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Reviews For: NEScaf Audio Filter

Category: Filters, Audio: (DSP and others)

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Review Summary For : NEScaf Audio Filter
Reviews: 33MSRP: 29.00
Description:
The NEScaf is a switched capacitive audio filter based on the MF10 chip. It is
designed to be simple to build and use.

It is more flexible than previous filters for QRP rigs. It has two panel- mounted
controls -- a single center-detent potentiometer that sets the center
frequency of the filter's bandpass (default value settable between ~415Hz and
~1kHz), and a dual-ganged potentiometer that provides a continuously
variable bandwidth control (from ~60Hz to ~1500Hz). This ability to smoothly
vary the bandwidth is very useful.

The NEScaf is designed to be driven with a phones or speaker level signal.
Product is in production
More Info: http://www.newenglandqrp.org/wordpress/nescaf/
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00334.9
W8YT Rating: 2008-05-04
Awesome filter! Time Owned: 0 to 3 months.
First tried it on my FT-817ND, and it quiets the QRN better than my expensive mechanical filter for CW. The directions are excellent, and it went together smoothly after I figured out how a DPDT switch works. It also seems to work better in a metal RF enclosure. This is really a bargain for the money, and a very useful addition to the shack.
K9EX Rating: 2008-04-26
Super Bargain - Good with QRP Kit Rigs; Great with the FT-817 Time Owned: 3 to 6 months.
I built my NEScaf last Fall and have used it with good results with my QRP kit rigs: the Ten-Tec 13xx series xcvrs, my lil MFJ Cub and an OHR 100.

However, this little gem really shines when used with my FT-817 - it's a perfect match for the FT-817! I roll the FT-817 RF Gain back a little and just keep the NEScaf on all the time, adjusting the NEScaf bandwidth and frequency controls, as needed. I tend to favor lower frequency tones, so I keep both controls at around 10 o'clock - that combo works great for around 400 Hz CW signals while also taking out some the FT-817's "tinny" sound.

It really improves the FT-817 receiver section - it quiets the noise and provides some much needed additional selectivity and filtering for CW signals at all levels. The FT-817 simply sounds great with this filter and the improvement is so genuine that I wouldn't/can't use my FT-817 without it.

Inexpensive and easy to build, the NEScaf is a wonderful improvement for the FT-817 (and other rigs lacking stock filtering) - what a great buy!
G0DJE Rating: 2008-01-22
Very effective, excellent value Time Owned: 0 to 3 months.
Shipped very speedily to the UK. Clear and complete instructions, extremely logical. Quality components well packaged. I recommend the optional connector pack...saves a lot of hunting around for the sake of $4 extra!

Performance is superb. For CW it is great at bringing signals out of the noise. For SSB it has proved very effective at eliminating QRM...a result I was not expecting - breathed new life into my TS-530 on 80M SSB!

If you haven't already then go out and get soldering iron and a £5 multimeter and build this kit. It is very worth while.
NH7O Rating: 2007-12-28
Worthy Time Owned: more than 12 months.
I'll agree with the foregoing posts. I use mine all the time for weak signals.
W7RDP Rating: 2007-08-27
great filter Time Owned: 6 to 12 months.
I built one of the first runs of the kit, a great addition to my NorCal 40A. I did change out the LMF10 with a LMF100, the kit now ships with the LMF100. Great value and it also works as a "zero beat" indicator with the NorCal 40A.
KC0PET Rating: 2007-08-09
Best SCAF Filter Time Owned: 3 to 6 months.
Particularly for CW operation no reason to buy anything more expensive. The kit goes together well and it really works.

I combined mine with a CW tune indicator and an audio amp to make a great station accessory.

KC0PET
WB7AVF Rating: 2007-04-30
Nice! Time Owned: 0 to 3 months.
I'm still preparing to enclose it in an RF proof box, but initial tests (even with some stray BCI coming in) were great. REally pulls up the CW sigs and the output is very strong.

N2HTT Rating: 2007-04-10
Easy build - works great! Time Owned: 0 to 3 months.
Goes together in an evening, with really nice instructions including phased build with tests at the end of every phase. Mine went together without difficulty, but I did have a problem with the LM10 chip seating in the socket - DIP sockets are not provided, but are recommended. I had no audio out from the LM10 at first, but a little poking and prodding and everything then worked fine.

No enclosure is provided, but there is a little connector kit you can add on if you need audio/power connectors.

The kit fits nicely in an LMB CR-332 enclosure, looks great and works great.

Very good functionality and you can't beat the price.
AE6RQ Rating: 2007-01-27
A valuable addition Time Owned: 0 to 3 months.
The NEScaf circuit board was a quick and easy build, taking about 1.5 hours. Directions were straight forward and clear. Parts were kitted correctly, and the board is of very good plated through-hole quality.

The enclosure layout and drilling took _much_ longer, mainly because I decided to squeeze a Norcal keyer (http://www.eham.net/reviews/detail/4951) with pot for speed control and the NEScaf into the same 4" x 3.3" x 2.2" Jameco aluminum cabinet. Sure it isn't backpack portable now, but the combination makes a really attractive and functional accessory for my shack... but I digress...

The NEScaf does a great job with just a tiny bit of ringing when the bandwidth is narrowed down to its minimum. I really like the ability to continuously change the filter center frequency and bandwidth and the adjustment pots for gain and default center frequency are very thoughtful.

I also have a Oak Hills Research SCAF which lacks an easily adjustable center frequency (well - I could have easily added an external pot...) and which has a switch selectable set of discrete bandwidths. The NEscaf and OHR unit perform similarly and equally effectively. I do not notice any additional hiss added by the audio output amplifier.

For $30, this is a really good value, especially for CW operators.

Thanks NE QRP club!

-Dave
AE6RQ
VE3RPF Rating: 2007-01-21
A GR8 Filter Time Owned: 6 to 12 months.
I put the NEScaf filter together in about 1.5hrs. Easy construction and works super. For under $30 it is a great value.