[Elecraft] K6SE Sprint Summary for Team Elecraft

[N2EY@aol.com]

In a message dated 9/11/02 11:13:21 AM Eastern Daylight Time, W1CG@QSL.net 
writes:

> The reason 
>  the K2 had the best close in IMD dymanmic Range and Blocking range ever 
>  measured by the ARRL Lab is that it is the only amateur rig I'm aware of 
>  prior to the Ten Tec Orion to use their narrow xtal filters as the roofing 
>  filters (the filter following the first mixer).  

Actually, there are lots of rigs like that. Here's a short list of the ones I 
know offhand (there are lots more):

Ten Tec:

Argosy/Argosy D (525) Single conversion w/premixer injection, 9 MHz IF
Omni (various models from A to VI+) 
Corsair I and II

Drake:

TR-3, TR-4, TR-4cw 

National:

NCX-3
National 200

Swan:

350, 500, 700 (various models)

>  Filters with the mod do 
>  even better.  Most ham rigs use a 15 kHz roofing filter as they have a FM 
>  mode and need it, or the designers follow the lead of designers of FM mode 
>  rigs and continue to use 15 kHz roofing filters, or else they haven't 
>  figured out how to do it yet, or worse, don't care.  

I think the dominant reason for the wide first filter is that it is at 70 or 
45 MHz. It is not a high performance filter, either. This compromise is a 
direct result of the decision to make the first conversion an up-conversion, 
which makes general coverage easy - at the price of poorer performance in 
other areas. 

> Being a single 
>  conversion superhet helps the K2 reduce the number of birdies and may 
>  improve the IMD also.  

The main idea is to put the selectivity knothole as close to the antenna as 
possible. This is not a new idea - the January 1957 QST article titled 
"What's Wrong With Our Present Receivers?" by W1DX laid all of this out 45+ 
years ago.  

>  So the K2 is a $900 QRP or $1300 100 W SSB rig.  

The K2 is a completely different animal than the Yaecomwood products. Apples 
and oranges. "Conventional" HF ham rigs of the past 15-20 years are 
fundamentally general coverage SSB transceivers with lots of easy-to-include 
features like lots of memories. Basic radio performance, CW, QRP, and 
user-serviceability are not given high priority. 

>  It's better than anything 
>  in it's price class, and some of its features rival or exceed the most 
>  expensive rigs.

It all depends on what you feel are the most important features and 
performance issues. I have never noticed any drift in my K2, but then again I 
don't expect a ham rig to behave as a frequency standard. On the other hand, 
I rate rigs with non-defeatable AGC or poor QSK as Not Acceptable. And I am 
extremely wary of owning a ham rig that I cannot work on myself. 

>  But it does have its warts.  Let's be realistic.  You 
>  can't get a Icom 756 ProII, a FT1000D, Kenwood 870, or a Ten Tec Orion for 
>  $1300.

Before the K2, I was saving up for an Omni 6. A complete set of optional 
filters for that rig cost only a little less than a basic K2. At the rate I 
was saving, I would have gotten the Omni about 2006. 

Considering the fact that an Orion costs about as much as three K2/100s, it's 
reasonable to expect world-beater performance from it. But how long will an 
Orion operate from a ten AH gel cell, when the output is turned down to 5 
watts? ;-)

--

As for service: K2 #2084 came with two left cabinet sides. An email inquiry 
to Aptos was answered in 41 minutes (including transmission time) and a 
replacement was on the way that day. Gotta luv it.

73 de Jim, N2EY