[TenTec] Omni V vs. TS-570

[Steve Ellington]

A Kenwood TS-570 has been the guest of my shack for the past week. 
I spent many hours and dozens of QSOs comparing the two rigs and 
feel a need to report my findings to the TenTec crowd. 

The TS-570 is Kenwood's most modern rig. It's computer interface is
second to none running at 57.6kb through a 9pin serial port directly to
the pc. 
Rig control software was available through their Webb page and
performance in that area was awsome. Every button, knob and display was
controlable bi-directional. I was impressed.

Kenwood makes claim to "incredibly clear and powerful audio". However 
their manual specifies 1.5 watts at 10% distortion. Hardly what I would
call incredible. SSB and AM sounded quite good but cw was terribly
distorted at low volume levels using an 8 ohm speaker or headphones.

Being a cw operator, I look at radio somewhat differently than the
average phone operator. I'm interested in the clarity and purity of the 
recieved cw tone, proper agc response to qrn, narrow filter performance,
full break-in capabilities and of course a good transmit tone.

Concerning transmitt, the TS-570's tone was reported by all to be
excellent but somewhat softer than the Omni. Under weak signal
conditions, switching to the Omni in mid qso resulted in such comments
as "sounds like you turned on the amp", cpy better now om etc.

QSK on the 570 was fairly smooth and quite but relatively slow. I ran
the what I call the "dit busting test". Another stations tries to break
me while I'm sending a string of dits. I sent a string of dits at 25
wpm. I was never able to hear the other station breaking. This test was
duck soup for the old Omni V. 

The TS-570 is advertised as a "DSP radio". This is totally incorrect. A
true DSP radio uses dsp technology from the front-end to the audio
amplifier. No coils or transformers are needed in the R.F. chain. Such
receivers are available from Collins for about $16,000. The DSP in the
570 is simply a dsp unit between audio stages and offers less flexiblity
than outboard units such as the MFJ or Timewave. 

So here we are on 80 meters at night with S9 static trying to work
another station who is also S9, a tough test for any radio. I had
installed the 500hz filter in the 570. There is only 1 slot for extra
filters. The Omni V has the 500, 250 plus the extra 500hz filter. 
Contact was establised but copy on the 570 was difficult. I kicked in
the 500hz filter which automatically kicks in a 600hz dsp filter. Noise
level from the qrn increased considerably and copy was impossible. Yes,
Kenwoods filters tend to boost qrn! I then pushed the N.R. button. This
is supposed to eliminate such noise. This resulted in sound resembling
something from a horror movie. Howling, chattering and muttering sounds
eminated from the speaker with an occasional cw note poping through in a
broken, unreadable manner. I had to switch to the Omni V quick to see if
I could salvage the qso.

Flipping the antenna switch and setting the dial, I could hear the other
station under the qrn. I punched the .25 filter into action and the
station immediately rose far above the qrn. Then I hit the NAR button
kicking in the extra 500hz filter, cranked up the audio bandpass filter
and enjoyed what sounded like a code practice oscillator! 

The TS-570's audio on cw was not only distorted but flat, mushy and
indistinct compared with the TenTec. Another observation was the keyer
in the TS-570. The keyer worked like a champ but sometimes my dits were
blipped out of the sidetone. This occurred mainly when using qsk under
noisey band conditions. I suspect it's something to do with
microprocessor timming.

My conclusion is simply that the TS-570 is a well constructed, modern,
stable, versatile rig not to be taken seriously by cw operators. These
same test were run last year on a Yaesu FT-1000MP with virtuall the same
results. Japan has a long way to go the outdo the Omni V on CW. 

73 to all: N4LQ
Donations accepted

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