| KW6G |
Rating:     |
2010-12-26 | |
| Works well, but still learning how to use it. |
Time Owned: 0 to 3 months. |
My Christmas present this year. Have been plagued by what I believe is Plasma TV noise for over 2 years now. Needed to do something, so I opted for the Timewave ANC-4. I get 15-20 db max of noise reduction with the supplied wire noise antenna (as measured on my 756proII scope). It definitely performs as advertised. It will reduce the noise, but not eliminate it altogether. Still learning how to tweak the thing, though.
Manual is good with clear instructions. It would be cleaner, however, if it had a whip antenna. Pulled the cover and noted that the PC board has a pad for one, so if you wanted, you could solder a nut onto the board and get a whip from Radio Shack, drill a hole in the top and away you go.
I constructed a short dipole per the manual to see if I could get a more significant null. It did not work as well; not sure why. When I plugged in the dipole to the RCA jack a noticeable lack of gain happened when the plug was fully inserted, engaging the shield portion of the RG-58 Coax. Not sure what is happening with that! Checked the antenna with a ohm meter - no shorts, so I am still puzzled. Next step is to take the dipole outside and try again. I will update this review after that gets done. |
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| K9OZ |
Rating:     |
2010-11-25 | |
| Works in my situation |
Time Owned: 0 to 3 months. |
I've been battling very bad line noise, and made the jump to buying a noise reduction device from Timewave, the model ANC-4. It uses a second antenna, picks up the noise, moves it 180 degrees out of phase, and removes the noise before it hits your radio.
It sounded too good to be true, but it does work.
It's not simple, and not 100 percent. After reading reviews, I saw a lot of positive, but also saw people who said it did nothing and they returned it.
For the first couple days I was in the did nothing category, but I kept experimenting with different receive antennas, until I found a combination that worked. If you aren't picking up the noise on the second antenna, you can't use it to phase out the other noise. So that's the key.
Now I'm using the dipole as my main antenna, and the vertical as the noise antenna. I have it set up so I can switch antennas quickly, using the vertical as main and dipole as receive.
Meanwhile, my noise has gotten worse, so this is the only thing keeping me on the air right now. A video is on my blog, at k9oz.blogspot.com, showing how it works.
I'm a cw operator, and I've been unable to detect any key clicks and have asked several people to listen for them, with no reports.
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| N4GG |
Rating:  |
2010-11-19 | |
| Not up to par |
Time Owned: 6 to 12 months. |
| No, no, no. As K9YC indicated these will add key clicks and have modest (at best) dynamic range. Do you really want a low dynamic range box in series with that nice new K3 or even FT-1000MP that can do 145 dB BDR? Worst problem is the phase shift control should only control phase shift, and over 180 degrees. In this very weak design the phase control only covers about 150 degrees, so with the two switch positions you can cover 300 degrees out of 360 degrees. hat's why you will often need to move the noise antenna - which should not be necessary - to get the phase angle you need because the ANC-4 can't. Next problem is the phase control severely changes gain at the same time. This is why it can take minutes instead of seconds to find a null - if you find one at all. Its a sloppy deign and performs as such. Buy the MFJ - much better for similar $$. Or break your piggy bank and buy the best - the DXE. |
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| WB4BYQ |
Rating:      |
2010-07-22 | |
| All stations need one |
Time Owned: 0 to 3 months. |
Install a 40 foot dipole up the tower about 25 feet ran rg-58u coax into the shack connected the main antenna either a yagi or dipole, and adjusted the controls and the buzz, tones, will disapear. plan to purchase a second one. i also us the SGC ADSP2 DSP speaker and the station sounds great. I can live with the slight reduction in signal strength, most of the time the
difference is not even noticed. Get one.
WB4BYQ |
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| KM3F |
Rating:     |
2010-02-11 | |
| Another use for the ANC-4 |
Time Owned: 0 to 3 months. |
I bought a used one to see if it would be of benifit with powerline noise.
I work 2m SSB with a transverter, so wondered if this unit would be effective on the IF output of the transverter at 28.200 taking in the noise source for procesing at that freqency while the interference comes through at 144..
It works at this point in the circuit, as well.
Don't forget to read the manuel for the options of BC notching etc.
Also it has an RF sensing circuit to tranfer the transmitt path 'pass through'. The circuit holding time is adjustable as well so pay attention to this per the mode you are using.
It will make a difference in some applications.
The loss on recieve of signal strength is notable but not a big issue most of the time.
The coupling where interference cancellation is done is in a toriod, so has some loss.
It cannot lower the noise floor you would normally hear if the interference were not present.
Overall I would reccomend this unit for those who have a large enough issue with local noise.
Understanding what it does and how is key to your conclusion about the unit.. |
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| WB9KPT |
Rating:      |
2010-01-31 | |
| Works great - now I can hear more signals! |
Time Owned: 0 to 3 months. |
I read all the reviews, and other articles online, before I purchased the ANC-4 via an eBay auction. My problem is that I live adjacent to one of the regional rail lines in the Philadelphia suburbs. I can see the electrical lines behind my house when I look out the window. I have a high noise level all the time (S9 or greater on many of the HF bands). So I took the plunge to see if this would help my receive situation.
I use an ICOM AH-4 antenna tuner on a 100 foot long wire with my ICOM IC-7000. I mostly operate digital modes, with some SSB during contests.
I was completely surprised when I was able to notch out a substantial amount of noise with an indoor 4 foot long piece of wire as the noise antenna... on several bands (20, 30 and 40 meters). In some cases it made the difference between being able to decode a PSK31 signal without errors, compared to not getting any copy at all. I have worked many weak stations, and increased my country count since getting the device.
All the other reviewers are correct, you must be patient and try all the controls in various positions to find the best notch.
When the weather improves, I will be putting up an external noise antenna - and hope to do even better. |
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| N3LCW |
Rating:      |
2010-01-01 | |
| An amazing device. |
Time Owned: more than 12 months. |
I've had this for years now and it still handles new noise problems that keep popping up.
I think many miss the instructions' suggestion of noting the S meter level with the noise problem on the main antenna, switching to no antenna (or grounded) then turning up the noise gain until the S meter reads the same level of the main antenna with the noise, and then adjusting the phase control trying both phase ranges switch positions, and even the freq. range. Using this method I have been able to eliminate ALL noise problems at this QTH using a 20 ft noise sensing antenna.
It is amazing to hear weak signals buried under noise. If you use indoor antennas this can be especially useful to wipeout locally generated noise from TV LO's, computers, etc.
It's an amazing device.
Andrew
N3LCW
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| W6OP |
Rating:      |
2009-12-02 | |
| Works great |
Time Owned: 0 to 3 months. |
I have a new energy efficient furnace that makes a terrible buzzing noise at any frequency a DX station is on. I had the dealer add an RFI kit to it which helped a lot. I can always turn it off for awhile anyway if it bothers me. However, several neighbors have now upgraded their furnaces. I really don't want to hunt them all down and convince them they need an RFI kit so I decided to try the ANC-4.
Initially I connected it to my 2m/440 vertical on the roof without much effect. Then I disconnected my transmit antenna and listened to just the ANC-4. I couldn't hear much. So I connected just the inner conductor on the coax to the VHF antenna. Now I could hear the buzzing. Once I did that I reconnected everything and was able to eliminate the noise in my receiver. I have done further experimenting and basically you need to first listen to the ANC-4 with your main antenna disconnected. If you can't hear the noise, it either isn't a local noise or you need to move the ANC-4 antenna. I use two antennas right now. One is the VHF antenna, just the inner conductor for neighborhood noise and the other is a wire in the shack that picks up my own furnace noise. Since I need my VHF sometimes I am going to add a loop around my yard connected to a spare coax I already have out there.
Pete W6OP |
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| KC9NUE |
Rating:  |
2008-12-27 | |
| pretty pass-through paperweight |
Time Owned: 0 to 3 months. |
| I have constant electrical noise 7-9 under 10mhz and below 5mhz forget it at my house. I guessed since the noise lessened quickly a couple blocks away and was gone at about a quarter mile away with my portable and was still there after killing my breaker box that it was electrical lines behind the neighbor house or one of those green electrical boxes seen in yards every 5 houses. I tried the ANC4 with my outdoor vertical and every noise antenna from a 1 to 50 foot wire, small dipole, 50 foot across dipole, inside, outside, N-S, E-W, vertical, horizontal...with absolutely zero change in amount/quality of the noise no matter what settings tried. It passed the signal apparently intact every time. I fiddled with it for three days before contacting the good folks I bought it from who took it back minus a 10% restock fee. They said it worked fine on the bench so no point in sending me a replacement to try like I said I would. I guess there is no hope for certain types of noise. |
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| W2HLD |
Rating:      |
2008-11-02 | |
| Performed better than my expectations |
Time Owned: 0 to 3 months. |
| The most significant noise issue I have experienced since moving to this location four years ago has been the pick up of the horizontal oscillator noise from my neighbors TV. The noise signal is spaced out on the spectrum every 16 KHz.. and as luck would have it, lands right on 7.238 MHz, a frequency that I spend more than 90% of my operating time on with nets and long time friends. Bottom line is that the unit does the job of removing the unwanted noise signal and does it extremely well. To get it to work correctly requires that you spend some time in the correct positioning of the "noise pickup antenna", or "noise probe". This is well documented in the technical material that is sent with the unit. The time was well spent and after a few hours of experimenting, I was able to find the "sweet spot" that effectively nulled out the noise. Would I suggest you run out and buy this product? .. from what I have experienced... YES! |
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