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k3 SWR readings seem generous

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Paul-285

Re: Re: k3 SWR readings seem generous

>"I always use 5W, ... when I tune up my external ATU."

I have my K3 set to use 0.2 Watt for tuning my external LDG tuner as
it will theoretically tune with 0.1 Watt.

Works great.

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Stewart Baker

Re: Re: k3 SWR readings seem generous

I need a little more RF tickling the spider's legs to get them to
move off the open wire feeder :-)

Stewart G3RXQ
On Sat, 03 Jan 2009 21:22:49 -0500, [hidden email] wrote:
>
>>"I always use 5W, ... when I tune up my external ATU."
>
> I have my K3 set to use 0.2 Watt for tuning my external LDG
tuner as

> it will theoretically tune with 0.1 Watt.
>
> Works great.
>
>
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Jeff Kinzli N6GQ

Re: k3 SWR readings seem generous

In reply to this post by Mike Scott-7

Mike, I see the same thing. My Autek says my antenna is 2.5:1, the K3
(#476) says 1.2:1 at the same frequency (numbers mentioned were on
40M).

My Palstar SWR meter pretty much agrees with the Autek.

-Jeff N6GQ

On Thu, Jan 1, 2009 at 17:47, Mike Scott <[hidden email]> wrote:

> I have been working on antennas today and have a puzzle. I am finding that
> the K3 SWR indications are unbelievable generous.
>
> With my 40M inverted V fed with RG8X (50 ohm) coax I see that the K3 seems
> generous in the SWR indication on tune with ATU bypassed. I have noticed a
> slight change in SWR with K3 power setting so the following was taken with
> K3 tune power set to 100 watts. If I set it to 10 watts the discrepancy is
> greater...
> SWR SWR SWR
> Freq. K3 VA1 Daiwa
> 7.00 MHz 1.3 1.92 2.0
> 7.05 MHz 1.2 1.92 1.9
> 7.1 MHz 1.2 1.98 1.95
> 7.15 MHz 1.3 2.26 2.1
> 7.2 MHz 1.9 2.60 2.3
> 7.25 MHz 1.5 2.88 2.6
> 7.3 MHz 1.6 3.32 2.7
>
> The Daiwa is the CN-101L cross needle meter. The VA1 is the Autek Rx Vector
> antenna analyzer. The VA1 does not have a tuned input so it is possible
> that it can be fooled by local broadcast stations. I don't suspect this
> issue here as there aren't any close by broadcast stations that I am aware
> of. The Daiwa and the VA1 tend to agree pretty well anyway. The K3
> measurements are the outliers. This antenna on a "Tenna Dipper" shows
> minimal SWR at 7.040 MHz, just where I tuned it a few years ago. The LED
> does not extinguish indicating higher than 1:1 SWR at the minimum. If you
> look at the numbers, I guess I don't believe the K3, Do you think my antenna
> is below 1.6 to 1 across the entire 40M band?
>
>
> So now on to 20M dipole fed with RG58 (50 Ohm Coax)...
> The Tenna Dipper fully extinguishes at 13.805 MHz indicating that my antenna
> is bit too long but is close to 1:1 at that frequency.
>
> Freq K3 VA1 Daiwa
> 13.81 -- 1.12 --
> 14.0 MHz 1.1 1.24 1.31
> 14.1 MHz 1.1 1.30 1.70
> 14.2 MHz 1.1 1.55 1.85
> 14.3 MHz 1.2 1.69 1.85
>
> RG58 may have some losses on this band so perhaps all of the SWR indications
> are generous, some more than others. The dipole is a low one and probably
> isn't 72 ohms at the feed point.
>
> Mike Scott - AE6WA
> Tarzana, CA (DM04 / near LA)
> K3-100 #508/ KX1 #1311
>
>
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ab2tc

Re: k3 SWR readings seem generous

Just for the record, I have excellent agreement between an external (MFJ-949E) SWR/Wattmeter and the indication on the K3, both at excellent SWR and poor ones such as those offered by my G5RVs when the external tuner is bypassed. Poor agreement here should not be considered normal.

Jeff Kinzli N6GQ wrote

Mike, I see the same thing. My Autek says my antenna is 2.5:1, the K3
(#476) says 1.2:1 at the same frequency (numbers mentioned were on
40M).

<snip>

hb9ari@bluewin.ch

Re: k3 SWR readings seem generous

Just a dumb question:
How do you insert the external SWR meter on the same node as the K3
internal SWR bridge?
I don't find an easy solution for my own comparisons.

HNY and 73 QRO,

Rudolf, hb9ari

ab2tc wrote:

> Just for the record, I have excellent agreement between an external
> (MFJ-949E) SWR/Wattmeter and the indication on the K3, both at excellent SWR
> and poor ones such as those offered by my G5RVs when the external tuner is
> bypassed. Poor agreement here should not be considered normal.
>
>
> Jeff Kinzli N6GQ wrote:
>
>> Mike, I see the same thing. My Autek says my antenna is 2.5:1, the K3
>> (#476) says 1.2:1 at the same frequency (numbers mentioned were on
>> 40M).
>>
>> <snip>
>>
>>
>>
>
>
> -----
> AB2TC - Knut
>

Don Wilhelm-4

Re: k3 SWR readings seem generous

Rudolf,

There is no way to do that external to the K3. It would only be
possible if one were to dig into the hardware and insert the external
wattmeter into the signal path between the KPA3 and the KAT3.
Unfortunately, that would require cutting traces inside the K3.

73,
Don W3FPR

hb9ari wrote:

> Just a dumb question:
> How do you insert the external SWR meter on the same node as the K3
> internal SWR bridge?
> I don't find an easy solution for my own comparisons.
>
> HNY and 73 QRO,
>
> Rudolf, hb9ari
>
>

hb9ari@bluewin.ch

Re: k3 SWR readings seem generous

Don,

Thank you for the explanations;
the difference between external SWR and
K3 SWR without ATU should be less then
the differences announced ?

73,

Rudolf, HB9ARI

Don Wilhelm wrote:

> Rudolf,
>
> There is no way to do that external to the K3. It would only be
> possible if one were to dig into the hardware and insert the external
> wattmeter into the signal path between the KPA3 and the KAT3.
> Unfortunately, that would require cutting traces inside the K3.
>
> 73,
> Don W3FPR
>
> hb9ari wrote:
>> Just a dumb question:
>> How do you insert the external SWR meter on the same node as the K3
>> internal SWR bridge?
>> I don't find an easy solution for my own comparisons.
>>
>> HNY and 73 QRO,
>>
>> Rudolf, hb9ari
>>
>