[Elecraft] K1 and K2 Receiver Performance

[James R. Duffey]

The K1 receiver performance is not in the same class as the K2 and other
high performance receivers. Your TS830 has a good receiver, much better than
the K1, but probably short of the K2.

At the Duke City Hamfest a couple of years ago,  Fred, KT5X, had his K2 and
a 20 M Moxon set up. I brought myy K1. The hamfest station, N5M was
operating on 14.025 about 100 ft away. With the hamfest station off the side
of the Moxon, the K2 could operate at 14.030 with no trace of N5M at all,
and still operate comfortably with some trace of N5M at a couple of
kilohertz away. With my K1, I still heard it on 14.060. The only way I could
work weak to moderately strong signals at 14.060 was with the attentuator
kicked in, and even then there were some artifacts. This made a beliver out
of me about the K2's strong front end.

The K1 does not do well in crowded strong signal conditions. This is
aggravated by the inability to turn the AGC Off without going through the
menus or converting the XIT button to AGC, which one can do. However, the
XIT is useful in crowded pileup conditions, as is the ability to turn off
the AGC.

The price the K2 pays for its superb performance is a 5X or so increase in
power dissipation on receive.

The K2 really shines with its bulletprroof front end, which is the key to
good receiver performance. Then it becomes a rather ordinary receiver: its
crystal filter has a poorer shape factor than many other modern rigsm and is
asymmetrical;  standard as well as optional aftermarket filters available
for many rigs including your TS-830 are much better than the K2's filter,
and there is no passband tuning/IF shift like most modern rigs have. DSP or
any audio filtering is optional, and without the DSP there is no notch/peak
filter.

The barebones K2 receiver does not have many features we take for granted in
today's  receivers, inncluding SSB, a noise blanker, and audio (both analog
and digital) filtering. These are all options. I doubt if there are many
barebones K2s out there.

Having said all this, we at AA5B, running a barebones 2 band K1 finished 2nd
nationwide in 1A Battery FD this year running my K1.  With an external
keyer, required for competitive contestingm it gave a good account of
itself.

Don't get me wrong, one of these days I will get a K2. Maybe in May, when my
youngest daughter graduates from college. :^)= In the meantime I am more
than happy with my TS-850, which has a really good receiver, and my OHR 500
and Classic, both which have receivers with very good front ends. For high
performance in a protable/small rig it can't be beat. But it is not the
ultimate receiver.  I suspect that the K3 will be though. :^)= - Dr.
Megacycle KK6MC/5
--
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Antenna Question

[James R. Duffey]

Tom - You should use a 1:1 balun to feed the balanced line with the K2
tuner. You can easily make one by wrapping a dozen or so turns of RG-58
through a type 43 or 61 core FT140 or larger. Diz, at



is a good source of these toroids.

Alternately, you can slip a half dozen type 73 ferrite beads over RG-58. The
beads are available from Mouser as part number 2643540002. COvering hte
whole assembly wiht heatchrink tubing keeps things from moving around.

I would avoid using a 4:1 balun. On those bands where the antenna impedance
is low the balun will make it lower and harder to match and will result in
more loss in the tuner.

If you have trouble tuning the antenna, you can add an additional section of
feeder to help the match. Others have popinted this out sa well.

If you feed the antenna with balanced feeder you don't need to make the
dipole resonant, yoiu can make it any convenient length. Some lengths have
advantages over than others, but if you make it shorter than about 0.4
wavelengths, SWR on even a balanced feeder will be high and losses will be
large for long runs. - Dr. Megacycle KK6MC/5

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Low antennas in high places

[James R. Duffey]

Vic - I often operate QRP field operations from such a location at Gallisteo
Dam. It has a long steeply sloping ground to the East and Northeast. I use
an inverted vee for 40 M and 20 M at 24 feet in a painters pole.
Propagation is great and I do pretty well in the QRP field contests. It is
worth looking for such locations and trying them out. If you have any
further questions drop me an e-mail. - Duffey
--
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Interesting Tuner applet

[James R. Duffey]

Daan - Here is the match I get for your problem:

Input C 226.6 pF
Coil 1.2 uH
Output C 174.7 pF

SWR 1.0
Percent loss 1.0
dB loss 0.0 (actually this means less than 0.1, teh lowest value the applet
shows)

It is a bit different than yours and the automatch, but it is low none the
less. I get the same automatch that you do.

This points out that although a T-match can achieve a non unique match,
there usually is not a significant difference in loss in these matches.

Here is how I tune a T-match tuner, and the applet as well.

1. Set all controls at maximum.

2. Reduce the inductance untill you see a dip. It might be a shallow dip, or
it may be a deep dip, but  you should see a dip.

3. Reduce the output cap until you see a dip.

4. Reduce the input cap until you see a dip.

5. Tweak the inductor if the dip is not at 1:1.

6. Go back and tweak the output cap, input cap, and inductor to get to the
lowest SWR.

7. If you still have a high SWR, see which control impacts the SWR the most.
Turn it one direction off the dip. Tweak the other two controls in turn to
get a dip. If the SWR is lower than when you started, turn the initial
control in the same direction and tweak the other two controls until you get
a new dip.  Repeat unitl you get the lowest SWR. If the SWR is higher than
before, turn the control in the opposite direction and proceed as above.

8. You may find that only two of the three controls affect the SWR dip. If
that is the case, concentrate on those two.

This all becomes second nature after doing it several times.

I keep a cheat sheet on top of the tuner with the correct settings for each
band/antenna combination. That makes band changes quick. You can also use
those "Post It" pointers that administrative assistants use to show you
where to sign a document to indicate proper settings.

I hope that this helps. - Dr. Megacycle KK6MC/5

--
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Internal battery question

[James R. Duffey]

Charles - A well charged Gel Cell should have a voltage in the neighborhood
of 13.2 to 13.8 V. It appears that you did not fully charge the battery, or
the battery is incapable of accepting a good charge. Others have pointed
this out as well, you need a charger/supply that is capable of of overcoming
the Schottky diode voltage drop in the K-2.

You might want to try charging the battery out of the K2 to see if it will
take a charge and how that will last when reinstalled in tthe K2.

The battery in the K2 is a bit undersized for extended QRP use at 5 W. This
is exacerbated by the common use of float charging, which does not fully
charge a Gel-Cell, or takes forever to do it. The use of a smart charger is
recommended. There are some issues with using a smart charger, but they are
covered in the technotes area of the Elecraaft site. - Dr. Megacycle KK6MC/
--
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Antenna Analyzers

[James R. Duffey]

After 25 years of using a home built noise bridge to tune antennas, I love
the MFJ 259B that my wife gave me for Christmas. It is a wonderful tool. I
have had no problems with mine. It does eat batteries though, and there are
a few on the list who remember Doug Hendricks, Dave Gauding and myself doing
our best the Three Stooges act tuning one of the first NorCal Doublets at
W5JAY's house 3 or 4 years back at Arkiecon. Among the comedy of errors
included using W5JAY's MFJ 259B connected to an 24 AH Gel Cell. "I got tired
of taking the back off to change those damn batteries" was Jay's
explanation.

The tool is no better than the craftsman using it.  An antenna analyzer will
not automatically help you to build a better antenna if you don't understand
basic antenna and transmission line principles, but it will help you to
understand those principles.

I find the MFJ very valuable in the field to quickly verify that the antenna
is operating OK.  - Dr. Megacycle KK6MC/5
--
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Winding Toroids

[James R. Duffey]

A crochet hook makes a fine toroid winding tool. I use a partially
straightened out paper clip.

A few years back I gave a talk on baluns at the SW ARRL convention in
Riverside. Some of you may remember it. I demonstrated how to wind a torroid
to a large group using a roll of toilet paper for the core, a piece of rope
for the wire and a straightened out coat hanger as the tool. People got the
picture quickly. This is a good demo the next time someone at your club says
they don't build because winding toroids is a pain. :^)= There used to be
pictures of me doing this demo on the net, but thankfully they have
evaporated. - Dr. Megacycle KK6MC/5
__
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.): 
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] K1 enthusiast wonders ??

[James R. Duffey]

Let me present a dissenting point of view on the K1. I am the fourth owner
of K-1 SN0004 with a 40/20 M module. I have had it for 2 years. I have found
that the more I use it the less I like it.

I find the K1 both too much radio and too little radio at the same time.

I use it primarily for portable operation. As I don't use it all the time in
the shack, I find that I need the reference card to recall all of the
functions when I use it in the field. Being menu driven and with many of the
switches having several functions I often make mistakes.  The code speed
goes up  when I try to change filter settings for example. I don't need all
of those functions in a portable contest radio, and I think that cramming
them all into a small radio significantly detracts from the ability to
seamless operate the radio. Thus, the radio is too much.

But, there are significant performance compromises made. There is no RF
gain. The NE602 front end mixer has problems in crowded band conditions.
These two issues are exasperated by the fact that the AGC cannot be turned
off without going into the menus. The filter has a pretty poor shape factor,
with a very gentle roll off on the high side. The fact that the filter is
adjustable means that optimum peformance is not possible at any bandwidth.
The built in keyer requires 2 key strokes to send what is in memory, a big
delay in contests. 

I bought the K-1 to replace an aging OHR Classic, also a 20 M and 40 M rig.
I find myself returning to the OHR more and more. It is a simple receiver
with no bells and whistles. But it uses a crunch proof diode balanced mixer
in the front end that runs circles around the K1's NE602. After a few hours
with the K-1 on 40 M for Field Day, we switched to the OHR and were much
happier with its performance. As the OHR does not have an RF Gain control
and the AGC is not switchable, the preference for the OHR is likely due to
the higher performing front end and better IF filter. We eventually replaced
the OHR with a K2 when the 15 M station QRTed at dark. It was preferable to
both the K1 and the OHR.

There are some nice features of the K1. The tilt stand is very nice in
getting the rig off the table and at eye level, a common problem with QRP
rigs. The provision for repetitive CQing is nice on sparsely populated bands
during contests. I like the provision to monitor the battery voltage.  The
audio is generous and much better than the K2. The rig has generous power
output and 5 watts is possible on all bands. The built in power meter is
nice to have.

I must admit that many of these opinions may be colored by a feeling of
betrayal by the K1. It is the only rig to have failed me in the field. At
the start of Field Day it failed to work on 40 M. 20 M was fine. After
opening the rig, removing the filter board, inspecting it to find nothing
obviously wrong, cleaning it, and reseating it; it again worked OK. Don't
know what the problem was, but it left me with less confidence in the K1
than I had before. I don't need that kind of stress prior to a major
operating event.

I have often thought of upgrading with a 4 band module and the built in
tuner. I believe that would also require a firmware upgrade in a rig as old
as mine. The total for these upgrades is about 90% of what I paid for the
rig, and I question if putting that much money into a rig I am not real
happy with is worth it to me. But it does point out the fact that adding
options quickly raises the price of an Elecraft rig.

Having said all that, I realize that rig preference is a personal thing.
Most are happy with their K1s. The K1 does not really fit what I am looking
for in a portable rig for contesting. The more I use it, the more these
shortcomings are apparent to me. I have decided that performance is more
important to me than the bells and whistles of the K1.

I respect the opinions of those who love their K1s and this is not meant to
denigrate them. I just am not one of them. - Dr. Megacycle KK6MC/5
__________
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.): 
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Granite?

[James R. Duffey]

 Ron - I agree with you;

"And I've seen brownish granite, greenish granite and gray granite..."

In Suoth Dakota (Milbank I think), a lovely shade of pale red granite is
quarried. My mother's (WN0MZI) headstone is made of it.

Before anybody asks, I passed most of the color blind tests I have taken .
:^) - Duffey
__________
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.): 
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Elecraft] Batteryt Life

[James R. Duffey]

I have posted how to calculate battery life here before. John gave a pretty
good reply, but there are a couple of other points that should be made.

1. A lead acid battery is rated assuming the current is drawn at the 20 hour
rate. If you draw more current than this, you will get less capacity from
the battery. At the 10 hour rate, the capacity is diminished by about 10%,
at the 5 hour rate it is diminished by 25%, and at the 1 hour rate it is
diminished by 40%.

2. It is difficult to fully charge a lead-acid battery by trickle charging
it at a constant voltage. Trickle charging at a constant voltage will only
restore about 85% of the battery's capacity. To do better than this you need
to use one of the "smart" chargers or triple mode charges such as those
based on the Unitrode (now TI?) 3906.

If you do not realize this you can get substantially less life from the
battery than you anticipate.

My K-1 draws about 70 mA on receive with the headphones and volume set for
comfortable listening in the field. The transmitter draws about 1.1 A on
transmit. With half of the time spent listening, and half of the time spent
transmitting with a 40% duty cycle I get an average current draw of 0.276 A.

If you constant voltage charged the battery, you will have a 20 hour
capacity of 3.4 AH. At a current draw of 276 mA, I am pulling current out of
the battery at a 12 hour rate. Since this is greater than the 20 hour rate
our capacity will be diminished by about 10%. Reducing the capacity by this
amount leaves 3.06 AH capacity. Dividing by the average current draw,
0.276 A, we get 11 hours capacity.

Of course, in actual operation the average current draw can vary quite a
bit, usually on the down side (we forgot to include bathroom time and
emergency antenna repairs in the above calculations) so it is best to only
use these numbers as a guide and not to really expect to get that last hour
or half hour out of the battery.

I hope that this helps. - Dr. Megacycle KK6MC/5


______
James R. Duffey KK6MC/5
Cedar Crest NM 87008 DM65

___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
http://mailman.qth.net/mailman/listinfo/elecraft
You must subscribe to post.
Subscriber Info (Addr. Change, Unsub etc): 
http://mailman.qth.net/subscribers.htm
Elecraft page: http://www.elecraft.com