Re: K3S to be discontinued


Rob Sherwood
 

The K3S is excellent in respect to transmit composite noise.  Transmit IMD, on the other hand, is quite different at various power levels.  The sweet spot is around 35 watts, but much worse at 12 watts and 100 watts.  Here is composite noise data.  Hopefully the formatting will hold up. 

Rob, NC0B

 

Transmit Composite Noise Rig Comparisons 20 meters values in dBc/Hz

Rig @ 100 watts                2 kHz offset        10 kHz offset      20 kHz offset      100 kHz offset

K3S                                                                         -141                       n/a                         -143

FTdx-101D                           -133                       -137                       -138                       -141

IC-7851                                                                 -129                       n/a                         -138

IC-7610                                                                 -128                       -130                       -142

Flex 6400                                                             -122                       -127                       -139

IC-7300                                                                 -121                       -121                       -124

FTdx-3000                                                           -120                       n/a                         -121

TS-890S                                -116                       -119                       -127                       -139

Rig @ 30 watts                   2 kHz offset        10 kHz offset      20 kHz offset      100 kHz offset

FTdx-101D                           -129                       -134                       -135                       -137

K3S                                                                         -132                       n/a                         -140

IC-7851                                                                 -123                       n/a                         -133

IC-7610                                                                 -122                       -124                       -127

Flex 6400                                                             -120                       -125                       -137                                      

FTdx-3000                                                           -117                       n/a                         -117

TS-890S                                -112                       -115                       -124                       -135

IC-7300                                                                 -110                       -109                       -116

 

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of Wes
Sent: Sunday, November 03, 2019 10:32 AM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] K3S to be discontinued

 

If TX IMD is the issue, K3 and K3S transmitters are a real mixed bag.  My old K3 at 30 watts is fantastic, with IMD at all frequencies better than -40 dBc (ARRL method).  The same radio at 10W is the worst of my two radios, except at 24 MHz where the K3 and K3S tie at -22 dBc.

 

It's been hard to keep up with these measurements since the KLPA3A in the K3S has been replaced twice and the KPA3A is IIRC, on the fourth version.

 

Wes  N7WS

 

 

 

On 11/3/2019 8:16 AM, Martin Sole wrote:

I suspect the quality of the transmitter particularly with regard to its composite noise spectrum to be a large player. Some radios with high end receiver performance have rudimentary (I'm being kind) transmitter composite noise performance.

See what NK7Z, NC0B and K9YC have written about this.


Martin, HS0ZED


On 03/11/2019 21:30, Mark Morin wrote:

My experience is that the type of rig does make a difference for close coexistence. We’ve found on DxPeditions that an upgraded K3 with KPA500 and a Kenwood TS-590s also with KPA500, can coexist quite well with antennas about 300 ft apart. On most bands, we can operate SSB and CW simultaneously with tolerable QRM. Other times we have tried different high-end rigs in similar setup and found that opposite end of same-band operation was nearly impossible due to QRM. I suspect it’s mostly the receivers that makes the difference. 

Mark VA2MM

 

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