Overdrive RK-56 knockoff with FT-857D

So I got a pair of the "Overdrive" RK-56 knockoff mics to play with.

I was using Astatic 636L's for use in my Jeep Wrangler, which I frequently drive around in with the windows open and music blasting.

The 636L worked well, but has very restricted audio, pretty pinched sounding ,particularly bad with FM repeater use, which is frequent for me.

So the RK56 knockoffs are a LOT more natural sounding in response and have really great drive level too.

I hooked one up to a few Kenwood HF rigs in the house and also for the FT-857D, all of which have more than enough mic gain to use these mics.

The noise cancelling quality was my primary mission with better audio quality while doing it. These do the trick. If you don't talk _directly_ into these, with the lip guard literally on your lip, your audio will just disappear if you have the gain adjusted right. You should set up the gain while talking normally, pretty much against the screen. People could barely hear the music in the background at deafening levels in the Jeep, doing 70mph down the highway with the windows down. Perfect.

I didn't try it on a standard 2m/440 mobile rig though, so I can't say if they have enough output for the 2k Ohm input of an FT-7800/8800R.

I got mine here.

Black DP-56 Noise Reducing microphone

Have bought a few things from them so far with no issues.

It's a Chinese knockoff of a Turner Road King 56. Most of the CB shops have them.

The link in the first post takes you right to a giant picture of it. It's slightly smaller in the outside dimension than the 636L but it's pretty deep, so it's a decent handful of a mic.

It's actual name is the Overdrive CDL-56k, I didn't have the package handy when I first wrote this up.

Not a lot else to say, the PTT is a nice heavy button and switch inside and there's an isolation transformer coming off the mic element. The mic comes wired commonly for four wire so it does relay PTT switching if needed.

In my particular mic, red of all things was the ground. For ham rig use I came up with

Red - mic GND
Blue - PTT
White - Audio
Shield - Common GND

I just looked up the 4-wire pinout and worked backwards with a continuity checker from there.

There is some of the 'chuffing' that comes with a noise canceller and talking pretty much on top of a mic element. This isn't a hi-fi mic for sure, but definitely sounds better than the 636 or the Road Devil that I've tried previously.

The noise cancelling really works well. Again yesterday was doing about 50mph with the windows down and music blaring in the Jeep and people really had no idea from all the reports I got, and that was FM on a repeater.

What I'm curious about is if they can drive the 2kOhm input on a Yaesu FT-7800/7900/8800, I don't want to bother rewiring one of mine at this point. So far that answer has been no with the 636L and some others I've played with, without using a pre-amp.

I keep the remote mic in the car for running the codes for the link system here when I have to. Pretty easy to just pop it off and on with the RJ connectors.

A mic with a pre-amp works nicely for making up for the impedance mismatches too. The Road Devil or the M6B works on the 2k input rigs, but the Road Devil sounds lousy for FM and the M6B sounds fine, but isn't noise cancelling.

Hmm there's enough wires in the cord to enable the up/down buttons, I'd just have to add some tiny momentary switches. Maybe when I'm sufficiently bored enough.