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				 Why did this work (160m antenna)? 
 
			
			Very clear this time - - thanks for your effort to describe it in detail.I'm curious about the lawn staples - - could you describe them - - material,
 length, source, price - - Thanks.
 Chuck W6PKP
 
 "hasan schiers"  wrote in message
 ...
 Richard, thanks for your patience. I'll try to be more concise, as it is
 much simpler than the comments we've exchanged so far.
 
 I tried 2 antennas in different configurations:
 ==================================================  ===================
 1. Feeding the center conductor of the Inverted L. Coax runs underground
 50'
 or so, then connects to my radial plate/coax connector. That arrangement
 stunk. Band noise S-0, strong signals S-7. Worked about 10 or 15
 stations..
 Lots of calls unanswered. VERY PREDICTABLE, a poor performer to be sure.
 
 2. Feeding the Inverted L conventionally...same result as 1 above.
 Perfectly
 predictable.
 
 3. Shorting the Coax at the shack end and feeding as a random wire
 ....stupid idea...dead short....I didn't even load it, there were no
 signals
 to listen to, OF COURSE. (You have to understand, I was in a hurry and not
 thinking very clearly.)
 
 END OF Inverted L Experiment.
 ==================================================  =============
 Begin CW-80 Experiment: (OCF Dipole with Line Isolator) up 42'. 85' one
 side, 51 feet other side.
 
 CW-80: 50' underground coax, then about 45' of vertical coax to the
 feedpoint of the CW-80 (OCF)
 
 1. I did not feed it conventionally, as I didn't want to chance heating up
 the "Line Isolator" located 22' below the feedpoint of the OCF. In other
 words, I didn't just plug the CW-80 coax into the tuner and try to tune it
 up on 160. I was afraid this might cause the "Line Isolator" to fry (the
 one
 located 22' below the feedpoint of the CW-80)....that is how the CW-80 is
 constructed...it comes with the line isolator, and you attach your coax to
 the line isolator. Shack  Coax, abt 95'  Line Isolator  22' Coax
 Feedpoint.
 
 50' of the 95' from the shack to the "Line Isolator" is underground in a
 plastic pipe (along with 3 or 4 other coax cables)
 
 2. Fed the center conductor of the shack end of the coax as a "random
 wire".
 I just pushed the center conductor into the coax connector on the back of
 the antenna tuner and made sure the shell was not connected to the tuner.
 
 The worked rather well, as my description earlier details. I'd call this
 combo a winner. As I said in my prior post, if I had built an antenna to
 work on 160 and got the results I am getting with this option, I would
 have
 concluded that I had a "good" antenna. (For the real estate in use)
 
 3. Shorted the center conductor to the shield and fed that to my tuner
 center conductor output as a random wire. (Thus using both the shield and
 the center conductor in parallel as a "random wire". This configuration
 did
 not work any better (and perhaps slightly less band noise) than solution 2
 above.)
 ==================================================  ================
 The full layout of the tower and two wire antennas:
 
 Tower is 48'. At 46' or so, I have a 10' metal horizontal cross boom for
 pulleys (see below) At 50' I have a 6 element log periodic for 13-30 mhz.
 at
 60' I  have a dual band homebrew J-Pole for 2/70cm. So the total vertical
 height is about 65', with whatever loading the LP has. The LP only has a
 14'
 boom.
 
 So, I have a 48' tower with a 10' cross boom at the top section holding a
 pulley on each end. One pulley has the CW-80 OCF feedpoint on it with coax
 hanging down 5' away and parallel to the tower, to ground level where it
 goes into the pipe, underground for about 50' to the shack.
 
 The other pulley on the other side of the cross boom holds up my 80m
 inverted L...about 42' vertical and then a sloping wire to complete its
 proper length for 80m. (about 25' or so). Its feedpoint is about 6" above
 ground level above a radial plate with 33, 60' radials made of #14 THHN
 (insulated) wire, stapled to the lawn. The vertical wire is about 5' away
 and parallel to the tower (on the opposite side of the tower from the
 CW-80
 OCF.
 
 Hopefully, this clears things up.
 
 The only experiment I'm left with is adding a KW-80 80m trap to the 80m
 inverted L and then adding sufficient wire to get resonance on 160. I take
 from your prior comments that you don't think this arrangement will work
 any
 better than the "dumb luck antenna" I stumbled into. I'm inclined to
 agree,
 as the 42' vertical section of the Inverted L isn't all that great for
 160...but one never knows.
 
 I just don't want to compromise the current performance of the 80m
 Inverted
 L...it is doing a wonderful job on 80m. I worked England on cw and S92RI
 in
 Sao Tome & Principe Is.on SSB, first call. (West Africa). Making repeated
 observations comparing the CW-80 (conventional feed)  and the Inverted L
 has
 shown the Inverted L receive strength about 2 S-units better on paths
 beyond
 1000 or 1500 miles. On real DX paths, the Inverted L is quite a bit
 stronger
 than the CW-80. Of course, the noise level on the Inverted L is higher
 than
 on the CW-80...all the time. It is rare that I have to listen on the CW-80
 and Transmit on the Inverted L....but it has happened. This inverted L
 project has been one of my most enjoyable projects in ham radio in years.
 Measuring the input Z as I went from 0,2,4,8,16,26,33 radials was a rush,
 as
 was running 2:1 vswr bandwidth changes with each radial increment
 increase.
 The results were downright text book! Falling input Z, decreasing 2:1 vswr
 bandwidth as radials were added. Nice predicatable slope.
 
 When Reg gave me his rule of thumb equation for radiation resistance of an
 inverted L, that allowed me to begin calculating efficiency based on
 feedpoint Z...further fun. And, to compliment Reg, I found two other
 sources
 for the calculation of Rrad of an inverted L and they both agreed with Reg
 within an ohm (about 25.4 ohms predicted)...although their formula was
 different. Reg must have some sort of magic reference library, or he has
 made a bajillion measurements. No matter, his formula worked and was
 confirmed by two other sources. So far, I've been able to lower my input Z
 to about 29 ohms, so my efficiency (I know... a crude measurement at best,
 but better than nothing) is 25.4/29 or 87%. I'll be adding an additional
 17
 radials when weather and motivation improve, for a total of 50 radials.
 I'm
 not expecting any real improvement in performance, but I have the wire, I
 have the plate, I have the ss hardware, and I have the lawn staples. If I
 break 90%, I'll be very surprised.
 
 Again, thanks for taking the time to chat about my two projects.
 
 73,
 
 ...hasan, N0AN
 
 
 
 
 
 
 
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