When and why would the red mic light come on? Do I have any control on that?

It sounds like you are using the wrong mic for the radio or the mic has been wired incorrectly or the mic has become faulty or the radio has become faulty. Unplug the mic and see if the radio receives and works correctly. You should be using a Yaesu model MH-36b or a MH-42B microphone.

Here are the pinouts for the 4 wire and 6 wire D104 mics. they were great microphones back in the 1980s. I used to have one on my Ten-Tac HF ham radio.

Astatic (4 wire) Astatic (6 wire)
1- Shield 1- Shield & Blue
2- White 2- White
3- Red 3- Red
4- Black 4- Black
Yellow NC

you just need to know what the pin out is for your 10M Radio. here is what each pin is
4 WIRE MIC CABLE
Pin Number
1 Audio Shield
2 Audio Lead
3 Transmit Control
4 Receive Control
here is the manual.
https://www.manualslib.com/manual/452637/Galaxy-Dx-98vhp.html?page=8#manual

Dead battery?

it doesn't make a difference what color wire it is as long as the wire is connected to the function it is going to control If your mic has a red , blue , black , and shield wires but your radio isn't set that way you have to set it to the way your radio is . you have to find out where ground is then audio in and audio out then the last is the shield.

If the mic mute switch is not on and there is no red light in the mic arm then its likely you have a check in the 'mute mic' box in your sound manager. Open Volume control, choose options->properties-> recording. Check for checks in the boxes and remove them. Also make sure the slider for the mic is about half way up.

the tx/rx liight is green when your radio is recieving signals and turns red when you are sending signals. the ANT light is red when your SWR is too high (over 3)

1. turn the knob labeled swr cal all the way counter clockwise
2. set the rf swr cal switch to the CAL position
3 key up the mic and hold it while you rotate the swr cal knob until the needle reaches the swr cal postition
4. set the swr cal rf switch to the swr position
5. key up the mic while on chanel one (record the the number)
6. switch to chanel 40 key up the mic (record the number)
if the number on chanel one is lower than the number on chanel 40 then your antenna is too long.

The Board have three sound port one for rear one for front and one for mic plug in the mic pin into the mic port red colored.
Then go to the realtek control panel located in the taskbar like a red speaker open it and go to the I/O
options and the mic options turn on front mic.

Make sure the headpiece is charged. Turn the headpiece off by pressing the little black button on top of the earpiece and holding for about 5 seconds. Turn the earpiece back on again the same way. You should have a slow flashing blue light on the mic boom. The base station will now try to find the earpiece and within about 20 seconds the red light on the base should be steady and blue light on top should be on.
If this doesn't work you may need to manually pair the earpiece to the base by pressing and holding the Listen Volume Adjust + Button and headset Call Control Button on the earpiece until the light on the mic boom flashes red and blue repeatedly. As above, the base station will now try to find the earpiece and within about 20 seconds the red light on the base should be steady and blue light on top should be on.

Hello...

Try this one:

1.Click on Start
2.navigate to Control Panel
3.click on Sound, Speech and Audio Device
4.click on Sounds and Audio devices
another window will appear
click on the Voice tab
on the Voice Recording
click on Volume
there should appear another window
adjust the Mic Volume

hope this helps

Most headsets do not come with a volume control interface but your mic can be adjusted by going to Sound and audio devices via the control panel of your start menu. The volume can be accessed through the audio tab. Also, depending on the program you are using i.e. Skype, Team Speak or other, your volume settings can also be adjusted within that program as well. Hope this helps.