How does VOX work?

[shortride]

Are there Astatic D-104 desk microphones being used with amateur transceivers with VOX capabilities and how is VOX set up on a transceiver? I was doing some reading and it's not clear to me how the system works with or with the key on a D104 or stock microphone.

I have been studying for an amateur radio ticket and wanted a general idea how the VOX system works. Please don't get too technical. I'm most interested if a D-104 will work with VOX.

 

[nd5y]

On all the radios that I have owned VOX will work with any microphone. Most HF radios have adjustments for VOX sensitivity and delay. VOX sensitivity adjusts the sound level from the microphone needed to key up the radio. VOX delay adjusts the time that the radio stays keyed up after the sound level drops below the sensitivity threshold.

 

[shortride]

On all the radios that I have owned VOX will work with any microphone. Most HF radios have adjustments for VOX sensitivity and delay. VOX sensitivity adjusts the sound level from the microphone needed to key up the radio. VOX delay adjusts the time that the radio stays keyed up after the sound level drops below the sensitivity threshold.

So the VOX adjustment will key the D-104 by way of the microphone keying circuit within the transceiver without even touching the key on the desk mic? That's interesting! Is there an adjustment to active VOX separate from the VOX sensitivity and delay setting?

 

[nd5y]

Yes. There should be a switch on the radio to turn the VOX function on & off. Some modern radios might have all of that in menus instead of pots and pushbuttons.

If you wanted to you could probably disconnect the PTT swich from the mic and only have the mic element wires going to the radio mic connector and VOX would still work. Like I said, it shouldn't make any difference what type of mic you use as long as the impedance and audio output are what the radio requires.

 

[SCPD]

Watch what you say when VOX is engaged it can be embarrassing and also get you in trouble.....

 

[Token]

Are there Astatic D-104 desk microphones being used with amateur transceivers with VOX capabilities and how is VOX set up on a transceiver? I was doing some reading and it's not clear to me how the system works with or with the key on a D104 or stock microphone.

On all the radios that I have owned VOX will work with any microphone.

There are a couple of different questions being answered, and the answer quoted above makes an assumption. As nd5y said, any mic should work with VOX, VOX is a function of the radio, not the microphone.

Yes, D-104 mikes are/have been used with VOX capable radios. How it works and how the key on the microphone relates depends on how your specific D-104 is wired, there are many options to how they might end up.

The D-104 is just the microphone section, and not the microphone stand with key and base (there was even a hand held D104-M for mobile use). The base of the microphone (such as model T-UG9 or T-UG9-D104 or T-UG8 or G stand) contains the push to talk switch (s) and the pre-amplifier if so equipped. The switch bar is on the side of the riser portion of the base, and this is squeezed to talk, there may, or may not, be a push-to-talk bar on the base.

If you have a D104 with a T-UG8 or a G base you might have to slide the clip up the switch bar, depressing the switch bar, for VOX to work. This is because the microphone element might not be in circuit during receive operation, and until the switch is pressed the audio from the mic never goes to the VOX circuit. Some very old radios required this configuration, and some users preferred it even on newer radios.

If your microphone is factory wired and only the plug has been changed over the years then no matter what the base used you should be good to go, but since no new D104’s have been made since 2001 there is no telling who has had their hands inside that thing or for what radio it might have been configured at some time in the past. I have found that the older the base the more likely it has the microphone out of line during RX, although at any age this is a rarity.

So the answer is…probably your D-104 will work with VOX just fine. But if not all is not lost, any D-104 can be made to work with VOX, you just might have to reverse some past owners modifications. If you have an amplified base mic the battery must be good for your VOX to work.

T!

 

[AgentCOPP1]

I've never really liked VOX. It's generally not very accurate even with adjustments, and I just like pushing buttons more haha (especially the buttons of people who annoy me).