K3 transmitter gain setting?

[Dave, G4AON]

Following the release of the latest manual, I note the emphasis on
needing to set the transmitter gain on each band, at both low (5W) and
high (50W) power levels. What isn't clear is whether it's preferable for
those with an _accurate_ Wattmeter, to set the gain based on the K3
display or an external meter. Having previously set the K3 power
metering on the 20m band, the differences per band are not great and
perhaps academic, but I would like to know which is the best method of
setting the gain as the manual doesn't mention using an external power
meter at this point?

For what it's worth, I used an LP-100 power meter and set the gain for
the power as indicated on the external meter. Having set each band, both
at 5W and 50W, exited the menu, etc. The power levels were within 1 Watt
at the 50 Watt power output setting on "tune" on every band... The
LP-100 is a calibrated unit and within 5%.

Dave, G4AON
K3/100 #80
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[dj7mgq]

Hallo Dave,

after having done this last evening...

Adjust the built power meter on 20 meters by measuring the power with an
external meter, exit the menu and then set your power to 5W. Go to 160 (make
sure that you are always in band) and push the tune button. Wait for a couple of
seconds until the power (K3 display) settles at 5 watts. Repeat for all bands.

Repeat the above for 50W.

Repeat for transverter interface.

In other words you do not need a power meter for the TX gain part, it is
required only for the power meter adjustment. The gain is set auto-magically by
the K3. Also you do not need to be in any menus, etc.

One word of caution, I built my K3 at our club station, where we do not have a
connection to the Internet, and was not sure about where the 60m QRGs in the US
& UK actually are. I tried to do the TX gain for 60 meters something like 100kHz
too low. And while the K3 did transmit, I was too far down the flank of the
filtering for TX gain to work. Took me a while to figure out....

vy 73 de toby
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[wayne burdick]

This is an internal gain calibration step that requires power to be set
at exactly 5.0 and 50 W respectively. There's no need for an accurate
wattmeter at this point. The K3's watt metering can optionally be
calibrated in a later step (CONFIG:WMTR).

We'll clarify this in the manuals.

73,
Wayne
N6KR


On Nov 22, 2007, at 3:13 AM, Dave G4AON wrote:

> Following the release of the latest manual, I note the emphasis on
> needing to set the transmitter gain on each band, at both low (5W) and
> high (50W) power levels. What isn't clear is whether it's preferable
> for those with an _accurate_ Wattmeter, to set the gain based on the
> K3 display or an external meter. Having previously set the K3 power
> metering on the 20m band, the differences per band are not great and
> perhaps academic, but I would like to know which is the best method of
> setting the gain as the manual doesn't mention using an external power
> meter at this point?
>
> For what it's worth, I used an LP-100 power meter and set the gain for
> the power as indicated on the external meter. Having set each band,
> both at 5W and 50W, exited the menu, etc. The power levels were within
> 1 Watt at the 50 Watt power output setting on "tune" on every band...
> The LP-100 is a calibrated unit and within 5%.
>
> Dave, G4AON
> K3/100 #80
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>

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