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Is it my KX3/antenna or is it lousy band condx?

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Jim Brown-10

Re: Is it my KX3/antenna or is it lousy band condx?

On 8/13/2017 9:09 AM, Walter Underwood wrote:
> The 16 foot wire on the ground is a radial “system”. One radial is a lot better than none, but you could use more. The length isn’t especially important

Right.

> because it is capacitively coupled to the ground.

It's also inductively coupled. BUT -- that's NOT how or why radials
work. AND a connection or coupling to earth does NOT make a transmitting
antenna work better. That's because the earth is a big resistor, so it
burns any power fed into it, whether with a direct connection or by
capacitive or inductive coupling. In other words, it WASTES transmitter
power.

> Ground resistance swamps any resonance.

Yes, but as noted above, not in a good way. :) There's a folded dipole
antenna made with a big resistor in the middle of it, the effect of
which is to "broadband" it by "swamping" the resonance, AND to burn half
of the transmitter power. In other words, the transmitter puts power
into the antenna, but half of it is wasted in that resistor.

73, Jim K9YC

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Bill Breeden

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Jim Brown-10

Jim,

All of the transmitters at my place, a K3, a Yaesu FT817 and FT-920, and
a Drake T-4XB, have "single ended" (unbalanced) outputs.

73,

Bill - NA5DX

On 8/13/2017 11:52 AM, Jim Brown wrote:

> Great advice!
>
> With one exception, every transmitter and receiver I've ever seen has
> had an balanced output -- that is, a coaxial connector of some sort.
> Current flows in loops -- the center conductor feeds one side of the
> loop, the chassis feeds the other. The exception was my very first
> transmitter, a military surplus BC-459, which had a single terminal
> fed from the output of an internal matching network. The return for
> output current was the chassis, which was mounted to the chassis of
> the military vehicle or aircraft in which it was used, and the chassis
> of that vehicle or aircraft acted as the other half of the antenna.
>
> The suggestion to use a BNC to female "dual Banana" adapter is a very
> good one. I've used one for exactly this purpose with my K2 and KX3
> when operating portable. It makes a very easy way to connect wire
> antennas.
>
> 73, Jim K9YC
>
> On 8/13/2017 5:43 AM, Bob McGraw K4TAX wrote:
>> Forget about "what you've been told". Do your own research using
>> various publications such as ARRL Antenna Book or other like
>> publications. Personally in the "I've been told" area, it seems
>> hams have more incomplete and inaccurate information than correct and
>> complete information.
>>
>> Bob, K4TAX
>>
>>
>> Sent from my iPhone
>>
>>> On Aug 13, 2017, at 7:31 AM, rich hurd WC3T <[hidden email]> wrote:
>>>
>>> Hi all, particularly Walter (since he mentioned it):
>>>
>>> I've been bedeviled by a question with multiple possible answers.
>>>
>>> I'm a fan of the idea of using a field antenna as Walter describes
>>> by using
>>> a BNC - to binding post connector directly to the radio.
>>>
>>> I'm leery of that because it flies in the face of what I've been
>>> told about
>>> these antennas: I'm assuming the radio BNC connection is unbalanced
>>> and
>>> the wires form a balanced antenna, more or less. I've seen deployments
>>> with end-fed 9:1 baluns and without, even documented on YouTube with
>>> great
>>> successes.
>>>
>>> I can tell you that the 9:1 balun setup doesn't seem to be working
>>> for my
>>> current field deployment but I'd sure like to understand why a balun
>>> isn't
>>> recommended in this setup. I'd love to just take the wire and put
>>> it on my
>>> WonderPole and go for it, but I'd like the understanding first.
>>> Why does
>>> this work? :)
>>>
>>> Thanks.
>>>
>>> On Fri, Aug 11, 2017 at 13:19 Walter Underwood <[hidden email]>
>>> wrote:
>>>
>>>> You can get a quick look at band conditions at
>>>> http://bandconditions.com <
>>>> http://bandconditions.com/>
>>>>
>>>> Using Buddistick on 40 m is a real challenge. I would not be
>>>> surprised if
>>>> that was an S-unit or more below a full-size dipole.
>>>>
>>>> Try the simplest field antenna for the KX3, two wires connected
>>>> directly
>>>> to the rig. Get a BNC to double binding post adaptor. Get a wire 26
>>>> to 29
>>>> feet long, throw it in a tree and hook one end to the red post. Get
>>>> a 16
>>>> foot wire, lay it on the ground and connect it to the black post.
>>>> Let the
>>>> ATU tune it and see you can hear.
>>>>
>>>> wunder
>>>> K6WRU
>>>> Walter Underwood
>>>> CM87wj
>>>> http://observer.wunderwood.org/ (my blog)
>>>>
>>>>> On Aug 11, 2017, at 9:54 AM, Tommy <[hidden email]> wrote:
>>>>>
>>>>> The band has been really crappy lately. Keep tuning around and
>>>>> listening.
>>>>>
>>>>> 73!
>>>>>
>>>>> Tom - KB2SMS
>>>>>
>>>>>
>>>>>
>>>>>> On 08/11/2017 12:33 PM, Mike Parkes wrote:
>>>>>> Okay I am reaching our to the Elecraft enthusiasts here for some
>>>> feedback
>>>>>> if anyone cares to chime in.
>>>>>> I am just getting back on the air after years away from the
>>>>>> hobby, so I
>>>> am
>>>>>> not that familiar with band conditions in general. It looks like the
>>>>>> sunspot cycle is heading for the cellar (if it isn't already there).
>>>>>>
>>>>>> Recently bought a KX3 and a Buddistick vertical (like, 2 weeks ago).
>>>> Love
>>>>>> the KX3 it is a great radio... however... so far my efforts to hear
>>>> much of
>>>>>> anything, much less make a contact with someone, has been
>>>>>> frustrating to
>>>>>> say the least. I live in an apartment and am surrounded by power
>>>>>> lines
>>>> for
>>>>>> one thing. The background noise level on 40 is pretty bad varies
>>>>>> but is
>>>>>> s7-9 mostly. I took my setup to a nearby park and the bands were
>>>>>> definitely quieter. So the local manmade noise level is an issue
>>>>>> (and
>>>> one
>>>>>> reason I chose the KX3 was the hope that its rcvr and filtering
>>>>>> could
>>>> help
>>>>>> with that.)
>>>>>>
>>>>>> Have yet to make a single contact, so I am just wondering if I just
>>>>>> happened to choose a really lousy period of solar conditions for
>>>>>> HF? Or
>>>> is
>>>>>> the base loaded vertical a joke?
>>>>>>
>>>>>> I would love to be able to find another ham even close by just to
>>>>>> try
>>>> and
>>>>>> get some sort of an HF QSO even if it is with someone down the
>>>>>> block.
>>>>>> ...I can tune down to the AM broadcast band and was able to hear
>>>>>> some
>>>> local
>>>>>> AM stations. :)
>>>>>>
>>>>>> Mike AB7RU
>>>>>>
>>>>>> (On a side note the tuner in the KX3 is great!. That thing was
>>>>>> able to
>>>> get
>>>>>> a match for 80 meters on the Buddistick which was showing
>>>>>> something like
>>>>>> 25:1 swr. The KX3 tuner clicked and rattled for a while and found a
>>>> match
>>>>>> to <2:1. Not sure how much actual RF is going out, probably not
>>>>>> much...
>>>> but
>>>>>> I was amazed it could tune to that high an SWR.)
>>>>>> ______________________________________________________________
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>>>>> ______________________________________________________________
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>>> --
>>> 73 (or 72 for the QRP folks),
>>> Rich Hurd / WC3T
>>> DMR ID: 3142737
>>> Northampton County RACES
>>> EPA-ARRL Public Information Officer for Scouting
>>> Latitude: 40.761621 Longitude: -75.288988 (40°45.68' N 75°17.33' W)
>>> Grid:
>>> *FN20is*
>>> ______________________________________________________________
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>
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Barry K3NDM

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Jim Brown-10

Jim,
You got it. That is why my first recommendation is for ground
independent antennas. For portable use, any antenna that can be hung by
a single support should work nicely so long as it approximates 1/2 wave
on the lowest frequency. An inverted V with it's center up a tree fed in
the center with ladder line from a small current balun will work nicely,
and it could even be sloping if the center can't be high enough. I have
found sloping delta loops work nicely when fed with ladder line and a
4:1 balun. DO NOT worry about matching. If you are reading this, you
probably have Elecraft gear. That means you really need a truly awful
mismatch for your tuner not to be able to deal with it.

73,
Barry
K3NDM

------ Original Message ------
From: "Jim Brown" <[hidden email]>
To: [hidden email]
Sent: 8/13/2017 1:10:17 PM
Subject: Re: [Elecraft] Is it my KX3/antenna or is it lousy band condx?

>On 8/13/2017 9:09 AM, Walter Underwood wrote:
>>The 16 foot wire on the ground is a radial “system”. One radial is a
>>lot better than none, but you could use more. The length isn’t
>>especially important
>
>Right.
>
>>because it is capacitively coupled to the ground.
>
>It's also inductively coupled. BUT -- that's NOT how or why radials
>work. AND a connection or coupling to earth does NOT make a
>transmitting antenna work better. That's because the earth is a big
>resistor, so it burns any power fed into it, whether with a direct
>connection or by capacitive or inductive coupling. In other words, it
>WASTES transmitter power.
>
>>Ground resistance swamps any resonance.
>
>Yes, but as noted above, not in a good way. :) There's a folded
>dipole antenna made with a big resistor in the middle of it, the effect
>of which is to "broadband" it by "swamping" the resonance, AND to burn
>half of the transmitter power. In other words, the transmitter puts
>power into the antenna, but half of it is wasted in that resistor.
>
>73, Jim K9YC
>
>______________________________________________________________
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>This list hosted by: http://www.qsl.net
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Ken G Kopp

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Jim Brown-10

The antenna Jim's is referring to (below) is ... I believe ... better known
as
a "T2FD". In a case of conning the unknowing B & W ... and maybe even
themselves ... sold hundreds of them to the Army National Guard. You see
them hanging above every armory here in MT.

> Yes, but as noted above, not in a good way. :) There's a folded dipole
>> antenna made with a big resistor in the middle of it, the effect of which
>> is to "broadband" it by "swamping" the resonance, AND to burn half of the
>> transmitter power. In other words, the transmitter puts power into the
>> antenna, but half of it is wasted in that resistor.
>>
>
>
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Jim Brown-10

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Bill Breeden

Typo on my part -- I meant to write UNBALANCED. :)

Thanks for catching it!

Jim

On 8/13/2017 10:22 AM, Bill Breeden wrote:

> im,
>
> All of the transmitters at my place, a K3, a Yaesu FT817 and FT-920,
> and a Drake T-4XB, have "single ended" (unbalanced) outputs.
>
> 73,
>
> Bill - NA5DX
>
>
> On 8/13/2017 11:52 AM, Jim Brown wrote:
>> Great advice!
>>
>> With one exception, every transmitter and receiver I've ever seen has
>> had an balanced output

Jim Brown-10

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Jim Brown-10

On 8/13/2017 10:32 AM, Walter Underwood wrote:
> Without the wire on the ground, the chassis is the other terminal, like your BC-459 (previous message), but also includes your body when you touch it, which changes the impedance of the antenna system.

Yep. But in a vehicle, the VEHICLE'S chassis is the return. That's how
mobile antennas work. And at home, an end fed wire with no radials uses
the power system in your house as the counterpoise. While this can work,
it also puts RF in your house and picks up noise from your house. And
our body is the return for the antenna of our VHF/UHF talkie.

On 8/13/2017 10:22 AM, Barry wrote:
> Jim,
> You got it. That is why my first recommendation is for ground
> independent antennas. For portable use, any antenna that can be hung
> by a single support should work nicely so long as it approximates 1/2
> wave on the lowest frequency.

There's a gotcha there. It's quasi-ground-independent ONLY when there's
a current minima at the feedpoint, and it isn't easy to make a single
wire do that on all bands where we want to operate, because some are not
harmonically related, and because a half wave is pretty long on 80 and
40M. :) And when it's an end fed full wave or 3/2 wave, the resulting
pattern is pretty loby. But it is certainly true that when we CAN rig
and load an end-fed half-wave, it's a pretty efficient antenna,
especially if it's vertical.

73, Jim K9YC
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Vic Rosenthal

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Ken G Kopp

It's not a "con." It is a trade off that provides wide frequency coverage with a simple, sturdy antenna in return for a few dB of loss. Quite reasonable if you are the National Guard.

Vic 4X6GP

> On 13 Aug 2017, at 20:28, Ken G Kopp <[hidden email]> wrote:
>
> The antenna Jim's is referring to (below) is ... I believe ... better known
> as
> a "T2FD". In a case of conning the unknowing B & W ... and maybe even
> themselves ... sold hundreds of them to the Army National Guard. You see
> them hanging above every armory here in MT.
>
>
>> Yes, but as noted above, not in a good way. :) There's a folded dipole
>>> antenna made with a big resistor in the middle of it, the effect of which
>>> is to "broadband" it by "swamping" the resonance, AND to burn half of the
>>> transmitter power. In other words, the transmitter puts power into the
>>> antenna, but half of it is wasted in that resistor.

k6dgw

B&W Folded Dipole over an Armory

In reply to this post by Ken G Kopp

Ummm ... let's be truthful here. The B&W folded dipole can be found in
radio catalogs from the 50's. We all knew [I was a kid with a new
license then and even I knew] that the doohicky at the center of the top
wire was a 400 or so ohm non-inductive resistor, and half the power [3
dB] heated it up. There was no subterfuge and B&W wasn't "conning"
anyone, it was very clear in the specification sheet. 300 ohms at the
feed point, hams often fed them with 300 ohm TV twinlead of the day to a
balanced link coupled to the final tank circuit. A 4:1 transformer
netted 75 ohms which nicely matched that twinlead too.

Nor did the Nat'l Guard get conned, they had a specific need for an
MF/HF antenna that was light, easy for a couple of troops to erect, and
very broadband ... their operating frequencies are [were] sort of
day/night separated, rarely if ever harmonically related, and required
ranges were in the several hundred miles or so miles. It was a great
antenna for a specific purpose which is why you see [or saw] them at
many military installations, some of which were Nat'l Guard Armories.

For 10 months in high school, I worked coastal marine from So
California. Very large V-Beams on 200 ft towers with two terminating
resistors at the ends. Moderately broad patterns into the Pacific, very
little off the backs [not many ships back there]. 5 KW from the TX, 2.5
KW into the resistors, 2.5 KW to all the ships at sea. Great antenna
for the purpose.

As with all things in Engineering, antenna choice is a basket of
trade-offs. The Nat'l Guard rarely tries to work DX. Broadband however
was near the top of their list.

Incidentally, the "T2FD" [TTFD] acronym arose from the "Tilted
Terminated Folded Dipole" developed by the US Navy during WW2, designed
to have one end hoisted on a ship's mast and the other anchored near the
deck. Lowered the elevation angle of the main lobe, something important
to them. Hams associated it with someone's call which I can't remember
at this point.

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 8/13/2017 10:28 AM, Ken G Kopp wrote:
> The antenna Jim's is referring to (below) is ... I believe ... better known
> as
> a "T2FD". In a case of conning the unknowing B & W ... and maybe even
> themselves ... sold hundreds of them to the Army National Guard. You see
> them hanging above every armory here in MT.
>

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Ken G Kopp

Re: B&W Folded Dipole over an Armory

Skip's /K6DGW is totally correct ....

73!

K0PP

On Sun, Aug 13, 2017 at 1:36 PM, Fred Jensen <[hidden email]> wrote:

> Ummm ... let's be truthful here. The B&W folded dipole can be found in
> radio catalogs from the 50's. We all knew [I was a kid with a new license
> then and even I knew] that the doohicky at the center of the top wire was a
> 400 or so ohm non-inductive resistor, and half the power [3 dB] heated it
> up. There was no subterfuge and B&W wasn't "conning" anyone, it was very
> clear in the specification sheet. 300 ohms at the feed point, hams often
> fed them with 300 ohm TV twinlead of the day to a balanced link coupled to
> the final tank circuit. A 4:1 transformer netted 75 ohms which nicely
> matched that twinlead too.
>
> Nor did the Nat'l Guard get conned, they had a specific need for an MF/HF
> antenna that was light, easy for a couple of troops to erect, and very
> broadband ... their operating frequencies are [were] sort of day/night
> separated, rarely if ever harmonically related, and required ranges were in
> the several hundred miles or so miles. It was a great antenna for a
> specific purpose which is why you see [or saw] them at many military
> installations, some of which were Nat'l Guard Armories.
>
> For 10 months in high school, I worked coastal marine from So California.
> Very large V-Beams on 200 ft towers with two terminating resistors at the
> ends. Moderately broad patterns into the Pacific, very little off the
> backs [not many ships back there]. 5 KW from the TX, 2.5 KW into the
> resistors, 2.5 KW to all the ships at sea. Great antenna for the purpose.
>
> As with all things in Engineering, antenna choice is a basket of
> trade-offs. The Nat'l Guard rarely tries to work DX. Broadband however
> was near the top of their list.
>
> Incidentally, the "T2FD" [TTFD] acronym arose from the "Tilted Terminated
> Folded Dipole" developed by the US Navy during WW2, designed to have one
> end hoisted on a ship's mast and the other anchored near the deck. Lowered
> the elevation angle of the main lobe, something important to them. Hams
> associated it with someone's call which I can't remember at this point.
>
> 73,
>
> Fred ("Skip") K6DGW
> Sparks NV USA
> Washoe County DM09dn
>
> On 8/13/2017 10:28 AM, Ken G Kopp wrote:
>
>> The antenna Jim's is referring to (below) is ... I believe ... better
>> known
>> as
>> a "T2FD". In a case of conning the unknowing B & W ... and maybe even
>> themselves ... sold hundreds of them to the Army National Guard. You see
>> them hanging above every armory here in MT.
>>
>>
> ______________________________________________________________
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>
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> Message delivered to [hidden email]
>

Dave Heil

Re: B&W Folded Dipole over an Armory

In reply to this post by k6dgw

The U.S. Department of State uses many of these B&W folded dipoles in
Africa and other nations with HF transceivers meant to be used by those
with little or no radio operations experience. All the user needs do is
consult a list of places and frequencies (which are all programmed into
memory), key the microphone and talk. These antennas weren't made to
work DX and neither were the transceivers. Any easy way to make up for
the inefficiency is to switch on one of the 500 or 1000 matching
amplifiers, none of which requires manual band switching or tuning up.

Dave K8MN

On 13-Aug-17 19:36, Fred Jensen wrote:
> Ummm ... let's be truthful here. The B&W folded dipole can be found in
> radio catalogs from the 50's. We all knew [I was a kid with a new
> license then and even I knew] that the doohicky at the center of the top
> wire was a 400 or so ohm non-inductive resistor, and half the power [3
> dB] heated it up...
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Phil Kane-2

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Ken G Kopp

On 8/13/2017 10:28 AM, Ken G Kopp wrote:

> The antenna Jim's is referring to (below) is ... I believe ... better
> known as a "T2FD". In a case of conning the unknowing B & W ... and
> maybe even themselves ... sold hundreds of them to the Army National
> Guard. You see them hanging above every armory here in MT.

It's the "standard" Federal agency antenna as well.

I had one at my former house. It worked far better than what I am
limited to now at a rental apartment - a 30-foot wire fed by an "un-un"
. That was much better than its predecessor there which was no antenna
at all - and the price was right (surplus gift from someone who was
moving away).

I sure miss my R-8 vertical......

73 de K2ASP - Phil Kane
Elecraft K2/100 s/n 5402

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon
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Barry K3NDM

Re: B&W Folded Dipole over an Armory

In reply to this post by Dave Heil

Dave,
They are used by a greater number than just state. The military,
all, are using HF ALE. It's used because, you are correct about
operators, a link can be set up by just IDing with whom you wish to
talk. The radios run up and down the spectrum until they find each other
and can make a solid linkup. No antenna is flat across that much
spectrum, so in recent times, the T2FD has been employed. It seems
auto-tuners don't keep up with the sounding rate from some of these
radios. It was interesting to me to see the magnificent antenna field at
Rockwell-Collins in Iowa augmented with a T2FD so that they could do
work with their ALE radios. Harris Corp. does the same.

73,
Barry
K3NDM

------ Original Message ------
From: "Dave Heil" <[hidden email]>
To: [hidden email]
Sent: 8/13/2017 4:03:25 PM
Subject: Re: [Elecraft] B&W Folded Dipole over an Armory

>The U.S. Department of State uses many of these B&W folded dipoles in
>Africa and other nations with HF transceivers meant to be used by those
>with little or no radio operations experience. All the user needs do
>is consult a list of places and frequencies (which are all programmed
>into memory), key the microphone and talk. These antennas weren't made
>to work DX and neither were the transceivers. Any easy way to make up
>for the inefficiency is to switch on one of the 500 or 1000 matching
>amplifiers, none of which requires manual band switching or tuning up.
>
>Dave K8MN
>
>On 13-Aug-17 19:36, Fred Jensen wrote:
>>Ummm ... let's be truthful here. The B&W folded dipole can be found
>>in radio catalogs from the 50's. We all knew [I was a kid with a new
>>license then and even I knew] that the doohicky at the center of the
>>top wire was a 400 or so ohm non-inductive resistor, and half the
>>power [3 dB] heated it up...
>______________________________________________________________
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Ed Tanton

Re: B&W Folded Dipole over an Armory

In reply to this post by k6dgw

I have an NOS stainless steel version of the 160M B&W antenna that I bought 20 or 30 years ago. Now I can't put it up because I don't want to interfere with the pattern of my HyGain HyTower. If anyone is interested in it, just send me an email. It will not be inexpensive. Thanks.

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Barry <[hidden email]>
Date: 8/13/17 4:59 PM (GMT-05:00)
To: Dave Heil <[hidden email]>, [hidden email]
Subject: Re: [Elecraft] B&W Folded Dipole over an Armory

Dave,
They are used by a greater number than just state. The military,
all, are using HF ALE. It's used because, you are correct about
operators, a link can be set up by just IDing with whom you wish to
talk. The radios run up and down the spectrum until they find each other
and can make a solid linkup. No antenna is flat across that much
spectrum, so in recent times, the T2FD has been employed. It seems
auto-tuners don't keep up with the sounding rate from some of these
radios. It was interesting to me to see the magnificent antenna field at
Rockwell-Collins in Iowa augmented with a T2FD so that they could do
work with their ALE radios. Harris Corp. does the same.

73,
Barry
K3NDM

------ Original Message ------
From: "Dave Heil" <[hidden email]>
To: [hidden email]
Sent: 8/13/2017 4:03:25 PM
Subject: Re: [Elecraft] B&W Folded Dipole over an Armory

Roger D Johnson

Re: B&W Folded Dipole over an Armory

In reply to this post by k6dgw

Roger D Johnson

B&W Folded Dipole over an Armory

In reply to this post by Ken G Kopp

Cebik, W4RNL, modeled two versions of the T2FT. One 165ft long and the other 100ft.
Here is what he said about these antennas:

Terminator Resistor Losses
Although transmitting uses have been made of the T2FD, its chief use appears to
be as a short wave reception antenna. In this application, the excess available
receiver gain can largely make up for losses incurred in the terminating resistor.

The losses in the terminating resistor are considerable, ranging from nearly
half power to amounts in excess of 90% of the available RF power. The pattern of
losses is not a simple smooth curve, but varies throughout the operating range
of the antenna. The following graph plots the losses in terms of dB. For
reference, a 3 dB power loss represents half the power being dissipated in the
resistor. Higher values indicate more of the power being dissipated rather than
being radiated (or transferred to the receiver).

73, Roger

On 8/13/2017 3:36 PM, Fred Jensen wrote:
> Ummm ... let's be truthful here. The B&W folded dipole can be found in radio catalogs from the 50's. We all knew [I was a kid with a new license then and even I knew] that the doohicky at the center of the top wire was a 400 or so ohm non-inductive resistor, and half the power [3 dB] heated it up. There was no subterfuge and B&W wasn't "conning" anyone, it was very clear in the specification sheet. 300 ohms at the feed point, hams often fed them with 300 ohm TV twinlead of the day to a balanced link coupled to the final tank circuit. A 4:1 transformer netted 75 ohms which nicely matched that twinlead too.
>

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k6dgw

Re: B&W Folded Dipole over an Armory

Not sure where he got the "chief use" from, all the T2FD's I've ever
seen [and can remember] were transmit/receive, usually using KWM-2A's.
But, yes, the amount of power dissipated in the termination depends on
the frequency vs the overall length. We used them in the 60's in SE Asia
and our maint depot guys would adjust the length so that the lowest loss
areas were around our assigned frequencies which were generally in the
2.5 to 10 MHz range, usually two of them [day/night], sometimes a third.

Same situation with the large V-beams and Rhombics in commercial
servicewhich accounts for the land area occupied by a commercial MF/HF
TX site: One V-beam does not fit all frequencies.

TheT2FD's sure beat a fan dipole since, once on the ground, we had way
more important things to do than adjust antennas. [:-)

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 8/13/2017 2:41 PM, Roger D Johnson wrote:

> Cebik, W4RNL, modeled two versions of the T2FT. One 165ft long and the
> other 100ft.
> Here is what he said about these antennas:
>
> Terminator Resistor Losses
> Although transmitting uses have been made of the T2FD, its chief use
> appears to be as a short wave reception antenna. In this application,
> the excess available receiver gain can largely make up for losses
> incurred in the terminating resistor.
>
> The losses in the terminating resistor are considerable, ranging from
> nearly half power to amounts in excess of 90% of the available RF
> power. The pattern of losses is not a simple smooth curve, but varies
> throughout the operating range of the antenna. The following graph
> plots the losses in terms of dB. For reference, a 3 dB power loss
> represents half the power being dissipated in the resistor. Higher
> values indicate more of the power being dissipated rather than being
> radiated (or transferred to the receiver).
>
> 73, Roger

Lynn W. Taylor, WB6UUT-2

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by rich hurd WC3T

If you are end-feeding a wire, and it's near a half-wave on the band
you're operating (let's say 32 3/4 feet, and 14.300 MHz) an end-fed wire
is going to be close to infinite impedance, and you need some kind of
Un-Un (9:1 being common) to step up from 50 ohms or thereabouts.

If you're trying to operate on the same frequency, and the wire is more
like 48 feet, the impedance will be a whole lot lower and no transformer
is indicated.

This is the myth of the "random" wire, and why one "random" wire works
like gangbusters, and the next "random" wire is kinda lousy.

Antenna theory matters.

73 -- Lynn

On 8/13/2017 9:09 AM, Walter Underwood wrote:
> In July, five SOTA operators put up seven different antennas on a summit and compared their performance with WSPR. Six of the antennas were mostly within 3 dB of each other. The EARCHI antenna (end-fed with transformer) was between 6 and 15 dB worse than the others. So in one experiment, the 9:1 transformer did not help.
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Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by rich hurd WC3T

Walter,

This was a super informative writeup, thank you!

I have one question for you. If you throw a 26-29 foot wire in a tree, but it is impractical to sit right at the end of the wire (too many branches in the way, or whatever) to operate, how would you extend it? For example, operate from a table 20 feet away.

Thanks!
Barthold
AD0RM

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of Walter Underwood
Sent: Sunday, August 13, 2017 10:10 AM
To: Reflector Elecraft
Subject: Re: [Elecraft] Is it my KX3/antenna or is it lousy band condx?

In July, five SOTA operators put up seven different antennas on a summit and compared their performance with WSPR. Six of the antennas were mostly within 3 dB of each other. The EARCHI antenna (end-fed with transformer) was between 6 and 15 dB worse than the others. So in one experiment, the 9:1 transformer did not help.

http://reflector.sota.org.uk/t/seven-sota-antennas-compared-using-wspr-on-a-summit/15635 <http://reflector.sota.org.uk/t/seven-sota-antennas-compared-using-wspr-on-a-summit/15635>

When the antenna is connected directly to the KX3, there is no transmission line, so there is no need to match the antenna to the transmission line. It is putting the ATU at the feed point of the antenna.

The 26-29 foot length is chosen to avoid very high or very low impedances in the ham bands down to 40 m Especially, it is not a 1/2 wave on any band. That makes it easier to match. If you want to work 80 m, use a 53 foot wire.

The 16 foot wire on the ground is a radial “system”. One radial is a lot better than none, but you could use more. The length isn’t especially important because it is capacitively coupled to the ground. Ground resistance swamps any resonance.

I first heard about this antenna on this list. It was recommended by Wayne, N6KR. It is documented on page 9 of the instructions for the KXAT1 antenna tuner, “...for backpacking use on 40/30/20 meters, a wire length of 24-28 feet will generally provide good results. […] Ground system: Use a at least one ground radial, cut to at least 1/8th wavelength on the lowest band used (16' on 40 meters). When possible, use two or more radials, with one cut to 1/4 wavelength on each band."

http://www.elecraft.com/manual/E740054%20KXAT1%20man%20rev%20B.pdf <http://www.elecraft.com/manual/E740054%20KXAT1%20man%20rev%20B.pdf>

There is similar advice on page 10 of the KX2 manual.

http://www.elecraft.com/manual/E740282%20KX2%20owner%27s%20man.pdf <http://www.elecraft.com/manual/E740282%20KX2%20owner's%20man.pdf>

Finally, stop trying to think about “balanced” and “unbalanced” because those words are used in bizarre, inconsistent ways. Voltage, whether DC or RF, is always between two terminals. With a center-fed dipole, the two terminals are the elements. With this setup, the two terminals are the wire in the air and the wire on the ground.

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Aug 13, 2017, at 5:31 AM, rich hurd WC3T <[hidden email]> wrote:
>
> Hi all, particularly Walter (since he mentioned it):
>
> I've been bedeviled by a question with multiple possible answers.
>
> I'm a fan of the idea of using a field antenna as Walter describes by using a BNC - to binding post connector directly to the radio.
>
> I'm leery of that because it flies in the face of what I've been told about these antennas: I'm assuming the radio BNC connection is unbalanced and the wires form a balanced antenna, more or less. I've seen deployments with end-fed 9:1 baluns and without, even documented on YouTube with great successes.
>
> I can tell you that the 9:1 balun setup doesn't seem to be working for my current field deployment but I'd sure like to understand why a balun isn't recommended in this setup. I'd love to just take the wire and put it on my WonderPole and go for it, but I'd like the understanding first. Why does this work? :)
>
> Thanks.
>
> On Fri, Aug 11, 2017 at 13:19 Walter Underwood <[hidden email] <mailto:[hidden email]>> wrote:
> You can get a quick look at band conditions at
> http://bandconditions.com <http://bandconditions.com/>
> <http://bandconditions.com/ <http://bandconditions.com/>>
>
> Using Buddistick on 40 m is a real challenge. I would not be surprised if that was an S-unit or more below a full-size dipole.
>
> Try the simplest field antenna for the KX3, two wires connected directly to the rig. Get a BNC to double binding post adaptor. Get a wire 26 to 29 feet long, throw it in a tree and hook one end to the red post. Get a 16 foot wire, lay it on the ground and connect it to the black post. Let the ATU tune it and see you can hear.
>
> wunder
> K6WRU
> Walter Underwood
> CM87wj
> http://observer.wunderwood.org/ <http://observer.wunderwood.org/> (my
> blog)
>
> > On Aug 11, 2017, at 9:54 AM, Tommy <[hidden email] <mailto:[hidden email]>> wrote:
> >
> > The band has been really crappy lately. Keep tuning around and listening.
> >
> > 73!
> >
> > Tom - KB2SMS
> >
> >
> >
> > On 08/11/2017 12:33 PM, Mike Parkes wrote:
> >> Okay I am reaching our to the Elecraft enthusiasts here for some
> >> feedback if anyone cares to chime in.
> >> I am just getting back on the air after years away from the hobby,
> >> so I am not that familiar with band conditions in general. It looks
> >> like the sunspot cycle is heading for the cellar (if it isn't already there).
> >>
> >> Recently bought a KX3 and a Buddistick vertical (like, 2 weeks
> >> ago). Love the KX3 it is a great radio... however... so far my
> >> efforts to hear much of anything, much less make a contact with
> >> someone, has been frustrating to say the least. I live in an
> >> apartment and am surrounded by power lines for one thing. The
> >> background noise level on 40 is pretty bad varies but is
> >> s7-9 mostly. I took my setup to a nearby park and the bands were
> >> definitely quieter. So the local manmade noise level is an issue
> >> (and one reason I chose the KX3 was the hope that its rcvr and
> >> filtering could help with that.)
> >>
> >> Have yet to make a single contact, so I am just wondering if I just
> >> happened to choose a really lousy period of solar conditions for
> >> HF? Or is the base loaded vertical a joke?
> >>
> >> I would love to be able to find another ham even close by just to
> >> try and get some sort of an HF QSO even if it is with someone down the block.
> >> ...I can tune down to the AM broadcast band and was able to hear
> >> some local AM stations. :)
> >>
> >> Mike AB7RU
> >>
> >> (On a side note the tuner in the KX3 is great!. That thing was able
> >> to get a match for 80 meters on the Buddistick which was showing
> >> something like
> >> 25:1 swr. The KX3 tuner clicked and rattled for a while and found a
> >> match to <2:1. Not sure how much actual RF is going out, probably
> >> not much... but I was amazed it could tune to that high an SWR.)
> >> ______________________________________________________________
> >> Elecraft mailing list
> >> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> >> <http://mailman.qth.net/mailman/listinfo/elecraft>
> >> Help: http://mailman.qth.net/mmfaq.htm
> >> <http://mailman.qth.net/mmfaq.htm>
> >> Post: mailto:[hidden email]
> >> <mailto:[hidden email]>
> >>
> >> This list hosted by: http://www.qsl.net <http://www.qsl.net/>
> >> Please help support this email list: http://www.qsl.net/donate.html
> >> <http://www.qsl.net/donate.html> Message delivered to
> >> [hidden email] <mailto:[hidden email]>
> >>
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > <http://mailman.qth.net/mailman/listinfo/elecraft>
> > Help: http://mailman.qth.net/mmfaq.htm
> > <http://mailman.qth.net/mmfaq.htm>
> > Post: mailto:[hidden email]
> > <mailto:[hidden email]>
> >
> > This list hosted by: http://www.qsl.net <http://www.qsl.net/> Please
> > help support this email list: http://www.qsl.net/donate.html
> > <http://www.qsl.net/donate.html> Message delivered to
> > [hidden email] <mailto:[hidden email]>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> <http://mailman.qth.net/mailman/listinfo/elecraft>
> Help: http://mailman.qth.net/mmfaq.htm
> <http://mailman.qth.net/mmfaq.htm>
> Post: mailto:[hidden email]
> <mailto:[hidden email]>
>
> This list hosted by: http://www.qsl.net <http://www.qsl.net/> Please
> help support this email list: http://www.qsl.net/donate.html
> <http://www.qsl.net/donate.html> Message delivered to [hidden email]
> <mailto:[hidden email]>
> --
> 73 (or 72 for the QRP folks),
> Rich Hurd / WC3T
> DMR ID: 3142737
> Northampton County RACES
> EPA-ARRL Public Information Officer for Scouting
> Latitude: 40.761621 Longitude: -75.288988 (40°45.68' N 75°17.33' W)
> Grid: FN20is
>

Elecraft mailing list

Re: Is it my KX3/antenna or is it lousy band condx?

I prefer to use the end fed wire in an inverted "L" configuration with the vertical leg running down a FG pole to the radio.
Mel, K6KBE

From: Barthold Lichtenbelt via Elecraft <[hidden email]>
To: 'Walter Underwood' <[hidden email]>; 'Reflector Elecraft' <[hidden email]>
Sent: Thursday, August 31, 2017 7:28 AM
Subject: Re: [Elecraft] Is it my KX3/antenna or is it lousy band condx?

Walter,

This was a super informative writeup, thank you!

I have one question for you. If you throw a 26-29 foot wire in a tree, but it is impractical to sit right at the end of the wire (too many branches in the way, or whatever) to operate, how would you extend it? For example, operate from a table 20 feet away.

Thanks!
Barthold
AD0RM

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of Walter Underwood
Sent: Sunday, August 13, 2017 10:10 AM
To: Reflector Elecraft
Subject: Re: [Elecraft] Is it my KX3/antenna or is it lousy band condx?

In July, five SOTA operators put up seven different antennas on a summit and compared their performance with WSPR. Six of the antennas were mostly within 3 dB of each other. The EARCHI antenna (end-fed with transformer) was between 6 and 15 dB worse than the others. So in one experiment, the 9:1 transformer did not help.

http://reflector.sota.org.uk/t/seven-sota-antennas-compared-using-wspr-on-a-summit/15635 <http://reflector.sota.org.uk/t/seven-sota-antennas-compared-using-wspr-on-a-summit/15635>

When the antenna is connected directly to the KX3, there is no transmission line, so there is no need to match the antenna to the transmission line. It is putting the ATU at the feed point of the antenna.

The 26-29 foot length is chosen to avoid very high or very low impedances in the ham bands down to 40 m Especially, it is not a 1/2 wave on any band. That makes it easier to match. If you want to work 80 m, use a 53 foot wire.

The 16 foot wire on the ground is a radial “system”. One radial is a lot better than none, but you could use more. The length isn’t especially important because it is capacitively coupled to the ground. Ground resistance swamps any resonance.

I first heard about this antenna on this list. It was recommended by Wayne, N6KR. It is documented on page 9 of the instructions for the KXAT1 antenna tuner, “...for backpacking use on 40/30/20 meters, a wire length of 24-28 feet will generally provide good results. […] Ground system: Use a at least one ground radial, cut to at least 1/8th wavelength on the lowest band used (16' on 40 meters). When possible, use two or more radials, with one cut to 1/4 wavelength on each band."

http://www.elecraft.com/manual/E740054%20KXAT1%20man%20rev%20B.pdf <http://www.elecraft.com/manual/E740054%20KXAT1%20man%20rev%20B.pdf>

There is similar advice on page 10 of the KX2 manual.

http://www.elecraft.com/manual/E740282%20KX2%20owner%27s%20man.pdf <http://www.elecraft.com/manual/E740282%20KX2%20owner's%20man.pdf>

Finally, stop trying to think about “balanced” and “unbalanced” because those words are used in bizarre, inconsistent ways. Voltage, whether DC or RF, is always between two terminals. With a center-fed dipole, the two terminals are the elements. With this setup, the two terminals are the wire in the air and the wire on the ground.

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

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Mike Parkes

Re: Is it my KX3/antenna or is it lousy band condx?

In reply to this post by Mike Parkes

Bob,
Thank you very much for sharing all that. I like your dipole approach
there, getting at least one end up in the air at the roof level of that
condo. I could possibly do something like that, slingshot a line to the
rooftop of this apt bldg somehow ... Maybe with some kind of batman grapple
hook thing on the end that can snag on something hi. My big concern here is
how close the power lines are. Anyway. I am still mulling it over and
continue to work with the buddistick (or the metal downspout on this bldg
which tunes up surprisingly well on all bands).

Mostly I am just trying to keep the faith right now that something will
work out here. There is a lot of background noise here...tuning across the
bands I hear one weird "signal" after the other, swooshing in and out as i
tune the bands, which must be the horrid interference thrown out from all
the WiFi routers around here... 60 cycle noise, buzzes, pops, I mean it is
a real cacophony of sounds. There must be all kinds of intermodulation
sorts of interference, the rfi mixing with the kx3's receiver. The NB and
NR of the kx3 actually does a good job knocking a lot of that back. So far
not one contact though. Trying *not* to see my investment as a rather
expensive mini boat anchor.

I think I will buy some China HT and at least get on 2 meters (not sure I
am ready to spend the $260 on a 2 meter module for the kx3 just yet,
although I will probably add it at some point anyway.)

I wish there was some way to at least scare up some local 10 meter (line of
sight) activity here so that I could at determine if this radio is
transmitting okay. Some local HF qso's would be great... But I am not a
part of a local ham club or anything here to try and set up a sked with
anyone. Anyway... I appreciate your thoughts there, I am still trying to
figure out what I really hope to get out of ham radio. So far it is QSOs on
this Elecraft mailing list :) which is a great group here... This band is
always open as long as the internet works. :) 73s, mike.

On Aug 13, 2017 7:18 PM, "Bob McGraw K4TAX" <[hidden email]> wrote:

> Mike:
>
> Glad to share my thoughts and experiences.
>
> As to using a dipole, feed it in the center with coax RG-58, RG-8X. And
> the dipole does not have to be in a straight line. On the balcony or
> patio, a single center support and droop the ends down in an inverted V
> style. Or stretch it out as straight as you can between two supports and
> droop the ends if it is longer than the two supports are spaced.
>
> I used both of these combinations when we lived in a condo in South FL.
> With one of my antennas I had it vertical by dropping a Dacron fishing
> line from the roof of a 3 story building down to our balcony on the 2nd
> floor. I moved it away, sideways from the balcony so as not to attract the
> attention the upstairs neighbor. Connected the end of my 20 M dipole and
> hauled it up such that the feed point was about at the ceiling level of our
> balcony or the floor level of the upstairs neighbor. The other end made it
> just about to the ground. A nice fishing weight attached to the lower end
> kept thing taught. I used some #30 Teflon covered wire which was white.
> Looked more like a spider web and couldn't be seen from 15 ft or so against
> the white building. I just tied a knot in the end and attached the
> Dacron. The center insulator was a piece of plastic from a milk jug, and
> the #30 wire was not stripped but just tied with a couple of 1" or so
> pigtails. Strip the ends and attach the coax. Found some white marine
> RG58 for the feed line. It was in place for about 6 years. No one noticed
> or said anything. Worked great. Fortunately our condo was only 30 units
> most of which were seasonal occupancy. Thus empty most of the year. Only
> about 12 to 15 full time residents.
>
> Just be creative. The site I refer to is that of DJ0IP. He designs
> antennas for portable operation, back pack operation and such. Thus small,
> compact and lightweight. He also has great information on
> baluns........good ones........and bad ones. Correct applications and
> incorrect applications.
>
> Yes, digital modes are very conducive to low power and noise conditions.
> The new FT8 mode which is included in the WSJT-X latest version is fast and
> good. Not a rag chew mode by any means, but one can make contacts with
> the simple exchange of calls, grid squares, signal reports, 73 and log
> it. Lots of activity on that mode. Much faster, actually 4 times, than
> JT-65 which is more like watching paint dry. I've been active on 6M the
> past 2 weeks on FT-8 mode and this weekend with the Perseid meteor shower
> using MSK144.
>
> If you are trying to work the lower frequencies, below 7 MHz, you will
> really need a much larger antenna. Not saying it can't be done but more
> antenna and more power is generally required. For a while I use my
> mobile HF Hustler antenna and a pair of vice grip pliers to clamp the
> insulated base to the rail around the balcony. Worked OK but I was also
> running 100 watts.
>
> Good luck, let me know if I can assist.
>
> 73
>
> Bob, K4TAX
>
> K3S s/n 10163
>
> On 8/13/2017 8:13 PM, Mike Parkes wrote:
>
> Hi Bob
> Thank you for your detailed reply! As for radials, I am just using the one
> radial that came in the kit. It has to be tuned for each band. My setup has
> to be taken down and set up each time so a lot of radials could be an issue.
>
> I like your 20 MTR dipole thought. I have always had good results with
> wires. I could possibly string up a 20m dipole.
>
> The digital modes are great I used to work a lot of that, and getting back
> on those modes could help with weak signal work.
>
> And your points on the attenuation and backing off rf gain are great. I
> was totally unaware of how that could help with noise on the bands.
> Thanks again, excellent help
> 73
> mike
>
> On Aug 11, 2017 10:04 AM, "Bob McGraw K4TAX" <[hidden email]> wrote:
>
>> Mike:
>>
>> Comments in general..........the bands aren't in the best of conditions.
>> Summertime makes for static crashes being created some 500+ miles away on
>> 40 meters. And living in the midst of other apartments and power lines
>> doesn't help. Then to make matters seemingly worse, a vertical seems more
>> prone to pick up noise as noise is largely a vertical component.
>>
>> As to the vertical, my experience with verticals is that they do require
>> a significant ground radial system in order to reduce the radiation loss.
>> This is even after "tuning" for a low SWR. And your "mighty" amount of
>> power doesn't help your cause either. HI HI. I'd try a simple coax fed
>> dipole for say 20M which shouldn't be to difficult to get in the air a few
>> feet there at the apartment. I operated from a ground floor condo unit
>> for a few years. The new digital modes are a dream for weak signals both
>> TX and RX. I'm really enjoying WSJT-X and the new FT-8 mode.
>>
>> As to the receiver in the KX3, it is darn good. However, noise on
>> frequency can not be removed by any filtering. It just stomps on the
>> receiver and its AGC. As a suggestion, use the attenuator and/or back
>> the RF Gain down. Based on work of Rob Sherwood and others, optimum
>> receiver performance is attained when the receiver noise floor is some 10
>> dB to 15 dB below band noise. Since we can't actually change the receiver
>> noise floor, we can bring the signals and noise down close to the receiver
>> noise floor with the internal attenuator and RF Gain. Most hams run too
>> much RF gain thinking it is necessary to hear weak signals. More gain =
>> more noise. Law of Physics.......with a few exceptions usually not
>> available to hams. Think absolute zero and super cooled semiconductors.
>>
>> To do the math, if the KX3 noise floor is -125 dBm and the band is at -97
>> dBm or S-5 the difference is 28 dB. Accounting for having the receiver
>> noise floor 10 dB below the signal, this says the receiver should have a
>> combination of 18 dB attenuation and RF Gain reduction thereby bringing the
>> signal + noise to about -115 dBm.
>>
>> Hope this helps.
>>
>>
>> On 8/11/2017 11:33 AM, Mike Parkes wrote:
>>
>>> Okay I am reaching our to the Elecraft enthusiasts here for some feedback
>>> if anyone cares to chime in.
>>> I am just getting back on the air after years away from the hobby, so I
>>> am
>>> not that familiar with band conditions in general. It looks like the
>>> sunspot cycle is heading for the cellar (if it isn't already there).
>>>
>>> Recently bought a KX3 and a Buddistick vertical (like, 2 weeks ago). Love
>>> the KX3 it is a great radio... however... so far my efforts to hear much
>>> of
>>> anything, much less make a contact with someone, has been frustrating to
>>> say the least. I live in an apartment and am surrounded by power lines
>>> for
>>> one thing. The background noise level on 40 is pretty bad varies but is
>>> s7-9 mostly. I took my setup to a nearby park and the bands were
>>> definitely quieter. So the local manmade noise level is an issue (and one
>>> reason I chose the KX3 was the hope that its rcvr and filtering could
>>> help
>>> with that.)
>>>
>>> Have yet to make a single contact, so I am just wondering if I just
>>> happened to choose a really lousy period of solar conditions for HF? Or
>>> is
>>> the base loaded vertical a joke?
>>>
>>> I would love to be able to find another ham even close by just to try and
>>> get some sort of an HF QSO even if it is with someone down the block.
>>> ...I can tune down to the AM broadcast band and was able to hear some
>>> local
>>> AM stations. :)
>>>
>>> Mike AB7RU
>>>
>>> (On a side note the tuner in the KX3 is great!. That thing was able to
>>> get
>>> a match for 80 meters on the Buddistick which was showing something like
>>> 25:1 swr. The KX3 tuner clicked and rattled for a while and found a match
>>> to <2:1. Not sure how much actual RF is going out, probably not much...
>>> but
>>> I was amazed it could tune to that high an SWR.)
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>>
>>
>