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Reviews For: Timewave DSP-9

Category: Filters, Audio: (DSP and others)

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Review Summary For : Timewave DSP-9
Reviews: 20MSRP: 219.99 c.1995
Description:
DSP noise filter
Product is in production
More Info: http://www.timewave.com/dsp9.html
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00204.9
WB0FDJ Rating: 2013-08-05
Hey, it works! Time Owned: 0 to 3 months.
When I downloaded the manual from Timewave for this old audio filter, I noted that the date on the schematic is 1994. Thats a realllly long time ago. And yet, this old thing does a nice job.

So why bother to review something this ancient? Well I needed a simple audio filter but wanted more than just "selectivity": i.e. flexibility and a bit of noise reduction. I did my homework here on eHam, looked around ePay and scored one of these. This thing is going to be very helpful for me.

I have a bunch of "old stuff" that shares the same receiver specs: wide and noisy. This is going the make my use of the HW-8, Argonaut 509, even my Argonaut V (where I have it running now) much more enjoyable. On CW the 500 Hz setting is plenty adequate and the random noise reduction does a fairly nice job of eliminating the static and crud from the sig. If you own older radios and are looking for an older audio DSP unit, this one works well. Considering the age of design I am actually impressed.
N8TI Rating: 2011-12-31
Works very well. Time Owned: more than 12 months.
I have had this filter for at least ten years. I bought it used. I only use it for CW as I don't run SSB. It works really well on CW as the bandwidth filters work great. In fact, you are better off pushing the bypass button when you are tuning the bands as you will run past stations when you have the narrow filter on. Great for getting rid of adjacent unwanted signals. You don't need a manual for this item. Simple push buttons. I would buy this item again.
K7LZR Rating: 2011-09-08
Great filter! Time Owned: more than 12 months.
This is a great no frills filter that just works well. I use it with various receivers but mainly with a Yaesu FT-817nd.

The notch filter really shines, removing offending carriers almost instantly. The bandpass filters are nice, especially on CW. Using these, I can often pick out signals which would otherwise be RF mush.

The random background noise filter works well, and once adjusted properly it has minimal distortion and voices rise out of the noise nicely.

The physical dimensions of the DSP-9 make it an ideal match for the FT-817 and other small radios as well.

The controls are simple and easy to use so that adjustments for optimum receive can be made very quickly. Filters can be used alone or in combination.

Although there are newer DSP options for the FT-817 et al such as the internal BHI units, these require modifications of the radio. For those who don't wish to modify their rigs, the DSP-9 is a great option.

I actually downgraded form the DSP-9+ to this one because the audio quality seems to me to be better than that of the DSP-9+.

These units are a great buy on the used market, averaging about $60.00 in price. If you can find one then I'm sure that you won't be disappointed.
AB7KT Rating: 2010-04-16
Works as good as ever Time Owned: more than 12 months.
I came to this review after having a discussion on the phone with a ham buddy of mine. We both bought Timewave DSPs soon after they first came out. At the time, I was running a Ten Tec Omni D that had audio filtering but no DSP. I was flatly amazed at what this thing did back then. Today, I am running an FT-950 with DSP, roofing filters and all that. I also have an Icom 7000 with good internal filtering. Never the less, I am still impressed by the DSP-9.
I honestly think it is as relavant today as it was many years ago when I first bought it.
I also appreciate the fact that Timewave continues to support these old DSPs. I have upgraded the EPROM in mine twice including within the last few years.
My buddy said that this is one of the few pieces of gear he has ever bought that was absolutely everything he hoped it would be. I agree.

Does anyone know when these first came out ?
N1TCH Rating: 2010-02-27
Excellent addition Time Owned: 3 to 6 months.
I bought this to use with my TS-520SE and haven't been disappointed. Except for a little echo with some settings I have no issues. I can hear more than some with newer more complex rigs. The fact that the controls are easy and seperate from the rig and easy to adjust makes it a top notch (so to speak) performer. And for less than $60 on EBay.
K4SPS Rating: 2009-12-13
The end of 'white noise' Time Owned: 0 to 3 months.
Bought this simpler model from E-bay and it is a great match for my Drake TR7. Previous experience with a DSP-9+ was great, but this model is even more appropriate for my older ssb transceivers as it has only (and I need only) voice and cw filtration. I highly recommend Timewave products.
This unit works better than the dsp mode on my most recent and 'state of the art' style Yaesu tranceivers. Get one of these for your ears - you will not be disappointed! K4SPS
N3WJ Rating: 2008-12-01
A successful trial by fire Time Owned: 3 to 6 months.
I picked up a DSP9 this past summer at a local hamfest for $50. It sat around until this past week when I got the, some might say crazy, idea to try working the CW CQWW running QRP with a Yaesu 817 I have not used much in the past few years. Although I have the 500hz crystal filter installed in the 817 there would be no way that was narrow enough for a contest so I decided to hook up the DSP9. I have to say I was very impressed! It worked well in isolating signals I could barely copy without the DSP given all of the strong QRM during the contest. It also adequately reduced noise levels to help pull in the signals. You can really get this thing down narrow.

When I tired of all of the CW noise, I tried some QRP SSB since I figured that part of 20 meters would be a bit less crazy. I do not have any filtering in the 817 for SSB. Although I did not need the narrow filtering for phone, the DSP9 did a nice job of overall reducing noise, especially random tones of folks tuning up near the station I was trying to copy.

The only issue I have with the DSP9 is it does not handle strong adjacent signals particularly well. This became a bit of a nuisance during the contest and occasionally I had to widen out the filtering more than I would have liked. This may be my failure to set the unit properly but I did follow all instructions on matching outputs. For this reason alone I did consider giving a 4 instead of a 5 but, overall, for the money, I really think that this is an incredible buy if you can find one.
WD8PNL Rating: 2008-11-16
Has one series but correctable design error Time Owned: more than 12 months.
In the Operating Manual for the DSP-9, Timewave Technology Incorporated specifies the power demand as 12VDC to 16VDC of feed voltage with a current draw of 1A. All drawn current passes through the 2.0 Ohm 2 Watt carbon composition resistor identified in the circuit schematic as R13, but identified on the curcuit board as R14. With 1A of current drawn through a 2.0 Ohm resistor, the power dissipation by the resistor is 2W. Consequently, this 2 Watt carbon composition resistor is underrated in its heat dissipation in the sense that there is absolutely no overhead margin for heat dissipation. Over time, the resistor suffers heat damage from the heat it produces, and the heat it radiates causes heat damage to two other components that are mounted in close proximity on the circuit board: electolytic capacitor C38 (its vinyl jacket had melted), and silicon diode D2. In the case of my DSP-9, some heat conduction was also at play: the through-hole solder joints were sputtered and had accumulated carbon residue where both conduction-heated leads of the resistor passed through the circuit board.

Correction of the design error amounts to fabricating a resistor network that physically fits within the available space, has sufficient heat dissipation with some overhead margin, and does not radiate so much heat as to damage nearby components. To repair/correct my DSP-9 I first removed the resistor, the electrolytic capacitor, and the silicon diode. Then I cleaned away the carbon residue from the circuit board. Next I installed a new silicon diode D2, and a new electrolytic capacitor C38 which has a more narrow body than the original in order to gain more clearance between the side of its body and the heat source. Lastly I took three 5.6 Ohm 2 Watt carbon film resistors and stacked them above each other with their bodies in a horizontal attitude and spaced from each other (like rungs of a ladder) to allow adequate air flow around the body of each. The stack is a parallel-equivalent net resistor of 1.867 Ohm, has heat dissipation of 6 Watt, and its three resistors are spaced well away from the body of the electrolytic capacitor C38.

As for its performance, the DSP-9 performs quite well, as other reviewers have reported.
N2UGB Rating: 2008-04-20
Great for non-filtered rigs Time Owned: 3 to 6 months.
I noticed the recent review and wanted to add my own. I purchased mine, used of course, 3 months ago. I give in a 5 based on what it was capable of delivering at the time of manufacture.

Just what I needed. I have OHR QRP rigs that are greatly aided with the DSP-9 in line. And, for my remaining TS-520 hybrids, without CW filters, the Timewave is absolutely necessary.

So, if you have a non-filtered QRP transceiver or an older rig that you bought used without a filter, keep an eye out for a DSP-9. Folks who now have the latest and greatest rigs already DSP equipped, frequently sell them to raise a few bucks (like all of us).

Keep an eye out for this seasons hamfest offerings.
N7PZI Rating: 2008-04-20
Great Unit Time Owned: 3 to 6 months.
I have owned the DSP 9 for a little over 3 months. I bought it at a hamfest for $35.00. This is the first DSP unit I have ever owned and I have to wonder why I waited so long!
I'm lucky enough to live in a rural area with very little QRM so I have always believed that my FT 980 was doing a wonderful job on receive, but after hooking up the DSP 9 my socks were blown off. I am now hearing stations that don't even wiggle S meter and am often working them with no problems at 100 watts through a vertical.
This unit is very good at tuning out the usual hash and is particularly good at filtering out those who insist on tuning up over the top of a good DX station. Even though the DSP 9 only has roughly 4 pre-set states, it doesn't take very long to pick the proper combination of settings to get all but crystal clear reception. This unit is particularly good with CW.
This is my first venture into the DSP world so I am not sure what newer units are capable of, but can't wait to find out! This one was built in 1993.
When the discretionary funds warrant it, I will be looking at a newer generation unit.

Dave - N7PZI