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Show all reviews of the Kenwood TS-590S
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of the Kenwood TS-590S.
Nov 1, 2013 19:51
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Time owned: 6 to 12 months
Comparison using the bench mark radio K3
How the TS-590S technology represents a leap forward relative to the K3
I will look at various aspects of both radios and try to give some unique input that many might have not considered by others .
1: 160m , 80m and 20m
The two radios use roughly the same technology so the difference is minimal
Another name for the 1st rf amplifier is the image rejection amplifier .
Radios like my old Kenwood TS-530s with its 9 mhz IF , used a sharp manually tuned 3 stage image rejection amplifier , along with a good roofing filter , to keep undesirable signals out of the IF strip form this part of the radio spectrum that is known for have very strong broadcast and other transmitter signals .
One reason for going up conversion is that you can get away with using broadband , no tune , image rejection amplifiers.
On the Kenwood TS-590s the radios 11.374 mhz IF is more then 4mhz away form the 40m band which is important if your using a no tune broad band first amplifier .The radio uses both the rf amplifier selectivity and the roofing filter to keep unusable signals out of the IF strip
The K3 uses a IF thats within 1mhz of the 40m band so it totally reliant on the roofing filter ,which unlike dsp , only has a finite amount out of rejection .
Based on the previous analysis , I give the TS-590S the edge on 40m .
3: 30m :The TS-590s uses the up-conversion triple IF configuration given it superior image rejection at the 2nd IF but with only a 2.7khz roofing at the 2nd IF so I would have to conclude that the K3 is a better radio on 30m if the band gets crowed .
4: 17m : The K3 uses down conversion and the TS-590s uses triple conversion ,up conversion. Considering the characteristics of the band , both radios are roughly equal .
5: 12m , 10m , 6m
It used to be unless you lived on a island in the middle of the Pacific , having a radio with incredible sensitivity and a very low noise floor was a feature that had no real practical use . Thanks to dsp technology ,these performance characteristics now have value and and can be used .
The TS-590s receiver on these three bands , using the triple conversion ,up conversion mode was able to achieve a noise floor of -144 dbm and a rx sensitivity of .13 uv which is at the top of the pack .
The K3 using its down conversion IF simply can't come close to those numbers so the TS-590s has the edge .
6: General coverage RX : The TS-590s comes complete ,no extra cost , high performance GC radio that uses the up conversion ,triple conversion rx .
On the K3 you have to buy another box and it comes with a disclaimer that it may not work correctly on some frequencies because the 8.2mhz IF .
Definitely the edge goes to the Kenwood TS-590s
7 : Transmission :
The K3 uses a 70es era down conversion set up and pushes the signal through a distortion causing roofing filter to achieve a given bandwidth .
The TS-590s uses a more modern approach .
It achieves a cleaner signal by using the up conversion mode with advanced ddr oscillator feeding the mixer combined with a low distortion 15 kHz roofing filter to achieve the ssb signal .The point here is that the TS-590s uses dsp to shape the audio frequency response of the signal and not the roofing filter that I think is a better way to do it .By doing it that way , one could use a narrow , lower inter mod audio bandwidth when using a lot of processing or a wide audio bandwidth when processing is off or at a lower point.
Upgrade ability :
You might think that the K3 would definitely have the edge there with all its options if they suit your fancy and thats probably right so I give it the edge on this point . There is one point you might want to consider . I think , but don't know for sure , that on a up conversion configured transmitter if we one day get some new WARC bands that all will be needed is a software upgrade to allow the transmitter to operate on those new bands . On a down conversion radio like the K3 you might end up with a nice but very frustrating radio like what happened to me in the early 1980es when I bought a non WARC band Yeasu FT-101 ZD . I sure hope with my TS-590s radio , I won't fall into that trap again !
In conclusion , its hard for any conventional radio built today to outperform a radio that has the ability through software control to change its block diagram in a significant way as conditions warrant to better adapt to the needs of the user .The TS-590s uses software that works with you and not for you which is a important point because who really has the time to fiddle (excluding those people who are trying to win a Sherwood test lol) with all those knobs on a typical 10k radio. .Thats the secret behind the TS-590s and makes it a revolutionary as the TS-520S did in the way to made obsolete the separate transmitter , receiver configuration in the 70es . Way to go Kenwood !
Last edited by WA4AXT; Today at 09:11 PM.
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