[Elecraft] KAT3 in 6m

[Johnny Siu]

Hello Vic,
 
There is slightly different Z between the two RF paths through the ANT 1/2 relay switching.  
 
I think it is really no harm to have a swap between ANT 1 and ANT2 socket for 6 metre antenna if any elecrafter would like to have a try.  In fact, at the very first beginning, I have exactly the same feeling that the difference in cable length of 1-2 cm won't matter.
 
Anyway, it is an observation in my case and I am not sure whether it would be applicable in others. 

TNX & 73,


Johnny VR2XMC

從︰ Vic K2VCO <k2vco.vic at gmail.com>
收件人︰ Johnny Siu <vr2xmc at yahoo.com.hk>
副本(CC)︰ "elecraft at mailman.qth.net" <elecraft at mailman.qth.net>
傳送日期︰ 2011年08月17日 (週三) 8:51 AM
主題︰ Re: KAT3 in 6m

Well, that takes care of most of my points. There is a possibility that even 'bypass' is 
different for ant1/2, because, as you know, 'bypass' compensates for the reactance of the 
traces, etc. and does not actually remove the tuner from the circuit.

What makes me quibble is that I don't think that the very small difference in cable 
lengths -- 1 or 2 cm -- could possibly make a difference at 6 m.


On 8/16/2011 3:48 PM, Johnny Siu wrote:
> Perhaps, I should clarify my measurement. The power readings were taken by LP100A on a
> Bird dummy load under 'BYPASS' mode. To reiterate, in my case, I got higher RF output when
> connecting my 6m ant to ANT 1.
>
> TNX & 73,
>
>
> Johnny VR2XMC
> *從︰* Vic K2VCO <k2vco.vic at gmail.com>
> *收件人︰* elecraft at mailman.qth.net
> *傳送日期︰* 2011年08月16日 (週二) 11:37 PM
> *主題︰* Re: [Elecraft] KAT3 in 6m
>
> But keep in mind that the antenna tuner parameters are saved per band AND per antenna. So
> the tuner may be set slightly differently for the two antenna outputs. I suspect that if
> you set the tuner to BYPASS and checked with a dummy load they would be the same.
>
> Also many digital wattmeters have poor resolution. Maybe the difference between 82 and 92
> watts is just one bit and the power is close to 87 watts in both cases!
>
> On 8/15/2011 11:00 PM, Johnny Siu wrote:
>  >
>  > Hello Group,
>  >
>  > I found something interesting. As some of you may be aware the pin 1 wire to ANT1 is
>  > shorter than pin 2 wire to the ANT 2. All the way through, I connect my 6m hamstick to
>  > ANT2 and 20m hamstick to ANT 1.
>  >
>  > Last evening, I did a swap with 6m hamstick on ANT 1(the one with shorter pin 1 wire).
>  > I got 92w out which is more than the usual 82w. In other words, the length of the
>  > wiring from the pin to ANT socket does matter. In my case, I got higher RF output when
>  > connecting my 6m ant to ANT 1.
>  >
>  > There is no adverse effect to 20m hamstick which is connected to ANT 2. I just share my
>  > experience with other elecrafters with low RF output in 6m.
>  >
>  > TNX& 73,
>  >
>  >
>  > Johnny VR2XMC ______________________________________________________________ Elecraft