Current use K3/10 vs. K3/100

[Bill Frantz]

Remembering the thread about how much current a K3/100 used when
powered off, I decided to run a test as I installed the KPA3 in
K3 #6299. The table below lists power use before (K3/10) and
after (K3/100) 100w amp was installed. A monospaced font will
help legibility.

Test conditions: Direct connection to a 12v battery. RF and AF
gain at zero. CW mode. No RS-232 connection. P3 power unplugged.
IF out disconnected. MFJ dummy load. Tuned to 14.0475. Fluke 87
meter for current. Internal K3 meter for voltage. Straight key
held down until current reading stabilized (c10 seconds.)

K3/10            K3/100           Measurement
0.1microA N/A V  4.1mA N/A V      Power off idle current
873mA 12.1V      969mA 12.1V      Receive
2.57A 10.8V      2.87A 11.0V      Transmit 5W
3.19A 10.4V      3.53A 10.6V      Transmit 10W

The K3/100 uses 11% more power on receive, 12% more power on QRP
transmit, and 11% more power on ten watt transmit. It may be
worth removing the 100w amp for QRP battery field day like operations.

Note that the PA temperature calibration changed the value by 3
degrees C. (This time I put a brewing thermometer next to the
radio to act as the "standard" temperature. The last time I
think I used the wall thermometer.) The MacIntosh K3 Utility did
the Wattmeter calibration. As far as I know, these were the only
changes to the radio's settings.

Cheers - Bill, AE6JV

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[wayne burdick]

Bill,

During K3/100 testing, did you try the current-drain measurements with CONFIG:KPA3 set to PA BYP? This may be lower than what you get with KPA3 set to PA NOR and the POWER control set to QRP levels.

73,
Wayne
N6KR


On Jan 5, 2014, at 11:58 PM, Bill Frantz <[hidden email]> wrote:

> Remembering the thread about how much current a K3/100 used when powered off, I decided to run a test as I installed the KPA3 in K3 #6299. The table below lists power use before (K3/10) and after (K3/100) 100w amp was installed. A monospaced font will help legibility.
>
> Test conditions: Direct connection to a 12v battery. RF and AF gain at zero. CW mode. No RS-232 connection. P3 power unplugged. IF out disconnected. MFJ dummy load. Tuned to 14.0475. Fluke 87 meter for current. Internal K3 meter for voltage. Straight key held down until current reading stabilized (c10 seconds.)
>
> K3/10            K3/100           Measurement
> 0.1microA N/A V  4.1mA N/A V      Power off idle current
> 873mA 12.1V      969mA 12.1V      Receive
> 2.57A 10.8V      2.87A 11.0V      Transmit 5W
> 3.19A 10.4V      3.53A 10.6V      Transmit 10W
>
> The K3/100 uses 11% more power on receive, 12% more power on QRP transmit, and 11% more power on ten watt transmit. It may be worth removing the 100w amp for QRP battery field day like operations.
>
> Note that the PA temperature calibration changed the value by 3 degrees C. (This time I put a brewing thermometer next to the radio to act as the "standard" temperature. The last time I think I used the wall thermometer.) The MacIntosh K3 Utility did the Wattmeter calibration. As far as I know, these were the only changes to the radio's settings.
>
> Cheers - Bill, AE6JV
>
> -----------------------------------------------------------------------
> Bill Frantz        | If the site is supported by  | Periwinkle
> [phone]      | ads, you are the product.    | 16345 Englewood Ave
> www.pwpconsult.com |                              | Los Gatos, CA 95032
>
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[Bill Frantz]

On 1/6/14 at 9:32 AM, [hidden email] (Wayne Burdick) wrote:

>During K3/100 testing, did you try the current-drain
>measurements with CONFIG:KPA3 set to PA BYP? This may be lower
>than what you get with KPA3 set to PA NOR and the POWER control
>set to QRP levels.

I retried the measurements changing "PA NOR" to "PA not
installed" and "PA not installed" after power cycling
(rebooting) the radio. Most numbers differed only by one in the
least significant value. [Welcome to digital measurements. :-)]
The 10 watt measurements were 40mA less than yesterday,
3.49A@10.3V vs. 3.53A@10.6V but the difference isn't very
significant and may be explained by the difference in voltage.
(However, I would expect higher current with less voltage.)

Cheers - Bill, AE6JV

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