[Elecraft] KX3 vs. K3 and other rigs?

[TF3KX]

I am watching the KX3 evolution with great interest. It appears to bear lots
of resemblance to the K3, but it is not clear to me where these two will
differ. Or, for that matter, how the KX3 will compare against some of the
other rigs around today.

Is there any place that shows, or can someone list up, the primary
differences between, say, KX3 and K3? Not only in terms of technical specs
(IMD, etc.), but also the internal structure (both with similar RF/DSP
architecture?), features, etc.?

73 - Kristinn, TF3KX
..proud maker and owner of K2 #6425

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[Wayne Burdick]

On Jun 5, 2011, at 8:49 PM, TF3KX wrote:

> I am watching the KX3 evolution with great interest. It appears to
> bear lots
> of resemblance to the K3, but it is not clear to me where these two
> will
> differ. Or, for that matter, how the KX3 will compare against some
> of the
> other rigs around today.
>
> Is there any place that shows, or can someone list up, the primary
> differences between, say, KX3 and K3? Not only in terms of
> technical specs
> (IMD, etc.), but also the internal structure (both with similar RF/DSP
> architecture?), features, etc.?

Hi Kristinn,

The KX3 uses a different transceive architecture from the K3 -- one
that is more consistent with a portable, lightweight radio that has
lower current drain and a lot fewer components. But it's not a toy. It
will have performance comparable to many full-size transceivers. We'll
have a lot more to say about this when we complete the update from
prototype to field test.

As far as features go, the KX3 is exactly midway between the KX1 and
K3. Like the KX1 it is fully self-contained, with optional internal
batteries, ATU, and attached keyer paddle. But it covers 160-6 m, like
a K3, as well as all modes. It has a user interface that's very
similar to the K3's, including the same full-sized LCD, five encoders
(optical for VFO A), and full-custom knobs and switches. It has many
of the same special features as the K3, including built-in decode/
display of CW, RTTY, and PSK31; dual VFOs; full stereo audio effects,
etc.

It has extremely low current drain for a state-of-the-art DSP-based
transceiver, at about 150 mA minimum (LCD backlight off). You should
get from 5 to 15 hours of operation from internal batteries depending
on your transmit/receive ratio.

For further details please see our home page (click on the KX3 photo).

73,
Wayne
N6KR

[juergen]

Hi Kristinn

What i dont get is why people expect so much performance from a
so called portable rig. A rig designed for portable operation generally uses poor antennas and is optimized for weight, size and battery life.

While its nice having great receiver specifications, you do have to be realistic about the real world requirements that is placed on the receiver when operating portable.

For me battery life, convenience and power output are very important requirements rather than world beating receiver specifications.
I would gladly have 30 watts output over ultimate receiver performance. Most military manpacks run 20 to 30 watts for good reasons.

10 watts and a wire in the tree type of operation does not demand a receiver with 100db of IMD dynamic range.

If the KX3 does deliver incredible receiver performance for a bargain price I wont say NO, however I can live with lesser receiver performance when operating with marginal antennas.

What I would prefer to see is an antenna tuner that will tune a 9 to 13 ft whip on all bands, or alternatively a end fed wire on all bands. A low noise figure receiver is important when using short portable antennas.

We all waiting for the KX3 tech specs with baited breath. Time will tell whether we will get a 10,000 dollar contest radio that fits into the palm of your hand! After all my years of operating, I have yet to have my DC receiver overload on 40 meters when operating portable with full size low dipoles.

73
John

--- On Sun, 6/5/11, TF3KX <kris...@gmail.com> wrote:

[Wayne Burdick]

John,

You can also think of the KX3 as a full-featured (if ultra-compact)
desktop radio, with a full 100 W if you add the external amp. Hence
the excellent receiver performance :)

73,
Wayne
N6KR

[Buddy Brannan]

More to the point, and maybe I'm missing something very obvious, wouldn't having as good a receiver as possible be nothing but good for portable, compromise antenna operation? I mean, wouldn't you want your receiver to do as much with the available radio energy as possible, especially when you have to make compromises on antennas? Also, "Can't work 'em if you can't hear 'em" eems to apply here. What good is a bigger signal if you can't hear who's hearing you?

I, for one, am really looking forward to seeing the KX3. Pedestrian portable is very appealing to me, especially since I can't stick my rig in the car (because I don't have one...a car, I mean).
--
Buddy Brannan, KB5ELV - Erie, PA
Phone: (814) 860-3194 or 888-75-BUDDY

[Jack Chomley]

The KX3 will be just what I need, for my kayak, marine mobile ;-)
http://vk4djc.webs.com/apps/photos/album?albumid=11608735

73,

Jack VK4JRC

[Mark Bayern]

I think part of the problem when discussing 'good receiver
performance' is in the definition. In a trail friendly radio I expect
a receiver that is able create a readable signal with a very
inefficient antenna. To me a TFR doesn't have to worry so much about
blocking locally produced strong signals. I wouldn't expect a TFR to
do well as well as a K3 at a multi-transmitter contest site such as
Field Day.

Mark AD5SS

[Dave KQ3T]

Here are a couple of additional factors to consider.

1. Increasing the output power to 20 or 30 watts would have an impact on
either the weight of the KX3 (more batteries needed to maintain a
desired battery life) or the battery life (the existing batteries would
not last as long at the higher power level).

2. It is much easier to add an external power amplifier, if desired,
than to significantly improve receiver performance at a later date.

73,
Dave, KQ3T

On 6/6/2011 12:25 AM, juergen wrote:
> Hi Kristinn
>
> What i dont get is why people expect so much performance from a
> so called portable rig. A rig designed for portable operation generally uses poor antennas and is optimized for weight, size and battery life.
>
> While its nice having great receiver specifications, you do have to be realistic about the real world requirements that is placed on the receiver when operating portable.
>
> For me battery life, convenience and power output are very important requirements rather than world beating receiver specifications.
> I would gladly have 30 watts output over ultimate receiver performance. Most military manpacks run 20 to 30 watts for good reasons.
>
> 10 watts and a wire in the tree type of operation does not demand a receiver with 100db of IMD dynamic range.
>
> If the KX3 does deliver incredible receiver performance for a bargain price I wont say NO, however I can live with lesser receiver performance when operating with marginal antennas.
>
> What I would prefer to see is an antenna tuner that will tune a 9 to 13 ft whip on all bands, or alternatively a end fed wire on all bands. A low noise figure receiver is important when using short portable antennas.
>
> We all waiting for the KX3 tech specs with baited breath. Time will tell whether we will get a 10,000 dollar contest radio that fits into the palm of your hand! After all my years of operating, I have yet to have my DC receiver overload on 40 meters when operating portable with full size low dipoles.
>
> 73
> John
>

______________________________________________________________

[WILLIS COOKE]

I will start by stating that the Texas DX Society has found the Kenwood TS-480
to have a receiver that is adequate for DXpedition and Field Day work.  As
contest director of TDXS I am in complete agreement with this finding.  I know
only what has been published on this forum about the KX3 which leads me to
believe that the KX3 will probably have a better receiver than the TS-480 and
approach that of the K3.  The architecture of the KX3 promises to be a good deal
more flexible that the TS-480 with a control head and remote transceiver.  The
TS-480 is not in the picture for a back pack operation.  My opinion is that the
KX3 will be a great winner if it equals the TS-480 because it is more flexible. 
If it is as good as the K3, that is even better.  If any design team is capable
of K3 performance in a flexible package, it is Wayne, Eric, et. al. and I am
eager to see how they come out.  They are very brave to give us the preliminary
peek we now have and I am eager to see the final product, but not so eager that
I want them to release it before they are ready. 

 Willis 'Cookie' Cooke
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart

[juergen]

Hi Dave

The point you make about the added complexity is valid.

However from a communications effectiveness point of 20 watts is a much more realistic power level, especially for SSB QSO's. Most of the Mil Manpacks use this output power level.

I operate portable using mil HF manpacks with the power varying between 20 and 30 watts. I also have a SGC2020. 95% of the time on the first call I can get through and have the standard cookie cutter qso's and move on. If you try and do the same with 10 watts its very frustrating and much more of a struggle. These are NA Q's not local stuff. 5 to 10 watts is good power level for CW. For SSB 20 watts is far more effective, even with simple whips. Everyone will say its only 3db, however that 3db makes a huge difference when using simple antennas especially on SSB.

While the AMP might be the answer, looking at the projected images and size, it will be a huge hassle carrying another box around. If you consider the size of Yaesu FT857, which runs a full 100 watts of output and its design is very neatly integrated into a tiny package, the KX3 with an external amplifier will be awkward by comparison.

A FT857 with some AA batteries was carried to the top of Mount Kilimanjaro by HB9BXE. The operator successfully had many qso at 20 watts of output. He probably would not have packed a KX3 and amplifier if it was available then.

I dont see why a duplicate of the KX3's PA could mot be offered as a piggy back box with another set of 8 batteries. I would rather follow that option than the 100 watt linear option. It certainly would be a lot smaller and portable than the 100 watt PA. I am sure many homebrewers will explore this option.

Anyway time will tell. There is always the hombrew/modification option. The KX3 has a lot of potential and the design is 98% there.

73
John

--- On Mon, 6/6/11, Dave KQ3T <kq...@comcast.net> wrote:

> From: Dave KQ3T <kq...@comcast.net>
> Subject: Re: [Elecraft] KX3 vs. K3 and other rigs?
> To: elec...@mailman.qth.net

[Dave KK7SS]

Back in the late '60's I helped develope and test the first RACAL military SSB Manpack (basically 3-8 Mhz).
It used an flexible tape whip approcimately 10ft long.
This was end loaded using a permeability tuned circuit internal to the rig.
Although it worked well, I don't believe there is enough room in the KX3 for such a circuit.

Also, the antenna was mounted directly on the face-plate to minimize losses (Hah!) I'm pretty sure the PCB mounted antenna socket on the KX3 (a guess!) would not be able to take the stress.

As for "if your can't hear them... etc.", my K2 could hear the rare DX but, with my low backyard dipole, most of the time I couldn't work them... but it was still a thrill to be able to hear them.

My best qrp SSB dx (to date) with 5W + dipole is Beijing on 20M. Just dumb luck <Grin>

73 to all. :-)

--
Dave G KK7SS
DN06ig Richland, WA

'59 Morris Minor 1000
'65 Sprite - in process
'76 Midget - shared with my #4 son.
'06 Honda Civic Hybrid

[Wayne Burdick]

We could offer a KXPA30 amplifier to deal with the need for more power
in a much smaller size. But not anytime soon....

73,
Wayne
N6KR

[Stephen Prior]

Wayne,

Don't forget the KXPA200 for the car!

73, Stephen G4SJP

[Alan Bloom]

On Mon, 2011-06-06 at 07:28 -0500, Mark Bayern wrote:
> ...a trail friendly radio ... doesn't have to worry so much about

> blocking locally produced strong signals. I wouldn't expect a TFR to
> do well as well as a K3 at a multi-transmitter contest site such as
> Field Day.

But I think Field Day would be a prime application for the KX3. A
bullet-proof front end and a low-phase-noise transmitter are essential
when you have antennas spaced close together like on a FD site.

Also, I suspect a lot of people are going to use the KX3 for their fixed
station as well. It would make a great starter rig for a new ham or as
a second rig for an old timer.

Alan N1AL

[Alan Bloom]

On Mon, 2011-06-06 at 08:10 -0700, juergen wrote:

> However from a communications effectiveness point of 20 watts is a
> much more realistic power level, especially for SSB QSO's.

The difference between 10 and 20 watts is only 3 dB, half an S-unit.
Compared to the 20-30 dB of QSB you often find on the HF bands, you
would hardly even notice such a small difference. I think it is quite
rare that 3 dB would be the difference between making a contact or not.

Alan N1AL

[Eugene Balinski]

All,

The improvement in communications effectiveness of 20
watts verses 10 watts is valid - much more than the 3 dB
increase in power would seem to suggest. I have seen the
same results as with my SG-2020 as was mentioned below.
Part of the effectiveness of that particular radio is the
VOGAD speech processor as well. A similar algorithm for
the KX3 speech process might be something to consider
later.

A small 30W PA with antenna tuner that would mount to
the back of the KX3 would be simply amazing. Include a
larger rechargeable battery pack and it probably couldn't
get much better - IMHO

73

Gene K1NR

K2 6Kxx

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[Wayne Burdick]

Effective speech processing will be a given. A 30-W PA is purely
hypothetical at this point.

Just to save a lot more postings on this subject: The KX3 will be
limited to 10 watts PEP in its basic form.

73,
Wayne
N6KR

[Keith-K5ENS]

I know many a contest station that would and have spent $1000's for an extra
3db. There must to a reason.

Keith, K5ENS

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[Alan Bloom]

World-class contest stations are a different animal. If the extra 3 dB
adds an extra 0.1% to the contact total, that could easily be the
difference between winning and coming in number 2.

But for the average ham a 0.1% increase in your total contacts is such a
small difference that you would never even notice it.

Alan N1AL

[Bruce Beford]

Agreed. And at that level of competition, operator skill makes a much bigger
difference in score than 3 dB of power. Sadly, many who try to compete at
that level just don't seem to understand this.

Bruce, N1RX

> World-class contest stations are a different animal. If the extra 3 dB
> adds an extra 0.1% to the contact total, that could easily be the
> difference between winning and coming in number 2.

> But for the average ham a 0.1% increase in your total contacts is such a
> small difference that you would never even notice it.

> Alan N1AL


On Mon, 2011-06-06 at 11:14 -0700, Keith-K5ENS wrote:
> I know many a contest station that would and have spent $1000's for an
extra
> 3db. There must to a reason.
>
> Keith, K5ENS
>

______________________________________________________________

[Byron Servies]

The KX3 (K3 Extremely Portable is how I think of it) does have 3db of
additional power compared to the intended market: 5w QRP portable.

The portable QRP market is where Elecrafts' roots lie, after all, so
it should be no surprise that the KX3 is aimed at that target. Having
an optional external 100w amplifier makes it practical for field day
and other mobile operations, too, and perhaps some really constrained
home stations where even a small K3 will not fit.

On Mon, Jun 6, 2011 at 11:14 AM, Keith-K5ENS <Ke...@nelasat.com> wrote:
> I know many a contest station that would and have spent $1000's for an extra
> 3db.  There must to a reason.

73, Byron N6NUL
----
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org

[drewko]

There is another way of looking at it-- how many additional contacts
would potentially be available by utilizing an increase of just 3db?

I don't know the answer but there is a somewhat analogous situation in
astronomy having to do with the brightness of stars. They are also
measured on a logarithmic scale, called magnitude, each magnitude
representing twice or half the brightness level of the following or
preceding magnitude. A difference of one magnitude does not appear
very large to the eye, yet the ability to see one magnitude fainter
can yield three times as many stars. I imagine some similar effect
might pertain to radio waves.

BTW, I'm not asking for more power in the KX3; would be quite content
with 10 watts, same as my K3.

73,
Drew
AF2Z

[Pete Smith]

It is pretty widely accepted in contesting that an improvement in
*either* receive or transmit capability of 1 dB will yield a useful
increase in the number of QSOs over a 48-hour contest, even if it has an
indiscernible effect on 99.5 percent of your contacts.

73, Pete N4ZR

The World Contest Station Database, updated daily at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com,
spots at telnet.reversebeacon.net, port 7000

[Rose]

There's a saying among VHF / UHF'ers in reference
to coax and connector losses that every .5db counts.

73! Ken - K0PP

[Gary Gregory]

The 10W output of the KX3 can be increased to 100W via the amplifier for
mobile and portable operation. To increase the output from 10 to say 30W
will greatly restrict the battery life and I don't see any real advantage.

Either the KX3 is a QRP radio or not....adding another 10-20W available on
battery power makes it less attractive to me.

In VK we seem to be able to work the world on 400W and yet there are those
in VK who want a change to 1Kw....will it allow us to work more
stations?.....maybe...maybe not. Perhaps we are just too lazy to make a few
extra calls and think it is good to be told we are 20db over S9 instead of
5/9 plus....

I have worked a lot of stations running QRP and a dipole antenna and the
last was from NY to VK using 5W, I went QRP also and we worked for 10
minutes or so. It was fun for me to work him also.

My 2 cents worth...keep the change!

73's
Gary

--

VK4FD - Motorhome Mobile
Elecraft Equipment
K3 #679, KPA-500 #018
Living the dream!!!

[Jim Lowman]

I can understand the advantage of even 1 db to a serious contester over
the period
of a lengthy contest but for my needs, and keeping in mind maximizing
battery power,
the 10w of the KX3, and even 5w, is fine. I have other rigs that are
capable of 100w
in the shack, but now that I'm retired I plan to do a lot of portable
work, especially
since summer is on the way in the northern hemisphere. Fortunately,
here in soCal
it's nice enough to do portable operations most of the year, without the
need for
much more than a jacket in winter.

I guess that getting older tends to mellow one out. In the past I was
an extremely
serious contester, especially for Field Day, but now I'll be content to
improve on
last year's score in a given contest. Sure, in a stocked pond you're
pretty much
guaranteed to catch fish, but where's the fun in that?

Being DX in VK-land gives you a bit of an advantage. I'd say that 400w
is more
than enough power, but I'm sure that there are those of us here in the
US who
would use more power than 1500w it it were allowed.

72/73 de Jim - AD6CW

On 6/7/2011 8:40 AM, Gary Gregory wrote:
> The 10W output of the KX3 can be increased to 100W via the amplifier for
> mobile and portable operation. To increase the output from 10 to say 30W
> will greatly restrict the battery life and I don't see any real advantage.
>
> Either the KX3 is a QRP radio or not....adding another 10-20W available on
> battery power makes it less attractive to me.
>
> In VK we seem to be able to work the world on 400W and yet there are those
> in VK who want a change to 1Kw....will it allow us to work more
> stations?.....maybe...maybe not. Perhaps we are just too lazy to make a few
> extra calls and think it is good to be told we are 20db over S9 instead of
> 5/9 plus....
>
> I have worked a lot of stations running QRP and a dipole antenna and the
> last was from NY to VK using 5W, I went QRP also and we worked for 10
> minutes or so. It was fun for me to work him also.
>
> My 2 cents worth...keep the change!
>
> 73's
> Gary
>

[Ron D'Eau Claire]

True at UHF/VHF. The world if HF is quite a different place for most of us.

If your purpose is to find that sweet second or two where a very brief
exchange might be confirmed on HF, a difference of a few dB might count, as
Pete notes.

But for communications involving a lengthy exchange of information such as
in a rag chew, typical QSB on HF means one must have a lot more than a dB or
two of "headroom" above the minimum readable signal to be successful in most
situations.

I'm one of the great many Hams who is not a contester nor do I focus on
brief 5NN exchanges with a DX station, so I never expect anything less than
a 6 dB change - an S-unit - to be noticeable *over time* on HF. I start
getting really interested if I find the opportunity to make a 10 dB
difference.

That said, many places where one might throw away a dB or so adds up. It's
the difference between managing your station's system gain (or loss)
'budget' and deciding whether any single change is worth making.

73,

Ron AC7AC

[dave]

To try to put some meaningful numbers on the value of a few extra dB I
looked at some recent contest scores. Actually not at the scores
themselves but the number of Q's made. There is of course wide
variability in this. A lot appears to depend on whether it is
primarily a NA contest or international. But it might give some clue
about the value of additional power.

To hopefully remove some of the many variables, I looked only at the
top few stations. The assumption is that these guys have good stations
with good antennas in good locations. Have to believe that they put in
nearly equal effort, i.e. approx the same number of hours. Implicit
also is the assumption they are approx equally good operators.

In the 2010 ARRL 160m contest these power levels made this many Q's:

1st 2nd
QRP 805 718
LP 1078 1038
HP 1989 1776

In 2010, with the low sunspot numbers, this was basically a NA
contest. Not much in the way of DX activity.

Assuming other things are equal - which may or may not be the case -
it looks like 13 dB (5w to 100w) is worth about a 33% increase in Q's.
And 25 dB (5w to 1500w) will yield somewhat more than double.

In the 2010 ARRL Sweepstakes:

1st 2nd
QRP 982 835
LP 1257 1244
HP 1466 1453

This is a NA contest.

Here 13 dB was again about a 33% increase and 25 dB something less
than double. Indeed having a KW was not much help here.

But if we look at longer distance and check the 2010 ARRL
International DX contest (looking at stations in NA, not EU or other
continents):

1st 2nd
QRP 1021 912
LP 2872 2738
HP 4362 4474

Here 13 dB gives nearly 3x as many contacts. 25 dB gives about 4.5x as
many.

It looks like a few extra dB may be valuable on longer paths, but not
worth much within NA, which is about what you would expect.

This does not address the question of what 3 dB is worth. A little
hard to figure. Within NA 13 dB yields about 33%. So what would 3 dB
yield? Dunno, but my guess is not much.

How much is 3 dB worth on longer paths? Again hard to say but there is
probably some threshold, or minimum required, to work the DX. Is that
threshold 3 dB, i.e. 10w? Honestly probably not. Somewhere between 5w
and 100w, but unknown.

Maybe some enterprising souls could get together, a few run 5w, a few
run 10w, a few 25w, and a few 50w. Compare results when it is over.

73 de dave
ab9ca/4

[David Gilbert]

It all depends how close the desired signal is to the noise level.
Check out

http://www.ab7e.com/weak_signal/mdd.html

However, the original argument that 20 watts is better than 10 watts
seems pretty silly to me since you can carry that flag all the way up to
power levels that create their own ionosphere. We can all gain >FAR<
more ERP from wisely choosing/building a better portable antenna
compared to a backpack whip than we would from doubling the power out of
the rig.

73,
Dave AB7E

[Dave KK7SS]

IMHO it's the need to shout louder than the other guys in a pile-up!
I've been DX and heard the roar!!

>> I know many a contest station that would and have spent $1000's
>> for an extra 3db. There must to a reason.

--
Dave G KK7SS
DN06ig Richland, WA

'59 Morris Minor 1000
'65 Sprite - in process
'76 Midget - shared with my #4 son.
'06 Honda Civic Hybrid

[R. Kevin Stover]

Aye, and there's the rub of the matter.

I just spent 20 minutes surfing the web looking for the definition of
"QRP". Of the half dozen or so well known sites I visited, in the
US and abroad, the definition of QRP is 5 Watts CW and 10W SSB MAX. Not
20 if you got it, not 30 if running on an outboard PS, etc...

The simple fact is you can't support more than 10W out and keep battery
life in the realm of reality. You can't just put a bigger battery in it
and keep the form factor.

I really don't see what the problem is.
If you're using it as a trail radio weight and battery life mean
everything. If your a dedicated QRPer 10W is the limit. If you want to
use the radio mobile buy the amp. If you want to run mobile with ridiculously inefficient antennas, and QRP your a masochist
and need to be ignored. ;-)

If none of the above fits buy a K3 and be well.

On Wed, 8 Jun 2011 01:40:27 +1000
Gary Gregory <gary...@gmail.com> wrote:

> Either the KX3 is a QRP radio or not....adding another 10-20W
> available on battery power makes it less attractive to me.

--
R. Kevin Stover
AC0H

[Eric Swartz - WA6HHQ, Elecraft]

Let's end the power/QRP discussion.

73, Eric
List moderator

[Peter Wollan]

I've seen this kind of calculation before, and for some events, like
Field Day, it's clear that QRP can compete on scores quite
effectively. But that's using CW, and probably also PSK31. Dave's
numbers suggest that it might also be different for North American
contacts (for those of us within North America), compared to crossing
an ocean. But for me, SSB is much less effective -- I've too often
been able to copy people easily, and have them not react to my 10
watts at all.

But to me, that means use CW for contests, and if I try SSB I
shouldn't worry about not getting through. Meanwhile, I'll work on
better antennas, and be more persistent so that when the propagation
gods smile I'll be there.

Still, I may get this 100-watt thing when it comes out, or at least
within a year or two.

Peter W0LLN

On Tue, Jun 7, 2011 at 12:20 PM, dave <ho13...@gmail.com> wrote:
>
> To try to put some meaningful numbers on the value of a few extra dB I
> looked at some recent contest scores.

[Alan Bloom]

Interesting analysis Dave. Assuming everything is logarithmic, a 33%
increase in contacts for a 13 db power increase implies 7% more contacts
for 3 dB more power:

10^[(3/13) * log(1.33)] = 1.07

And 100% more contacts for a 25 dB power increase implies 8.7% per 3 dB:

10^[(3/25) * log (2)] = 1.087

However, I think that overstates the advantage of higher power. The
higher-power stations also probably had better antennas and other
equipment as well. But it does put a useful upper bound on the number.

In a non-competitive situation I would expect the difference to be even
less.

Alan N1AL

[Jan Erik Holm]

Well when I was in to EME on 2m I was hunting for
every .1 dB I could find.

/Jim SM2EKM
--------------

[Jim Brown]

On 6/7/2011 6:14 AM, Pete Smith wrote:
> It is pretty widely accepted in contesting that an improvement in
> *either* receive or transmit capability of 1 dB will yield a useful
> increase in the number of QSOs over a 48-hour contest, even if it has an
> indiscernible effect on 99.5 percent of your contacts.

On the basis of statistical analysis of scores, one of the guys in our
contest club came up with the number that 1 dB is good for a 2.6%
increase in a Sweepstakes score. 3dB would be good for 1.026 x 1.026 x
1.026 = 8%, 7dB would be good for 20%. The advantage can show up in
several ways -- your ability to get over the other guy's noise, to hold
a frequency, to get answered sooner when there are multiple callers, to
pick up a rare multiplier.

It doesn't matter how you get the advantage -- better antenna, low loss
in the feedline, or power amp, and as you noted, it also helps to be
able to hear better, whether by reducing RX noise, using dedicated RX
antennas, choking noise sources, choking feedlines to reduce noise
pickup, exploding the chargers for power tools and mobility scooters,
etc. :)

73, Jim K9YC

[Eric Swartz - WA6HHQ, Elecraft]

These threads were closed earlier this morning. Please take the
discussion off-list.

73,
Eric
List moderator (Really! )

On 6/7/2011 11:26 AM, Jim Brown wrote:
> On 6/7/2011 6:14 AM, Pete Smith wrote:
>> It is pretty widely accepted in contesting that an improvement in
>> *either* receive or transmit capability of 1 dB will yield a useful
>> increase in the number of QSOs over a 48-hour contest, even if it has an
>> indiscernible effect on 99.5 percent of your contacts.

> On the basis of statistical analysis of scores, .html