Transmission1

I am looking for a circuit / kit to build a decent vox with ant-vox, delay and sensitivity etc.

I've searched and searched. I know these circuits were around a long time ago,
20 plus years ago, and now they seem to have disappeared.

It's a very long time since I've sat down to draw circuits and
sadly, I've forgotten most of what I used to know... design and build.

The only way I can see to do it is to to run two vox kits
with one operating as the anti vox with some 555's doing delay control.

Any help appreciated.

Or get a second hand Signalink??

What do you mean exactly when you say 'internet linking' and why do you need anti-vox?

Are you just looking for something to key a radio that has the audio in and out wired to the soundcard of a PC? If so, you can make an effective circuit using little more than a couple of op-amps and an opto-isolator.

I too have been trying to build an alternative to buying a Signalink interface. I've tried four different circuits before i found the one I'm now using and this is the Dogs B****cks. Before I forget here is the link http://www.qsl.net/ve3rgw/sbvox.html
The circuit as is works great but there is no means to alter the delay, I have added a 4.7meg pot in series with the 2meg resistor connected between pins 2 & 16 of the mono stable. This allow you to increase the vox delay.
I have also added two LEDs switched by transistors one connected to pin 6 and the other to pin 10 this allows you to see if it's the vox or antivox circuit that has latched. I have used a relay to switch the TX, audio in and out of the radio is through 600 ohm transformers.
If you build this circuit you will not be disjointed.
Enjoy
Best wishes
Ron

Would you say that this was a.......... Ultravox!



Sorry....... coat....... got it.........

kingkey wrote: Before I forget here is the link http://www.qsl.net/ve3rgw/sbvox.html

Again.. this topic of "anti-vox"... Why? Its bad enough that the first thing to even TRY and PTT your radio is the audio it should have been transmitting. If you wanted VOX built into a remote speaker microphone of a handheld that you carry outdoors, I can understand the anti-vox, but for a "closed" hard-wired system?

Can anyone explain this, as I have built quite a few VOX circuits with NO anti-vox and they've all been 100%.

I've spoken to you before about this. My problem is that I have audio looping back from the PC and tripping the vox circuit. There is nothing I can do to stop it, Ive tried everything. It would appear to be a problem with the teamspeak program as I have no problem with Skype.
The anti vox circuit fixes the problem by disabling the vox circuit when I'm transmitting on my handheld.

Methinks this is a software/setting issue!!

kingkey wrote:I've spoken to you before about this. My problem is that I have audio looping back from the PC and tripping the vox circuit. There is nothing I can do to stop it, Ive tried everything. It would appear to be a problem with the teamspeak program as I have no problem with Skype.
The anti vox circuit fixes the problem by disabling the vox circuit when I'm transmitting on my handheld.

Ah yes.. i remember speaking to you now, sorry.

Anti-VOX is not what I thought it was then.. I was getting the wrong end of the stick completely!

Under your PC soundcard settings:
Go to PLAYBACK
un-tick your PC soundcard input (Mic / Line In)


I used to have the same problem, and the soundcard was playing everything from my input (Mic or Line In) on the Output (Speakers)

If your soundcard doesn't have that option, grab a £2 USB jobbie from China because they DO have that option.

Alternatively, set your handheld / mobile to a higher priority than the RoIP node radio (you're using digital right?)
I actually have my kit set up the opposite of above, so my node radio is the highest priority.. This means that if anyone speaks at the same time as me, THEY win, and I get to at least hear what they say. The alternative is that two people talk (double) and no-one hears ANYONE.

PITA to get set up isn't it? Now that i have everything dialed in, my set up is pretty rock solid, and requires little supervision.