[Elecraft] [Elecraft-K3] K3S to be discontinued

[Wayne Burdick]

Joe,

Not everyone uses an amp with their 100-W rig (in fact, far less than half). Like other 100-W radios that are compatible with field use, the K3/K3S/K4 must make ~100 W from a 12-15 V mobile, solar, or battery supply. But it also has to be efficient at this power level.

If you only need amp drive power, the IMD improves. And the K4 is capable of predistortion, which means that at amp drive levels, IMD performance should be truly outstanding.

The transformer ratio is 16:1, the same as most other "12 V capable" 100 W transceivers. If you go to 25:1, drain current goes way up, precluding the use of standard 20/25-A power supplies and making the radio a lot less portable.

73,
Wayne
N6KR


> On Nov 4, 2019, at 4:45 PM, Joe Subich, W4TV <lists at subich.com> wrote:
> 
> On 2019-11-04 6:20 PM, Wayne Burdick wrote:
>> At home, use 13.8 to 14.2 V for lowest IMD. In the field, the K3 (and
>> now, the K4) automatically scales maximum power output based on
>> supply voltage, and can run down to as low as 11 V.
> 
> It is a shame that the maximum power output along with bias levels and
> transformer ratios were not selected for lowest obtainable IMD.  Output
> power (100 W) became the only specification that counted even though
> 60 W would have been enough to drive the KPA-500/KPA-1500 with truly
> outstanding IMD.
> 
> 73,
> 
>   ... Joe, W4TV
> 
> 
> On 2019-11-04 6:20 PM, Wayne Burdick wrote:
>> Hi all,
>> We've chosen to have the K4 continue to be a field-capable radio, inheriting the characteristics that have always made the K3/K3S (and the K2 before it) the preferred rig for FD, DXpeditions, and multi-transmitter stations. Thanks to a lightweight but rigid internal aluminum frame, the K4 weighs only slightly more than the K3/K3S, while integrating in a large LCD in a way that increases width by less than 3 inches. (Unlike on many rigs, our front panel includes separate optical encoders for VFO A, VFO B, and RIT/XIT.)
>> Current drain of the K4 is half that of most competing high-performance desktop radios, so it can be used with emergency power. At home, use 13.8 to 14.2 V for lowest IMD. In the field, the K3 (and now, the K4) automatically scales maximum power output based on supply voltage, and can run down to as low as 11 V.
>> 73,
>> Wayne
>> N6KR
>>> On Nov 4, 2019, at 3:07 PM, Buck <radiok4ia at gmail.com> wrote:
>>> 
>>> Perhaps the K4 should have been a 40V radio and the K3S remain as the 12V "portable" or "field" version.
>>> 
>>> k4ia, Buck
>>> K3# 101
>>> Honor Roll  8B DXCC
>>> EasyWayHamBooks.com
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