Rig ergonomics and performance comparison


Rick <mrfarm@...>
 

Assuming you like the ergonomics of a given rig, the one parameter that I look at the most is the close-in IMD3 (Third Order Intermodulation Distortion).

Currently the Ten Tec Orion series is about the best overall, but this is only for the ham band only receiver. Some don't like the ergonomics of the rig but others prefer it, so part of the selection process has to be based on what you like (assuming you try it out first and as far as I know only Ten Tec has a month trial period with return privileges if you are not satisfied for any reason). IMD3 for 20/5/2 kHz spacing is 92/96/95 and the TOI (Third Order Intercept) using the ARRL method of calculation is +20/+20/+21

The FT-2000 looks physically impressive but the IMD3 and TOI seem shockingly low for a rig in this price class. Curiously, the ARRL Review does not comment on how poor it is considering the IMD3 of 95/85/64 and TOI of +16/+11/-22

The ICOM Pro Series can no longer compete with some of the newer transceivers in the $2000 - $4000 price class in terms of IMD3 with 20 and 5 kHz numbers like 103/77. I would expect the 2 kHz IMD3 to be low, perhaps in line with the FT-2000? The TOI for 5 kHz is -18 dB. The Pro Series may be preferred by some for the ergonomics and of course nothing can thus far touch the spectrum display for one built-in to the rig.

Just for the record, I have a Pro 2 and find it to be quite good for casual use although a bit large for portable use and heavy on the receive power consumption. I also have a Ten Tec Argonaut V with some of the poorest IMD3 and TOI numbers of any modern rig, but it is fun to use for casual QRP and near QRP power levels, but it has some very amateurish design issues.

The Ten Tec Omni VII is the one rig that seems to have pretty good numbers for an under $3000 general coverage receiver at 91/84/82 and TOI of +11/+6.5/+6.5 although the K3 will be better in that category.

My rig preferences are somewhat different than the average ham as I prefer a rig with nominal 12 vdc power and keeping receive draw reasonable, portability and lightweight for emergency use, ease of interfacing for digital modes, solid performance, and excellent spectrum display. The K3 is not going to be able to compete with that last item but it sure looks good for the others. Just sending in an ICOM 756 Pro 2 to the repair shop costs around $50 ... just for the shipping! If you can repair most everything yourself (swapping out boards and replacing mechanical parts), the value is increased even more for those of us who do a fair amount of servicing.

73,

Rick, KV9U

Jon Pellant wrote:

I ordered a K3 on the heels of field day. I have been wanting to get a 'real' HF radio for a while as I currently only use a Yaseu FT-857D. I had been looking at the TenTec Orion, FT-2000, and ICOM 756ProIII. Durring field day, I got to use the ProIII, FT-2000, and K2. I was very impressed with the K2's bang for the buck and blindly ordered a K3 on faith.



Jon Pellant <w1jp@...>
 

Thanks for your feedback. I trust my gut instincts sometimes and my gut
made me blindly order a K3. I trust I won't be dissappointed.

Jon
w1jp

--- In Elecraft_K3@yahoogroups.com, Rick <mrfarm@...> wrote:

Assuming you like the ergonomics of a given rig, the one parameter
that
I look at the most is the close-in IMD3 (Third Order Intermodulation
Distortion).

Currently <snip/>


bill_w4zv <w0zv@...>
 

--- In Elecraft_K3@yahoogroups.com, Rick <mrfarm@...> wrote:

My rig preferences <SNIP> and excellent spectrum
display. The K3 is not going to be able to compete with that last item
Oh yes it will. With its wideband buffered 8.125 MHz IF output, a $15
Softrock kit, free Rocky software, a 1 GHz Pentium PC and a decent
sound card, the display will run circles around the Pro2/3 band scope.

http://www.dxatlas.com/rocky/

73, Bill


bigfork04
 

--- In Elecraft_K3@yahoogroups.com, Rick <mrfarm@...> wrote:

Assuming you like the ergonomics of a given rig, the one parameter that
I look at the most is the close-in IMD3 (Third Order Intermodulation
Distortion).

Currently the Ten Tec Orion series is about the best overall, but this
is only for the ham band only receiver. Some don't like the ergonomics
of the rig but others prefer it, so part of the selection process
has to
be based on what you like (assuming you try it out first and as far
as I
know only Ten Tec has a month trial period with return privileges if
you
are not satisfied for any reason). IMD3 for 20/5/2 kHz spacing is
92/96/95 and the TOI (Third Order Intercept) using the ARRL method of
calculation is +20/+20/+21

The FT-2000 looks physically impressive but the IMD3 and TOI seem
shockingly low for a rig in this price class. Curiously, the ARRL
Review
does not comment on how poor it is considering the IMD3 of 95/85/64 and
TOI of +16/+11/-22

The ICOM Pro Series can no longer compete with some of the newer
transceivers in the $2000 - $4000 price class in terms of IMD3 with 20
and 5 kHz numbers like 103/77. I would expect the 2 kHz IMD3 to be low,
perhaps in line with the FT-2000? The TOI for 5 kHz is -18 dB. The Pro
Series may be preferred by some for the ergonomics and of course
nothing
can thus far touch the spectrum display for one built-in to the rig.

Just for the record, I have a Pro 2 and find it to be quite good for
casual use although a bit large for portable use and heavy on the
receive power consumption. I also have a Ten Tec Argonaut V with
some of
the poorest IMD3 and TOI numbers of any modern rig, but it is fun to
use
for casual QRP and near QRP power levels, but it has some very
amateurish design issues.

The Ten Tec Omni VII is the one rig that seems to have pretty good
numbers for an under $3000 general coverage receiver at 91/84/82 and
TOI
of +11/+6.5/+6.5 although the K3 will be better in that category.

My rig preferences are somewhat different than the average ham as I
prefer a rig with nominal 12 vdc power and keeping receive draw
reasonable, portability and lightweight for emergency use, ease of
interfacing for digital modes, solid performance, and excellent
spectrum
display. The K3 is not going to be able to compete with that last item
but it sure looks good for the others. Just sending in an ICOM 756
Pro 2
to the repair shop costs around $50 ... just for the shipping! If you
can repair most everything yourself (swapping out boards and replacing
mechanical parts), the value is increased even more for those of us who
do a fair amount of servicing.

73,

Rick, KV9U

Jon Pellant wrote:
I ordered a K3 on the heels of field day. I have been wanting to get
a 'real' HF radio for a while as I currently only use a Yaseu
FT-857D.
I had been looking at the TenTec Orion, FT-2000, and ICOM 756ProIII.
Durring field day, I got to use the ProIII, FT-2000, and K2. I was
very
impressed with the K2's bang for the buck and blindly ordered a K3 on
faith.
As it looks from the Elecraft web site you won't be alone ordering
blindly, I am one of them to.


Eric Swartz - WA6HHQ, Elecraft
 

The K3 transmits through both bandpass filters (before the final
amplifier stages) and through low pass filters after the PAs.

The bandpass filters do an excellent job of removing out of band noise
generated in earlier stages. The low pass filters afer the PA remove
any hamonic energy generated in the final PA stages.

73,
Eric WA6HHQ
Elecraft

--- In Elecraft_K3@yahoogroups.com, "CR" <vk3he@...> wrote:

Hi Chris

I was incorrect, the K3 uses lowpass filters and not bandpass filters
in the TX chain, so they are still needed. However with the great
IMD dynamic range figures that most are expecting its only in cases
where you have 2 transmitters on the same band where the receiver will
be challenged. Until we see what the phase noise performance of the K3
is like we can only presume that it will be good and this wont be a
issue.

I do believe that the W3NQN filters have very good performance, they
are so good in fact that its possible to use a dual band yagi on the
same boom and receive on one band while another station is
transmitting on another band.

Most people use the bandpass filters to null the second harmonic.
Several stations use stubs along with these filters for added
attenuation. Phase noise especially if its very bad will also be
reduced, however i would think that most multi multi contest stations
would avoid using radios with poor phase noise performance. If
a receiver is phase noisy it follows that the transmitter would
probably also have a bad case of phase noise on transmit.


I feel confident that the K3 will deliver.

Craig

--- In Elecraft_K3@yahoogroups.com, G3SJJ <g3sjj@> wrote:

Craig, I think I am correct in saying that the various bandpass
filters
available, eg ICE, Dunestar were created to reduce tx phase noise
from
adjacent current design radios in MO and SO2R setups. I have a
pair of
the Dunestar 600s here and they do just that, although antenna
separation plays a big part also. We used them for several years
in our
GU8D operation in the IOTA Contest and they were very effective.

One of the things that has impressed me in the K3 discussions was the
in-band close-in figures. A couple of years ago we did some in-band
checks here using 2 FT1kMPs with roofing filters and tx amps. I
haven't
got the actual data to hand but with mono band antennas on 20m
separated
by 70m, we were able to operate SSB and CW to within about 100KHz. I
wouldn't have thought the Dunestars would have made any difference
but I
honestly cannot remember.

I'm looking forward to getting my K3 shortly to do some more
tests. In
particular at the beginning of October we have the RSGB 21/28MHz
Contest
which I won last year using just the MP. This year I am intending to
run
SO2R with the MP and K3 and will be looking to do in-band dual
mode as
well as dual band. That should be interesting.

73 Chris G3SJJ


CR wrote:

It will be interesting to see if the Elecraft K3 needs external
bandpass filters when used in a multi multi contest environment.
Considering what the cost is for a full set of W3NQN filters, it
certainly make the K3 a popular if you dont have this additional
cost
or weight to carry around on an expedition or in contest station.

I also wonder if a Tracking Preselector will become a future option
for the K3. The Yaesu U tune preselector is a great feature although
old hat! However if the K3's front end is bullet proof it would be
hard to justify the additional expense and marginal performance gain
from a preselector. When bad IMD, Keyclicks and phase noise dominate
the value of such filters is questionable. However it might be handy
in places like Europe. Its going to be torturous operating a perfect
receiver like the K3 and hearing the good, the bad and the ugly
knowing very well its not your receiver when you hear the bad!

Such is the price of perfection!

Craig
VK3HE

--- In Elecraft_K3@yahoogroups.com
<mailto:Elecraft_K3%40yahoogroups.com>, "Jon Pellant" <w1jp@> wrote:

Thanks for your feedback. I trust my gut instincts sometimes and
my gut
made me blindly order a K3. I trust I won't be dissappointed.

Jon
w1jp

--- In Elecraft_K3@yahoogroups.com
<mailto:Elecraft_K3%40yahoogroups.com>, Rick <mrfarm@> wrote:

Assuming you like the ergonomics of a given rig, the one
parameter
that
I look at the most is the close-in IMD3 (Third Order
Intermodulation
Distortion).

Currently <snip/>


Eric Swartz - WA6HHQ, Elecraft
 

Hmmm - That must be a new form of energy ;-) Of course I meant
'harmonic'.

73, Eric


--- In Elecraft_K3@yahoogroups.com, "Eric C. Swartz"
<wa6hhq_lists@...> wrote:
.... The low pass filters afer the PA remove
any hamonic energy generated in the final PA stages.