here's a summary of what I got w/o comment
hi:if u have receipt, send it back!cul leo aa4mm
Craig:
Gee, I really like mine, but I will admit that I
had to play with it for a couple of weeks before
I got real comfortable with it.
I don't know how to give you suggestions other than
just keep on keeping on - you'll get used to it.
What kind of radio are you using it on - maybe I can
compare with mine -
73
Tom, NM1Q (tomf@neca.com)
I bought a DSP 9+ a couple of months ago,and I also was not too
impressed.
If you had a resonable strength signal with some noise on it I seemed to
clean up
things rather well,making copy more comfortable. But when it came to the
real weak
ones,tring to pull someone out of the mud,it didn't work well. It worked
great
removing carriers on SSB (notch function)and also worked very well at
removing some
types of impulse noise on SSB signals. But also seemed to distort SSB
signals,
probably due to low sampling rate of 8 KHZ. Really weak SSB signals
sometimes just
disappeared when DSP was turned on.
In frustration I got rid of the DSP 9+ hoping to get one of the new
DSP 599ZX
(or whateverits called) but can't find one,apparently the factory isn't
shipping any units to distibutors.
I bought the "DSP Blaster" software from K6STI and used it during
the CQ WW SSB
contest on 160 Meters.On a few QSO's it made enough difference that I
made the QSO
when I probably couldn't have with out the DSP Blaster. The DSP Blaster
works at 16 Khz
sample rate so you dont get the distortion on SSB signals. The noise
reduction feature
doesn't work as well as I'd like,but I guess getting rid of S9 noise is
kind of tough!
It doesn't seem to remove impulse noise nearly as well as the DSP 9+
unit however.And
the CW filter bandwidth is not nearly narrow enough(250,Damn computers, I
hit the wromg key and sent you messgage before I
was done! HI
As I was sayind the CW BW of 250 Hz isn't narrow enough for my liking on
the Blaster
softare from K6STI.But I'am hoping he will improve it in the future.
So to me it seem like nothing works perfect,I would like to try the new
Timewave unit,
But I just dont understand why I cant buy some little box to replace all
the 800 foot
beverages I dont have !!!!!!!!! But I guess thats what makes the low
band so much fun.
ALSO Please update you list to include : K8RF EX: WT8N
73 and good DX - Dan K8RF
I, too, have reservations about these audio DSP filters. I bought the
MFJ unit because I thought it performed better than the Timewave and
JPS models which I also "auditioned". I still find the MFJ to make only
a marginal improvement on either CW or phone. The Timewave DSP59+ was
very "hissy" sounding and also had some clock-like audio spurs. A second
DSP59+ also had the same problem and these artifacts were also noted later
in a QST review. I found that unacceptable. The JPS unit would sometimes
break into oscillation in narrowband CW settings. The MFJ was also
somewhat "hissy" but much better than the Timewave. I am not a big-time
phone operator but the DSP filters do distort voice signals quite a bit.
In the CW mode, using very narrowband filtering, I also sense some distortion.
The filters are claimed not to ring, but instead I sense that they cause
some rounding of the keying envelope and sound "mushy". Also, the MFJ filter
can only be tuned for a CW pitch as low as 300 Hz, which is not low enough
for me. I like to listen at about 200 Hz which gives better discrimination
against off-frequency QRM.
In short, I think that an audio DSP filter still doesn't beat good IF filters
in the radio and GOOD EARS.
73, John W1FV
I bought a DSP9 in 94 and came to the conclusion that it was not
helping me. I sold it to WA3EUL and he swears by it! Weird.
RE DSP-9+: I finallly just advertised mine on the packet cluster and sold it.
It will lower the noise on a station you can already copy, but won't do
anything useful on a station that is already below the threshold of being
copied. I then tried an NIR-12 and had the same frustrating experience and
sold it at Dayton (after only a few hours use). I haven't found any audio
filter device as effective as the simple peaking filter included in the
TS-930.
73,
Jim, K9RJ
I have a W9GR dsp11 that I like real well, however it took me some time to get
the right combination to get it to perform as per expectations,,,,I can not give
u any adivse other than not to give up on it,,,, if u do ur job I can assure u ,
it will do its job...I have have worked several new ones and new band ones, that
I could not even copy wid out it,,,, that doesnt mean to infer that it will make
a 229 signal into a 599, but it will improve it to the point , that all other
factors being complete, you can hear the station well enough to work it...
hang in there.... good luck,,,,, johnW8WEJ
Ive had one for over a year now and havent had a lot of miricles
come out of it> Once in a while it will make the difference so thats why
I havent sold it. Ive found that with my old 751a it worked ok but with
my current 930 it is sometimes dsp overkill. I will often use the phone
setting for cw to just tweak in a signal and not overwhem myself with
filter ring. Just my 2 cents worth cul de JOhn
I own both the 9+ and Timewave 59+. I use the 9+ for mobile vhf/uhf work as
it's
main advantages are: 1. slighly less listener fatigue from the lower audio hiss
2. the narrow cw filter is useful for the rare cw QSOs on vhf
I find the 59+ is far superior in it's ability to function as a precise narrow
CW filter and about the same as the 9+ for SSB work. I'm becoming a
mostly-CW op
these days. My advise is to sell or take back the 9+ and buy the 59+ or the new
JPS NIR-12 unit. Much more money but much more useability, in my opinion.
73
John Farber, KG6I
These DSP boxes make my head hurt. I have an NIR-10 with latest ROM's
AND a DSP9+ AND a SCAF at the end. At least the SCAF does not make my
head hurt, and it takes out the hiss from the DSP boxes.
I am going to modify my RITTY cable any day now to use K6STI's DSP
Blaster and see if that works better. Any day now.
I may even take the ANC-4 out of the box and try it before it becomes a
museum piece.
--
I have a JPS NIR10 filter. I had been pleased with its adaptive
bandpass filtering function when I was using an old TenTec Delta.
The fancy broadband noise cancelling function has never lived up to
my hopes, it reduces background noise for good signals, but not for
the marginal ones. Anyway, I then 'upgraded' to an ICOM 738 and
found that the dsp no longer offered much of an advantage. It soon
became clear that the problem was bad
intermod/harmonic/whatever distortion. Even without the filter, I
could hear better and more pleasantly on the old TenTec when there
was no qrm, with qrm the icom's sharper IF filering made it superior.
Since the TenTec then failed, I went full time with the icom.
Recently I bit the bullet and dug into the rig to see what I could
do. After spending hours tracing the lousy schematic, I found I
could tap into the output of the detectors, before the audio chain.
So I now have an outboard audio amp (an old hifi preamp). Now the
dsp works again. Even without the dsp, there is a huge increase in
cw readability going to narrow IF (500 hz), whereas before it made
little difference unless there was qrm. All that fancy digital stuff
and they mess up something as low tech as audio amps!
So, after this meandering,
the point is, maybe your audio has too much distortion for the dsp to
function properly.
Craig Clark
soon to be ex-NX1G
send me e-mail and I'll put you on our mailing list
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