Question about ALC and Comp on FTDX3000

Discussion in 'General Technical Questions and Answers' started by KE0EYJ, Jul 24, 2019.

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  1. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    Question about ALC and Comp on my new-to-me FTDX3000.

    I have always been told to keep the mic levels within the line of the ALC (actually, best to keep around half or less). The problem is, when I do this, there is no way to achieve above 0% compression on my radio. I have to exceed the level of the ALC line to get any compression. Comp is set to 50%, but I went all of the way to 100, and it did nothing. I still must boost my mic gain so that the ALC is exceeded, before I get any compression. I was always told that exceeding the ALC will produce splatter. Does this radio have different parameters?

    I'm currently leaving it on 50% comp, but must raise the mic gain to peak above the line before I achieve the 5 to max 10% comp I'm looking for. (and I'm assuming that's about what I want for comp).
  2. WE4E

    WE4E Premium Subscriber QRZ Page

    I've had several Yaesus over here and they all behave more or less the same regarding the processor. As I mentioned previously, the compressor is pretty aggressive. I generally don't use it, although I do use a little outboard compression between the mic and the radio so I don't need it.

    The compressor metering is in dB, not in percent. 5dB of compression is plenty. With the compressor off, set the mic gain for 1/3 or so deflection of the ALC. Turn on the compressor and adjust for an occasional deflection of the meter in the COMP position. I would not exceed 5dB. More than that will really only serve to pump up room noise and make the audio a little harsh. Listen in headphones with the monitor function on and you'll see what I mean.

    And yes, when that's all done, the ALC will be up near the top of the scale. The compressor operates in the IF, and I don't know where the ALC metering is picked off, so I can't say with detailed certainty why that is. These radios don't have a compressor output level like Kenwoods do, so there's really nothing you can do about it. I have to defer to the Yaesu engineers in it not having a detrimental effect on the signal.
    KE0EYJ likes this.
  3. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    Thanks... I've been running an Icom 7300 for a while, and it seems like I was able to compress the signal more and keep the ALC within range. Not sure if it makes much difference in the signal, or purity, or whatnot. If I run the FTDX3000 as suggested, with the ALC peaking in the bottom half or less, I get a pretty low average output -- lower than my Icom (and I thought my Icom was low).
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Get an amplifier.:)
  5. WE4E

    WE4E Premium Subscriber QRZ Page

    Yaesus of the Common Era behave differently that Icoms as related to that. Not that I advocate it, understand, but you can hammer 'em pretty good before things turn ugly. That is to say, they're forgiving. I have an FT1000D and an FTdx5000 and they're remarkably similar when it comes to the compressor. Set the mic gain for a mid-scale ALC reading, turn on the Processor, set it for <5dB of gain reduction, and the ALC will jump right up to the line. I've seen that on an FT2000, and FT991a. They will for sure get some thick audio and the average power will come up. There's a balance to be struck however, and it's been my direct experience that a little goes a long way. Set your mic gain for mid-scale ALC as I suggested with the processor off, turn on the processor, dial in a little gain reduction, and you should see your ALC come right up. It occurs to me that there's a reason they put a range on the meter scale.

    Well then there's that. :D
    KE0EYJ likes this.
  6. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    I'm only able to get 5db of compression (which I want) until the ALC is exceeded.

    Is this normal?? If I'm supposed to keep the ALC at half, then how am I supposed to achieve any compression, if I want to stay clean?
  7. KQ9J

    KQ9J Premium Subscriber QRZ Page

    I think it is normal. I have mine set so that the compression just barely flicks upward on voice peaks. If I put the meter in the ALC position, those same peaks make it run near the top of the scale. I've never had any complaints about signal quality or splatter...and lots of the guys on my net have spectrum scopes or panadapters to keep an eye on everybody else's signal :p
    KE0EYJ likes this.
  8. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    I have been asking for reports, but conditions have been so awful -- even on 40m. One JA op I spoke with said my signal was excellent, but he was 600 miles out. Nobody local was available to test with. Not sure if someone 600 miles out would be able to detect splatter, or not. I tried pushing it to make the 0 to 5db of processing, and also comp on, but minimal to half ALC activation. Both seemed fine to him. He had no scope, but he listened to my transmission up to 3khz to the side, and said there was no splatter. I was 5/9 +20db to him.

    I did work Indonesia last night (from Seoul) but the guy's signal was so overdriven, I figured it useless to ask.
  9. G0GSR

    G0GSR Ham Member QRZ Page

    Hi Derek.
    Forget about asking other Amateurs unless you know them and trust that they can give an accurate report, most can't.
    Why not try one of the network of web SDR's to check your own signal?
    Waterfall displays are not the last word in accuracy but its easy to compare your signal with others of similar strength.

    I don't have a FTDX3000 so can't hep with settings but I have seen some poor signals from them. They are obviously not user-proof. The bad ones do sound "over-compressed" but does anyone mention this to them? Of course not.

    It's rather annoying to me that none of the big manufacturers cannot get ALC , compression and power overshoots right after so many years of "experience".
    Its always an afterthought coming way down the list after bells, whistles and eye-candy but its so important.
    It sounds to me like both Yaesu and Icom are using the ALC as the only "compressor" just by driving it harder instead of having another compressor and using ALC for its intended purpose, over-drive prevention. I maybe wrong but this is how they seem to work.

    At least Kenwood seems to have realised that these should be separate functions and have separate compressor input and output controls. The amount of compression and ALC can be set independently (as it SHOULD be) . The problem is, the Kenwood "processors" sound awful IMHO.

    The only radios with effective speech processing are the full SDR's like Flex and Anan where they use their massive CPU power to do very effective speech processing for SSB. But huge CPU's are not required if sensible processing is done in DSP, this should be included in every modern radio.
    So why isn't it?

    Hope you manage to find the settings that work best for you.

    Last edited: Jul 26, 2019
    K0OKS and KE0EYJ like this.
  10. VK5MRD

    VK5MRD Ham Member QRZ Page

    Hello friends,

    I run a Yaesu MD100a8x desk mic with my Yaesu FTDX3000. I have also got into the parametric section and have adjusted my TX audio which I am very happy with the result. My question is "Generally" where do people set their mic gain to? I do run proc but it is set low and my mic gain level is 21. I do see the ALC around the top of the scale. I had the mic gain set higher before and saw ALC overshoot. My signal looks clean and sounds good. Just wondering if anyone has any recommendations as to mic gain level etc.

    Thanks in advance

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