K3: RF Calibration / RF output

[Edward R Cole]

I obtained a brand-new calibrated 25H element for my Bird43 power
meter, today.  I checked power out on my K3/10 set to 12.0w.
80m = 11w
40m = 11w
20m = 11.5w
15m = 11.5w
10m = 11.5w
all measurements into a Bird 25w coaxial termination

I assume running the Tx gain calib. at 5w will result in adjusting
the upper end of power output to 12.0w.  Or is the power that I am
seeing the max available?

I had previously measured output at 15w with my 100H element but this
is apparently in error.  The 100H element is old so probably out of
calibration and accuracy at 15% full scale is not that good, anyway.

I tested at 5.0w at 28 MHz comparing the reading using the 25H
element with a 5A element and got exactly the same reading.


73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
DUBUS Magazine USA Rep [hidden email]
"Kits made by KL7UW" http://www.kl7uw.com/kits.htm
======================================
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[Bill W4ZV]

Edward R. Cole wrote

I obtained a brand-new calibrated 25H element for my Bird43 power
meter, today.  I checked power out on my K3/10 set to 12.0w.
80m = 11w
40m = 11w
20m = 11.5w
15m = 11.5w
10m = 11.5w
all measurements into a Bird 25w coaxial termination

Bird accuracy is +/-5% of full scale (25W for your slug) or +/- 1.25 Watts, so the above is within spec.  If you want better accuracy, consider the LP-100A which is +/- 5% of reading.  At 12 Watts, this would be +/- 0.6 Watts or twice as good as a Bird...and probably cheaper as well considering the cost of a comparable set of slugs.

http://www.telepostinc.com/lp100.html

73,  Bill

[Edward R Cole]

Bill,

The 25H element was special-ordered thru Radiodan W7RF
<<mailto:[hidden email]>[hidden email]>,
who has the ability to run NBS traceable calibration, so with no
better reference, I am taking the readings on the new element as
accurate (and my standard for HF).  A little late to save me money on
Bird elements as have 16 ranging from 5w to 2500w, and HF to
1800-MHz.  If I had the cash it would be nice to send meter and
elements to Dan for calibration.

A note that may be of interest:  I ran the wattmeter calibration on
my K3 and setting 5w to accurately output 5w as indicated by the Bird
25H required changing my WTMR LP setting from 70 to 50.  I then ran
the Transmit Gain Calibration and have 12.5w indicated output from
160m-10m.  On 6m the 25H is out of freq. range so reads low, but I
have both a 5A and 50A element that indicates I'm getting close to 8w.

I will be interested to see what the output of my new 300w amp runs
at these levels (previously getting 270w with 11.5w; Bird 500H).  I
was getting 125w out on 6m with my Mirage A1015G.  The Harris
Platinum Amp should provide 10-dB (800w) on 6m.

----------------------------------
Date: Tue, 13 Mar 2012 04:39:11 -0700 (PDT)
From: Bill W4ZV <[hidden email]>
Subject: Re: [Elecraft] K3: RF Calibration / RF output
To: [hidden email]
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=us-asci

Edward R. Cole wrote

 > I obtained a brand-new calibrated 25H element for my Bird43 power
 > meter, today.  I checked power out on my K3/10 set to 12.0w.
 > 80m = 11w
 > 40m = 11w
 > 20m = 11.5w
 > 15m = 11.5w
 > 10m = 11.5w
 > all measurements into a Bird 25w coaxial termination

Bird accuracy is +/-5% of full scale (25W for your slug) or +/- 1.25 Watts,
so the above is within spec.  If you want better accuracy, consider the
LP-100A which is +/- 5% of reading.  At 12 Watts, this would be +/- 0.6
Watts or twice as good as a Bird...and probably cheaper as well considering
the cost of a comparable set of slugs.

http://www.telepostinc.com/lp100.html

73,  Bill





73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
DUBUS Magazine USA Rep [hidden email]
"Kits made by KL7UW" http://www.kl7uw.com/kits.htm
======================================
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html