[Elecraft] K2 SSB audio - fuzzy around the edges

[Don Wilhelm]

Joe,

It is difficult to say what others may perceive as "fuzzy around the edges".
May I suggest that you operate the K2 into a dummy load and listen to it 
yourself on your FT-1000D.  Actually it would be better to record the 
output of the FT-1000 and listen to the recording because it is 
difficult ot talk and listen critically at the same time.  For best 
results, adjust the antenna (usually a short wire will do) until the 
signal into the receiver is about S-9.  You can use that recording 
technique to evaluate the effects of various levles of compression.

The K2 audio bandwidth should be in the vicinity of 2.4kHz - I don't 
know what the FT-1000 has for bandwidth.
If your audio is a bit too high or low pitched, you will find good 
success by changing the filter passband position slightly.  Normally the 
low frequency -3db corner of the passband should be positioned at 300 Hz 
for best intelligibility.  If you use Spectrogram to measure the filter 
passband placement, you can normally have good sounding audio.  If you 
are not familiar with using Spectrogram to align the filters, I have 
information in part 3 of the article on K2 Dial Calibration at my 
website www.w3fpr.com.
Checking your OP1 filter with Spectrogram may be the best first step, 
then evaluate the result.

73,
Don W3FPR

Joseph Szczubelek wrote:
> I have a K2, mid 5000 serial number, mic input wired for Kenwood, 50 amp 12 volt Amidon power supply, with a KPA100 running 100 watts. I can easily switch my HM-10 mic between transceivers using seperate audio cables for each radio to perform on air testing. When using a Heil microphone HM-10 with dual element (HC-4 or HC-5) with Heil shielded cable and mic plug wired for Kenwood and no external pre-amp for the K2, audio setting SSBA is at 2, and compression setting SSBC is at 2-1, and asking other hams for a critical audio report I am being told that I sound a little fuzzy around the edges on the K2. I am using an Amidon type #43 toroid with seven turns of mic cable just before the mic input to the K2. Any extra Heil mic cable is coiled up as common mode choke about 5 inches in diameter. The distortion might be a little more with the wider HC-5 element. The HM-10 mic works fine and gets great audio reports on a Yaesu FT-1000D - same antennae and same
>  power levels. Only when asking for an audio report does the "little distortion" report come up. I have also applied the grounded K2 mic connector mod.
>
> Is this as good as it gets with the K2 audio ?  
>
> Am I asking for too much for Heil HM-10 with the K2 to sound like the Yaesu FT-1000D ?
>
> Does audio compression in the KSSB create a little distortion in the audio ? 
>
> Thanks
>
> Joe - K9DMV    
>   
>