[arm-allstar] BF888 VOX wont turn off

[Doug Crompton]

Chris,

 Well in the situation I am talking about it comes from the node
transmitter. it really has nothing to do with the receiver being triggered
by noise which should never happen if it is PL'ed. The TX RF gets into the
circuitry and triggers it to key again. This is probably triggering the COS
line that in turn triggers the TX when it gives the courtesy tone. This
then happens over and over in a ping pong effect. You could probably do
some RF filtering on those lines but in an existing node the easiest way is
just to get the RF away from it.


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*


On Tue, Jan 2, 2018 at 11:01 PM, Chris Souleles <csouleles at prodigy.net>
wrote:

> Thanks Doug I will check that out.  In my house I normally use an antenna
> mounted in my attic and only sometimes use a rubber duck antenna.  If it is
> RF interference that could be why I notice it less in my house than mobile
> where I always use a rubber duck antenna inside the car.  I have a spare
> mag mount antenna so I will experiment and see if that helps when I am
> mobile.
>
> But I have a question.  Where does the RF come from if the node isn't
> being otherwise keyed?  Would it be something generated in the vehicle and
> being picked up in the node?
>
> Chris W6CS - 73
>
> ------------------------------
> *From:* Doug Crompton <wa3dsp at gmail.com>
> *To:* Chris Souleles <csouleles at prodigy.net>
> *Cc:* ARM Allstar <arm-allstar at hamvoip.org>
> *Sent:* Tuesday, January 2, 2018 7:26 PM
> *Subject:* Re: [arm-allstar] BF888 VOX wont turn off
>
> Chris,
>
>  One thing you have to be aware of is RF feedback keying which often
> happens when you make a node with a portable radio using the rubber duck
> antenna. I recommend either using an external antenna or a dummy load on
> these nodes. For a 1 watt radio the dummy load could be two 100 ohm 1 or 2
> watt carbon resistors or any combination that gives 50 ohms - four 200 ohm
> 1/2w etc. Must be non inductive. That would work fine around your house. If
> you need further range they make cheap small mag mount antennas with 10
> foot coax leads. This would get the RF away from the source. Mount the
> antenna on a metal surface to act as a ground plane.
>
>
> *73 Doug*
>
> *WA3DSP*
>
> *http://www.crompton.com/ hamradio <http://www.crompton.com/hamradio>*
>
>
> On Tue, Jan 2, 2018 at 8:29 PM, Chris Souleles <csouleles at prodigy.net>
> wrote:
>
> I have been getting some random unintended transmissions from the node and
> I really don't know if it has anything to do with the VOX or not.   At
> times it would unintentionally key another node I was connected to and I
> would get the courtesy tone back.  I am running TSQLCH on my node radio and
> all the radios I contact it with so I have both the transmit tone and the
> receive tone decode enabled.   This seems to happen more mobile, but also
> happens in my shack but less often.  Since I couldn't figure out the VOX, I
> decided to remove the mic from the BF888 and it seems better, but I have
> not been mobile with it since I removed the mic.  Chris - W6CS - 73.
>
>
> ------------------------------
> *From:* Doug Crompton via arm-allstar <arm-allstar at hamvoip.org>
> *To:* ARM Allstar <arm-allstar at hamvoip.org>
> *Cc:* Doug Crompton <wa3dsp at gmail.com>
> *Sent:* Tuesday, January 2, 2018 3:25 PM
> *Subject:* Re: [arm-allstar] BF888 VOX wont turn off
>
> Big question - is the VOX actually working? The PTT probably overrides it
> in node operation??? Also try using the real BF888 programming software
> and/or set the VOX timeout to 0 or some real low number.
>
>
> *73 Doug*
>
> *WA3DSP*
>
> *http://www.crompton.com/ hamradio <http://www.crompton.com/hamradio><http://www.crompton.com/
> hamradio <http://www.crompton.com/hamradio>>*
>
>
>
> On Tue, Jan 2, 2018 at 4:27 PM, "Chris Souleles via arm-allstar" <
> arm-allstar at hamvoip.org> wrote:
>
> > I have a couple BF888 radios that I use in nodes.  The other day I
> > discovered the VOX was on.  Using CHIRP I tried to turn it off, but each
> > time I read the file back from the radio, it was still on even though I
> had
> > uncheked the box in the file I sent to the radio.  I then tried to turn
> it
> > off manually by holding the PTT and MONI buttons while turning on the
> radio
> > in CH 1-5 (per the manual).  This also did not turn it off.  As an aside
> I
> > have used the manual method to turn off voice prompts and that works, but
> > turning off VOX does not.
> > Anyone else had this problem and know how to get it turned off.
> > Thanks,  Chris - W6CS - 73.
> > ______________________________ _________________
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