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Re: K3 Field-Test Firmware, rev 3.33 (Improved receiver low-frequency response)

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Jerry Lockett-2

Re: K3 Field-Test Firmware, rev 3.33 (Improved receiver low-frequency response)

Boy it really sounds good Wayne. AM broadcast quality. Outstanding job. I
really like it!

Jerry -n6jp-

On Fri, Sep 18, 2009 at 11:49 AM, Wayne Burdick - N6KR, Elecraft <
[hidden email]> wrote:

> Hi all,
>
> Thanks for your interest in the latest K3 field-test firmware (attached).
> It can be installed the same way as beta releases; see instructions on our
> web site.
>
> Please carefully read all the release notes for this revision, below. There
> are many changes besides the low-frequency AF improvement.
>
> One additional point I'd like to make regarding this. Remember that the K3
> is a *communications* radio, first and foremost. This is why the NORMalized
> low end of the AF passband is set to 100 Hz in SSB and AM modes. (That's a
> 2.8 kHz WIDTH, a center frequency of 1.5 kHz, and thus a lo-cut value of
> 0.10 kHz.) Putting the filter low edge at 100 Hz at all three points in the
> receive chain -- crystal filter, 15 kHz IF, and AF -- minimizes
> adjacent-channel low-frequency QRM.
>
> Now, with the release of this new firmware, you can override our sensible
> low-frequency cutoff :) When you adjust SHIFT, WIDTH, or LOCUT such that the
> passband is skewed lower, you'll get much richer/fuller bass, but you are of
> course inviting additional QRM on the low end. So be ready to NORMalize
> again if necessary.
>
> Let me know how your testing goes.
>
> 73,
> Wayne
> N6KR
>
> MCU 3.33 / DSP 2.30, 9-18-2009
>
> * IMPROVED RECEIVE LOW-FREQUENCY RESPONSE in
> AM, SSB and CW modes. (For best results, use headphones or external
> speakers with extended bass.) NORMalizing the DSP passband still
> sets the low-frequency bound to about 100 Hz in AM and SSB modes.
> But by using SHIFT, WIDTH or LO CUT, you can extend the audio
> response to around 50 Hz. User-configurable NORM1 and NORM2
> settings, or presets I/II, can then be used to store desired values
> (per-mode). The two lowest MAIN:RX EQ ranges (50 and 100 Hz)
> can be used to further enhance bass.
>
> * SUB RX NOISE BLANKER NOW FULLY INDEPENDENT OF MAIN:
> This includes the on/off state and NB LEVEL settings. Note: Set
> CONFIG:NB SAVE to YES if you wish to keep the noise blanker ON
> even when changing bands. The NB on/off state is stored on a per-band
> basis for both main and sub receivers.
>
> * DSP INTERNAL ERROR MONITORING: The DSPs now do additional
> self-checking so they can automatically detect and prevent any type of rare
> AF output anomaly. If you hear anything unexpected, please report
> the associated information to Elecraft. While in the TECH MD menu entry,
> tap 1 (main) or 2 (sub) to display the most recent data, shown in
> hexadecimal.
> If it is “FFFF”, no error has been detected. After writing down the values,
> tap CLR to reset them, allowing additional errors to be trapped if
> necessary.
>
> * PL TONE DEVIATION ADJUSTABLE: Tapping '1' in CONFIG:FM DEV
> changes menu entry name to "PL DEV" and allows setting PL tone deviation
> from 300-600 Hz in 30-Hz steps (default is 360 Hz).
>
> * EU REPEATER 1750 HZ PL TONE BURST: In FM mode, if PL TONE is
> selected and the tone pitch is set to 1750 Hz (using the PITCH switch), a
> 500 ms tone burst at 1750 Hz will be transmitted on each activation
> of PTT. As a reminder, the -T icon will flash briefly at the start of each
> of
> each transmission, then turn off until you’ve finished transmitting.
>
> * EXTENDED 6-METER TUNING RANGE: The VFO can now be tuned
> down to 44 MHz to monitor signals that may be correlated with 6-meter
> band openings. Since the K3 has narrow band-pass filters, loss rapidly
> increases as the VFO is tuned below 49 MHz (-34 dB typ. at 45 MHz). If a
> preamp is in use ahead of the band pass filter (such as an Elecraft PR6),
> the
> noise figure may still be adequate for monitoring strong 44-49 MHz signals.
>
> * KEYPAD (1-9) SWITCH TONES WORKING FOR M>V AND V>M, M1-x:
> Some keypad switches weren't producing a dual tone during memory
> store/recall operations and message play.
>
>
>

AD4C2009

Re: K3 Field-Test Firmware, rev 3.33 (Improved receiver low-frequency response)

I installed tonight the new FW 3.33 released and man oh man,what a big difference in audio quality,my K3 now goes down to 50Hz,reception in AM broadcasting is a delight and also when I tune ESSB stations in my Sony headphones or my HiFi speaker is like hearing a broadcast on AM as well,for the ones interested to hear and also see my audio now,I have prepared a couple of audio graphs and a recording from a guy at PA with wide audio that talked to me few mins ago on 40M,this new FW is a success at least on my K3.

AD4C
K3 and K2

"The difference between genius and stupidity is that genius has its limits". -- Albert Einstein

--- On Sat, 9/19/09, Jerry L <[hidden email]> wrote:

From: Jerry L <[hidden email]>
Subject: Re: [Elecraft] K3 Field-Test Firmware, rev 3.33 (Improved receiver low-frequency response)
To: "Wayne Burdick - N6KR, Elecraft" <[hidden email]>
Cc: [hidden email]
Date: Saturday, September 19, 2009, 12:13 AM

Boy it really sounds good Wayne. AM broadcast quality. Outstanding job. I
really like it!

Jerry -n6jp-

On Fri, Sep 18, 2009 at 11:49 AM, Wayne Burdick - N6KR, Elecraft <
[hidden email]> wrote:

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