[Kenwood] 850 vs 450

Thu, 23 Oct 2003 19:28:49 -0700

Thanks, Roy!

Great info.

Just curious what your opinion of the 570d(g) is compared to the 450 and 850?

thx

bob

At 09:39 AM 10/23/2003 -0700, you wrote:
>Hello Bob,
>  I've been running a 450 for about 2 years now and just got an 850,
although I've also had a 440, 940, 830 and 870, so I'm sort of familiar
with Kenwood rigs.
>
>The 450 comes with 1 - 12 khz, 2 - 6 kHz, and 1 2.7 kHz filters.  The only
crystal filter is the 2.7 kHz filter which is in the 8.83 MHz position.  My
450 came with an additional 2.7 kHz crystal filter for the 455 kHz
position.  When both are engaged, the actual bandwidth is about 2.4 kHz,
but I don't really notice any difference.  To get rid of "monkey chatter"
in SSB, all you have available is IF shift, or else you must buy a narrower
IF filter such as the YG88SN-1 1.9 kHz SSB filter.  The IF shift works fine
so long as you don't have anyone talking on the other side of the offending
signal.
>
>     The 800 and 900 series of rigs which includes the 850 has High cut
and low cut knobs which Kenwood calls "slope tuning".  This requires equal
width filters in both the 8.83 MHz IF as well as the 455 kHz IF.  The knobs
move one IF relative to the other which makes the signal narrower on one
side only.  The stock 850 has 2.7 kHz filters in both IF's.  I think the
8.83 MHz filter is the standard YG88S and the 455 kHz filter is probably a
ceramic filter to cut costs.  You don't need a narrower SSB filter, because
you can narrow down the signal with the High Cut and Low Cut adjustments.
The shape factor will be worse than a narrower filter because the actual
slope of the attenuation will be the same as the original filter, but most
people won't notice the difference.
>
>     The nice thing about both rigs is that you can use any filter in any
mode.  I've notice that when "opening up" the passband to 6kHz, I can get a
full appreciation of what some people's audio sounds like.  So long as
there isn't anyone else nearby, you can get really good audio from some
stations.  With others, it doesn't matter.  I've also used audio DSP's to
cut out the QRM with a 6kHz passband on my rig.  I've used the JPS NIR-12
and Timewave 599ZX and both work very similar to the Kenwood slope tuning
or Icom's Variable Passband Tuning (PBT) function.  Nine times out of ten,
the level of the interfering signal is less than the desired signal, so an
audio DSP works just as well as an IF DSP.
>
>     Even though the displays of the rigs show the limited choice of
filter selection, you can actually put any Kenwood or Kenwood compatible
Inrad filter width in the slot.  For example, if you are a SWL, you can put
a YK88A-1 into the 8.83 MHz CW narrow filter position and select it along
with the 12 kHz 455 position for great sounding AM with good steep skirts
or add in the Inrad 4 kHz filter in the 455 CW position to chase AM DX
stations.
>
>     You can get a visual picture of what slope tuning does by downloading
the 850 manual and looking at page 33, or page 50 of the TS-830 manual
which gives a comparison between IF shift and slope tuning.
>
>     While I just got the 850, I've been studying it for quite a while so
I am familiar with the differences between it and the 450.  Ignoring the
additional CW features of the 850 over the 450, here are some of the
differences that may interest you:
>
>- Variable bandpass tuning on the 850 as opposed to IF shift on the 450.
>- Variable noise blanker adjustment on the 850, only NB1 and NB2 for 450,
although I've heard that the 850 NB isn't very good, but can be modified.
The 850 has an adjustable NB1 level and NB2 width.
>- 6, 12, 18 dB attenuation on the 850, single 20 dB attenuation on the 450
>- 850 has AGC of slow, mid, fast, off.  450 has only slow and fast (no off)
>- The 850 allows you to monitor your TX audio, the 450 does not.
>- The 850 speech processor is adjustable, the 450 is either on or off.
This makes the monitor function not really necessary on the 450, you simply
adjust the mike gain while looking at the ALC reading.
>- The 450 allows you to clear the RIT/XIT with the touch of a button
because it uses optical encoders, the 850 must be manually adjusted to zero
or turned off because it is controlled by a pot and there is no center
detent.  This is a big issue for some.
>- As with most Kenwood rigs, "AIP on" means that the preamp is OFF.  This
should be the standard setting rather than keeping the preamp on in the
default setup.  This will result in lower S-meter readings, but much fewer
IMD problems.
>- The 850 has the 8.83 MHz IF out in the back.  This is a wide band signal
which can be fed into an SM-220/BS-8 or SM-230 to get a real time spectrum
display of all received signals near your tuned frequency.  Sort of like a
poor man's 756/Pro/2 spectrum display.  It is very handy at locating
stations during contests or Field Day or while SWL'ing or seeing who is
causing QRM.  The 450 does not have this output and the only way you can
get it is to tap into it inside the radio and add a buffer before bringing
it out.
>-  The 850 allows you to add on the Kenwood DSP unit, although if you are
going to spend that much, you're probably better off getting a used 756Pro,
870, or TS-2000.
>- Obviously the 850 is much bigger and heavier than the 450.
>
>If I've misstated something or if anyone can add anything else, feel free
to do so.
>
>
>Hope that helps.
>
>73
>Roy
>AD6ZU
>
>_________________________Original Message____________________
>
>Hi Guys
>
>Thanks to all who have replied on and off list to my post looking for a 450
>or an 850.
>
>I'd like to know what the differences in the 2 radios are. CW is not a
>concern for me, but being a musician, good audio quality is.
>
>For starters, do both radios come stock with the same filters?  I'm new to
>all this and appreciate all the help so far!
>
>
>thx
>
>bob
>- - -
>
>Your moderator for this list is:
>Larry Wilson KE1HZ [email protected]
>
>_______________________________________________
>Kenwood mailing list
>[email protected]
>http://mailman.qth.net/mailman/listinfo/kenwood
>