Cobra 200 GTL-DX Disable Talkback
The Cobra 200 GTL-DX has a built-in talkback function. Some models allow switching this function on or off as desired, others have the ability to adjust the volume. This particular version of the Cobra 200 GTL-DX has a fixed volume, which the customer doesn’t want.
Luckily, the service manual has details for a mod to adjust the preset level of the talkback function. The mod simply comprises of changing the value of a single resistor, in this case R109. The resistor is a 33K ohm SMD device, and located in a quite densly populated area of the PCB.
If the talkback function is to be maintained but a higher or lower volume is required, it’s simply a matter of changing this resistor to one of a different value.
As can be clearly seen, some very intricate soldering skills are required if changing the resistor.
The talkback audio path is taken from the path that runs from the ALC switch to the echo processor, this is then fed via a few more components into the audio amp.
By removing the resistor we are simply breaking the path to the audio amp, thus completely muting and disabling the talkbak circuit.
To give an example of the size of the SMD resistor that has to be removed, here it is after removal, placed on my fingertip.
Hopefully you will appreciate just how tiny and closely spaced these components are and the extreme dexterity required to remove, or indeed to replace, these tiny modern SMD components.
5 thoughts on “Cobra 200 GTL-DX Disable Talkback”
Wow I can’t believe how small that part is. Lucky you have good eyesight
Super bra det var jag sökte!
Ett stort Tack för att du delar med dig av din kunskap 100%.
Super good that was what I was looking for!
A big thank you for sharing your knowledge 100%.
Jag lyckas inte hitta R109 på service manualen inte häller var den är placerad på krets kortet vore tacksam om du kunde rita in på schemat och var i radion den sitter.
Hello again! I do not manage to find the R109 on the service manual does not pour where it is placed on the circuit board would be grateful if you could draw on the schedule and where in the radio it is located.
Hi, if you are using the service manual from here, I’ve just had a look and noticed this manual is for a different version of the radio. You need to look for R208 which is between C233 and C241
Hej, om du använder servicehandboken härifrån har jag bara tittat och märkt att den här handboken är för en annan version av radion. Du måste leta efter R208 som ligger mellan C233 och C241
Tack jag har hittat R109 och tagit bort den lilla motståndet. Och nu funkar det som jag vill!. Det var jag som missade att titta i hela servicemanualen.
Stort tack för att du delade med dej!.
Med vänlig hälsning, Lasse Jakobsson
Thanks I found the R109 and removed the small resistor. And now it works the way I want !. I was the one who missed looking in the entire service manual. Many thanks for sharing with you !. With kind regards, Lasse Jakobsson