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Author Topic: Sherwood Report Numbers On The New Kenwood TS 890S.  (Read 3363 times)
K4RVN
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Posts: 261




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« on: October 18, 2018, 09:08:38 AM »

Would you Elmers who understand the Sherwood numbers please post a reply as what you think of the new 890 Kenwood Transceiver
after you take a look. I would like to know how it stacks up with the ICom 7610 and also the 990 Kenwood.  I don't know what I'm looking at but the reports are on the Sherwood site. Thanks for any replies.

Frank
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AF5CC
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« Reply #1 on: October 18, 2018, 11:37:19 AM »

Hi Frank,

Didn't know he had tested it until your post.  The close in 3rd Order IMD range is equal to the Icom 7851, which is pretty impressive.  This means that it can handle lots of loud signals before it starts to generate intermod products in the receiver-various noises that will cover up weak signals you are trying to copy.  Its dynamic range of 105db is 7DB better than the 7610 with its IP+ on (which lowers sensitivity) or 15db with the IP+ off on the 7610.  It is 18db better than the TS990.  This means overall that it has a very good, crunch-proof receiver that can hold its own with anybody, and exceed most, in the most crowded band conditions.

Its dynamic range is not noise limited either, which means it has a very clean synthesizer, and you won't have to deal with much phase noise.  Sherwoods LO noise measurement supports this, and this might be the best of any rig on his table.

I have some other thoughts I will share about the TS890 but have to run to an appointment now so I will share those when I return.

73 John AF5CC
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G3RZP
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« Reply #2 on: October 18, 2018, 02:13:08 PM »

Just remember that these days, unless you live out in the RF quiet wilds, the amount of receiver performance on sensitivity, IMD and phase noise you can actually use is limited by the external noise from all the digital crap from your neighbours' ( which could mean those within 30 - 50 miles or more) consumer electronics - and maybe even from your own home!
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K4RVN
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« Reply #3 on: October 18, 2018, 04:10:06 PM »

Hello John and thanks for the informative posts on Sherwood numbers. I am looking forward to seeing your other thoughts on the Kenwood TS 890S. Please don't forget and thank you.

Frank k4rvn
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AF5CC
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« Reply #4 on: October 18, 2018, 10:52:27 PM »

Glad to help Frank.  While the receiver numbers are impressive on the 890, the rig would probably be overkill for most of us, unless you are a hardcore contester with very good antennas.  I am sure at my shack I wouldn't notice a difference between it and an Icom 7300 or 7610, in terms of receiver performance.

I really have no interest in buying one, as it costs $4400, only does single receive, and only does 100 watts.  For that kind of money I want a rig that does dual receive and/or 200 watts.  For $700 less I can get a Yaesu FTDX5000 which does dual receive and 200 watts out, and its narrow space IMDR is only 2 or 3db worse than the TS890.

73 John AF5CC
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KD7RDZI2
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« Reply #5 on: October 19, 2018, 01:25:54 AM »

According to his tests I would not be stick to the Dynamic Range Narrow Spaced. Kenwood must have made an impressive work using the consolidated downconversion architecture. Its oscillator has such a low noise (-155) LO Noise (dBc/Hz) that does not pose limits to its dynamic range. In practice even a very close strong station should not rise the noise level of the wanted signal. If it rises it must due to the output of the interfering station that is not as clean (nothing can be done with any receiver then). The blocking dynamic range is far higher then the 16bits ADC used by truly SDR transceivers such the IC-7610. This means very strong station will not saturate the receiver, probably never ever. The Kenwood has even on the rear the possibility to add a preselector or other ancillaries that might be useful for contests where you transmit on another band at the same time without damaging or saturate the receiver. Overall I would probably prefer the Kenwood. In theory the ADC may have some advantages but some figures such as Blocking are not convincing, yes some people say I should learn to use attenuators. I have attenuators and use them with parsimony when really necessary (ham neighbor using KW accross the road, during contests on the same band), but in principle IMHO they (I mean the attenuators) should be banned. I think you will have never the need to use an attenuator with this new Kenwood at least for what I see from the results of this tests. Usually Kenwood rigs are notorious for having a great TX modulation too. The IC-7300 and 7600 are extremely good. Consider the TX as well. It is not simple at all to make a punchy clean TX with low spurs and artifacts.
« Last Edit: October 19, 2018, 01:29:17 AM by KD7RDZI2 » Logged
KM1H
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« Reply #6 on: October 19, 2018, 09:47:06 AM »

Doesnt Sherwood farm out most of his reviews? In that case Id expect some differences in the results.

Carl
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K4RVN
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« Reply #7 on: October 19, 2018, 04:30:30 PM »

Thanks John. I also balked at the price as I am not interested in contests so would not know the difference on rag chew QSOS.
I paid about 1600 less and went for the 7610 SDR type, two receivers with touch screen. That's enough of a challenge for me from now on. Thanks to all for your comments.

Frank
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WE1X
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« Reply #8 on: October 25, 2018, 06:25:26 AM »

Rob's performance list is simply a base line for comparing radio dynamic ranges and little more. Even Rob has stated this in so many words. Selection of a rig has far more to do with user needs, location and application. Further, how the op interacts with the rig (ergonomics) is equally important as is receive audio quality. Note that for years Rob used his trusty Icom 781 in contests even though more advanced rigs were available to him.  Also I seem to recall Rob stating that a difference of 7dB dynamic range is inconsequential and that the top 10 or 15 rigs on his list are excellent performers per dynamic range.

Harry WE1X
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G8JNJ
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« Reply #9 on: October 25, 2018, 08:41:14 AM »

The problem with the Sherwood reports are that they tend to fixate readers on specific figures and a subsequent ranking, which may, or may not, be applicable to specific scenarios.

Remember the days when receiver sensitivity used to be a big deal. These days most receivers have a sensitivity which is more than sufficient to be able to detect the Galactic noise floor, so it's no longer a differentiator.

However technology moves on and the Intermodulation free dynamic range of even quite moderate receivers is now more than good enough for typical operators in an urban environment (not on a hilltop with a big beam in a contest, or having a ham neighbour who likes to operate on the same bands and at the same time as you), where external factors such as nearby noise sources tend to be the limiting factor rather than receiver performance. So like the receive sensitivity figure in days gone by, it should probably no longer be used to rank receivers.

Other considerations such as operating ergonomics, control layout and tools such as panoramic displays then become more important to the operator in an urban setting.

Likewise the introduction of SDR techniques mean that some of the previous benchmark 'static tone' IMD tests that were used to 'sort the men from the boys' are no longer applicable and new methodologies, such as NPR testing as advocated by Adam Farson, AB4OJ,  http://www.ab4oj.com/test/main.html#NPR are more likely to show up poor performers.

One other factor that really should get more attention in reviews is the appalling transmit IMD performance of even top of the line radios. Many of which are still worse than 'tube' based radios from several decades ago.

It's no good having a top of the range receiver if a wanted signal is being masked by the IMD products from a nearby operator, that are only 20-30dB down at several KHz away from the occupied speech bandwidth.

Modern PA design and ALC characteristics should really be a lot better than they are, but nothing will change whilst folks concentrate on receive performance, as this is the only specification that manufacturer's currently seem to respond to and publish in sales brochures and sell as a competitive advantage.

Regards,

Martin - G8JNJ







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KM1H
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« Reply #10 on: October 25, 2018, 09:21:21 AM »

Excellent post Martin.

Carl
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K6AER
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« Reply #11 on: October 28, 2018, 08:10:33 PM »

Doesnt Sherwood farm out most of his reviews? In that case Id expect some differences in the results.

Carl

Rob Sherwood has his own lab. I have been there several times. In 2013 I sold him a 2.6 GHz HP VSA.
« Last Edit: October 28, 2018, 08:12:54 PM by K6AER » Logged
K4RVN
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« Reply #12 on: October 28, 2018, 11:00:11 PM »

Martin if you understand the Sherwood numbers I would be interested to read what you think of the Kenwood TS 890 and how it stacks up against the Icom 7610 and Kenwood 990.
73,

Frank
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G4AON
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« Reply #13 on: October 29, 2018, 02:32:24 AM »

As Martin pointed out, just looking at one specific test is not showing the whole picture. I did ask Rob why he doesn't include TX IMD figures in his tables and he said there were too many variables... There's no answer to that.

Even the ARRL reviews are prone to picking the good points and favouring some brands over others. Take their review of the Elecraft K2 for example, the review article gives an image rejection of 74 dB, which appears quite good. They don't mention the band or the fact that on 12/10 metres the figure is nearer to 45 dB, which is plain awful!

Other basic facts missing in many ARRL reviews is the ability of the ALC to control the power output when running on less than full power. Most reviews show the CW envelope at full power, not what happens at 20 Watts. A classic problem when running a linear that only requires around 20 Watts drive, as many modern ones do.

I'm sure the new Kenwood will be fine, just don't get hung up on figures in the Sherwood list.

73 Dave
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G8JNJ
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« Reply #14 on: October 29, 2018, 06:33:58 AM »

Martin if you understand the Sherwood numbers I would be interested to read what you think of the Kenwood TS 890 and how it stacks up against the Icom 7610 and Kenwood 990.
73,

Frank

Hi Frank,

The point I was trying to make is that with modern top end radios the Sherwood figures don't mean that much (other than for rough guidance purposes), and that none of the static two tone tests used by Sherwood (and others) really make much sense these days, as a lot depends on the conditions the radio operates under.

High end radio 'A' may perform better than radio 'B' under one type of scenario, but the situation may reverse under a different scenario. Two tone IMD testing is only a snapshot of performance under a particular set of test conditions. Different radio architectures behave differently under dynamic conditions, and SDR based radios behave differently to more 'traditional' superhet designs.

In theory the TS-890S looks to be better in terms of 100kHz Blocking and both wide and narrow spaced Dynamic Range, but I don't know enough about the rest of the radios architecture to say if the Sherwood figures tell the whole story.

What do you intend to use it for ? Contesting ? What antenna system will you use it with ? Where is your station located - on top of a hill miles from anywhere, or in an urban conurbation ?

Be honest with yourself - do you really need a high end radio for your situation (most don't), whilst some folks only chase specmanship / bragging rights (which is fine if it's important to you). Would other considerations such as radio ergonomics, or purchasing a better antenna system or linear amp, offer more bang for your bucks ?

'Horses for courses' etc.

Regards,

Martin - G8JNJ


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