Baofeng UV-5 DIY Microphone

[Buick Mackane]

Cobbled this together with parts from my junkbox. The casing is an old noise cancelling mic. The lead is from an old pair of headphones. A condenser mic i had laid about and a few jack plugs. Its not a speaker mic. I have added a 3.5mm socket to plug in an extension speaker. As it will only be used for homebase use.

I could have bought a speaker mic for a fiver. But i enjoy making stuff and already had the parts..How does it sound ? Not tried it on air yet. Probably like I'm upside down in a wheelie bin full of water

[NightProwler]

I like your fluffy rug

[rob42]

I have a question that's related to this, if anyone can help, please.

First, the issue: I'm sure that a lot of you will be aware of the weak modulation that these little Baofengs suffer with. I've been running some test transmissions, which have suffered with this issue.

The fix? I have an external mic/speaker combo on order (I don't yet have a collection of gear from which I could build one) which I hope will be no worse, even if it's no better. So, would it be okay, do you think, to put a adjustable preamp in circuit? I thinking that the external mic/speaker could be plugged into a custom made preamp black box, in which the two circuits could break out. That way both the mic signal and the speaker signal could be redirected; the speaker return to a better speaker that could be housed in the black box, maybe even run through its own amp for tone and bass processing (clearly, the box would need a hole in the side that's as larger as the speaker cone) and the mic signal run into the preamp before going to the Baofeng.

I have read the suggestion that enlarging the small mic hole in the body of the HT may help, but I don't like modding gear in a way that can't be undone, plus I'm not convinced that it would make a whole lot of difference.

Your thoughts and / or suggestions are welcome.

[Antoni]

The mic gain on the Baofengs et al is sufficient. The bigger hole really does work!

At Lowe, we chose a good product from Taiwan for a police force to use on their radios, they liked it. But... they said the transmit audio was poor. I checked them closely and they were, particularly in the higher audio frequency range.
The solution was to take a box of abt 250 units, fit a No.5 pointed tip to a Weller (500F temperature) and carefully poke it into the mic hole. The result (after practicing) was a clean and larger mic-hole. The audio was much improved. I asked the factory to change production and they did. I could tell you a similar story abt the bloody awful Maruhama 618 scanner.

Why all this hassle? Why is it continuing to this day?

Think abt the polish language - the old joke where a Pole went to the optician who asked him "can you read the bottom line?" "Read it? I know him!" was his reply. Fact is some languages use a lot of consonants. My favourite word is Skrzyżowania which is the word for a crossroads. [ https://forvo.com/word/skrzy%C5%BCowanie/ ] Imagine that with no high frequency in the audio path.

In China and Taiwan there just aren't as many S Z X Ch Sh sounds and so they don't notice the problem when they test their kit.

Some DSP codecs address this difference in languages.

Get in there and modify your mic!

[Buick Mackane]

The receive audio doesn't require any processing, Its fine when fed to an external speaker, As for TX audio being weak Ive never had any complaints, But i rarely use the radio, As pointed out above sometimes the tiny pin hole in the mic casing needs widening..Be careful messing about with pre-amps,Too much drive and pop goes the weasel

[rob42]

@Antoni. You make some very interesting points that I would have not thought of. Thank you very much.

Possibly, I'll try and open up the Mic Hole. As I said, I do have this hand-held Mic/Speaker combo on order, so I'll see how that turns out first.

I think that the fact that I don't like to have the HT close to my head, is adding to the issue, hence the need for the said add-on.

@Buick. Thank you for the advice. I have this wiring schematic. Does it look correct, to your eye?

a2658c0b9e854ad2286a0d15670c879b.jpg

QST: Digging around, I have come across this Vivanco unit. Maybe a good base from which to start?

side_shot.jpg

top_shot.jpg

I will also put my meters to work and discover what signals I have, compared to what signals I'm likely to generate, as a before and after kind of test.

[Buick Mackane]

Yes same schematic I used. Bare in mind one plug is a standard 3.5mm the other is 2.5mm