Chris Johnson elecr...@ozy.us wrote:
1) Is phase noise the measurement of the instability of an DDS?
That's one contributing factor. But the DDS signal drives a mixer, and the
other input to the mixer may be the larger source of phase noise in transmit
mode.
2) How does this impact TX
Thanks Wayne and Alan, for that super detailed info. The radio side of things
are still very magical to me! I'm a software guy, not a hardware guy. :)
I don't own a K3, but two KX3's for my knob radios. I use a Flex 6700 and
6300 for home use. I'm assuming the 6700's -147 dBc@10kHz,
Pardon my ignorance, but can I get some clarification on a few things?
1) Is phase noise the measurement of the instability of an DDS? If so, does
this mean a cheap part is being used? Does a GPSDO or a OCXO reduce phase
noise?
2) How does this impact TX only, and why does it create such
On 06/08/2014 09:21 PM, Chris Johnson wrote:
Pardon my ignorance, but can I get some clarification on a few
things?
1) Is phase noise the measurement of the instability of an DDS?
Yes. To oversimplify a bit, if the frequency/phase of the oscillator is
varying back and forth at a 20 kHz
On 02/04/2014 16:19, Wayne Burdick wrote:
The K3 and KX3 both have very low phase noise. It can vary a bit from band to
band and from one unit to the next. Sherwood measured one example of each, but
typically both measure right around -140 dBc/Hz at 20 kHz.
When we designed the K3, we were
On Jun 6, 2014, at 4:33 AM, Stewart Bryant stew...@g3ysx.org.uk wrote:
My understanding is that the KX3 is worse than the K3 on TX
phase noise sidebands. Is that what you would expect?
No. Both have very, very low transmitted phase noise.
73,
Wayne
N6KR
http://www.sherweng.com/table.html
The LO Noise (dBc/Hz):
144 KX3
138 K3
130 R390A
121 FT-1000D
117 ICOM 720A
I'm wondering why the KX3 Lo noise is so much better than the K3.
The R390A value strange since the first local oscillator is a quartz
crystal.
I've owned a Icom 720A and own a
Can anyone really hear the difference between any of the top rated rigs
(Sherwood list) in the real world (not in a lab)?
Bill K-Line
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help:
Yes, when your neighbours FTDX5000 at 300 metres away spews noise over
three adjacent bands. Compounded by idling the FT and making up the
power with an amp which only makes the problem worse by another 15dB.
Adjacent bands are clear when a Dunestar BPF filter inserted between his
FT and amp.
The FTdx5000 does that in RX mode? Nasty! :-)
Phil W7OX
On 4/2/14, 7:17 AM, Mike Harris wrote:
Yes, when your neighbours FTDX5000 at 300 metres
away spews noise over three adjacent bands.
Compounded by idling the FT and making up the
power with an amp which only makes the problem
worse by
It's easy to demonstrate this. My real-world setting is Field Day,
and the example is actually what my team experienced.
Take four rigs in a Field Day setting, within 100 yards of each other.
Make sure one of them is a K3, and the others are Y/K/I types.
On the same band, any of the Y/K/I rigs
The K3 and KX3 both have very low phase noise. It can vary a bit from band to
band and from one unit to the next. Sherwood measured one example of each, but
typically both measure right around -140 dBc/Hz at 20 kHz.
When we designed the K3, we were trying to improve on the phase noise numbers
Not that I know of, but when it transmits, it wipes out nearby receivers.
73,
Don W3FPR
On 4/2/2014 10:55 AM, Phil Wheeler wrote:
The FTdx5000 does that in RX mode? Nasty! :-)
__
Elecraft mailing list
Home:
That is why I try to encourage the local Field Day group to use only
Elecraft gear. Even though we do not typically operate more than one
transceiver on a single band, the YKI types can cause problems on other
harmonically related bands. We used to have a Yaesu FT-900 on SSB, and
it caused
Like Don said, not in receive, but in transmit, driving an Alpha 9500 to the
full 1500 out, a close neighbor (about 5 blocks away) was noticeable on my K3
within 5-10 KHz of his transmit frequency. That said, the FTdx5000 was MUCH
cleaner than the FT-1000MP he had prior to obtaining the 5000.
I agree, Matt, and every rig I use now is an
Elecraft (K3, KX3, K2, ...).
But the question the OP posed was K3 vs. KX3: I'm
wondering why the KX3 Lo noise is so much better
than the K3
73, Phil W7OX
On 4/2/14, 8:06 AM, Matt Zilmer wrote:
It's easy to demonstrate this. My real-world
Message -
Sent: Wednesday, April 02, 2014 3:38 PM
Subject: Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Like Don said, not in receive, but in transmit, driving an Alpha 9500 to
the full 1500 out, a close neighbor (about 5 blocks away) was noticeable
on my K3 within 5-10
is KX3 phase noise so much less than the K3 ?
Like Don said, not in receive, but in transmit, driving an Alpha 9500 to
the full 1500 out, a close neighbor (about 5 blocks away) was noticeable on
my K3 within 5-10 KHz of his transmit frequency. That said, the FTdx5000
was MUCH cleaner than
' was shown to be quite poor with it's radiated signals even on
receive. Or, did I read the lab reports incorrectly?
Dave (G0DJA)
- Original Message - Sent: Wednesday, April 02, 2014 3:38 PM
Subject: Re: [Elecraft] Why is KX3 phase noise so much less than the K3 ?
Like Don said
I think Bill's question spoke to phase-noise on receive, not transmit.
I'm fairly certain all of us are aware of the transmit problem from some
transceivers.
To Bill's question, I'd say No, I cannot hear the difference when the
measured noise is in the -135to -140 range, other noise sources
That's a silly comment. Last time I checked, people nearby a trashy
transmitter have to listen as well. They didn't create no smoking rules
in public places to protect smokers from their own smoke.
Dave AB7E
On 4/2/2014 7:55 AM, Phil Wheeler wrote:
The FTdx5000 does that in RX mode?
The KX3 isn't perfect. During SOTA activations, Gary W5ODS and I each use a
KX3, with the roofing filter option. He with an end-fed wire, and me
usually with an AlexLoop. I can often hear his code (a pink noise sound)
even when he is in a band higher in frequency, as well as when I am in a
higher
Better hope there's no Flex's transmitting too close to your location
either.
Chas
, Bill W2BLC wrote:
Can anyone really hear the difference between any of the top rated rigs
(Sherwood list) in the real world (not in a lab)?
Bill K-Line
Did you turn on RX ISO? That is an isolation preamp that reduces LO leakage
during receive. That sounds like a different problem that you are hearing, but
it is recommended when you are operating a KX3 near other rigs.
wunder
K6WRU
On Apr 2, 2014, at 9:40 AM, Chip Stratton
Why does the ARRL lab test show the KX3 TX phase noise as about -124
dBc/Hz (Fig 5 of their report) and Sherwood show this as -144 dBc/Hz,
both at 10 kHz spacing? That is a huge difference.
The ARRL report shows that the KX3 never goes below about -135 dBc/Hz,
even 1 MHz away.
Is there an
Thank you Fred K6DGW - you are correct - I was referring to phase noise
on RX.
So far as noise from XMIT on other rigs, I have no experience. I live in
a rural area and have an extremely low ambient noise level. A noisy RX
exposes itself immediately.
As I recall, the quietest rig I ever had
No! And I have them all. My TenTec Eagle hears as good as my FT5K and our
beloved K3 and KX3
George, W6GF
On Wednesday, April 2, 2014 10:02 AM, Charlie T, K3ICH pin...@erols.com
wrote:
Better hope there's no Flex's transmitting too close to your location
either.
Chas
, Bill W2BLC
First of all, the ARRL is showing (as you note) transmitted phase noise. Rob
lists receiver phase noise. Ideally, they should be the same, but are they really?
Second, there can be significant test sample variation and variation between
phase noise test sets.*
Third, phase noise
The Sherwood list ranking isn’t about how well radios “hear” in general. Under
the right conditions, most of the radios on the last (and a whole lot of radios
that aren’t) can hear everything our most beloved radio (whatever that is)
hears. The list is ranked in order of decreasing narrow
Larry,
Not knowing much about the R390A, but Sherwood ranks it very low in
phase noise. Xtal oscillators are easier to design with low phase
noise than synthesizers. This is primarily why later radios have a
problem with noise as most use synthesized LO's, and why the old
radios with xtal
Our field day has been all Elecraft for the last couple of years
with mostly K3s and a scattering of K2s. Last year we ran 9A QRP
battery + GOTA (+ satellite). We had antennas which allowed us
to run CW, SSB and Digital on the same band and had no
significant mutual interference. (We work hard
On 4/2/2014 1:42 PM, Bill Frantz wrote:
The bigest interference problem was phase noise from another club's
operation about 1/2 mile away. They were running 100 watts with I-K-Y
gear.
My biggest problem is from a retired east coast lawyer 8 miles from me
who runs an ICOM 7600 to a solid
I'll try to summarize:
lo phase noise is good:
it reduces unintended radiation from transmitters.
it reduces reciprocal mixing on receiving.
surveys during contests are very revealing.
The KX3 and K3 have similar very low amounts of phase noise.
Unless I want to make a career of it I should
33 matches
Mail list logo
