[Elecraft] Free DV (digital voice as reported in QST-Aprilissue)

Thu Apr 4 07:43:47 EDT 2013

Probably you are suffering the bandwidth issue about standard power meter.
Power meters used on shack are designed to measuring CW signals, single
tone signals. DV use a fixed bandwidth with multiple carriers that can
produce erroneous measures on standard watt-meters.

Edu YY4GMJ

On Thu, Apr 4, 2013 at 6:40 AM, John Sweeney <n3wt at comcast.net> wrote:

>
>
>
> > Since the subject is the Digital Voice with a K3.
> >
> > I have operated the DV voice with my K3 with the ALC showing the 5 to 7
> bars as recommended.  However, even if I set the power out to 50 watts or
> more, the maximum I can see on an external watt meter is at most 30 watts
> indicated.   I only see this limited power out indicated on the DV program,
> other digital modes programs I show as high or low as I set the power out
> for.
> >
> > Is this normal with the DV program, latest version?
> >
> > 73,  John,  N3WT
>
> > Lyle answered me offlist and told me to RTFM, page 18.  It's right there
> in black and white.
> >
> > 73 -- Lynn
> >
> > On 4/3/2013 3:37 PM, Don Wilhelm wrote:
> >> Lynn,
> >>
> >> I have no verification, but the KX3 is "similar" (but not necessarily
> >> the same).  Note that the KX3 voice calls for 5 bars on the ALC meter
> >> for voice, while the K3 calls for 5 to 7 bars.  That says that there may
> >> be some difference.
> >>
> >> We will have to wait for Lyle or Wayne to chime in with the real info on
> >> the KX3 ALC onset point.
> >>
> >> In the meantime, I would suggest that the answer is "yes" set the KX3
> >> audio for 4 bars and assume that is the "no ALC" point.  The 5th bar
> >> would then indicate ALC is being activated.
> >>
> >> The power control in the KX3 is similar to the K3, so if the audio level
> >> is too low, power creep will be the result.
> >>
> >> BTW, for those using the K2, the situation is similar, but the K2 ALC
> >> meter does not have the "VU meter" scale at the low end.  If the K2 ALC
> >> indicator flickers, it means ALC has occurred.  For the K2, increase the
> >> audio until you see an ALC indication, and then back off until it is
> >> gone.  The power control on the K2, K3 and KX3 are essentially the same
> >> - a closed loop system that attempts to produce the power output
> >> requested on the power knob.  Most transceivers do not do this closed
> >> loop power control, but instead use an open loop system that depends on
> >> the drive level alone.  That is why the traditional advice to use the
> >> audio drive level to control the power output works well with most
> >> transceivers, but it does not work well with Elecraft transceivers
> >> because they use a closed loop power control system.  Only Elecraft and
> >> some commercial transceivers use this closed loop power control system.
> >>
> >> 73,
> >> Don W3FPR
> >>
> >> On 4/3/2013 5:53 PM, Lynn W. Taylor, WB6UUT wrote:
> >>> Is it safe to assume this is true of the KX3 as well?
> >>>
> >>> -- Lynn
> >>>
> >>> On 4/3/2013 11:47 AM, Don Wilhelm wrote:
> >>>> Well, I 'thought' was in the manual, and it *should* be.
> >>>>
> >>>> Lyle has explained several times here on the reflector (and he should
> >>>> know, he designed it) that the onset of ALC action is at the 5th bar.
> >>>> The bars below that do not indicate ALC action at all.
> >>>>
> >>>> Due to the way the K3 controls power, if you do not have sufficient
> >>>> audio, the K3 will increase power (thinking there is not enough drive)
> >>>> and you will find your power drifting upward as you transmit.
> >>>>
> >>>> So adjust for 4 bars on the ALC meter (that is *no* ALC) so your power
> >>>> will be uniform throughout the transmission.  With the K3 you must
> have
> >>>> sufficient audio drive to allow the power controls to work as they
> >>>> should.
> >>>> Contrary to the advice given for most transceivers (which do not
> control
> >>>> power in a closed loop), the K3 power will behave strangely if you use
> >>>> that advice - which is to set the power for maximum and use the audio
> >>>> drive to control the power output.  That just will not work with the
> K3.
> >>
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