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The Monitor function on the IC-7610 & Other Radios: What its for.

Discussion in 'General Technical Questions and Answers' started by VK3BL, Dec 31, 2017.

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  1. VK3BL

    VK3BL Premium Subscriber QRZ Page

    Dear Ham Friends,

    I've put together a short video explaining how the monitor function on the IC-7610 works, and whether or not it truly reflects your transmitted audio.

    The video also covers the purpose of the monitor function transceivers have in a more general sense, and specifically what its good for and when to use it.

    You can find the video here, click the 'Watch on Youtube' for the best quality :)

    Please feel free to comment on the video, contact me and if you like subscribe. I really love making friends with Hams all over the world, and have had so much fun helping fellow hams around the world with my videos.

    73 from Jarrad VK3BL & the Rate My Radio Team :)
  2. K8JD

    K8JD Ham Member QRZ Page

    Is that something like the "sidetone" in CW mode?
    That's what I use all the time ~ Very few have ever heard my VOICE on the air.
  3. KM3F

    KM3F Ham Member QRZ Page

    First, every radio design does not do the monitor function the same way.
    Granted, after passing through the RF conversion process the audio may not stay the same.
    It is dependent on the band width and shape factor of the filter it passes through on the RF side .
    You may hear 5 kHz in a monitor but you won't hear it in the RF on most unmodified radios due to the filter shape and band width.
    Radio speech processing will greatly alter the audio and is not used for fidelity purposes.
    Most internal speech processing 'intentionally' attenuates the low end of the audio curve by design and intent.
    To add, you have to sound good in the monitor before you will ever sound good at RF despite the conversion limitations. It's a garbage in garbage out situation. If it's good in but poor coming out, you have an issue to solve.
    Next, the mike response need not be good past 4 kHz but should be near flat if internal equalization is to have the desired effect. You can't boost what is little or not there to begin with.
    Expensive Broad cast mike types are of little to no benefit for Amateur radio application no matter what type they are.
    Internal radio audio equalization usually is limited in range except maybe on very high end radios and some SDR designs.
    On my own station, I use a $20 Dynamic mike, wide range but the radio cannot pass more than 3 kHz as measured by testing from the mike jack to the 3 db down points both ends in an RF power sweep test.
    This becomes the limit no matter what mike is used.
    Going on, I use semi professional used low cost outboard audio processing as any radio station or sound provider might use
    Note, driving into ALC some does not mean clipping or distortion. The indicator is there to tell you where you are with audio drive and the tolerance you have..
    Proper mike mounting, Puff filter, signal processing, then drive the radio at the normal drive level with a small amount of ALC indication.
    The results is as good as you will ever hear providing you have a good talking voice..
    By the way the radio is one of the oldest designs still marketed from the 1990s and is unmodified in any way..
    Audio is equally as good on AM as SSB.
    AM on this specific type radio can be set up for no downward power indication on voice peaks with the adjustment of Carrier control level and observing the average carrier power output. For peak AM power a Peak reading power meter must be used.
    Lastly, set up your audio to your satisfaction..... not some one else's.
    Why? There are to many variables on the receiving end that changes what is heard.
    Use the monitor to force yourself to talk with clear dictions, more constant sound levels and note back ground sound and dial them out with the external processor's functions of downward expansion and proper drive levels..
    The above is for those who care.
    And NO this does not result is wide band QRM on the air.
    Remember the radio cannot pass any more with or without processing unless your careless about what is done and no more than over driving an amplifier with a stock radio out of the box..
    Good luck.
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Many modern rigs use demodulated RF to drive the MONItor function, so you absolutely hear the effects of bandpass filtering, but all the ones I know of that can do that are "DSP" rigs, and nothing predating those.

    Use headphones.
  5. VK3BL

    VK3BL Premium Subscriber QRZ Page

    Yes but you don't hear the affects of any PA overdrive or antenna system non-linearities. The monitor function doesn't guarantee your signal is clean or sounds the way you hear it.

    Watch the video for a full explanation.
  6. G0GSR

    G0GSR Ham Member QRZ Page

    I seriously doubt this. Does its level change when you adjust output power?
    AFAIK, the monitor function is purely a digital signal loopback, insensitive to any distortions at RF.
    In my case (IC-7300) the monitor output has a fixed but limited bandwidth and does not reflect the setting of the TX bandwidth filters.
    So a guide only....

  7. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    It’s interesting that the monitor output on my TS-820 does reflect which filter I’m using and the speech processing if engaged. I use headphones and always have a bit of monitor so I’m not talking into a black hole.
  8. KC8VWM

    KC8VWM Ham Member QRZ Page

    Monitor function is useful if you are recording a QSO. Without it, you only hear one side of the conversation.
  9. KM3F

    KM3F Ham Member QRZ Page

    7300 is a low end expensive SDR toy.
    Like I said, every radio does not do it the same way.
    You know very well that monitoring SSB at the output requires a carrier located at the proper side point, be supplied for demodulation.
    Better to use a stand alone radio for sampling, then you still have to tune it .
    If I have a problem i'm told about it.
    If the antenna has an issue the power meter and SWR tells me about it.
    Amplifier has an issue the metering tells me.
    PA overdrive! That's all taken care of in the setup.
    Attention to radio's ALC indication and the use of ALC feedback from the amplifier. Never happens... it can't if your paying attention to what your doing..
    Only problem I have is the equipment does not turn itself on and tune up for me before I get there.
    Good luck..
    Last edited: Jan 2, 2018

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