Topband: Inverted L with elevated radials for topband

[donovanf at starpower.net]

"Sooner or later everything old is new again" (Stephen King) 


February 1922 QST page 30 



The 1BCG antenna used for the transatlantic tests was a T cage 
over a radial counterpoise. The antenna is hung between two pipe 
masts 230 feet apart, and 108 and 75 feet high, respectively. 
The two horizontal sections of the T-vertical are each 50 feet long. 
The vertical section is 70 feet over the top of the counterpoise. 
The elevated counterpoise consisted of thirty 60 foot wires 
The operating frequency was 1500 kilocycles 


http://p1k.arrl.org/pubs_archive/4361 


73 
Frank 
W3LPL 

----- Original Message -----

From: "Bill Stewart" <cwopr at embarqmail.com> 
To: "Gabriel - EA6VQ" <ea6vq_ml at dxmaps.com> 
Cc: "topband" <topband at contesting.com> 
Sent: Thursday, March 5, 2020 8:13:08 PM 
Subject: Re: Topband: Inverted L with elevated radials for topband 

Hi Gabriel, 
These comments will be of little help as far as the technical info on the subject antenna 
and is a far cry from an excellently constructed antenna but it is very practical....in my 
opinion of course. 

However, I do use an Inv. L with a four wire counterpoise...or elevated radials if you 
prefer. Mine is approximately 50ft vertical and rest horiz....total, a quarter wave. The 
horizontal part is about 50 feet high and fairly flat. The antenna is completely covered 
over with tall pine trees. The CP wires go off from the base/feed point 10ft off the ground 
and at approximately 90 degrees apart. Each CP wire is about ten feet high and some are 
supported on tree trunks, others have some PVC posts for support and seems the CP wire 
lengths are a bit shorter than a 1/4 wave lgth, but my memory may not be too good on this 
part. I feed it with RG8X...I only run 100 watts(CW) on 160....no need for big coax in my 
case. I just used a door-knob cap between the vert and CP at the base....can't remember the 
value but think I just experimented until I got the SWR good....also think I did some trimming 
on the CP wires. I have had very good success with this antenna. With 100 watts I have been able 
to work several DXped. stns in the Pacific, JA. This season I have worked nearly 80 EU, Carib 
and Pac. stations. I had a lot of fun in the recent ARRL CW test. No, I don't get every station 
I call, but enough to keep me happy. The purist, with all their instruments and computer 
programs would laugh at my version, but it seems to be an easy antenna to get working and, 
at least in my case, a decent antenna. (I also use it for receiving...works well there too). 
Try it....easy to put up and if it don't work, go on to something else....hi. 
GL & 73 de Bill K4JYS/NC 

----- Original Message ----- 
From: "topband" <topband at contesting.com> 
To: "topband" <topband at contesting.com> 
Sent: Thursday, March 5, 2020 1:02:07 PM 
Subject: Topband: Inverted L with elevated radials for topband 

I have some doubts about installing and inverted L with elevated radials for 
160m. I have been searching in Google and find some contradictory 
information, so I would appreciate very much if you can help me with your 
own experience. 



The antenna would be supported by a 16 m (52.5 ft) high fiberglass pole 
placed on top of a 3m (10 ft) high small tower with the horizontal part of 
the L slopping down to a 5 m (16 ft) high mast about 23 m (75 ft) away. Two 
to four tuned elevated radials can be placed, although they will have to be 
bent due to space restrictions. 



Now the doubts: 



What impedance can I expect at the feed point with this configuration? 



How to match it in order to feed it with a 50 ohm cable? Some pages say 
that no match is required, only a choke. Other pages say a hairpin is 
necessary as the impedance can be too low. So other say that a tuner at the 
base is required? I am confused L 



What performance for DX can be achieved by this antenna? Is it really good 
or do you have some better suggestion for a really small lot where no ground 
radials are possible? 



Would it be worth to use a higher fiberglass pole, let's say 4 m (13 ft) 
higher, in order to lengthen the vertical section of the L? Would the 
difference be noticeable? 



Anyone has real experience setting up this antenna with elevated radials? 
Most information I can find on Internet is related to ground mounted 
antennas. 



Thanks in advance! 



73. Gabriel - EA6VQ 



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