[Elecraft] [ K2 KX1 K1 ] Advice sought on Elecraft radios

Tue Dec 30 01:45:49 EST 2008

Interesting observations, Dan. 

I don't have a Norcal 40 but I have built many receivers including single
conversion superhets like that.

First, for really "easy" listening, I turn the AGC off. I find that having
the band noise automatically pumped up loud between signals is very tiring -
sort of like living with a loud noise in the room I can't turn off. So I
turn the K2 AGC off for most work and ride the RF gain control. That way
signals sound natural, standing out nicely above the noise and, when the
signal pauses, the noise stays down at the same level. 

IIRC, the Norcal 40A does not have AGC. Nor do my homebrew receivers.  

Secondly, I find that really sharp I.F. filters are more tiring than wider
bandwidth filters. The primary reason for that is that, at narrow
bandwidths, all the band noise that comes through is almost on the same
frequency as the signal. In short, the noise competes with the signal like
QRM, not QRN. I can often copy CW, even very weak signals, much better with
a 1 kHz or wider filter than a narrower filter even though the wide filter
lets more total QRN through. My brain is better able to hear the signal in
the noise and pick it out if the noise isn't compressed into a narrow
bandwidth.

If the band is busy, it does require that you be able to copy one CW signal
while hearing several at once. That's a basic skill in CW, I think, but many
Hams today have never learned it, so they strive for very sharp filters that
cut out all but one signal. 

Even so, it's hard to pay attention to the 'voice' we want to hear if some
loudmouth is screaming in our ear. And, when the band if very active (e.g. a
contest) that happens often as very loud signals crowd close to the weaker
one we're copying. A narrow filter can subdue that "loudmouth" ;-)

But, almost all the time, I prefer listening to CW with a filter in the
range of 1 kHz wide. 

Setting up my K2 for no AGC and using wider filter bandwidths makes it just
a comfy to listen to over time as any other receiver I've used.

I also have a KX1 and it is a joy to listen to with its continuously
variable filter and quiet rx chain. (I disabled its AGC ;-) 

BTW, did you know that the designer of the NORCAL 40 is Wayne Burdick N6KR,
the chief designer of the Elecraft rigs?  

Ron AC7AC

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Daniel Paul Perez
Sent: Monday, December 29, 2008 9:32 PM
To: elecraft at mailman.qth.net
Subject: [Elecraft] [ K2 KX1 K1 ] Advice sought on Elecraft radios 

I was wondering if I might get some insight, perspective and counsel on 
Elecraft CW QRP DX radios from the group.

About six years ago, I lived across the street from MIT Lincoln 
Laboratory and Hanscom AFB.  Space was limited so I built a NorCal 40A a 
purchased a Hi-Q-Antennas 380 Tune A Dipole NVIS for portable use inside 
or on a porch.  Subsequently I purchased an older non-dsp built K2 QRP 
#502.

To the point, I'm still not all that happy with the level of noise on 
the K2.  If I connect a miracle antenna or the hi-q-antennas between the 
NorCal 40A and Elecraft K2 the Norcal 40A is much less fatiguing to 
listen to and seems to "hear" a little better.  Additionally, a couple 
of hams from the local clubs CWA and PART helped me set up the 
HI-Q-Antenna 380 TAD in September at my new home and then we tried a $5 
home made 20M dipole between two trees oer a shed that was 
"significantly" louder on both the K2 and Norcal.  The NorCal 40A and K2 
are being switched back and forth in the same setting and environment. 
We had an MFJ antenna analyzer to test with as well - the 380 TAD tunes 
1:1 beautifully and is optimized for 40M and military frequencies.  It's 
an impressive piece of engineering.  So here I am with an antenna(s) 
that cost more than the K2 radio, and satisfied with neither.  I've sent 
the K2 to Elecraft's Gary Surrency twice who certifies its one of the 
ten best sounding and 10 best built radios he's seen.  I'm using a 
Samlex power supply.  I purchased a Cobra Ultralite Sr. with a Balun 
Designs balun that I hope to have in the trees in the next few weeks 
when the tree guy gets out from under his ice storm damage workload. 
Maybe this wil be a game changer?

I'm thinking to go to a KX1, or K1 (build or purchase) or the Icom-703+ 
with 400 Inrad.  Would these be quieter radios more like the 40A?  I 
understand the 703+ and K2 are similar generation/concept designs.  Why 
is the Norcal 40A much quieter than the K2?  The radios are from the 
same pedigree and designer.  I thought about the basic K3 but I'm not 
sold on the K2.  Which receiver is better between the KX1, K1?  I like 
the concept of the KX1 as I'm a functional quadriplegic in an electric 
wheelchair and smaller packages appeal to me.  However, I also have 
profound hearing loss and would need ipod amplified speakers on the KX1. 
  The K1 appeals as well, but will it be as fatiguing as the K2?  Would 
the 703+ be quieter than all of the above as well ?  How much better is 
the K1 or KX1 receiver than the 703+?  I also have spare 28A and 60A gel 
cell wheelchair batteries - could I power the KX1 or K1 with these?

My interest is QRP DX [CW] and in general lifelong learning about the 
world and environment.  I have been essentially off the air for 20+ 
years and used to be 25-30wpm.  My first rig was an Icom 735.

Thanks for your advice and patience.

Dan
AD1P
Chesapeake1787 at post.harvard.edu

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