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Tuning clicks on bitx40 #bitx40help

radioant@...
 

Hi I'm Bob WB2TFG,
This is my first message on this group. I wanted to silence the tuning clicks on my bitx40. I have already tried putting the caps on the regulator and resistor on the power wire on the vfo and it didn't help the tuning clicks at all. So I looked at the output of the vfo with an oscilloscope and saw a large pulse coming out of the vfo when the tuning pot was turned. The pulse was about 2.5ms long with an amplitude of about 5volts. Could this be a software problem. Thanks from Bob Porter WB2TFG.

Jerry Gaffke
 

Probably not software.
There were some issues with etherkit libraries made available last spring,
the vco was getting reset each time the frequency changed.
But that was not a problem with the firmware shipped with the radio
using an earlier version of the etherkit libraries.
And not a problem for Allard's current firmware:  https://github.com/amunters/

You can hear tuning clicks with no antenna connected on most of these radios,
but the noise floor pretty much completely masks it with an appropriate antenna connected.

A 50 ohm resistor in the 12v lead to the raduino, plus caps to ground on both ends of that resistor
should be sufficient to stifle this.  If not, perhaps it has to do with how the wiring is routed
to the raduino.  Maybe arrange so the 12v and ground leads to the raduino leave from the same
region of the Bitx40, and place a cap across the two there.  Maybe an issue with length of leads,
or how the leads get routed.
 

On Fri, Jan 26, 2018 at 04:38 pm, <radioant@...> wrote:
Hi I'm Bob WB2TFG,
This is my first message on this group. I wanted to silence the tuning clicks on my bitx40. I have already tried putting the caps on the regulator and resistor on the power wire on the vfo and it didn't help the tuning clicks at all. So I looked at the output of the vfo with an oscilloscope and saw a large pulse coming out of the vfo when the tuning pot was turned. The pulse was about 2.5ms long with an amplitude of about 5volts. Could this be a software problem. Thanks from Bob Porter WB2TFG.

Jerry Gaffke
 

5v for 2.5ms on the vfo does sound like it might be that etherkit vco reset from last spring.
What firmware do you have installed now?

radioant@...
 

Thanks for the reply Jerry. And thanks for the advice. I tried putting a 1000uF and a .1uF cap across the input of the regulator and it made no difference. I even ran the raduano with a separate power supply and the clicks were just as loud.  When I observed the tuning clicks on the scope at the output of the vfo it looks like the RF signal stop's then the tuning pulse then the RF continues. I hear this can be a. problem. The version of software is I think 1.01 when the unit is turned on. Thank you Bob WB2TFG.

Allard PE1NWL
 

This may be due to the si5351 library version that is used by the original
stock firmware v1.01
Try upgrading the firmware https://github.com/amunters/bitx40
It has built in si5351 routines (no external library) and some other
patches as well to reduce the noise.

Using shielded wires to/from the volume pot also helped a lot in my case.
But I must confess I never got rid of the clicks completely. I can still
hear them when the antenna is disconnected.

73 Allard PE1NWL

On Sun, January 28, 2018 03:00, radioant@... wrote:
Thanks for the reply Jerry. And thanks for the advice. I tried putting a
1000uF and a .1uF cap across the input of the regulator and it made no
difference. I even ran the raduano with a separate power supply and the
clicks were just as loud.  When I observed the tuning clicks on the scope
at the output of the vfo it looks like the RF signal stop's then the
tuning pulse then the RF continues. I hear this can be a. problem. The
version of software is I think 1.01 when the unit is turned on. Thank you
Bob WB2TFG.

Billy Shepherd <dis60cd@...>
 

Any luck? I’m using probably the same kit and the clicks are extremely annoying. 

 

Using a 2 cap one resistor rc filter pretty much takes care of the clicks. Did it to mine and works great 
--
David

 N8DAH
Kit-Projects.com

Shop is open!

James Lynes
 

On my spare Raduino that I am using on a DC receiver, I added a diode and 4 parallel 150 ohm 1/4 watt resistors in front of the 5v regulator. Also added a bypass cap and electrolytic cap.

This helped but did not eliminate the clicks.

Interestingly, when I was running from a 9v battery,  the clicks would get worse when the voltage dropped. At this point the display washed out to illegible. 

James

Wayne Leake
 

 Well, D'ang, it was, after all, designed around 12 volts DC not 9 or 9 1/2, etc.
 The bareboard kit I have, which uses a separate power supply and PA final on one board, is set for 12 volts for all but the 510 output FET.
 Running lower than 12 volts for the exciter may well lead to things that you don't desire.