Topics

Ubitx tx/rx "chatter" (read old thread)

Kelly Mabry
 

Hi all! I have just connected a bc645 4 pin electret mic to my ubitx and am getting a 5 tx/rx "chatter" on transmit on a dummy load, when press ptt. When i release, all is fine, rx is lit and i hear rcv audio.  As a test, i enabled tx stop on the cec software,  and pressed ptt.  The tx indicator lights red for as long as i hold ptt, and then returns green as I unkey. This seems to indicate the ptt works as intended. After unselecting tx stop, the chatter returned. What am I missing? ...continuing to read thread...
73, 

Kelly K5AID 

Arv Evans
 

Possibly you have connected the audio lead to the PTT circuit and the rig is being keyed by audio.
Possibly you are getting RF into the PTT line (long curly cords are problematic).

_._


On Sat, Apr 20, 2019 at 2:35 PM Kelly Mabry <kmabry2007@...> wrote:
Hi all! I have just connected a bc645 4 pin electret mic to my ubitx and am getting a 5 tx/rx "chatter" on transmit on a dummy load, when press ptt. When i release, all is fine, rx is lit and i hear rcv audio.  As a test, i enabled tx stop on the cec software,  and pressed ptt.  The tx indicator lights red for as long as i hold ptt, and then returns green as I unkey. This seems to indicate the ptt works as intended. After unselecting tx stop, the chatter returned. What am I missing? ...continuing to read thread...
73, 

Kelly K5AID 

Evan Hand
 

That seems to be a common problem depending on antenna and antenna connections.  I had similar issues with an off center fed dipole and RF on the coax braid.  Fixed it with snap on ferrites on the coax, others have used blocking baluns.  Also a .o1 to .1 mf cap on the PTT line to ground has been listed as helping. 

the above are my experiences and thoughts, YMV
73
Evan
AC9TU

Kelly Mabry
 

Here is what I am using as a wiring guide. Specifically the 4 pin connector is the black as audio, brown as ptt and red as ground. Coming from the front left audio board, J6. (Sunil kit)
Kelly K5AID 

 

Hi Kelly,

Looks like you should have Pin1 on the new mic going to the red wire connection on the 3-pin board connector.  Also you should have Pin2 on the new mic going to the black wire connection and Pin3 going to the brown wire connection (and no connection to Pin4).  Is this the way you have it?

73,


Mark

Kelly Mabry
 

Not even close... doh... so embarrassing this is...

Will fix and retry...

Kelly K5AID 

Kelly Mabry
 

Update: chatter gone! I wired it as Mark directed, and it doesnt chatter!  

73 & thanks!
Kelly K5AID