14 votes

How do PTT buttons work?

The basic PTT (push to talk) button on the HT is a simple switch that is normally open and when it is pressed, the switch is closed (conducting). Internally to the radio, this applies power to the PA (...
user avatar
  • 18.1k
9 votes

How are DTMF tones sent through a mic?

DTMF is an audio-frequency based signaling system that sends tone pairs as audible frequencies,. Most DTMF microphones send the tones as though they were ordinary microphone audio to be transmitted, ...
user avatar
  • 842
8 votes
Accepted

How do I put an RJ-45 connector on to repair a Kenwood MC-59 microphone cable?

Here's how to repair a Kenwood MC-59 microphone cable (ships with the TM-V71a, probably the 710, and a few LMR radios as well). First, if you didn’t know already, behind the rubber boot at the end of ...
user avatar
  • 1,657
6 votes
Accepted

Transmitted audio coming out through my speaker

The manual, on page 56 says: TX monitor allows you to monitor the on-going transmission sound. This is convenient when you want to check the modulation sound quality of the transmission. In FSK mode, ...
user avatar
  • 8,171
6 votes

Is a connecting computer sound output equivalent to connecting a "dynamic" mic?

A dynamic microphone is basically a speaker in reverse. A diaphragm moves a magnet in proximity to a coil, varying the magnetic flux though the coil and inducing a current in it. You can in fact use a ...
user avatar
5 votes
Accepted

Mic ground vs ground

The problem you could run into is RF feedback into the sensitive mic input. This is particularly a problem if you run "QRO" - high power. It is best to use shielded multi-conductor cable, with the ...
user avatar
4 votes

How to use HT microphone with two jacks (Kenwood connector) as a substitue for KX-3 microphone?

The Elecraft rigs have flexible interfaces for alternate microphone settings. However, there is only the single TRRS plug for a Microphone on the KX3. You should be able to wire up your own ...
user avatar
  • 2,868
4 votes

Will Icom HM-133 work on IC-2800H

I have an IC 207H with a HM-133. The HM-133 came in a couple of flavors starting with the 133 then 133v HM-98s etc none of which replaced the HM-98 which came with the 207H. Dispite what ICOM factory ...
user avatar
  • 41
3 votes
Accepted

How to use HT microphone with two jacks (Kenwood connector) as a substitue for KX-3 microphone?

In the end I decided to build a simple adapter. Most handheld microphones available at cheap prices have two-jack "Kenwood compatible" interface. They have 3.5mm TRS jack and 2.5mm TRS jack. The ...
user avatar
3 votes
Accepted

Why do some ham radio microphones have a built in speaker?

I have a microphone with a speaker for the Kenwood in my truck - the body is tucked away out of sight, so the speaker in the body is muffled at best. The microphone is hung right there on the dash, so ...
user avatar
3 votes

Motorola Microphones

There's a couple of things that have to happen to make mics work on a radio. Obviously, correct pin out is important. Also, the impedance has to be matched or you won't get good audio out of it, but ...
user avatar
  • 4,213
3 votes

Will Icom HM-133 work on IC-2800H

There's a great reference for radio and microphone pinout diagrams here: www.qsl.net/g4wpw/date.html. That site indicates that the IC-2800H is meant to work with the HM-98 rather than the HM-133, but ...
user avatar
  • 8,922
2 votes
Accepted

Will Icom HM-133 work on IC-2800H

As a general rule if the pins match it will work. They are usually a standard configuration. The real question is the quality.
user avatar
2 votes

Will Icom HM-133 work on IC-2800H

The HM-98 uses a couple resistors for the up/down buttons, while the 133 uses digital signalling along with the rest of the keypad. It is MOSTLY compatible. For normal operation, it will work just ...
user avatar
1 vote
Accepted

Yaesu FT-70DR Earpiece

The FT-70DR uses the same microphones as the FT-60, including the SSM-17A that you seem to have missed. The plug looks to be a 3.5 mm TRRS. The FT-60 is a common HT that has been produced for years, ...
user avatar
  • 8,922
1 vote

Yaesu FT-70DR Earpiece

Going by the pictures (not much other information to go by), it seems the breakout cable has a standard headphone Jack and a smaller plug for the microphone. That seems a standard configuration. I ...
user avatar
1 vote

remote push to talk or process background sound out

I'm not sure exactly what you mean by "remote push to talk", but one possibility is that you want a switch that is more convenient, such as a foot switch. In that case you would want to get such a ...
user avatar
  • 8,922
1 vote
Accepted

Using Gaming Headset on FTDX3000

This answer has details that are not appropriately relevant because it does not match the actual features of the FTDX3000 microphone port. Update to come. I'm not familiar with the FTDX3000, but PC ...
user avatar
  • 23.1k
1 vote

VOX mic that emulates PTT

Unfortunately your RT1 radio will not easily support VOX operation. The only control of the PTT is on the main radio or the remote. There is no push to talk (PTT) connection brought out on the radio ...
user avatar
  • 18.1k
1 vote

VOX mic that emulates PTT

After a quick Google I wasn't able to find any devices on the commercial market but it doesn't sound too hard to DIY. Here's one: http://www.rason.org/Projects/basicvox/basicvox.htm Basically you ...
user avatar
  • 847
1 vote

MIC microphone ground vs common (PTT, chassis etc) ground

An audio interface is a very different situation than a microphone, even though they both produce the same sort of signal at the same voltage. The microphone, specifically, must be protected. ...
user avatar
  • 23.1k
1 vote

Old Yaesu FT-470 HT audio feedback with external speaker mic

Consider a DPDT switch, extremely common . Open the mic on receive. The radio likely mutes mic audio when squelch closed. When you get a keypress beep or open squelch, it's probably enough audio to ...
user avatar
  • 89
1 vote

Is the Kawamall DMTF 6pin microphone usable with the Kenwood TK-805D radio?

I'm looking at the Service Manual for the TK-805D and it shows +13.8 Vdc on pin 1 and +5 Vdc on pin 6. Mind you, these readings are hand written by whom ever posted this manual. Do you have the part ...
user avatar
  • 11
1 vote
Accepted

Baofeng UV-B6 transmits no audio

Usually this happens when you accidentally bend the inside of the jack (inside the radio) with the programming cable (or speaker mic) plug. In general you have to carefully open the radio and bend the ...
user avatar
  • 26

Only top scored, non community-wiki answers of a minimum length are eligible