I am a software developer with a Icom 7300 and I know for a fact you do not want the signal pumped with compression or ALC redlining or its gonna twist the signal.īut I am rather biased as I possess a DSO and have viewed all the wave forms we are describing on scopes and know what the hell is going on here, although I not a EE, I damn near understand almost as well as one which way is up here. Transceiver Icom IC-756 PRO II, power for DIGI modes 40 watts ANT G5RV for 160 - 10 m, home made, above ground 20 m, SOFTWARE MixW 3.2 reg. I tell you the other problem with fokes is they believe that technique is more important than knowledge. again not so much.Ĭlick to expand.Reply agreegin with NL7W who stated no ALC and no comp should be present whatsoever:īY GOLLY MOLLY THAT IS NEVER BEEN SAID BETTER !!!!ĭigital should be just that, non compressed or massaged in any form but raw square wave on the oscilloscope with sharp as razor edges where the waveform snaps high or low in a clean vertical line at each snap from zero to 1 or from 1 to zero.
I have created these instructions to assist when an operator is unsure of how to initially adjust the IC 756PRO3. Modest use of ALC compression circuitry on SSB voice is a known technique and is quite viable. He also has hands-on experience with Icom 756PRO-series radios of his own. This link is listed in our web site directory since Sunday Mar 22 2009, and till today 'KB2LJJ IC-756PRO modifications' has been followed for a total of 1702 times. The main category is Icom IC-756 that is about HF and 6 meters 100 Watt SSB CW AM & FM. and I find the thread starter's advice poor at best. An Automatic Level Control (ALC) circuit governs the signal strength going. About KB2LJJ IC-756PRO modifications The resource is currently listed in in a single category.
Uncompressed digital waveforms are critical to the ease of digital reception, signal cleanliness and or faithful reproduction.ĪLC limited or compressed digital signals are not desired - they are distorted! Why would we want to change digital waveforms using any ALC circuitry action? Makes no sense to me.
No ALC action is desired.ĭecent RF output of approximately 20 to 30 Watts can be had on digital modes without any ALC metering indication - without the ALC limiter or compressor distorting the digital waveform. That means there should be NO ALC meter action whatsoever. That means adjusting digital and or analog input levels and transmitter gain circuitry for thresholds below where the ALC "limiting" circuit shows or indicates any level whatsoever. The idea on all digital modes is NOT to affect or distort signal cleanliness with any amount of "ALC" limiting or compression whatsoever. ALC circuits affect all transmitted signals when they're indicating anything above "zero" on rigs' meters.