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Reviews For: MSC

Category: Filters, Audio: (DSP and others)

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Review Summary For : MSC
Reviews: 3MSRP: 195.
Description:
Super SCAF (switched capacitor audio filter)
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0034.7
DH5AK Rating: 2018-06-08
Does a very fine job! Time Owned: more than 12 months.
All switched capacitor filters have the advantage that they do not ring, even not at a very low bandwidth, as analog filters do. They do not produce any artefacts as many DSP based filters do. They just add a small portion of noise, but this is a really small disadvantage.

So the Smart Filter made by MSC does this job as most other of these SC-filters do. Its additional advantage is its simple usage due to its very intuitive designed front panel and user "interface".

After switching "Power on" the filter is in the SSB mode and you can set the frequency limits for the lowpass section (starting at some 100Hz) and the highpass section (ending at some 3000Hz) of this filter, both centered around 1000Hz, set by the two control knobs. The LED-scale shows which range of frequencies are heard now. There is nothing to guess, all is shown on the LED-scale.

After pushing the "SSB/CW Select" button the filter goes to CW mode. Here you have a different function of the two control knobs, one is "Bandwidth" going from some 900Hz down to a few 10Hz, the second is "Center Frequency" shifting this bandwith in the range from 200Hz - 1100Hz. The LED-scale shows how wide the filter is and where its bandwidth is placed in the range from 200Hz - 1100Hz.

What a fine and intuitive design! I underline what I stated at the intro of this review: NO ringing and NO artefacts come from this filter. The small portion of noise added through the SC-filter circuits does NOT disturb me at all!

I have been looking quite a while for this filter - and for its compareable companion, the "Super-SCAF" made by AFTRONICS. Both filters have the same chipset of SC-filters. Both work as well but the MSC filter is a LOT simpler to use. The Super-SCAF used BCD thumbwheel switches, which are a bit awkward to use. Both filters seem to be as rare as hen teeth, so if you find one on a ham radio swap meeting, buy it! You will not be disappointed by its performance, not of the MSC and not of the AFTRONICS filter. Just that the MSC filter is SO much simpler to use.

If you find one of these filters, bought it and plugged the mains supply in, at first they (may) seem not to work properly. These filters are OLD, they come form the early 90s! Therefore their electrolyte capacitors may be dried out. With a small sum of money and half an hour of work you can exchange all of the electrolyte capacitors by new ones. This is easy done. My MSC filter showed erratic behaviour and after soldering new capacitors to the board it worked perfect! Be very careful when doing this with the MSC filter, as its interna wiring is done by "Wire Wrap" with solid wires. These break easy. Even if you should find out that the SC filter ICs should be damaged (what hardly will happen) you can find these still at offered eb..

We have 230V mains voltage here in DL, but the filters need 110V as both use a transformer as they need an additional negative DC supply voltage. This was no problem for me as I had enough small mains transformers in my junk pile. It is surely easy to find a matching one where you live, if you have the same situation as I do.

So all in all, this filter does a very fine job for all audio filtering in a ham radio or SWL station. I give it a 5++!
K3YD Rating: 2001-09-27
Excellent Time Owned: more than 12 months.
This filter is a real aid with less selective transceivers on CW, phone and even digital modes when the narrow CW filter can't be used (i.e. PSK31) Unlike other audio filters I've used, this one adds no hum, ringing or noticeable distortion.
Downsides? Well, it operates outside the AGC loop, it can't be run on 12 V. DC, and it lacks the notch capability of a modern DSP filter. I think it's very similar to the electronics in the Alpha Delta VRC-2 speaker.
I've owned mine for about 12 years and continue to find it useful. It's a 4 relative only to my NIR-12 which has notch capabilities, but I still prefer the interface of the MSC Smartfilter.
KA1BTI Rating: 2001-09-27
Best Non DSP? Time Owned: 0 to 3 months.
Having used several different audio filters before, I can honestly say this one is the best of the bunch.... by Far!

Easy to use (I don't have a manual with mine) and versatile. In CW mode, it has adjustable center/bandwidth frequencies, and on SSB, adjustable Low/High Frequency cutoffs. Also a filter in/out switch, nice LED bar-type display, and a front panel phone jack.

It is not produced anymore (a shame) but you can still find them used. Well worth the small investment.