Towertalk
[Top] [All Lists]

Re: [TowerTalk] HIGH SWR because of loops between amp and wattimeter

To: "towertalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] HIGH SWR because of loops between amp and wattimeter
From: "David J. Sourdis - HK1A" <hk1kxa@hotmail.com>
Reply-to: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Date: Sun, 25 Apr 2010 13:55:54 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Me parece que tienes el cable coaxial acoplándose a la antena y al variar la 
longitud cambia la sintonía. Tienes un buen choke o balún? 

David  
HK1A
EC5KXA
ex-HK1KXA




> From: cx6vm.jorge@adinet.com.uy
> To: towertalk@contesting.com
> Date: Sat, 24 Apr 2010 20:44:09 -0300
> Subject: [TowerTalk] HIGH SWR because of loops between amp and wattimeter
> 
> Hello,
> 
>  
> 
> Today I was reading high SWR in my 20 mts yagi.
> 
>  
> 
> 2.5:1 in 14020
> 
> 1.9:1 in 14200
> 
> 1.7:1 in 14300
> 
>  
> 
> I have the radio connected to the amp, to the wattmeter and to WX0B
> six-pack. In all this runs I have small pieces of 50 ohms coaxial.
> 
>  
> 
> I connected the 20 mts yagi antenna direct to the K3 and the readings in the
> radio were:
> 
>  
> 
> 1.4:1 in 14020
> 
> 1.0:1 in 14200
> 
> 1.0:1 in 14300
> 
>  
> 
> I know will be some variation when you go through all the runs from radio to
> amp, wattmeter and antennas switch, but not too high that happens in 20 mts.
> 
>  
> 
> I tested all the other bands and SWR is lower when the antenna is connected
> directly, but not too much difference, for example:
> 
>  
> 
> SWR in the
> 
> Main setup
> 
> (amp, wattmeter,           SWR with antenna
> 
> Frequency          Antenna switch)              direct to the K3
> 
>  
> 
> 28030                    1.5:1                                     1.2:1
> 
> 28500                    1.1:1                                     1.0:1
> 
> 21020                    1.5:1                                     1.3:1
> 
> 21200                    1.2:1                                     1.0:1
> 
> 21300                    1.1:1                                     1.0:1
> 
>  
> 
> 14020              2.5:1                           1.4:1
> 
> 14200              1.9:1                           1.0:1
> 
> 14300              1.7:1                           1.0:1
> 
>  
> 
> 7010                      1.3:1                                     1.0:1
> 
> 7050                      1.7:1                                     1.3:1
> 
> 7100                      2.0:1                                     1.5:1
> 
> 3505                      1.5:1                                     1.5:1
> 
> 3550                      1.2:1                                     1.2:1
> 
> 3600                      2.5:1                                     2.5:1
> 
> 1810                      1.2:1                                     1.1:1
> 
> 1830                      1.7:1                                     1.6:1
> 
> 1850                      2.3:1                                     2.3:1
> 
>  
> 
> So SWR is reasonable higher when connected through the amp, wattmeter and
> antenna switch in all bands, except in 20 mts that there´s a big
> diference!...
> 
>  
> 
> Is not a problem of the sixpack. I connected the 20 mts antenna with the
> same runs of coaxial with a 2 position Daiwa switch and have the same SWR
> that it have when connected to the sixpack.
> 
>  
> 
> Any idea how can I lower the SWR in the 20 mts antenna when connected to the
> antenna switch?
> 
>  
> 
> Thanks,
> 
> Jorge
> 
> CX6VM
> 
>  
> 
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
                                          
_________________________________________________________________
Hotmail: Trusted email with Microsoft’s powerful SPAM protection.
https://signup.live.com/signup.aspx?id=60969
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>