Hi,
Frankly I'd be skeptical about all those numbers. They are way better than
those measured by ARRL and Sherwood and some are a physical impossibility.
The thermal noise floor (kTB) at 400Hz is -148dBm so any number at or below
this is physically impossible. To me it looks like all your numbers
Jay,
As promised, I went ahead and measured my K3 sensitivity. It is really
a K3S-. It doesn't have the USB I/O board but has the rest of the K3 ->
K3S upgrades. There general coverage bandpass filter board is installed.
Here are the results on 20-6M.
The sensitivities are as expected and
I assembled my K3/100 with the second receiver in December of 2010. The
weak signal performance was much better than my original IC-756 rig. I did
not install the automatic antenna tuner. I have continued to download the
software changes since then.
Two years ago I installed the general cove
Jan,
Check your antenna selections - ANT1 vs. ANT2 or RX ANT on vs. off.
The amount of attenuation you hear is about the same as the isolation
between the antenna selection in the K3 (40 to 50 dB).
The antenna selection is on a per band basis.
73,
Don W3FPR
On 3/15/2015 8:41 PM, Jan wrote:
I
Joe, Bill, and Buzz:
Check RX ANT selection on 80 Meters? Of course I che Never
mind. Thank the three of you for fixing the problem that has plagued me
for two months.
73,
Jan, KX2A
__
Elecraft mailing list
Home: http://m
> Can someone clue me as to how to chase this down?
The easiest, most accurate way is to actually measure sensitivity using
an XG-2 or XG-3 signal generator. You can check the S-meter on 80 and
160 compared to 20 meters and calculate the MDS on each band following
the method in the signal gener
I have a K3 that works fine on all bands except 75/80 and 160. I have
a backup rig, an IC-730 from the 1980's, that has 75/80 but not 160. I
did an A/B with the two rigs on 80 meters, and both the S-meter and my
ears tell me that signals are 5-7 S-units weaker on the the K3. S/N is
clearly
essage -
From: "Scott Manthe"
To:
Sent: Wednesday, November 14, 2012 12:02 AM
Subject: Re: [Elecraft] K3 sensitivity below 40 meters
> The real problem is that N0CE made his comment about "resonant" antennas
> to protect the feelings of his insecure buddies, at l
The real problem is that N0CE made his comment about "resonant" antennas
to protect the feelings of his insecure buddies, at least one of whom
reads this list, so they wouldn't be offended by the fact that his K3
hears better on 40 meters than the "good equipment" (read: high dollar
rigs) that
appropriate level of other receivers?"
>
> Now I know why people reply off line.
>
> Rich, n0ce
>
> - Original Message - From: "David Gilbert"
>
> To:
> Sent: Tuesday, November 13, 2012 6:12 PM
> Subject: Re: [Elecraft] K3 sensitivity below 40 me
To:
Sent: Tuesday, November 13, 2012 6:12 PM
Subject: Re: [Elecraft] K3 sensitivity below 40 meters
>
> Even that misses the point, I'm afraid. Remember that the original
> comment referred to the receive capability of an antenna.
>
> The only thing that matching or &qu
Even that misses the point, I'm afraid. Remember that the original
comment referred to the receive capability of an antenna.
The only thing that matching or "tuning to resonance" does is improve
the amplitude of the combined signal and noise feeding the rig ... it
does not improve the signal
Yes, I agree.
Given a bit of "benefit of doubt", I would think the poster would have
better said, an antenna "tuned to resonance" rather than a resonant antenna.
Many very good antennas are not inherently resonant, but resonance (and
therefore good power transfer) is achieved by means of some ki
Particularly as far as receiving goes, that's a totally erroneous
statement that has been dispelled many, many times. There is nothing
magical or beneficial about a resonant antenna short of the fact that it
sometimes makes it easier to match. Check out how (and how well) a
Beverage antenna
>
> In summary, even a good radio needs a resonant antenna.
>
Nah.
Rick K2XT
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Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mm
On Tue, Nov 13, 2012 at 1:13 PM, Richard Fjeld wrote:
> ...even a good radio needs a resonant antenna.
>
=
It's true that reception is often better if the antenna is matched, but
this doesn't mean that the antenna has to be resonant. An antenna's
resonance or non-resonance does not
Wilhelm"
To:
Sent: Tuesday, November 13, 2012 12:05 PM
Subject: Re: [Elecraft] K3 sensitivity below 40 meters
> The K3 S-meter can be calibrated with either the preamp on or off. I run
> with SMTR MD set to ABS, and I calibrate the S-meter with the preamp
> off be
nce I got the P3 and can see the signals beside my
passband that I am not hearing, I have been amazed.
In summary, even a good radio needs a resonant antenna.
Rich, n0ce
- Original Message -
From: "Richard Fjeld"
To:
Cc: "elecraft posting"
Sent: Tuesday, Novemb
The K3 S-meter can be calibrated with either the preamp on or off. I run
with SMTR MD set to ABS, and I calibrate the S-meter with the preamp
off because of that.
73,
Don W3FPR
On 11/13/2012 12:39 PM, Richard Fjeld wrote:
> I think it may be due to my final comment, but first, some info.
>
> M
Preamp on K3 is 11 dB, not 20. The range, using preamp or ATT, is 20 dB.
I always run the attenuator on 160 and 80 TX antennas, and the preamp on
some of my listening antennas.
73, Guy
On Tue, Nov 13, 2012 at 9:39 AM, wrote:
>
> Conventional wisdom historically has been that a receiver preamp
vember 13, 2012 8:39 AM
Subject: [Elecraft] K3 sensitivity below 40 meters
>
> Conventional wisdom historically has been that a receiver preamp is not
> used at 40 meters and below primarily because it is not needed, indeed
> it would typically degrade receiver performance. So why is
craft@mailman.qth.net
Subject: [Elecraft] K3 sensitivity below 40 meters
Conventional wisdom historically has been that a receiver preamp is not used
at 40 meters and below primarily because it is not needed, indeed it would
typically degrade receiver performance. So why is it necessary to engage the
20 dB p
The original question was *NOT* about the K3, but the KX3 which is
different than the K3 due to a different design architecture.
73,
Don W3FPR
On 11/13/2012 9:39 AM, k...@charter.net wrote:
> Conventional wisdom historically has been that a receiver preamp is not
> used at 40 meters and below pr
Conventional wisdom historically has been that a receiver preamp is not
used at 40 meters and below primarily because it is not needed, indeed
it would typically degrade receiver performance. So why is it necessary
to engage the 20 dB preamp on the K3 to get it to hear an S9 signal at
the appr
Hi Dave,
Our PR10 preamp module has an MDS in the -143 to -144 range on 10
meters. It doesn't get much better than that on any ham transceiver.
(Using it with a K3 requires a KXV3 or KXV3A module as well, since it
gets patched through the RX ANT IN/OUT jacks.)
The stock MDS of the K3 on 10
During the CQWW RTTY Contest this past weekend, I got the feeling
that the K3 receiver could have used some additional RF gain. I
was using the 250 Hz filter with +4 dB of I.F. gain dialed in.
Switching the preamp on and off produced just a barely
perceptible change in the background noise. I
OOps. I had the antenna connected via MFJ-1026, so turning on dummy still let
the reference antenna in.
After switching MFJ-1026 off, turning from dummy load to 2 ell quad
increases the noise level by about 5 db. Enough at this QTH.
Ignacy
--
View this message in context:
http://elecraft.365
Changing from dummy load to 2-el quad increases the noise marginally; about
1-2 db on P3. Definitely not enough gain.
I am not sure whether anything short of increased gain in RF amp would work.
Perhaps one can modify the 6m external preamp to work on 10m also.
The low noise made me happy. It m
Are you confusing "sensitivity" with "overall gain"?
Typically the higher frequency bands are much, much quieter than the lower
frequency bands but a 0.1 uV signal will produce the same volume from the
speaker on 10 (or 6) meters as it will on 80 meters (if you can hear it in
the band noise :-)
...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] En nombre de Barry N1EU
Enviado el: Lunes, 01 de Noviembre de 2010 03:42 p.m.
Para: elecraft@mailman.qth.net
Asunto: Re: [Elecraft] K3 sensitivity on 10M
Dave Hachadorian wrote:
>
> when I got to 10 meters, I got the distinct f
Dave Hachadorian wrote:
>
> when I got to 10 meters, I got the distinct feeling that I wasn't hearing
> enough
> band noise.
>
I've had the same experience and have commented in the past that I thought
the K3 needs to dial in a little extra gain on 10M. I've resorted to
cranking CONFIG Filter
I've had a pair of K3's for a couple of years now, but this past
weekend in the CQWW SSB was their first serious test on 10
meters. I used the 1.8 filter all weekend, but when I got to 10
meters, I got the distinct feeling that I wasn't hearing enough
band noise. I didn't have the time or equipmen
DOUGLAS ZWIEBEL'" ; "'Elecraft Reflector'"
Sent: Monday, December 15, 2008 11:14 AM
Subject: RE: [Elecraft] K3 sensitivity + preamp: looking for wisdom
Keith is quite right.
All receivers generate internal noise in their amplifiers. The goal is to
make sure this int
7:15
To: Elecraft Reflector
Subject: [Elecraft] K3 sensitivity + preamp: looking for wisdom
Hi...
The following request for information is not specific to the K3 (or
even to Elecraft). Please craft your response to be generic.
Despite being an active ham/contester for over 40 continuous years
(
Hi Ron,
This was an -excellent- layman's language explanation
about the functioning of front ends and pre-amps. Tell
the boss you need an "atta-boy" and a raise!
Merry Christmas!
Ken Kopp - K0PP
elecraftcov...@rfwave.net
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Elecraft mailing list
Keith is quite right.
All receivers generate internal noise in their amplifiers. The goal is to
make sure this internal noise does not compete with the received signal so
the only thing that limits the ability to hear weak signals is the
unavoidable atmospheric or "antenna noise".
Of course, the
DOUGLAS ZWIEBEL wrote:
>
> Hi...
>
> The following request for information is not specific to the K3 (or
> even to Elecraft). Please craft your response to be generic.
>
> Despite being an active ham/contester for over 40 continuous years
> (but not being an ee), I just do not understand how
sometimes, harmful at others.
I hope this helps.
Willis 'Cookie' Cooke
K5EWJ
--- On Mon, 12/15/08, DOUGLAS ZWIEBEL wrote:
> From: DOUGLAS ZWIEBEL
> Subject: [Elecraft] K3 sensitivity + preamp: looking for wisdom
> To: "Elecraft Reflector"
> Date: Monday, D
craft-boun...@mailman.qth.net] On Behalf Of DOUGLAS ZWIEBEL
Sent: Monday, December 15, 2008 11:15 AM
To: Elecraft Reflector
Subject: [Elecraft] K3 sensitivity + preamp: looking for wisdom
Hi...
The following request for information is not specific to the K3 (or even
to Elecraft). Please craft your resp
Hi...
The following request for information is not specific to the K3 (or
even to Elecraft). Please craft your response to be generic.
Despite being an active ham/contester for over 40 continuous years
(but not being an ee), I just do not understand how a "preamp" works.
It is not a "smart" devi
I am using the Elecraft XG1 signal generator to calibrate my K3's S meter. I
followed the instructions (pre-amp on, filters broad, etc) but the best I do
is calibrate to S-7 for 50mv. When I turn the XG1 down to 1mv the S-meter
reads 1 instead of 2-3 S units. I noticed that I had to add about 4
Seems I've found the problem but I should wait till monday to try to fix it.
As suggested by Gary at Elecraft I've checked some components and I found Q9
on the KPA3 board broken.
I think Q9 is both responsible of the power instability I've found and the
drop in a S point when KPA3 was enabled.
I'
max iw0gxy wrote:
Hi all,
I connected the XG2 signal generator to my K3 and I've injected 50microV
into the antenna. I have the standard S9 but when I rise the power to 13 and
up signal drop down to S8. If I turn the knob to 12W or less signal turn
back to S9.
I've noted this behavior on signal
Hi all,
I connected the XG2 signal generator to my K3 and I've injected 50microV
into the antenna. I have the standard S9 but when I rise the power to 13 and
up signal drop down to S8. If I turn the knob to 12W or less signal turn
back to S9.
I've noted this behavior on signals on air but to be
Question from today at local hamfest:
On the webpage:
Is it possible to phase lock the two K3 receivers?
They run off the same reference oscillator and are phase locked.
Do you loose sensitivity on either receiver doing this way? Not sure I
understood his question, but is volume level effecte
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