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Reviews For: Datong FL1

Category: Filters, Audio: (DSP and others)

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Review Summary For : Datong FL1
Reviews: 4MSRP:
analog audio filter
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
WK0F Rating: 2004-10-15
Great filter Time Owned: 0 to 3 months.
Picked one up off of eBay, and I'm surprised at the difference it makes with my IC-718. It is much more versatile than an internal filter. It really pulls signals out of the mud! Buy one if you can find one!
G4IRX Rating: 2004-06-13
Good performer, easy to use. Time Owned: more than 12 months.
Bought new in 1986.
I have used this filter under a variety of different operating conditions, it performs flawlessly and has never let me down once.
When used for SSB operation the auto-notch will lock on and track almost instantaneusly. For CW operation the bandwidth can be wound down to around 50Hz with no sign of ringing (a common problem with cheaper AF filters) and there is even an AFC facility to track the change in pitch of the signal.
Overall extremely easy to use.
Signal input/output is via a 5-pin DIN socket and power connection is a via a DIN speaker socket. There is also a front panel headphone socket.

I have a few minor complaints which prevent me from giving it the full 5 points:
- The control pots go noisy requiring an occasional clean with contact cleaning fluid.
- The original headphone socket was a 1/4" mono which I swapped for a stereo socket.

Datong uk no longer manufacture amateur radio products. A great loss in my opinion as they made some really excellent products.
W9CW Rating: 2003-11-30
Great Filter Time Owned: more than 12 months.
I've owned the Datong FL1 audio filter since 1980. Prior to its acquisition, I owned an Autek QF-1A. The FL1 is superior to the QF-1A in every respect. Dr. David Tong of the UK designed some exceptional products in the '70s and '80s. I prefer the FL1 for CW use over all the other filters currently on the market, including all of the external DSP filters. The FL1 controls are smooth, large enough to easily control with normal-sized fingers, and it simply works! The filter bandpass is easily adjustable and the filter provides sufficient stop band rejection without any ringing. The "Auto Notch" works as well as any DSP-based notch. I've used every external DSP audio filter, and I keep coming back to the FL1 and the later Datong FL3. No doubt, both are the pinnacle of analog op amp audio filter design. Some of the connectors on the back panel are UK-type connectors, but they are easy to find, or change out if necessary. And, it has the capability to work with an internal battery, rather than an external +13.8VDC source. If you can find an FL1, grab it - you won't be disappointed.
ON6AB Rating: 2002-12-15
Superb Time Owned: more than 12 months.
Guess I have the FL1 for about 20 years now...
Compared to the Timewave 59+ I own for a year, these are my findings:
The Timewave has of course much sharper filtering and far more "out-of-band" attenuation both in band pass and band rejection mode, but in my opinion it's overkill on AF. I produces quite a lot of "computer" out-of-band birdies too. (weak but noticeable).
The FL1 operation is smooth and precise and the auto/manual notch is exellent, able to produce a narrow notch of -30dB that is even capable of filtering out nasty tones in between the FSK441 frequencies. No birdies.
The Timewave has no manual notch filter. They should fire it's designer for this!
The sharp skirts of the Timewave filtering looks great on paper, but it makes listening rather unpleasant in SSB. That's why on very expensive transceivers, you can set the DSP skirts to steep or gradual (gradual - like the FL1 - hi). That's for instance the reason why the TS570 sounds so good (gradual DSP filtering).
Concerning noise reduction they are equal: the FL1 has none and the 59+ noise reduction is plain WORHTLESS.
The Timewave is nice for cw although it produces more ringing than the FL1 on very narrow filter settings.
I you want to buy a "good" Timewave 59+, please give me a call.
The Datong is not for sale...