Ham Radio Basics---Jim W6LG Discusses Setting the Mic Gain and Compression 

Thanks. That is excellent! 73, Jim

Okay Richard. Let me know how it goes. I have an IC7000 that I almost never use.....and should use! 73, Jim

Go to pages 121 & 122, what settings are you using? Is the mic connected directly to the front of the transceiver? Electret mics have tons of output and should drive the transceiver with very little mic gain unless they have padded that mic output. Get back to me as soon as you can. 73, Jim

Currently I have mic gain: 80%, TX wide L: 200, H: 2900, TX mid L: 300, H: 2900, TX nar L: 500, H: 2900. The iCM mic has a built in cable and I am using a Heil adapter to converter cable to convert it to the modular plug. I am going into the modular mic connector on the back of the rig. Thanks for your help Jim. 73 Rich

Jim W6LG just tested against the stock mic and getting the same results. Unless I talk very loud into the mic, the ALC meter doesn't move. Tried front and rear modular mic inputs. Would be interested to hear how your IC7000 reacts. 73 Rich

I did a lot of playing around and asking for audio reports. I have settled on a mic gain of 65% with a compression level of 5 on the IC-7000 with the Heil iCM. It's really strange the ALC meter doesn't move with the compression off when TX into a dummy load. Per your recommendation, I am running normally with compression on and I adjusted for 5 - 10db on peaks when rag chewing at a normal voice level.

Yes, exactly my experience. They have never used the ALC metering. Additionally, they very often say to me that I am the only one who ever told them that the audio was distorted. Amazing to hear a guy get a 5 by 9 and repeated be asked to say again. Thanks Steve & 73 de Jim W6LG

Thanks Tim. I got busy with other stuff for a few weeks including visits to doctors. 73, Jim W6LG

Thanks. That mic boom arm is from Plano, Texas. Northcomm Technologies, very nice people in Texas. 73, Jim

Thanks Tim! Nice to hear from you. 73, Jim

Thanks. I will do that. It was a bit chaotic on 20 meters. Thanks for your help. 73, Jim

Watched and heard the conditions go downhill fast. 73, Jim

Truly, it is a cancer on the bands with the broad, distorted, over processed signals and their outboard mixers. 73, Jim

I don't have one and it is not on the list. Since that is such a p;opular transceiver and one that has good ratings, there should be some videos already on YT. 73, Jim

Hi Steve, I admit to not fully understanding the question. The ALC meter does not have a db scale. . This I think is the crux of your questions: "Am I supposed to ignore the ALC once I turn on compression.." No and heck no! As I said, always keep the max ALC to about half scale...never ever more. I think I said something like that more than once. My guess is that you have some of the equalizer's setting adding to the mic gain and compression. If needed, turn the mic gain down. Good question Steve. Thanks for asking. And, in case someone wonders, external boxes are a waste of money and cause all kinds of distortion and splatter. The Icom has everything you need to produce a terrific, potent signal that can be heard around the planet. External devices were helpful when transmitters and transceivers did not have internal processing. Those days are long gone. 73, Jim

Jim W6LG I don’t have any external EQ equipment but you mentioned when adjusting the ALC to have the compression turned off at that point. With my compression turned off my ALC scale peaks no more than 1/4 of it. When I turn on the compression however and adjust the compression to around 5db peak, the ALC changes and increases dramatically. You didn’t mention anything about readjusting the ALC once the compression is turned on and adjusted.

Thanks. No, the bulb is not 50 ohms but I can get close with 2 bulbs. I hope to do that video today. Yesterday I was in another city at the cardiologist. All of that went okay. 73, Jim W6LG

No it is not. But, it is good for demonstrations andlaarned. Thanks Don73, Jim

I am working on that now. And, how wide is too wide? If someone spreads his/her distorted broad signal over 10kHz, that person is taking bandwidth that could be used by 3 guys not just one guy. Three kHz is about as much as anyone should need to be understood. We are communicators and NOT broadcasters. 73, Jim

Thanks Jim, I look forward to watching it. On SSB, I have opened my Yaesu out to 3000kHz and the guys in my club say it sounds much better, than 2400kHz standard.

Hi there well what i done in the end was set the Mic gain on 40% and the compressor on 2, the ALC doesn't move but the power meter on the radio goes up to 100 watts easy, so i cant see the ALC matters...i have had good reports and no problems....i use a Heil PR 781 Mic....Fred.

That doesn't sound right, its usually down to a high vswr but you recon thats ok, i would try it with a dummy load as well, but if its as you say it sounds like you have a problem with the radio...could do a reset on it i suppose...good luck with it....Fred.

Hi well if it does it with the dummy load it must have a fault on the radio, you could look on eham reviews, or contact Icom in Kent if yur in england, if not your local Icom agent....might e worth trying a reset on the radio...prob tell you in the Manual how to do it...Fred

I have a 7300 and after I adjusted the mic gain and compression correctly into a dummy load, I got a very low power output. Lots of others have reported the exact same thing. As a test I adjusted the ALC and compression using various permutations, with another ham listening to my audio on his transceiver at his house. The one that sounded the clearest to him had settings radically different from those gotten by following Icom directions or your directions (on 5 to 10 dB of compression). I quit using the 7300 a year ago and wonder if there was a firmware update that fixed this very common problem.

Hello and thanks! Is there an ALC meter position on the TS140. I think we sold that model in the store where I worked in the very early 1970's. I don't think it had a "monitor" function. So listening with another transceiver may be possible. Take care of that oldie! Snowed here 2 days ago. 73, Jim W6LG

Yeah, spring isn`t here yet, too. Snowed yesterday in PA and more to come.

The ALC "meter" is just a red bar under the S meter. You just have to keep the needle from going out of the red, according to the manual. My best mike is the dynamic one that Kenwood sold years ago. Got a photo of it on QRZ. It`s on an antique steampunk homemade boom from a garbage picked desk lamp arm. I jerry-rigged a section of garden hose, painted black to attach the mike to it. If you want to laugh, check it out.

Sorry, not me, thanks for asking. 73, Jim

I think it is a mistake for Icom to recommend 20db. I checked other recent transceivers from our friends at Icom and those manuals have the same information; exactly word for word. I use a few db for local and never more than 10db for DX. Let's look a little further at Icom's recommendation. Correct me if I am wrong. Ten db is 10 time compression. Twenty db is 100 times compression!!! At 20db on any transceiver that I have ever had sounded bad....really bad. Twenty db is 20db. There are no magic chips. Some devices might have less noise, less artifacts, less distortion. But 20db is 20db. And, that is way too much. Thanks for asking a very good question. I would like to add the following: Icom is a very nice company. I have had friends who worked there. I have visited Icom. The Icom IC-7300 is the best transceiver for the money. And, it is very likely, the most popular transceiver ever. I have only the highest regard for Icom and the very nice folks who work there including Ray. Ray is a marketing genius. So my criticism of the compression setting is just that. Nothing more. Regards, Jim W6LG

@@ham-radio Jim thanks for the quick and well-researched reply. You are always objective and a gentleman. Your RU-vid content is much appreciated.

Thanks Roy. How should I change the title? Or, what will work for the MacBook? I am working on the next video but have to leave for appointment with the cardiologist in another city. 73, Jim