[Elecraft] KX3 power out

[Dave B]

Hi.

I would not trust a Bird 43 or similar meter for any "Measurements"
whatsoever.

Especially if you cannot prove that the slugs and meter body were
calibrated together.

They are notoriously inaccurate, but are good for quick "power presence"
indications, and "ball bark" VSWR checks.

I honestly do not know why Bird 43's etc, are so coveted by the ham
community, they are awful things for making measurements..

Note that the difference between 8W and 15W, is a bit less than 3dB.
(2.73dB, or less than half an 'S' point!)

And for 3 and 2.5W it's 0.79dB  (Less than 1dB is not bad.)

Also, how good is the MFJ load at VHF, VSWR wise.  The spec says 1.5:1
above 30MHz.  What did the radio say about that?

73.

Dave G0WBX (Who's spent the last 30+ years working with QRO RF for a
living.  kHz to 10's of GHz, and many 10's of kW's.)


On 11/07/2020 20:40, elecraft-request at mailman.qth.net wrote:
> From: Frank O'Donnell <vfo77 at inkbox.net>
> To: "elecraft at mailman.qth.net" <elecraft at mailman.qth.net>
> Subject: [Elecraft] KX3 power out
> Message-ID: <07eb80bf-c36b-e2f8-b4f8-52144e84b09c at inkbox.net>
>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> After a fair time of non-use, today I got out my KX3 and started working 
> through configuration checklists. Among other things I thought I'd check 
> the power out.
>
> For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used a 
> Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I put 
> the KX3 in CW mode and keyed with the KXPD3 paddle. When changing to 
> each HF band I hit the ATU Tune button.
>
> On 40m and 20m I found that with the Pwr knob set to 15w, the Bird 
> showed about 8w out. With the Pwr knob set to 5w, the power out is about 3w.
>
> After changing the antenna port and Bird element, on 2m with the radio 
> set to 3w the Bird shows about 2.5w out.
>
> Any thoughts on these results, or suggestions on other things to check?
>
> Thanks and 73,
>
> Frank K6FOD

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