Baofeng/Retevis/Kenwood Hand Mic Adapter Cable (Amplified!)

[K9MKE]

Hello,

Inspired by the thread about modifying the Baofeng mic, something I have done for other radios, I decided to make an adapter cable. The benefit to this over cutting off the connector is the hand mic can be used elsewhere still and it can be compatible with other mics.

Because of this, I feel like I have the ultimate audio solution for the trusdx. Retevis sells what they call their "2-pin Mic Active speaker" (https://www.retevis.com/2pin-mic-active-speaker) on their website as well as found on eBay for about $30. This is a PTT Hand Mic with a Kenwood style connector which is also amplified and rechargeable battery powered. The Baofeng mic is only useable if you hold it up to your ear, but this one you can crank the volume up. For that matter if you really wanted to get crazy they also sell a bluetooth version of this mic for like $80 with an adapter dongle (https://www.retevis.com/hk009-bluetooth ... microphone).

The wiring on this one was stumping me for a bit, I was getting hung up on how the grounds were wired together. I did eventually figure it out and came up with this diagram.
There are really only three parts to this build; a 2.5mm TRS Female Jack cable stub (https://www.amazon.com/dp/B07ZT7JDNP?re ... TT9KSDQEGK), a 3.5mm TRS Female Jack cable stub (https://www.amazon.com/dp/B07ZT7JDNP?re ... 2675VY18YS) , and two 3.5mm Male plug cable stubs (https://www.amazon.com/dp/B07Y8KGJKL?re ... WJ5J3RDTFX). Total cost about $27, but you could also hack this together from patch cables or some other jacks and save some money. The nice thing about these is at least the colors are all consistent between Tip Ring And Shield.

trusdxMicDiagram.png (19.43 KiB) Viewed 11810 times

I used solder filled shrink tube butt connectors and adhesive filled shrink tubing to complete assembly.

Hope this helps someone!

73
K9MKE

[Steves999]

Thanks for this suggestion - I used mine for the first time today on a SOTA activation. It worked really well and I got better audio reports than with the internal mic.
I actually just chopped the original plug and put 2 3.5mm jacks on rather than make an adapter.
One thing that was strange is the Retevis colour coding of cabling... In case it helps anyone, mine was:

Mic = Blue
Speaker = Black
PTT = Green
GND = Red (this strangely labelled "Vcc" on the mic PCB, but works if used as common gnd for mic, speaker and PTT)

[kbuck]

I was wondering if anyone else had tried this yet or if @K9MKE @Steves999 - How are you finding this a couple of months down the line. - I have my Tr uSDX on order and was thinking of getting one of these amplified speaker microphones or just using a spare Yaesu MH-34 of course after a mod. Thanks

[HB9HJF]

Thinking of the Yaesu tiny hand mike..

I had built a patch lead adapter to get my Yaesu MH-34 mike to work as a microphone, and it's working quite well for me.

I obtained a 3.5mm TRRS breakout board, and soldred on 30cm of wire with a 3.5mm TRS male plug on the end. Then, I used heatshrink to secure everything around the breakout board. I also made sure to add some flying leads for the speaker connection as I did not yet wire this one up. At some time in the near future I will add a TRS socket onto that pair of flying leads to get the speaker input to the Yaesu mike.

I made up another cable/breakout board combination to be able to use the 3rd-party cheapo microphone from my RS-918 setup and that also appears to work based on listening on my main rig when I have the trusdx outputting into my dummy load, but I'm not sure about the audio quality from that particular example of a microphone.

[BrumasterM01]

@kbuck,

i have the modified amplified hand mic and found it performs very well. No issue with the speaker quality and its handy to be able to adjust the volume quickly. It is quite loud.

I no longer use headphones.

I can't speak to the TX microphone quality, since i have no way of hearing myself. I have had positive and negative audio reports on both the internal and external mic. Likely more to do with mic gain settings, radio performance and band conditions.

73

[kbuck]

@HB9HJF @ BrumasterM01

Thanks! Yeah, I think I will end up giving it a go.

I will probably get a 2-Pin Type K Speaker Microphone Extension https://a.co/d/efKO9VE and splice into that to do the mod as I don't have a 3D printer to design anything either.

I do still like the Yaesu MH-34 as HB9HJF says its small and very compact and seeing that I have one already, just makes sense (tight ham.. hihi) - I will probably get some 4 pole TRRS female sockets then that covers best of both worlds.

Hopefully someone will post a YouTube video with the Retevis amplified microphone. Think this would be good to see the performance with the truSDX including the TX audio - I know it weighs around 152 Grams for some I could see that being an issue but if it means you don't need to carry a separate speaker slight bonus I suppose. I'm strange when it comes to earphones, I can't seem to stand them for any longer than 10 minutes as I do enjoy listening to my surrounding sounds around me at the same time. (in case the enemy sneaks up on me)

[BrumasterM01]

Yep. It's not small or light. Attached a pic to compare with to the size of the radio.

Great idea with modifying the extension. Saves the mic for other radios. Works very well with the UV-5R.

Retevis Amplified Mic

USDX 3.jpeg.jpg (68.56 KiB) Viewed 11105 times

[MIRA]

Thanks for the advice, I ended up buying a retevis mic http://bit.ly/409F9wN to try out

[lobanz]

TrusdxHandsetAdapter_small.jpg (204.84 KiB) Viewed 9872 times

Hey guys! Thanks for the info in this thread! Using it I was able to build a nifty adapter to hook the Retevis powered handset to the trusdx. Used the wiring diagram from K9MKE and the handset extension cable suggested by kbuck. I'm recording the details here in case it can help someone else. (I did follow these instructions to make a second one, and it worked!)

Here are the parts I used:

- Handset: https://www.retevis.com/2pin-mic-active-speaker-us
- Handset Extension Cable: https://www.amazon.com/dp/B0868L754L
- TRS connectors: https://www.amazon.com/dp/B07Y8JGFS1/
- Cable for audio and mic: https://www.ebay.com/itm/175571153492?var=474913532206 (22AWG shielded 2 conductor), but this would work too: https://www.amazon.com/dp/B08XB78Q7S/ (unshielded 26AWG 3 conductor)

Handset extension cable pinout -- at least the ones I received. You probably want to double check this to make sure yours is the same. It only has 4 wires (colored red, white, black and green):

3.5mm plug:
- Tip: Not connected
- Ring: Red
- Sleeve: White

2.5mm plug:
- Tip: Black
- Ring: Not connected
- Sleeve: Green

I used two 6" pieces of cable, one for mic and one for audio, each with TRS connectors on the end. I used shielded cable with two conductors and connected the sleeve/shield terminal to the braid. Unshielded 3 conductor is probly fine. I used 22AWG which is much bigger than the wires in the handset extension cable. The shielded cable is nice and flexible though. I wired both the mic and audio cables as follows:

- Tip: Red
- Ring: White
- Sleeve: Braid

Following K9MKE's diagram (below) and DL2MAN's diagram (below), I wired the handset extension cable to the two TRS cables thusly:

Code: Select all

Mic Cable:                Extension Cable:
  - Tip (Red)        ->   3.5mm sleeve (White)
  - Ring (White)     ->   3.5mm ring (Red)
  - Sleeve (Braid)   ->   2.5mm sleeve (Green)

Audio Cable:
  - Tip (Red)        ->   2.5mm tip (Black)
  - Ring (White)     ->   2.5mm tip (Black)
  - Sleeve (Braid)   ->   2.5mm sleeve (Green)

Here is a pic. The cable on the top-left is the audio cable. Top-right is the mic cable. The cable on the bottom is the handset adapter cable (socket end). Note that the red and white of the audio cable are connected together (per DL2MAN's diagram, below), and the two braids are connected together.

TrusdxHandsetAdapterWiring_small.jpg (222.95 KiB) Viewed 9872 times

Here's K9MKE's diagram from his post:

trusdxMicDiagram.png (19.43 KiB) Viewed 9872 times

DL2MAN's manual diagram:




Here are the two posts I used.

Hello,

Inspired by the thread about modifying the Baofeng mic, something I have done for other radios, I decided to make an adapter cable. The benefit to this over cutting off the connector is the hand mic can be used elsewhere still and it can be compatible with other mics.
[...]
K9MKE

@HB9HJF @ BrumasterM01

Thanks! Yeah, I think I will end up giving it a go.

I will probably get a 2-Pin Type K Speaker Microphone Extension https://a.co/d/efKO9VE and splice into that to do the mod as I don't have a 3D printer to design anything either.
[...]

Hope that helps!

--- Lobanz

[km6slf]

In case anyone is looking to do this with a less expensive speaker mic, here's what I put together that works. (note that these are Amazon affiliate links - if my notes help you I'd appreciate you using them!)

Commountain Speaker Mic
https://amzn.to/4et8bQ0

Kenwood 3.5mm/2.5mm extension cable (2 pack)
https://amzn.to/3zeqBDD
4 wires:
Yellow - 2.5mm tip
Red - 3.5mm ring
Black - 3.5mm base
White - 2.5mm base

3.5mm pigtails (10 pack)
https://amzn.to/4c3Vc5t
Red - tip
White - ring
Black - base

You'll also need connectors or you can simply splice the wires directly. Use whatever connection/splice method you prefer.

Instructions: Cut and strip the Kenwood extension, exposing the yellow, red, black and white wires inside the outer insulation. Then strip those wires down to the copper wire inside to whatever length is needed based on your planned connection/splice method.

From here, you'll need to connect the 3.5mm pigtail wires to the newly stripped Kenwood extension cable wires. Depending on your connection/splice method, you may need to strip the pigtail wires, too.

The working connections are as follows and are formatted as connections from the Kenwood extension wires, identified by color and (pinout) to the Audio and Mic 3.5mm pigtail wires, identified by cable, color and (pinout).

Yellow (2.5mm tip, speaker) - Audio White (ring) and Audio Red (tip)
Red (3.5mm ring, mic) - Mic White (ring)
Black (3.5mm base, ptt) - Mic Red (tip)
White (2.5mm base, gnd) - Audio Black (base) and Mic Black (Base)

I hope this helps someone The TruSDX greatly benefits from an external speaker mic.

If you're interested in more details about my set up, I added this belt clip to the TruSDX and to a USB-C PD capable power bank. https://amzn.to/4c5VCs2. This allows me to clip them onto a strap on my backpack.

I rigged the power pigtail that came with the TruSDX to a 12v USB C PD trigger module. https://amzn.to/3z4igCx This allows me to power the TruSDX from any suitable USB-C PD power supply that supports 12V output to allow the TruSDX to use its full 10W power. (note that 45W USB-C PD power supplies don't generally support 12V). I recommend applying heat-shrink tubing to secure the module to the cable.

I'm in the process of building the DL2MAN end-fed linked antenna, and I have a working DL2MAN linked dipole that it works pretty well with.