KX1- 80m and random wire

[Pierre Desjardins]

Hi Elecrafters,

For field operations with a KX/40.30.20m, I currently use a 28 feet random
wire at the end of a 22 feet pole, and an single 16 feet radial on ground.
The computed impedance is 89 - j 341 ohms  at 7 MHz,  matched by the
KXAT1.

However, at the low end of 80 m, it should be around 54 - j 1316 ohms,
giving very high SWR. Can the ATU match such values?

    72, de VE2PID
    KX1 s/n 442
    K2/100 s/n 5170


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[wayne burdick]

Only if you roughly triple all of the L and C values in the ATU. This
would of course sacrifice tuning performance on the higher bands. A
better alternative would be to either use a longer wire on 80 m, or
insert an inductance in series with the wire. Some experimentation will
be required.

Then there's the T1  :)

73,
Wayne
N6KR


Pierre Desjardins wrote:

>
> For field operations with a KX/40.30.20m, I currently use a 28 feet
> random
> wire at the end of a 22 feet pole, and an single 16 feet radial on
> ground.
> The computed impedance is 89 - j 341 ohms  at 7 MHz,  matched by the
> KXAT1.
>
> However, at the low end of 80 m, it should be around 54 - j 1316 ohms,
> giving very high SWR. Can the ATU match such values?
>
>    72, de VE2PID
>    KX1 s/n 442
>    K2/100 s/n 5170

---

http://www.elecraft.com

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[John Young-10]

Until I get the KX1-8030 installed this is just speculation - so FWIW.
I have ordered the Altoids Longwire Antenna Tuner from www.qrpkits.com.
For $30 you get a small L network tuner with a max 16uh and 270pf.  As is,
the cap is only at the output end, but that can be made switchable
to put it at the input side when needed.

If the KXAT1 can't tune my antenna on 80 I will try the ALT as a
'pre-tuner'.

73  John
WA8KNE


Pierre Desjardins wrote:

> Hi Elecrafters,
>
> For field operations with a KX/40.30.20m, I currently use a 28 feet
> random
> wire at the end of a 22 feet pole, and an single 16 feet radial on
> ground.
> The computed impedance is 89 - j 341 ohms  at 7 MHz,  matched by the
> KXAT1.
>
> However, at the low end of 80 m, it should be around 54 - j 1316 ohms,
> giving very high SWR. Can the ATU match such values?
>
>    72, de VE2PID
>    KX1 s/n 442
>    K2/100 s/n 5170
>
>
> _______________________________________________
> 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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