no adjustment on either radio for S meter calibration. Their S meters indicated the same strength for the same test signal. On the other bands, the two radios basically tracked. The difference was about 5 dB on 40 and 15 meters, again the reported a higher value. The mismatch was the greatest on 20 meters, where the read the same signal as 8 dB stronger on its meter. I also found what I call a tracking difference between the two radios. The difference between S1 and S2 may be as little as one decibel or two. Below S8, both meters becomes increasingly more sensitive. On both radios, the difference between S8 and S9 appears to be 6 dB, a typical value.Ībove S9, the meter readings are fairly accurate, which is to say that meter markings track real relative decibel changes. Still, they are all we have to measure signals, and they are often quoted. S meters are not calibrated against an absolute signal strength reference. I think we have all learned that S meters are, at best, relative signal strength indicators. So, for me, spending the extra money made sense. On top of that, there is the color display and a number of other enhancements. Contesting on the IC-756 Proīut if there were more slots, it seems as if I would need to add 6 or so filters to be able to get the SSB and CW selectivity choices I would like. Of course this is not even possible because the has a single filter slot at each IF frequency.
Ajpw hacksįor me, I decided that the upgrade cost made sense because of the equivalent cost of the filters necessary to turn a into a PRO. In fact, given the cost difference between the two radios, I think that both are well worth their respective prices. I really do not want to give the impression that either radio is bad. Because I am comparing two radios here, it may appear as if one is good and one is bad. A few of my observations are contained at the end of this page. The ghost and the darkness netflixĪs of this writing, the radio is still quite new, and comments and observations are just starting to emerge. If you have any of your own observations, please email me, and I will add them to the list if appropriate. This gave me an opportunity to compare both radios side-by-side. If you can't find out the version of your 756-PRO (#02 or #03), look at the topside of the box. Trouble to find the diode-row ? It's about 1/2 inch located under the CPU. R R R I I I X X I I X X I X X X after version "2" mod. R R R I I I X X I I X X X X X X after version "3" mod.
R R R I I I X X I I X X I I I X diode-row IC756-PRO version "#03" When you have a version "#02" : remove diode 3751, 37 ! You have to remove 3 small diodes located on the left side of number "3751" (diodes 3752, 37) when you have a version "#03" Icom IC756-PRO. You can see on the right of the row the number "3751", that diode is already missing, hi. You have lift the dsp-box (with care !) out of the mainboard.Īfter removing the dsp, you can see a row of diodes with some spaces. When you removed the cover and you have the backside of the 756-PRO facing you, you can locate the dsp-box on the left-side (the shiny-box). You have to remove the bottomcover of the 756PRO. You need a very fine solderiron to remove the 3 diodes from the mainboard! Icom IC-756 PRO (IC 756 PRO IC756PRO) technical specifications
Icom IC-756 PRO (IC 756 PRO IC756PRO) technical specifications : Icom IC-756 PRO (IC 756 PRO IC756PRO) Expand tx-freqeuncy Icom IC-756 PRO (IC 756 PRO IC756PRO) CW Filter Shape Selection Icom IC-756 PRO (IC 756 PRO IC756PRO) Eliminate an adjacent channel noise problem (QST mod) Icom IC-756 PRO (IC 756 PRO IC756PRO) 6M oscillation problem
Mods for Icom IC-756 PRO (IC 756 PRO IC756PRO) : Schematics for Icom IC-756 PRO (IC 756 PRO IC756PRO) :
PDF Adjusments Procedures Manual with schematics for Icom IC-756 PRO (IC 756 PRO IC756PRO) : PDF User Manual for Icom IC-756 PRO (IC 756 PRO IC756PRO) : Icom IC-756 PRO Instruction Manual
Programming software for Icom IC-756 PRO (IC 756 PRO IC756PRO) : Programming interface schematics for Icom: