Teaberry Stalker XX random snap crackle and pop.......

[Lkaskel]

Hi Everyone,
I have a mint Stalker XX (US version) that has been recapped and aligned. The radio performs great!!! It has developed an interesting issue though. When the radio is warmed up (about 15 minutes or so) I randomly get a crackle or pop from the speaker. It is not in conjunction with any receive and does not sound anything like RF static. It actually sounds similar to a dirty control but adjusting any control does not affect it. because it begins after 15 minutes I am assuming that a transistor or diode may be breaking down but am very interested in your thoughts. Also, what would be your process for troubleshooting it? I was thinking about putting the scope on various parts of the circuits to see if I could see the noise and do an elimination process.

Thanks as always!!!

 

[Dmans]

Scope starting at the speaker and works backwards towards the audio chip seems like a sound (HaHa!) process to me.
Seriously.

73
David

 

[nomadradio]

Does turning the volume control up and down affect it? Or does the noise keep the same volume level with the volume control turned down?

Just pinning down whether the noise is upstream or downstream from the volume control would be a start.

73

 

[loosecannon]

i have experienced this before and it was the volume control pot itself.

It was very dirty and was difficult to turn.
after spraying it with contact cleaner and turning it back and forth multiple times it finally started playing nicely.

everything seemed great until i turned on the radio and it was crackly and poppy.
turn the volume up a bit and it went away.

was a strange problem and would come and go.
I eventually just replaced the pot after not being able to find a problem inside the radio.

i believe that the carbon track inside the pot was just too far gone.
LC

 

[brandon7861]

Could be a transistor going bad. If the clicks and pops are consistent, take some cold spray to each transistor one at a time to see which one lessens/eliminates the noise when cold.

 

[Handy Andy]

Awesome tool...



​

I'd tap around and bump these green Chiclets around the audio amp, Mic amp and RF strip - see if these cause issues.

You also may have some in the Power supply area that have "opened" and no longer work very well in "softening" the audiop crunch and electrical snaps and blows to the power supply from the outside.

Might want to tap around to see if something or a string of components are causing this "idle noise" problem"

 

[Lkaskel]

Does turning the volume control up and down affect it? Or does the noise keep the same volume level with the volume control turned down?

Just pinning down whether the noise is upstream or downstream from the volume control would be a start.

73

Great question!!! The volume of the crackle is not affected by the volume control. In fact, if the volume control is at its lowest level the crackle comes through loud and clear.

 

[Holydvr]

I had that happen on a 138XLR. I replaced the audio chip and the “popcorn” as I called it has never returned. Of course, your results may vary.