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

[Conrad PA5Y]

Wayne I bought a K3S, mainly to use as a transverter driver for which it is excellent. The transverter output is super clean. I also wanted to use it on 6m but there is not any power level where the TX IMD is anywhere near acceptable and it is much worse than an IC7300! I have engaged with your support team but got no useful help. I was advised to run test mode with an external PA! Basically the K3S PA is unusable for SSB on 6m for anyone with a conscience.  I have confirmed the performance with 2 other K3S radios, they are all very poor.  Its a good job that people only use FT8 on 6m these days! As for the SSB contests I will just have to pretend that things are ok 🙁

I sincerely hope that you pay close attention to 6m TX IMD with the K4 because the K3S completely fails in this regard.

73

Conrad PA5Y

________________________________
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> on behalf of Wayne Burdick <n6kr at elecraft.com>
Sent: 05 November 2019 02:31
To: Joe Subich, W4TV <lists at subich.com>
Cc: Elecraft Reflector <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] [Elecraft-K3] K3S to be discontinued

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
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to lists at subich.com
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to n6kr at elecraft.com

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to g0ruz at g0ruz.com