Here is some lunchtime testing results:
I don't think my calibrator is accurate on the scope, or the probe
from a textronics is not the same as the scopes maker, so these
are just comparisons...5 watts out selected, into the 49.8 ohm
resistor load.
X10 scope probe, 2 volts per division selected on the scope,
adjusted to give 4 full divisions on 80 meters at 5 watts out...
band wattage out per my meter oscope divisions
80 6 4
40 6.5 3.5
20 5 3.5
15 4 3.3
10 3 2.8
That ROUGHLY tracks.
The rig itself read about 6 watts on all the bands
give or take 1/2 a watt.
I then measured the rf with the oscope at the diode, RF side
(D9) and got the same results, rf voltage decreases with frequency.
On the C77 side (cold), I probed with the scope and the waveform
had spikes and looked odd but everything went UP with frequency.
That sort of makes me suspect the diode.
Anyone know what cross references roughly with a 1N5711.
I have lots of diodes in the junkbox.
Do other people have the low output problem at higher
frequencies?
Brett
N2DTS
>
> Back when I was gainfully employed, we ran into a serious
> problem with our metal film resistors. The film was etched
> in a spiral like a barber pole, resulting in a beautiful
> inductor in series with the resistor as measured at low
> frequency (or not at all). We had to change our tech
> description to specify non-inductive only. I wonder if these
> higher band low power readings (my rig, too,) could be
> because there is an implicit inductor in the power sense 1%
> resistors, and the K2 is doing what it is told from a
> reactive circuit.
>
> Maybe that is a player in the low power enigma?????????
>
> It might be something for Elecraft to look at in their spare
> time. :-)
>
> 73,
>
> Bill
> NA7Y
>
> PS: I have 7W on10M on the K2 display.
>
_______________________________________________
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.htmElecraft web page:
http://www.elecraft.com
Locked
