COIL and Balun Musings (LOADED ANTENNAS) including
an Inverted L. Just some basic things I have tried and
plan to try out. I discuss some measurements I made to
the Amidon 4 to 1 W2FMI balun, the RF works balun, a
balun for an inverted L and coil loading
an Inverted L. Just some basic things I have tried and
plan to try out. I discuss some measurements I made to
the Amidon 4 to 1 W2FMI balun, the RF works balun, a
balun for an inverted L and coil loading
INDUCTIVE LOADING OF ANTENNAS with emphasis on baluns and coils
and some examples of antennas I have used. ( Emphasis on end loading).
and some examples of antennas I have used. ( Emphasis on end loading).
hamelectronicsmagazine.com
this article is being appended at times May2011
this article is being appended at times May2011
----> this is a FREE on line magazine that I write to keep
occupied during my early retirement years...I also sell the odd
radio part and do the odd repair to older (1970s and 80s) type
gear email me ve3ab(at)personainternet.com
occupied during my early retirement years...I also sell the odd
radio part and do the odd repair to older (1970s and 80s) type
gear email me ve3ab(at)personainternet.com
Point FORM for this article being written
> baluns -- 4 to 1 ie W2FMI balun I bought and tested
>radio works 4 to 1 (large balun) I bought about 10 years ago compared..I use my
analyser
> a few 50 ohm to 75 ohm and 90 ohm balun (one I built myself and a few I bought
-- 2 versions of an inverted L for a city lot
.. > discussion of a loaded dipole for 80 and 40 (only about 72 ft long o/a) no traps just
an isolation coil that isnt too hard to build - or buy commercial coils
-- and some more stuff
> baluns -- 4 to 1 ie W2FMI balun I bought and tested
>radio works 4 to 1 (large balun) I bought about 10 years ago compared..I use my
analyser
> a few 50 ohm to 75 ohm and 90 ohm balun (one I built myself and a few I bought
-- 2 versions of an inverted L for a city lot
.. > discussion of a loaded dipole for 80 and 40 (only about 72 ft long o/a) no traps just
an isolation coil that isnt too hard to build - or buy commercial coils
-- and some more stuff
I hear many times on the bands and read where hams don't really like lossy
traps. I never use traps myself. I am forced to use coils in my antennas
because I don't have enough money to buy a country house with plenty of
land and a big tower with a LOG PERIODIC antenna on the top.
My wife works in the small town we now live in and I took early retirement
and am a relatively happy dweller in this "small city" of around 12,000
people. City of Elliot Lake Ontario Canada.
So I have coils in my little TGM Hybrid mini beam. It works for me. The HF2V
vertical has a coil and capacitor arrangement (that they say is not a
trap)..well whatever it is it works OK for me.
The real test for the little mini beam will be when I start operating 10 and 15
meters seriously. It has worked "just OK" on 20 but I am not a serious DXer
and I only operate contests like QRP contests to give out points and I enjoy
the casual operating. With simple antennas like I have..I don't try and
compete or anything. Different strokes for different folks..I enjoy what I do
with ham radio tinkering on the bench, building my website(s), fishing, and
helping other hams or would be hams when they email me for advice or a
manual or a few tips. Life is good. ]
The sun is waking up and soon (I hope) 10 and 15 will have some good
conditions.
Here pictured Left and below with the red enamelled wire is a coil which I
took from my Alpha Delta twin sloper for 160, 40 and 80 meters. I measured
it on this cheap tester at about 96 uh. (I have a better tester for L now).
Close enough though.
I had an alpha delta twin sloper up at my old QTH near Ottawa. On 160 it
seemed to work fairly well even without a big tribander on top of the tower
and the tower I was using at the time had a large TV antenna at about 47 ft
up. The sloper I was using was only up about 40 ft but there was a lake in
front of me to the south to USA. The swr curve was fairly broad for 160 as I
recall. Something like 100 khz or so of useable bandwidth with a reasonable
SWR.
I got a real nice report one evening on 160 cw with my Index Labs QRP rig
barefoot. The guy really thought my antenna was working well. See the
sketch I made of the antenna. I did not use the 80 meter (about 66 ft long)
leg of this Alpha Delta Twin Sloper. Mine was therefore not a "Twin" sloper
but more like a traditional 40 and 160 meter sloper (if there is such a thing
as a traditional one). The sketch I made below shows the basic antenna with
the large log periodic TV antenna (it came with the house when I bought it).
I later took it down and put up a self supporting ham tower.
traps. I never use traps myself. I am forced to use coils in my antennas
because I don't have enough money to buy a country house with plenty of
land and a big tower with a LOG PERIODIC antenna on the top.
My wife works in the small town we now live in and I took early retirement
and am a relatively happy dweller in this "small city" of around 12,000
people. City of Elliot Lake Ontario Canada.
So I have coils in my little TGM Hybrid mini beam. It works for me. The HF2V
vertical has a coil and capacitor arrangement (that they say is not a
trap)..well whatever it is it works OK for me.
The real test for the little mini beam will be when I start operating 10 and 15
meters seriously. It has worked "just OK" on 20 but I am not a serious DXer
and I only operate contests like QRP contests to give out points and I enjoy
the casual operating. With simple antennas like I have..I don't try and
compete or anything. Different strokes for different folks..I enjoy what I do
with ham radio tinkering on the bench, building my website(s), fishing, and
helping other hams or would be hams when they email me for advice or a
manual or a few tips. Life is good. ]
The sun is waking up and soon (I hope) 10 and 15 will have some good
conditions.
Here pictured Left and below with the red enamelled wire is a coil which I
took from my Alpha Delta twin sloper for 160, 40 and 80 meters. I measured
it on this cheap tester at about 96 uh. (I have a better tester for L now).
Close enough though.
I had an alpha delta twin sloper up at my old QTH near Ottawa. On 160 it
seemed to work fairly well even without a big tribander on top of the tower
and the tower I was using at the time had a large TV antenna at about 47 ft
up. The sloper I was using was only up about 40 ft but there was a lake in
front of me to the south to USA. The swr curve was fairly broad for 160 as I
recall. Something like 100 khz or so of useable bandwidth with a reasonable
SWR.
I got a real nice report one evening on 160 cw with my Index Labs QRP rig
barefoot. The guy really thought my antenna was working well. See the
sketch I made of the antenna. I did not use the 80 meter (about 66 ft long)
leg of this Alpha Delta Twin Sloper. Mine was therefore not a "Twin" sloper
but more like a traditional 40 and 160 meter sloper (if there is such a thing
as a traditional one). The sketch I made below shows the basic antenna with
the large log periodic TV antenna (it came with the house when I bought it).
I later took it down and put up a self supporting ham tower.
Below right pictured some commercial antenna coils. The red winding one
is the one from the Alpha Delta twin sloper (as being discussed). The
other two I bought at a ham fest and they measured at 86 microhenries). I
could not find much info on the web about them. They were manufactured
by Diamond Antenna some years ago. 86 UH is probably a good value to
load up a 80 meter dipole or sloper with. 86 uh will likely not be enough L
and XL to isolate a 33 ft section of antenna. like the alpha delta would.
But it would work on 30 meters and above. So you could make an 80 meter
shortened loaded dipole or sloper or other type of wire antenna and
squeeze in another band by strategically placing the coil at the right spot
on the antenna.
is the one from the Alpha Delta twin sloper (as being discussed). The
other two I bought at a ham fest and they measured at 86 microhenries). I
could not find much info on the web about them. They were manufactured
by Diamond Antenna some years ago. 86 UH is probably a good value to
load up a 80 meter dipole or sloper with. 86 uh will likely not be enough L
and XL to isolate a 33 ft section of antenna. like the alpha delta would.
But it would work on 30 meters and above. So you could make an 80 meter
shortened loaded dipole or sloper or other type of wire antenna and
squeeze in another band by strategically placing the coil at the right spot
on the antenna.
this page is being written and will take a
few days to work out..
you are welcome to come back a little
later for a look. Plenty of good ideas and
pictures and some test results will be
presented at that time.
73 Earl VE3AB (early May 2011)
I will be adding more examples of end
loaded antennas and a two band dipole
idea using end loading..stay tuned from
time to time..73 earl
few days to work out..
you are welcome to come back a little
later for a look. Plenty of good ideas and
pictures and some test results will be
presented at that time.
73 Earl VE3AB (early May 2011)
I will be adding more examples of end
loaded antennas and a two band dipole
idea using end loading..stay tuned from
time to time..73 earl