[Elecraft] [w2/K3] High SWR

[Geoffrey Mackenzie-Kennedy]

Hi Don,

Thanks for your reply.  According to the EZNEC and TLW programs, on 20m you 
should be seeing the following SWR values at the shack end of the coax.  I 
have also shown the total loss of the 450 ohm ladder line and the coax, but 
not the insertion loss of the 1:1 balun.  For this exercise I have assumed 
that your coax is RG-213, and is 90 ft in length.

14.00 MHz    SWR =  4.22 : 1      Feeder loss =  1.99 db
14.31 MHz    SWR =  1.87 : 1      Feeder loss =  0.94 db

The balun (which I have not included) will have some effect on the SWR and 
the total loss of the feed system, because the load presented to it by the 
ladder line and antenna is reactive - more so at 14.0 MHz than at 14.31 MHz.

I see that your W2 shows a SWR of 4:1 on 20m, was the measurement frequency 
close to 14.0 MHz or right across the band?

Please let me know if you do not have EZNEC nor TLW, and would like to see 
similar data for the other bands.

73,

Geoff
LX2AO


On November 09, 2012 2:29 PM, Donald Thompson wrote:


Hi Geoff,
The W2 is powered from shack supply, Astron RS-20.  The MJF-259 from fresh 
AA batteries.  K3 also on shack supply. K2 on internal battery.
The coax is connected to the balun at end of ladder line as supplied by 
W8AMZ, nothing else.
The coax is passed thru a polyphaser at the lightning control panel outside 
shack, just outside the wall.
The w2 coupler is inside shack at coax entrance.  The radio is grounded with 
1/2 in copper strap to lightning panel.
There are no chokes.
The SWR does not vary with hand on line anywhere inside shack on any band.
Thanks
Sent from my iPhone
Don