Many early adopters of the Elecraft KX3 portable HF transceiver have reported that the speaker seems to buzz while using CW if you turn the volume up to a loud level. The source of the buzz is actually the case vibrating due to the KX3's split case design. Inspired by some discussion on the KX3 yahoo group, I decided to try one of the proposed modifications myself and see what happened. The result is that I now have a buzz-free KX3! Here's how you do it:
The most common source of the case vibration causing the buzz is where the speaker mount comes in contact with the other half of the case. The picture below shows the three areas where you may find the edges of the speaker mount touching the other half of the case:
All you need to do is create a little gap between the three points using a file or dremel tool. Carefully file away about 1/32" from the two edges on the bottom half of the case:
On my unit, I also found that the bottom lip of the top case by the speaker made contact with the bottom of the case when it was assembled tightly. I used a flat file to carefully take a small amount of this lip off:
I touched up the exposed aluminum with a black sharpie and reassembled. You can see that there is now clearance all the way around the speaker mount:
I can now turn up the volume up to at least 30 without buzz. If I increase the volume between 30 and 40 (max) I still get some buzz coming from the bottom speaker lip, so I need to increase the gap shown in the picture a bit more. I rarely use the volume past 30 anyway, because the speaker starts to distort at those levels. Wayne from Elecraft has indicated that he has drawn up the changes to the case design already and there may be more fixes coming later.
The most common source of the case vibration causing the buzz is where the speaker mount comes in contact with the other half of the case. The picture below shows the three areas where you may find the edges of the speaker mount touching the other half of the case:
All you need to do is create a little gap between the three points using a file or dremel tool. Carefully file away about 1/32" from the two edges on the bottom half of the case:
On my unit, I also found that the bottom lip of the top case by the speaker made contact with the bottom of the case when it was assembled tightly. I used a flat file to carefully take a small amount of this lip off:
I touched up the exposed aluminum with a black sharpie and reassembled. You can see that there is now clearance all the way around the speaker mount:
I can now turn up the volume up to at least 30 without buzz. If I increase the volume between 30 and 40 (max) I still get some buzz coming from the bottom speaker lip, so I need to increase the gap shown in the picture a bit more. I rarely use the volume past 30 anyway, because the speaker starts to distort at those levels. Wayne from Elecraft has indicated that he has drawn up the changes to the case design already and there may be more fixes coming later.
