[Elecraft] Elecraft technology >> K2+

[George, W5YR]

Full agreement with Don re the FL1 and FL3. The FL3 is especially phenomenal
in its operation in all modes. For an analog filter, it produces almost
unbelievablely good results in filtering and notching.

These are no longer being made and are collector's items. Due to the
diligence of Dr. Megacycle at a hamfest, I am the proud owner of a virtually
brand new FL3 complete with all documentation, including the original bill
of sale. It fits precisely on top of the K2 and is close enough in color to
at least be in the family. I owe Jim a debt of gratitude for spotting this
one for me.

Be on the lookout on Ebay and every hamfest you attend for a Datong audio
filter. I bought my FL1 from a dealer because it was DOA out of the box -
think I paid him $10 for it! They sold back in the 70's for $300 or so! The
problem was a defective chip whose replacement I obtained at Radio Shack for
a buck . .

One last comment: the FL1 is a good audio filter but the FL3 .is an order of
magnitude better in all respects.

73, George W5YR
w5yr@att.net


----- Original Message ----- 
From: "Don Allen" <w9cw@intergate.com>
To: "Jim Brown" <jimbrown.enteract@rcn.com>; <elecraft@mailman.qth.net>
Sent: Monday, December 29, 2003 1:31 PM
Subject: Re: [Elecraft] Elecraft technology >> K2+


> Jim Brown wrote:
>
> >On Mon, 29 Dec 2003 11:59:49 -0500, Floyd Sense wrote:
> >
> >
> >
> >>My question is: does the KDSP2 auto-notch function degrade voice
readability
> >>or does it function more like the MFJ?
> >>
> >>
>
> I've owned some of the better DSP audio filters including the Timewave
> 599zx, JPS NIR-10, and dual-DSP JPS NIR-12.  All have fast acting and
> deep auto-notch functions.  However, the best auto-notch functions I've
> ever used are analog, and available in the Datong (Dr. David Tong in the
> U.K.) FL1 and FL3.  Both the FL1 and FL3 can be used in the auto-notch
> mode or manual notch, and the notch depths (to my ear) are as deep or
> deeper than any of the aforementioned DSP units.  More importantly,
> neither the FL1 or FL3 seem to distort the voice while using the notch
> function to the level a DSP-based notch does.  And, the auto-notch  is
> very fast in operation.  Both of these filters also include the normal
> bandpass op amp-based filters.  These units were available from around
> 1977 through 1984 I believe.  Just a thought, as not everything has to
> be DSP-based to work well . . .
>
> Don W9CW