Two mics on one boom OR using a ham radio mic with a PC

Audio Hardware & Software Sound Cards & DACs & Other Hardware
1

I've got an interesting predicament. I already have a microphone and desktop boom for use with ham radio. I want to start recording audio with an external mic for use in videos, and I'd rather not have another mic and/or another boom arm cluttering up my desk if I don't have to.

Info on the Ham Radio Mic
However this mic uses 4 pin XLR, and is unbalanced. Two of the pins are for PTT, two are for signal. It's a HEIL HM-12, if anyone is curious. If I can buy/make a cable to connect this to a standard piece of audio gear (I don't mind buying a small audio mixer or USB interface) that would be the ideal solution.

My Plan B

I'm not sure how to connect the HM-12 mic to any kind of standard audio gear, so I've been eyeing the AudioTechnica ATR2100 for a few weeks. It's affordable, seems be solid enough, and the advantage of having USB and XLR is that I don't have to buy anything extra to use it now, but the mic isn't useless if I want to use an external mixer. However, if I get one of these, I still would like to keep it on the same boom as the Heil mic. I've seen news channels have multiple microphones mounted together, and I'd basically like to do that with my Neweer microphone boom. If I can mount the two side by side, it means I don't have to swap mics out all the time, and I don't have to buy another $20 mic boom that takes up more space.

TLDR - I have a ham radio mic and a mic boom for it. I want to record audio now. I either want to connect the 4 pin XLR of the Heil mic to a PC, or I want to mount an AudioTechnica ATR2100 on the same mic boom as the Heil mic, side by side so I don't have to swap the mics out all the time.

2

When you say you want to record with it, do you mean just to the PC? Or is there some other device you want to record to?

There's some tutorials on how to wire this yourself (usually 4 pin to 1/4 inch) and then you can buy an adapter to go from 1/4 to 3.5mm (for standard PC).

Is there no mixer that takes 4pin and outputs into USB or 3.5mm something? I haven't exactly looked :)

3

I just want to record with a PC. I'm fine with using a USB XLR mixer (like the famed monoprice ones, or another) because I know typical built-in mic jacks suck. So if I know the two wires that carry the mic signal, and the two wires that are for the PTT switch, I would connect the two signal wires to a 0.25" mono jack and the two PTT wires to nothing?

And is there a 4pin XLR "selector switch" I can buy? I know I could use a 4 pole double throw switch and just make the XLR connections myself, but if there's a premade selector I can buy that would be awesome. Or even better, if I can connect the mic to both at the same time by making some sort of a splitter cable...but I doubt that's feasible. I just want an easy way to use the same mic for recording/radio without having to physically swap cables. Flipping a switch somewhere is not a problem, I've got desk space to mount a small toggle switch.