[AMRadio] open wire line (update)


Geoff/W5OMR ars.w5omr at gmail.com
Tue Nov 20 10:50:09 EST 2007


Due to 'operator error' (must be a short circuit between the mic and the 
operators chair) I find I don't need to do anything to the current 
antenna situation, save for making sure the SWR bridge (out of the 
transmitter, into the tuner, out to balanced feed-line) is connected to 
the proper coax connection on the tuner (DOH!)

(grab bow, slot an arrow, assume good balanced stance, aim, shoot arrow 
into foot)  DOH!

Yeah... I screwed up and connected the SWR bridge output to an antenna 
connection on the tuner, instead of the RF input connector (DOH!)
(me and my dumb-ass!  I wish hard living didn't come so easy to me!)

Still mysterious as to why the feed line (disconnected from the tuner) 
and loop showed to be 'open', instead of closed, like it did this 
morning.  (*shrug*)

So, I'll continue with plans to build the open wire feed-line.. I'm just 
not as pressed for time now as I was, prior to reviving the antenna system.

I'm gonna go with either 1/8" or 1/16" plexi-glass, drill holes 1/4" in 
from the 4 1/2 plexi strips and 'v' a notch with a triangle-shaped small 
wood file.

The wire I'll be using is 14ga stranded, insulated copper clad steel.

Due to the size of the coax hole (through the wall, near the ceiling of 
the shack) that the 450 ohm ladder line barely fits through now, I'll 
leave about 5' feet of that on the tuner, and connect the 4" wide 
feed-line outside.  There'll be a slight impedance bump, but nothing 
drastic or critical below 30Mc (I never get above 7.3Mc, anyway)

Thanks to everyone for the suggestions. 

I'd like to extend an invitation to all AM'ers;  look for activity on 
the bands late Wednesday evening.  I'll be either at the bottom of 3700 
(up to 3.725 - wherever there's a clear hole) or up around 3.880~90 
operating while my traditional turkey smoking process is taking place, 
over night.  If there's too many in any one particular round table, find 
a clear frequency and call CQ AM!   With a cold front draping across the 
nation and dropping the temperatures in Texas (at least) down some 30+ 
degrees, long distance conditions -should- be favorable.

-- 
Driving your AM Rig without a scope, 
is like driving your car at night, without headlights. (K4KYV)

73 = Best Regards,
-Geoff/W5OMR



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