Re: [Elecraft] OT:. G5RV's

[Eric Swartz - WA6HHQ, Elecraft]

End of thread. (and related G5RV threads under similar subject lines..)

We are now at 27 G5RV posts in less than 24 hours, several time the limit for OT 
posts.  In the interest of relieving email overload for Elecraft focused readers 
and others, please take further discussion off list.


(Please self moderate in the future and end these OT threads when they get to 
5-10 posts. I am not always available to close threads.)


Also, this is another of those list discussions that reoccur here over time. 
Much of this info is repeated in prior posts that can easily be searched for 
using 'G5RV' via the Elecraft  list Nabble archives at:

http://elecraft.365791.n2.nabble.com/

73,
Eric
Moderator
/elecraft.com/
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Fred Jensen]

The UK does not have a monopoly on such folk, Alan.  Just ask Tom, 
K5RC/W7RN.  10 acres on a hilltop in an extremely rural area ... 3 1/2 
years of legal battles with distant neighbors and the County government. 
 Tom prevailed, finally, and I operate his station remotely from time 
to time.


Our homeowners' association is pretty benign and benevolent here, and 
I've learned over the years that I can be a pretty adaptable ham, still 
satisfy my urge to radiate RF, and get along with my neighbors.


73,

Fred K6DGW
Sparks NV
Washoe County DM09dn

On 8/5/2016 5:34 AM, G4GNX wrote:


Attitudes towards structures in the
UK are very different to the USA and there are many snobs who claim
offense when they see something that appears above the roof line of an
average house.


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Richard Fjeld]

On 8/4/2016 4:00 PM, Alan Bloom wrote:
It's true that tuner losses are the manufacturers' dirty little 
secret. Loss is rarely specified, partly because it can be pretty bad, 
and partly because it is hard to measure, but also because it is not 
constant - it depends on the particular impedance being matched. 


I read about tuner losses often, and I've seen figures posted, but 
whenever I try to determine it, I can't.  The only way I can determine 
tuner loss is by signal reports.  While participating in round tables on 
80 meters, I go down in power as low as the K3 will go, and the 
participants in state, and in an adjacent state or two, still hear me as 
evidenced by carrying on a discussion.  I use open wire feedline with a 
loop cut for the bottom of 80 meters.


I know this is not an accurate way to measure tuner loss, but the loss 
doesn't seem to be a problem. ???


Dick, n0ce

--

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Jim Vohland]

When I started in the hobby, I worked 150 countries before I found out a G5RV 
didn't work. Took it down and haven't used it since. 

Sent from my iPhone

> On Aug 5, 2016, at 11:21 AM, William Lagerberg  wrote:
> 
> And you now dear list users, i have a G5RV and i really love it it works 
> allways, and give’s me good results :-))
> 
> Just have to say that.
> 
> Regards William PE1BSB
> 
> 
> 
>> On 05 Aug 2016, at 16:58, Phil Wheeler  wrote:
>> 
>> Alas, the poor G5RV.  Now that its been flogged to death, maybe we need a 
>> new target -- say the Windom?
>> 
>> Phil W7OX
>> 
>>> On 8/4/16 10:22 PM, Wes Stewart wrote:
>>> The tuner loss also depends on how it is adjusted. For example the very 
>>> popular high-pass Tee with three adjustable elements has an infinite number 
>>> of possible combinations that will effect a match on the same load Z.  One 
>>> of them is the lowest loss solution, all of the others aren't.
>>> 
>>> As I said earlier, in a letter to Dean Straw dated February 2, 1994 I 
>>> offered an example where the SPC tuner, then current in the handbooks, 
>>> could be used to match an impedance of 4.34 +j46 to 50 ohm. (I forget where 
>>> this came from but it was a real possibility)  I assumed Qc = 1000 and Ql = 
>>> 300 (generous). I used Touchstone to calculate the minimum loss and maximum 
>>> loss solutions The best case was 1.6 dB and the worst case was 7.8 dB.
>>> 
>>> With lower Q components, Qc = 500, Ql =200, the losses were 2.4 to 9.5 dB!
>>> 
>>> Wes  N7WS
>>> 
>>> 
>>> On 8/4/2016 2:00 PM, Alan Bloom wrote:
> It's a pity that too many newcomers, as well as many oldsters, are
> enamored by this piece of wire.
 
 The G4RV is definitely a compromise antenna.  However its advantage is 
 that is has low-enough SWR to be easily matched by most tuners on a number 
 of bands.
 
> ... the horrific losses that could be incurred even
> with high quality tuners,
 
 It's true that tuner losses are the manufacturers' dirty little secret. 
 Loss is rarely specified, partly because it can be pretty bad, and partly 
 because it is hard to measure, but also because it is not constant - it 
 depends on the particular impedance being matched.
 
 One exception is the old Drake tuners.  Their Pi-L topology makes the loss 
 almost independent of the load impedance.  If you can get it to match, you 
 know that almost all the power is going into the feed line. For example, 
 the MN-2700 that I designed when I was at Drake was specified at 0.5 dB 
 maximum insertion loss and I did a lot of testing and tweaking to achieve 
 that on all bands.
 
 Alan N1AL
>> 
>> __
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft@mailman.qth.net
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to pe1...@zendamateur.nl
> 
> 
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to n...@hotmail.com
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Lynn W. Taylor, WB6UUT]

The problem with every one of these antenna discussions is that some of 
us are looking for a reasonable set of compromises, and that discussion 
tends to get lost in the "this antenna ain't perfect!" discussion that 
invariably results.


When I bought this house, I knew the lot size, and I saw the power lines 
running along the back property line.


Someone said that rotating dipoles would outperform most of the 
alternatives.  That means a good mast, a rotor, and I'd have to make 
damn sure the mast couldn't fall across power lines.


I guess the bottom line is that perfect is the enemy of good enough.

-- Lynn

On 8/5/2016 6:37 AM, Don Wilhelm wrote:
What I am trying to communicate is that the user of a compromise 
antenna should understand its properties and limitations.  Despite 
what advertising and 'ham lore' would say, there is no 'magic' in any 
particular antenna.  They all have their limitations.



__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[William Lagerberg]

And you now dear list users, i have a G5RV and i really love it it works 
allways, and give’s me good results :-))

Just have to say that.

Regards William PE1BSB



> On 05 Aug 2016, at 16:58, Phil Wheeler  wrote:
> 
> Alas, the poor G5RV.  Now that its been flogged to death, maybe we need a new 
> target -- say the Windom?
> 
> Phil W7OX
> 
> On 8/4/16 10:22 PM, Wes Stewart wrote:
>> The tuner loss also depends on how it is adjusted. For example the very 
>> popular high-pass Tee with three adjustable elements has an infinite number 
>> of possible combinations that will effect a match on the same load Z.  One 
>> of them is the lowest loss solution, all of the others aren't.
>> 
>> As I said earlier, in a letter to Dean Straw dated February 2, 1994 I 
>> offered an example where the SPC tuner, then current in the handbooks, could 
>> be used to match an impedance of 4.34 +j46 to 50 ohm. (I forget where this 
>> came from but it was a real possibility)  I assumed Qc = 1000 and Ql = 300 
>> (generous). I used Touchstone to calculate the minimum loss and maximum loss 
>> solutions The best case was 1.6 dB and the worst case was 7.8 dB.
>> 
>> With lower Q components, Qc = 500, Ql =200, the losses were 2.4 to 9.5 dB!
>> 
>> Wes  N7WS
>> 
>> 
>> On 8/4/2016 2:00 PM, Alan Bloom wrote:
>>> > It's a pity that too many newcomers, as well as many oldsters, are
>>> > enamored by this piece of wire.
>>> 
>>> The G4RV is definitely a compromise antenna.  However its advantage is that 
>>> is has low-enough SWR to be easily matched by most tuners on a number of 
>>> bands.
>>> 
>>> > ... the horrific losses that could be incurred even
>>> > with high quality tuners,
>>> 
>>> It's true that tuner losses are the manufacturers' dirty little secret. 
>>> Loss is rarely specified, partly because it can be pretty bad, and partly 
>>> because it is hard to measure, but also because it is not constant - it 
>>> depends on the particular impedance being matched.
>>> 
>>> One exception is the old Drake tuners.  Their Pi-L topology makes the loss 
>>> almost independent of the load impedance.  If you can get it to match, you 
>>> know that almost all the power is going into the feed line. For example, 
>>> the MN-2700 that I designed when I was at Drake was specified at 0.5 dB 
>>> maximum insertion loss and I did a lot of testing and tweaking to achieve 
>>> that on all bands.
>>> 
>>> Alan N1AL
> 
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to pe1...@zendamateur.nl


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Phil Wheeler]

Alas, the poor G5RV.  Now that its been flogged to 
death, maybe we need a new target -- say the Windom?


Phil W7OX

On 8/4/16 10:22 PM, Wes Stewart wrote:
The tuner loss also depends on how it is 
adjusted. For example the very popular high-pass 
Tee with three adjustable elements has an 
infinite number of possible combinations that 
will effect a match on the same load Z.  One of 
them is the lowest loss solution, all of the 
others aren't.


As I said earlier, in a letter to Dean Straw 
dated February 2, 1994 I offered an example 
where the SPC tuner, then current in the 
handbooks, could be used to match an impedance 
of 4.34 +j46 to 50 ohm. (I forget where this 
came from but it was a real possibility)  I 
assumed Qc = 1000 and Ql = 300 (generous). I 
used Touchstone to calculate the minimum loss 
and maximum loss solutions The best case was 1.6 
dB and the worst case was 7.8 dB.


With lower Q components, Qc = 500, Ql =200, the 
losses were 2.4 to 9.5 dB!


Wes  N7WS


 On 8/4/2016 2:00 PM, Alan Bloom wrote:
> It's a pity that too many newcomers, as well 
as many oldsters, are

> enamored by this piece of wire.

The G4RV is definitely a compromise antenna.  
However its advantage is that is has low-enough 
SWR to be easily matched by most tuners on a 
number of bands.


> ... the horrific losses that could be 
incurred even

> with high quality tuners,

It's true that tuner losses are the 
manufacturers' dirty little secret. Loss is 
rarely specified, partly because it can be 
pretty bad, and partly because it is hard to 
measure, but also because it is not constant - 
it depends on the particular impedance being 
matched.


One exception is the old Drake tuners.  Their 
Pi-L topology makes the loss almost independent 
of the load impedance.  If you can get it to 
match, you know that almost all the power is 
going into the feed line. For example, the 
MN-2700 that I designed when I was at Drake was 
specified at 0.5 dB maximum insertion loss and 
I did a lot of testing and tweaking to achieve 
that on all bands.


Alan N1AL


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Don Wilhelm]

Alan,

I do understand the situation for those with limited antenna space and 
restrictions.  What I do not understand is the "magical" qualities that 
have been attributed to many antennas.  They are compromise antennas, 
and I want everyone to understand that they are a compromise.


If a ham wants to operate on multiple bands and can have only one 
antenna, that compromise may be necessary, but for those who can install 
no-compromise antennas such as a fan dipole, it will provide better 
performance than the G5RV or the 'Carolina windom'. A fan dipole can be 
operated on multiple bands without a tuner.


Of course, LB Cebik advocated the 44 foot dipole for 40 thru 10 meters 
(88 foot for 80 thru 20) because it has no sidelobes.  It works well, 
but must be fed with low loss parallel feedline which requires a good 
antenna tuner at the shack end of that feedline.


What I am trying to communicate is that the user of a compromise antenna 
should understand its properties and limitations.  Despite what 
advertising and 'ham lore' would say, there is no 'magic' in any 
particular antenna.  They all have their limitations.


73,
Don W3FPR


On 8/5/2016 8:34 AM, G4GNX wrote:

Don,

With respect for your wisdom and your good advice, in the UK in 
particular (home of the G5RV) the 'ordinary' ham has real-estate 
issues, big time!


Louis Varney's garden/back yard was of average British size, which is 
actually quite small when compared to 'average' gardens that I've seen 
in the USA. That was his prime reason for designing a compact wire 
antenna.


We have other issues with planning regulations and erecting a mast or 
tower over 40ft in height would probably meet with a brick-wall 
attitude from the local planning authorities. Attitudes towards 
structures in the UK are very different to the USA and there are many 
snobs who claim offense when they see something that appears above the 
roof line of an average house.


My back yard is even smaller than Louis's and I just don't have space 
for lengthy wires or even slopers. Even erecting tall supports is 
difficult as there's limited ground to dig holes to fill with concrete 
supports.


Maybe in the USA, the use of G5RV antennas doesn't make too much 
sense, but to us Brits, compact antennas are often the only thing we 
can use.



73,

Alan. G4GNX



__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[G4GNX]

Don,

With respect for your wisdom and your good advice, in the UK in particular 
(home of the G5RV) the 'ordinary' ham has real-estate issues, big time!


Louis Varney's garden/back yard was of average British size, which is 
actually quite small when compared to 'average' gardens that I've seen in 
the USA. That was his prime reason for designing a compact wire antenna.


We have other issues with planning regulations and erecting a mast or tower 
over 40ft in height would probably meet with a brick-wall attitude from the 
local planning authorities. Attitudes towards structures in the UK are very 
different to the USA and there are many snobs who claim offense when they 
see something that appears above the roof line of an average house.


My back yard is even smaller than Louis's and I just don't have space for 
lengthy wires or even slopers. Even erecting tall supports is difficult as 
there's limited ground to dig holes to fill with concrete supports.


Maybe in the USA, the use of G5RV antennas doesn't make too much sense, but 
to us Brits, compact antennas are often the only thing we can use.



73,

Alan. G4GNX

-Original Message- 
From: Don Wilhelm

Sent: Friday, August 05, 2016 12:41 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] OT:. G5RV's

Wes and all,

Yes, the G5RV, the Off-Center-Fed antennas (Carolina Windom for one
example) and the 43 foot vertical have become "magical" antennas, and I
am not certain why.

My best guess is that they are "salvation" for hams who want to operate
on multiple bands with one antenna, and they can be made to "work" in
one fashion or another.

All need a tuner of some sort, and the 43 foot vertical needs a remote
tuner at the base for efficient operation, or at least a matching
section for each band at the base for efficient operation.  One could
feed that vertical with low loss open wire line and put the matching
tuner in the shack, but most choose to feed with coax along with the
attendant losses incurred if no matching is done at the vertical base.

IMHO, resonant fan dipoles are a much better solution - whether those be
constructed as inverted Vee's or whether as parallel dipoles separated
by 1 foot or more to reduce interaction.

I use resonant parallel dipoles here.  The 80 and 40 inverted vee's are
supported on a 50 foot tower and the 80 meter legs are perpendicular to
the 40 meter legs, so there is no interaction.

I have another 3 band band fan dipole for 20, 15, and 10 hung as a
horizontal dipole with the radiators separated 1 foot from each other
(other than at the center point) and a similar 3 band fan dipole for 30,
17, and 12 meters.
That means 3 coax lines into the shack, or a remote antenna switch -
which I use because I have other antennas to deal with, a 60 meter
inverted vee, and a Gap Titan vertical.

As far as I am concerned, resonant dipoles are the preferred solution.
Other antennas may work, but are a compromise, and some (particularly
the OCF antennas) produce RF-in-the-Shack that can be difficult to suppress.

There is no "magic" with antennas.  Some antenna designs were created
when we had PA output circuits that could handle a wide range of antenna
impedances and used low loss open wire feedlines.  That is no longer the
case with the transceiver (or amplifier) that needs to operate into a 50
ohm load, and ATUs with limited matching range.

So take your pick and know the hazards and consequences of that choice.
Any antenna that you can feed power to will radiate, but some do it
better than others.  My choice is to use center fed dipoles which at any
length can be easily tamed, and I shy away from the OCF antennas which
can create RF-in-the-Shack problems.
There is no "magic" with antennas, the knowledge base for radiation from
a wire (or piece of aluminum) has been around for many long years, but
the resulting feedpoint impedance is what we commonly deal with along
with all its hazards and consequences.

73,
Don W3FPR 


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Wes Stewart]

The tuner loss also depends on how it is adjusted.  For example the very popular 
high-pass Tee with three adjustable elements has an infinite number of possible 
combinations that will effect a match on the same load Z.  One of them is the 
lowest loss solution, all of the others aren't.


As I said earlier, in a letter to Dean Straw dated February 2, 1994 I offered an 
example where the SPC tuner, then current in the handbooks, could be used to 
match an impedance of 4.34 +j46 to 50 ohm. (I forget where this came from but it 
was a real possibility)  I assumed Qc = 1000 and Ql = 300 (generous). I used 
Touchstone to calculate the minimum loss and maximum loss solutions The best 
case was 1.6 dB and the worst case was 7.8 dB.


With lower Q components, Qc = 500, Ql =200, the losses were 2.4 to 9.5 dB!

Wes  N7WS


 On 8/4/2016 2:00 PM, Alan Bloom wrote:

> It's a pity that too many newcomers, as well as many oldsters, are
> enamored by this piece of wire.

The G4RV is definitely a compromise antenna.  However its advantage is that is 
has low-enough SWR to be easily matched by most tuners on a number of bands.


> ... the horrific losses that could be incurred even
> with high quality tuners,

It's true that tuner losses are the manufacturers' dirty little secret. Loss 
is rarely specified, partly because it can be pretty bad, and partly because 
it is hard to measure, but also because it is not constant - it depends on the 
particular impedance being matched.


One exception is the old Drake tuners.  Their Pi-L topology makes the loss 
almost independent of the load impedance.  If you can get it to match, you 
know that almost all the power is going into the feed line. For example, the 
MN-2700 that I designed when I was at Drake was specified at 0.5 dB maximum 
insertion loss and I did a lot of testing and tweaking to achieve that on all 
bands.


Alan N1AL 


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Wes Stewart]

I guess a little discussion of semantics is in order.  Yes, EZNEC shows for 
example, that a 12 AWG wire, 102' long and say 50' above avg ground shows an 
impedance of ~98 +j0 at 14.32 MHz, so it is resonant in the 20-meter band, 
because the reactance is zero, and it could be called a "resonant dipole.".  
However, It also shows resonances at 4.61, 9.45, 18.74, 23.92 and 28.40 MHz. In 
common ham jargon as I called it, this length would not be considered a resonant 
dipole for those frequencies other than 4.61 MHz where it is one half wavelength 
long.


But if someone wants to call it a 20-meter dipole, be my guest.

On 8/4/2016 3:22 PM, Fred Jensen wrote:
Ummm ... my HP48GX says 102' is very very close to 3 half-waves at 14 MHz 
which sounds sort of resonant-ish.  Maybe a little known bug in my calculator?

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Wes Stewart]

I know handbook descriptions have declared this for years.  They're simply 
wrong.  The folded part is a transmission line, it doesn't radiate and it has an 
impedance different from the antenna.  Why not just add a hundred feet or so of 
transmission line to a 10' dipole and call it a 160 antenna? Doesn't work, does 
it?  Use the same logic on your example and it doesn't work either.  Sorry.


On 8/4/2016 5:34 PM, Nr4c wrote:

Let's see,  102 + 33 = 135. Isn't that pretty close to the length of an 80 Meter Dipole?  
The G5RV looks like two back-to-back inverted "L" antennas. The twin lead is 
not feed line but part of the radiator.

Sent from my iPhone
...nr4c. bill



__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Don Wilhelm]

Bill,

That is correct, but the currents on the 33 feet feedline should be 
balanced and of opposite polarity - so they cancel.  The current at the 
radiator center will be less than that of a full size 80 meter radiator, 
so it will be less efficient than a full size 80 meter dipole with the 
current maximum at the feedpoint center.


There are numerous ways to phrase this, but bottom line is that a 102 
foot radiator on 80 meters will not be as good an antenna as a full size 
radiator.  The current will be at a max at the parallel line to coax 
junction, but will be reduced when the current magnitude reaches the 
radiator.


Low SWR does not mean radiation efficiency.

Low SWR does mean the best efficiency for a match to a 50 ohm PA stage, 
but the overall radiation efficiency depends on the antenna and its 
feedline.  One has to compute the losses involved as well as the current 
into the antenna system.


Of course, I must say that if you can feed power into an antenna system, 
that power will all be radiated (other than feedline loss).  In the 
example given for a 102 foot radiator, the balanced currents on the 
feedline will not contribute to power loss - the current on that 
balanced portion of the feedline will be greater than that presented to 
the antenna, and the balanced feedline will be operating at an SWR 
consistent with the impedance at that feedpoint.


As I have previously stated, there is little "magic" in antennas - the 
principles have been around since the days of Maxwell and other greats 
such as L.B Cebik W4LNR (SK) and John Kraus W8JK (SK) who have 
substantiated those facts.  Non-resonant antennas can be great 
performers, but one must deal with the feedpoint impedances that they 
present.  Those two antenna gurus did not consider the matching problems 
to their antennas, they properly presented the antenna radiation properties.


73,
Don W3FPR

73,
Don W3FPR

On 8/4/2016 8:34 PM, Nr4c wrote:

Let's see,  102 + 33 = 135. Isn't that pretty close to the length of an 80 Meter Dipole?  
The G5RV looks like two back-to-back inverted "L" antennas. The twin lead is 
not feed line but part of the radiator.




__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Don Wilhelm]

Fred,

Dirt was young when I was first licensed too.
I do remember those days of link coils that you slowly advanced into the 
PA inductor and re-dipped the plate until the current draw was correct 
for the power level that you wanted to operate.  Those were the days of 
plug-in coils for each band.  Yes, I do have some of those plug-in coils 
and swinging link coils in my stash of "old stuff" in the attic.


Then came the Johnson Matchbox with its band switching capability (I 
have one of those too), and multi-band PA stages with a Pi-Network.


Those days are past.  Many new hams do not know how to 'dip the plate' 
and then increase the "loading " and re-dip the plate until the plate 
current was as desired.


I now do not recommend a transceiver to a new ham if it has 'tuning' and 
'loading' knobs - the information about how to do that properly is just 
not abundant today as it was in years past.


Add to that fact that the re-tuning had to be repeated for each band 
change or significant QSY in the band.


We have come a long way with the advent of solid state PA stages and 
broadband tuning with only a Low Pass Filter at the PA output - but the 
penalty of that is we now have to operate the PA stage into a 50 ohm 
load.  That is where the ATU comes into play.  The variability in the 
antenna feedpoint impedance has been moved from the PA output stage to 
the "tuning unit" to allow us to feed antennas that present an impedance 
of other than 50 ohms to the PA stage.


73,
Don W3FPR

On 8/4/2016 8:41 PM, Fred Jensen wrote:
 All this "matching bafflegab" was unheard of when I was a young ham.  
You fed your dipole with 75 ohm twin-lead, coupled it to the PA with a 
2 or 3 turn link coil, and as the reactance of the link changed the 
resonance, you compensated by "re-dipping the plate."


Of course, when I was a young ham, dirt was pretty young too. :-)



__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Edward R Cole]

Jim and all:

Interesting comments on the G5RV (I've never built one but have a 
local friend that uses one).


For years I used wire dipoles on HF bands: I made a 80/40m trap 
dipole, 80/40m dipole with removable clip at 40m length which we call 
the "Iditarod Special" as it was simple to use at remote checkpoints 
on the trail for changing prop day/night over 150-900 mi range in 
winter.  Sometimes the antenna was only 8-foot off the ground (high 
as one could reach without ladder), but worked surprisingly well for 
extreme NVIS.


I had a 80/40/20m fan inverted-V at home before putting up my tri-band yagi.

Now the inverted-V is 80/40m fan style.  It works better on 3800-4000 
than on 40m where bandwidth seems narrow.  The center is fed with 
commercial 1:1 balun at 40-feet and ends are 20-feet high which works 
well for NVIS.


I can tune it higher than 7100 using my tuner which is a Drake 
VN-2000 "oldie but goodie".  The tri-band yagi also needs help 
resonating which the Drake handles fine.


Accidentally my 600m inverted-L is 43 feet high.  I have a 122-foot 
long top leg of two parallel wires and the vertical is three parallel 
wires.  Base coil is 11x10 inch diameter fed near ground end with 
coax.  Ground radials are also very short for 472-KHz and consist of 
2-foot wide by 50 to 70 foot long chicken wire lain on the 
ground.  Efficiency is 0.8 % but it works for both Tx and Rx, having 
my signal been heard over 4,000 miles away in Buffalo, NY.  Normal 
ground-wave distance is about 250 mi running 100w output from 
amplifier (converted NDB transmitter driven by my K3 at 0.1mw).


73, Ed - KL7UW

73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
dubus...@gmail.com

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Fred Jensen]

My EFHW [granted, it is technically only one half-wave on 80 m] got a 
pretty good write up in QST not long ago, after I had it installed, and 
he elevated the far end into a tree.  While his review was pretty 
qualitative [:-(] which has become more common in QST these days, he 
still got the same impedance sweep 3-30 MHz as I do.  So, I'm not sure 
the electrical characteristics are all that dependent on dielectric loss 
in my fence.  The fence is very dry wood, our relative humidity runs in 
single digits most of the time, it was 6% last evening.


At any rate, it looks like I'm going to sell my KPA500/KAT500, just have 
to get up the nerve to part with them.  The antenna is rated at 500W 
ICAS [whatever that means quantitatively these days], but I'm loathe to 
nuke Toady, the neighbor's Lab whose run is directly on the other side 
of the fence.  I do occasionally turn on a couple of lamps in the 
bedroom on capacitative switches on 80 with 100W, that's enough.


My only connection with MyAntennas was to write them a $140 check, but I 
really am surprised how well it performs in a highly non-optimal 
configuration.  All this "matching bafflegab" was unheard of when I was 
a young ham.  You fed your dipole with 75 ohm twin-lead, coupled it to 
the PA with a 2 or 3 turn link coil, and as the reactance of the link 
changed the resonance, you compensated by "re-dipping the plate."


Of course, when I was a young ham, dirt was pretty young too. :-)

73,

Fred K6DGW
- Northern California Contest Club
- CU in the Cal QSO Party 1-2 Oct 2016
- www.cqp.org

On 8/4/2016 4:48 PM, Lynn W. Taylor, WB6UUT wrote:

What happens if the antenna is well above ground, away from any fences?

On 8/4/2016 3:55 PM, Guy Olinger K2AV wrote:

If we are just dodging the HOA, vs creating a remote site, or not
operating
at all, what you describe seems quite reasonable. One half wave on 80,
two
on 40, three on 30m, four on 20m, etc. allow a rather simple feed
mechanism, and any sloppiness will be mitigated to some degree in the
unavoidable dielectric loss of the fence and ground.



__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to k6...@foothill.net


-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7690 / Virus Database: 4627/12747 - Release Date: 08/04/16




__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Nr4c]

Let's see,  102 + 33 = 135. Isn't that pretty close to the length of an 80 
Meter Dipole?  The G5RV looks like two back-to-back inverted "L" antennas. The 
twin lead is not feed line but part of the radiator. 

Sent from my iPhone
...nr4c. bill


> On Aug 4, 2016, at 4:41 PM, Wes Stewart  wrote:
> 
> In my 1999 paper, /"Balanced Transmission Line in Current Amateur Practice"/ 
> (http://k6mhe.com/n7ws/Ladder_Line.pdf), published in the /ARRL Antenna 
> Compendium, Volume 6, /pp 174-178, I have this statement: "A popular 
> multiband wire antenna is the so-called G5RV. This antenna is rarely used as 
> was intended by Varney, but for some reason, the 102-foot length has taken on 
> mystical properties,"
> 
> It's a pity that too many newcomers, as well as many oldsters, are enamored 
> by this piece of wire.  First, a 102' length is not resonant on 20-meters, so 
> in common jargon, it's *not* a 20-meter antenna, any more than any other 
> random length would be. Second, I understand that the conventional wisdom is 
> that it has "gain" on 20-meters.  Maybe so, but the usual application has the 
> wire strung up between available supports that may, or may not, direct the 
> "gain" in a useful direction.  A coax-fed, rotatable, resonant dipole would 
> run rings around a G5RV.
> 
> (While it's off-topic on this off-topic subject, the fascination with the 
> "magical" 43-foot vertical is equally bewildering to me.)
> 
> In my published paper, space limited any discussion of tuner loss, however, 
> in 1994 (type)written correspondence with editor Dean Straw I gave him 
> examples of the horrific losses that could be incurred even with high quality 
> tuners, when used as proposed the the article* that got me going on this 
> subject.  It's interesting to note that to my knowledge, loss in tuners had 
> never been mentioned in any ARRL publications before this correspondence. 
> Shortly thereafter, "/How to Evaluate Your Antenna Tuner" /was published in 
> 1995.  Coincidence I'm sure.
> 
> BTW, any ARRL publication before 1994 with charts of transmission line loss 
> that include open-wire line is incorrect.  It's easily seen by inspection, 
> but apparenty I was to first to inspect it. Dean and I hashed out a correct 
> attenuation chart.
> 
> Wes  N7WS
> 
> * "/The Lure of the Ladder Line", QST, /December 1993, pp. 70-71
> 
> 
> 
> 
> : On 8/4/2016 11:08 AM, Ken G Kopp wrote:
>> As usual, Jim is correct ...
>> 
>> I have Lou Varney's original article.  The G5RV was designed as a 20M
>> --ONLY-- antenna.  It's now achieved some kind of cult ... read voodoo ...
>> status. (;-)
>> 
>> If one has an antenna that is partially fed with balanced line that's then
>> directly (!) spliced to a specific length of coax and then still requires a
>> tuner, why not run the balanced line directly to the tuner ... assuming it
>> has a balun ... or provide one at the tuner?
>> 
>> This same argument would apply to Varney's design for a 20M only dipole.
>> 
>> Maybe he didn't have a tuner of any kind, and wanted to use coax feed line
>> because there was a coax connector on his rig. (;-)
>> 
>> 73
>> 
>> K0PP
> 
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to n...@widomaker.com

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Jim Brown]

On Thu,8/4/2016 4:31 PM, Walter Underwood wrote:

There is one efficient way to broaden an antenna’s frequency range—lower the Q. 
That is usually done with large-diameter elements. You can cover all of the 80 
meter band with reasonable SWR using a “cage dipole”. That is what they do at 
W1AW. At VHF/UHF, you may see bowtie antennas, which are also low-Q.


Exactly right.  I've used that technique on my 160M Tee vertical.

On Thu,8/4/2016 4:37 PM, Elecraft K3 wrote:

Recently I have gotten into building no compromise rotatable dipoles.  By no 
compromise I mean full sized monoband rotatable dipoles - no traps, coils or 
cap hats 1/2 wave off the ground in free space.  These are relatively easy to 
build without a huge tower if you keep the weight down.  That’s not too hard to 
do without a boom to support the parisitic elements.  Great bang for the buck.


Exactly right -- height matters, and 1/2 wave is an excellent height for 
any dipole. I have two half wave fan dipoles for 80 and40 at right 
angles, up about 140 ft. Same idea, but  organic supports (redwoods). 
:)  Nothing's free though -- tree climbers cost money, and so does 130 
ft of tower, safely installed. :)


73, Jim K9YC

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Lynn W. Taylor, WB6UUT]

What happens if the antenna is well above ground, away from any fences?

On 8/4/2016 3:55 PM, Guy Olinger K2AV wrote:

If we are just dodging the HOA, vs creating a remote site, or not operating
at all, what you describe seems quite reasonable. One half wave on 80, two
on 40, three on 30m, four on 20m, etc. allow a rather simple feed
mechanism, and any sloppiness will be mitigated to some degree in the
unavoidable dielectric loss of the fence and ground.



__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Don Wilhelm]

Wes and all,

Yes, the G5RV, the Off-Center-Fed antennas (Carolina Windom for one 
example) and the 43 foot vertical have become "magical" antennas, and I 
am not certain why.


My best guess is that they are "salvation" for hams who want to operate 
on multiple bands with one antenna, and they can be made to "work" in 
one fashion or another.


All need a tuner of some sort, and the 43 foot vertical needs a remote 
tuner at the base for efficient operation, or at least a matching 
section for each band at the base for efficient operation.  One could 
feed that vertical with low loss open wire line and put the matching 
tuner in the shack, but most choose to feed with coax along with the 
attendant losses incurred if no matching is done at the vertical base.


IMHO, resonant fan dipoles are a much better solution - whether those be 
constructed as inverted Vee's or whether as parallel dipoles separated 
by 1 foot or more to reduce interaction.


I use resonant parallel dipoles here.  The 80 and 40 inverted vee's are 
supported on a 50 foot tower and the 80 meter legs are perpendicular to 
the 40 meter legs, so there is no interaction.


I have another 3 band band fan dipole for 20, 15, and 10 hung as a 
horizontal dipole with the radiators separated 1 foot from each other 
(other than at the center point) and a similar 3 band fan dipole for 30, 
17, and 12 meters.
That means 3 coax lines into the shack, or a remote antenna switch - 
which I use because I have other antennas to deal with, a 60 meter 
inverted vee, and a Gap Titan vertical.


As far as I am concerned, resonant dipoles are the preferred solution.  
Other antennas may work, but are a compromise, and some (particularly 
the OCF antennas) produce RF-in-the-Shack that can be difficult to suppress.


There is no "magic" with antennas.  Some antenna designs were created 
when we had PA output circuits that could handle a wide range of antenna 
impedances and used low loss open wire feedlines.  That is no longer the 
case with the transceiver (or amplifier) that needs to operate into a 50 
ohm load, and ATUs with limited matching range.


So take your pick and know the hazards and consequences of that choice.
Any antenna that you can feed power to will radiate, but some do it 
better than others.  My choice is to use center fed dipoles which at any 
length can be easily tamed, and I shy away from the OCF antennas which 
can create RF-in-the-Shack problems.
There is no "magic" with antennas, the knowledge base for radiation from 
a wire (or piece of aluminum) has been around for many long years, but 
the resulting feedpoint impedance is what we commonly deal with along 
with all its hazards and consequences.


73,
Don W3FPR

On 8/4/2016 4:41 PM, Wes Stewart wrote:
In my 1999 paper, /"Balanced Transmission Line in Current Amateur 
Practice"/ (http://k6mhe.com/n7ws/Ladder_Line.pdf), published in the 
/ARRL Antenna Compendium, Volume 6, /pp 174-178, I have this 
statement: "A popular multiband wire antenna is the so-called G5RV. 
This antenna is rarely used as was intended by Varney, but for some 
reason, the 102-foot length has taken on mystical properties,"


It's a pity that too many newcomers, as well as many oldsters, are 
enamored by this piece of wire.  First, a 102' length is not resonant 
on 20-meters, so in common jargon, it's *not* a 20-meter antenna, any 
more than any other random length would be. Second, I understand that 
the conventional wisdom is that it has "gain" on 20-meters.  Maybe so, 
but the usual application has the wire strung up between available 
supports that may, or may not, direct the "gain" in a useful 
direction.  A coax-fed, rotatable, resonant dipole would run rings 
around a G5RV.


(While it's off-topic on this off-topic subject, the fascination with 
the "magical" 43-foot vertical is equally bewildering to me.)




__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Elecraft K3]

John,

I think this is a reasonable conclusion.  Early on I used a G5RV and it was 
invaluable reference for my later antenna building experience.  I went to build 
doublets in the same space and I still keep an 80m doublet in the air.

Recently I have gotten into building no compromise rotatable dipoles.  By no 
compromise I mean full sized monoband rotatable dipoles - no traps, coils or 
cap hats 1/2 wave off the ground in free space.  These are relatively easy to 
build without a huge tower if you keep the weight down.  That’s not too hard to 
do without a boom to support the parisitic elements.  Great bang for the buck.

Another country heard from,

73 de Eric, KG6MZS
  
> On Aug 4, 2016, at 3:14 PM, John Frazier  wrote:
> 
> Over the years, immediately after a change in QTH, I have used the G5RV as an 
> interim antenna.
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Walter Underwood]

There is one efficient way to broaden an antenna’s frequency range—lower the Q. 
That is usually done with large-diameter elements. You can cover all of the 80 
meter band with reasonable SWR using a “cage dipole”. That is what they do at 
W1AW. At VHF/UHF, you may see bowtie antennas, which are also low-Q.

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

> On Aug 4, 2016, at 3:55 PM, Guy Olinger K2AV  wrote:
> 
> Hi Fred,
> 
> Loss *anywhere* would broaden the antenna. Famously the B folded dipole,
> fed at the center of one wire, and terminated with an RF resistor at the
> center of the other, has for decades been serving commercial installations
> with widely separated operating frequencies not connected by any fortunate
> harmonic relationship. That antenna has roughly an intentional 3 dB loss at
> a designed position in the antenna. See
> https://www.bwantennas.com/images/fdipole.gif for a drawing.
> 
> In the case of your EFHW, the broadening loss is the dielectric loss in the
> fence itself, and in the ground very close underneath.
> 
> The B folded dipole as a solution sticks in the craw of a lot of hams,
> because we always think there is some way to navigate the problems and keep
> the 3 dB for ourselves. The thought of heating up the air with half the
> power out from out two kilo-buck brick-on-key PileUpBuster brand amp just
> bothers us no end.
> 
> And where the power to the antenna cannot be increased by 3 dB to
> compensate, if we regularly work the barely open paths on the low bands for
> new DX and contest multipliers, that 3 dB can make a huge difference.
> 
> BUT...
> 
> If we are just dodging the HOA, vs creating a remote site, or not operating
> at all, what you describe seems quite reasonable. One half wave on 80, two
> on 40, three on 30m, four on 20m, etc. allow a rather simple feed
> mechanism, and any sloppiness will be mitigated to some degree in the
> unavoidable dielectric loss of the fence and ground.
> 
> In the past, particularly with tetrode final tube(s), a pi network would
> absorb ugly antenna impedances just by load and tune, easily servicing
> impedances that would croak transistor amps. Back in 1959 I regularly
> worked the traffic nets end-feeding 120 feet of wandering wire up about 20
> feet against a ground pipe, fed with about 30 feet of coax directly from an
> 807 tetrode and a pi network. I was not loud, but I won a BPL medallion. A
> later addition of a home brew 250TH amp improved things quite a bit for the
> folks on the other end, but the antenna was as much as I could ever do from
> that location.
> 
> 73, Guy K2AV
> 
> On Thu, Aug 4, 2016 at 6:22 PM, Fred Jensen  wrote:
> 
>> Ummm ... my HP48GX says 102' is very very close to 3 half-waves at 14 MHz
>> which sounds sort of resonant-ish.  Maybe a little known bug in my
>> calculator?
>> 
>> On a similar path, I decided to try out the 80-10 EFHW from MyAntennas as
>> an HOA Stealth antenna strung along the top of a 6' fence.  It's 130' long,
>> has a 6 turn series inductor wound on a Sch 40 PVC fitting a short distance
>> out from a heavy-ish box with an SO-239.  I figured there might be a 50 ohm
>> resistor in the box a la the famous B folded dipole that graces many
>> National Guard Armories.
>> 
>> The impedance sweep when I got it yielded close enough to 50+j0 ohms on
>> all bands ... except 60 m that my K3/100 is happy without the KAT3.  It
>> also revealed nearly infinite impedance between the bands, sort of ruling
>> out the resistor [I've come to believe it's a transformer, maybe of the
>> "auto" variety].
>> 
>> It works surprisingly well.  On 80 and 40 it's pretty NVIS, which happens
>> to be what I'm looking for.  Above 40, the pattern starts to become more
>> complex and much less vertical if I can believe EZNEC.  6' AGL is obviously
>> not optimal ... except for our HOA and the CC's ... but I'm very
>> surprised at how well it does, especially at the bottom of the cycle.
>> 
>> This list seems to have a number of antenna experts aboard [and maybe a
>> few who play antenna experts on TV] ... would anyone like to 'splain to me
>> how it achieves low SWR on all bands?  I could probably ferret that out
>> with enough time, but if someone already knows ...
>> 
>> 73,
>> 
>> Fred K6DGW
>> Sparks NV
>> Washoe County DM09dn
>> 
>> On 8/4/2016 1:41 PM, Wes Stewart wrote:
>> 
>> It's a pity that too many newcomers, as well as many oldsters, are
>>> enamored by this piece of wire.  First, a 102' length is not resonant on
>>> 20-meters, so in common jargon, it's *n
>>> 
>> __
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft@mailman.qth.net
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered 

Re: [Elecraft] OT:. G5RV's

[Guy Olinger K2AV]

Hi Fred,

Loss *anywhere* would broaden the antenna. Famously the B folded dipole,
fed at the center of one wire, and terminated with an RF resistor at the
center of the other, has for decades been serving commercial installations
with widely separated operating frequencies not connected by any fortunate
harmonic relationship. That antenna has roughly an intentional 3 dB loss at
a designed position in the antenna. See
https://www.bwantennas.com/images/fdipole.gif for a drawing.

In the case of your EFHW, the broadening loss is the dielectric loss in the
fence itself, and in the ground very close underneath.

The B folded dipole as a solution sticks in the craw of a lot of hams,
because we always think there is some way to navigate the problems and keep
the 3 dB for ourselves. The thought of heating up the air with half the
power out from out two kilo-buck brick-on-key PileUpBuster brand amp just
bothers us no end.

And where the power to the antenna cannot be increased by 3 dB to
compensate, if we regularly work the barely open paths on the low bands for
new DX and contest multipliers, that 3 dB can make a huge difference.

BUT...

If we are just dodging the HOA, vs creating a remote site, or not operating
at all, what you describe seems quite reasonable. One half wave on 80, two
on 40, three on 30m, four on 20m, etc. allow a rather simple feed
mechanism, and any sloppiness will be mitigated to some degree in the
unavoidable dielectric loss of the fence and ground.

In the past, particularly with tetrode final tube(s), a pi network would
absorb ugly antenna impedances just by load and tune, easily servicing
impedances that would croak transistor amps. Back in 1959 I regularly
worked the traffic nets end-feeding 120 feet of wandering wire up about 20
feet against a ground pipe, fed with about 30 feet of coax directly from an
807 tetrode and a pi network. I was not loud, but I won a BPL medallion. A
later addition of a home brew 250TH amp improved things quite a bit for the
folks on the other end, but the antenna was as much as I could ever do from
that location.

73, Guy K2AV

On Thu, Aug 4, 2016 at 6:22 PM, Fred Jensen  wrote:

> Ummm ... my HP48GX says 102' is very very close to 3 half-waves at 14 MHz
> which sounds sort of resonant-ish.  Maybe a little known bug in my
> calculator?
>
> On a similar path, I decided to try out the 80-10 EFHW from MyAntennas as
> an HOA Stealth antenna strung along the top of a 6' fence.  It's 130' long,
> has a 6 turn series inductor wound on a Sch 40 PVC fitting a short distance
> out from a heavy-ish box with an SO-239.  I figured there might be a 50 ohm
> resistor in the box a la the famous B folded dipole that graces many
> National Guard Armories.
>
> The impedance sweep when I got it yielded close enough to 50+j0 ohms on
> all bands ... except 60 m that my K3/100 is happy without the KAT3.  It
> also revealed nearly infinite impedance between the bands, sort of ruling
> out the resistor [I've come to believe it's a transformer, maybe of the
> "auto" variety].
>
> It works surprisingly well.  On 80 and 40 it's pretty NVIS, which happens
> to be what I'm looking for.  Above 40, the pattern starts to become more
> complex and much less vertical if I can believe EZNEC.  6' AGL is obviously
> not optimal ... except for our HOA and the CC's ... but I'm very
> surprised at how well it does, especially at the bottom of the cycle.
>
> This list seems to have a number of antenna experts aboard [and maybe a
> few who play antenna experts on TV] ... would anyone like to 'splain to me
> how it achieves low SWR on all bands?  I could probably ferret that out
> with enough time, but if someone already knows ...
>
> 73,
>
> Fred K6DGW
> Sparks NV
> Washoe County DM09dn
>
> On 8/4/2016 1:41 PM, Wes Stewart wrote:
>
> It's a pity that too many newcomers, as well as many oldsters, are
>> enamored by this piece of wire.  First, a 102' length is not resonant on
>> 20-meters, so in common jargon, it's *n
>>
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to k2av@gmail.com
>
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Ron D'Eau Claire]

When Varney created his G5RV in 1946 a great many Hams still operated on but
one Ham band and parallel (open wire) transmission lines were still common.
The 102-foot G5RV is a 1-1/2 wave center fed doublet at 14.15 MHz. According
to one of my favorite wire antenna writers, (John Heys, G3BDQ "Practical
Wire Antennas"), the original G5RV was fed with a matching section of 34
feet (10.36 meters) followed by any length of 75-ohm "transmitting" twin
lead (yes, 75 ohm twin lead was readily available in the late 40's and
50's). 

In the years following WWII there was proliferation of kits and commercial
Ham transmitters (compared to almost none pre war) and most of those were
"multi-band" types, typically covering 80,40,20 and 10 meters (no 30 or 15
meter bands in those days). Hams started trying to use their G5RV on other
bands. Also the masses of very cheap "war surplus" coax and the need for TVI
suppression started driving Hams away from open wire line. Varney updated
the design to try to accommodate multiband operation and coax feed in the
July, 1984 issue of "Radio Communication" (the RSGB magazine). In the yearss
since the G5RV has acquired a "mystical patina" as a wave-launching wire,
along with other oddities such as the W3EDP.

73, Ron AC7AC

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Fred Jensen]

Ummm ... my HP48GX says 102' is very very close to 3 half-waves at 14 
MHz which sounds sort of resonant-ish.  Maybe a little known bug in my 
calculator?


On a similar path, I decided to try out the 80-10 EFHW from MyAntennas 
as an HOA Stealth antenna strung along the top of a 6' fence.  It's 130' 
long, has a 6 turn series inductor wound on a Sch 40 PVC fitting a short 
distance out from a heavy-ish box with an SO-239.  I figured there might 
be a 50 ohm resistor in the box a la the famous B folded dipole that 
graces many National Guard Armories.


The impedance sweep when I got it yielded close enough to 50+j0 ohms on 
all bands ... except 60 m that my K3/100 is happy without the KAT3.  It 
also revealed nearly infinite impedance between the bands, sort of 
ruling out the resistor [I've come to believe it's a transformer, maybe 
of the "auto" variety].


It works surprisingly well.  On 80 and 40 it's pretty NVIS, which 
happens to be what I'm looking for.  Above 40, the pattern starts to 
become more complex and much less vertical if I can believe EZNEC.  6' 
AGL is obviously not optimal ... except for our HOA and the CC's ... 
but I'm very surprised at how well it does, especially at the bottom of 
the cycle.


This list seems to have a number of antenna experts aboard [and maybe a 
few who play antenna experts on TV] ... would anyone like to 'splain to 
me how it achieves low SWR on all bands?  I could probably ferret that 
out with enough time, but if someone already knows ...


73,

Fred K6DGW
Sparks NV
Washoe County DM09dn

On 8/4/2016 1:41 PM, Wes Stewart wrote:


It's a pity that too many newcomers, as well as many oldsters, are
enamored by this piece of wire.  First, a 102' length is not resonant on
20-meters, so in common jargon, it's *n

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[John Frazier]

Wes..

Over the years, immediately after a change in QTH, I have used the G5RV 
as an interim antenna. My personal experience is that it is a reasonable 
performer, as compared to a single band, resonant half-wave dipole, at 
the same height, fed by the same coax/length.


While I certainly don't accept as Gospel everything that Tom W8JI 
publishes, I generally find his work to be sound and educational.


How do you reconcile your position versus Tom's on this antenna?

I'll attempt to list the link here, but if it doesn't "take", just 
search "W8JI G5RV". His hands-on A/B testing is interesting, along with 
his modeling showing well less than 1db difference between the G5RV and 
resonant half-wave dipole on 80 40 20, and within 1.5 db on 15. He 
suggests a length ratio of roughly 80/20% versus the apparent standard 
of 67/33%.


Like all antennas, construction, proximity to interfering objects, and 
height make a huge difference in performance.


73 John W4II

http://www.w8ji.com/g5rv_facts.htm
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Joe Subich, W4TV]

On 8/4/2016 4:41 PM, Wes Stewart wrote:
> First, a 102' length is not resonant on 20-meters, so in common
> jargon, it's *not* a 20-meter antenna, any more than any other random
> length would be.

*Not* true ... 102' is three half-waves on 20 meters:
   984/2 * (3 -.05) / 14.15 =  102.6'

Check the ARRL antenna book for the formula of a "harmonic wire" -
in this case three half waves.

73,

   ... Joe, W4TV

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Alan Bloom]

> It's a pity that too many newcomers, as well as many oldsters, are
> enamored by this piece of wire.

The G4RV is definitely a compromise antenna.  However its advantage is 
that is has low-enough SWR to be easily matched by most tuners on a 
number of bands.


> ... the horrific losses that could be incurred even
> with high quality tuners,

It's true that tuner losses are the manufacturers' dirty little secret. 
Loss is rarely specified, partly because it can be pretty bad, and 
partly because it is hard to measure, but also because it is not 
constant - it depends on the particular impedance being matched.


One exception is the old Drake tuners.  Their Pi-L topology makes the 
loss almost independent of the load impedance.  If you can get it to 
match, you know that almost all the power is going into the feed line. 
For example, the MN-2700 that I designed when I was at Drake was 
specified at 0.5 dB maximum insertion loss and I did a lot of testing 
and tweaking to achieve that on all bands.


Alan N1AL
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT:. G5RV's

[Wes Stewart]

In my 1999 paper, /"Balanced Transmission Line in Current Amateur Practice"/ 
(http://k6mhe.com/n7ws/Ladder_Line.pdf), published in the /ARRL Antenna 
Compendium, Volume 6, /pp 174-178, I have this statement: "A popular multiband 
wire antenna is the so-called G5RV. This antenna is rarely used as was intended 
by Varney, but for some reason, the 102-foot length has taken on mystical 
properties,"


It's a pity that too many newcomers, as well as many oldsters, are enamored by 
this piece of wire.  First, a 102' length is not resonant on 20-meters, so in 
common jargon, it's *not* a 20-meter antenna, any more than any other random 
length would be. Second, I understand that the conventional wisdom is that it 
has "gain" on 20-meters.  Maybe so, but the usual application has the wire 
strung up between available supports that may, or may not, direct the "gain" in 
a useful direction.  A coax-fed, rotatable, resonant dipole would run rings 
around a G5RV.


(While it's off-topic on this off-topic subject, the fascination with the 
"magical" 43-foot vertical is equally bewildering to me.)


In my published paper, space limited any discussion of tuner loss, however, in 
1994 (type)written correspondence with editor Dean Straw I gave him examples of 
the horrific losses that could be incurred even with high quality tuners, when 
used as proposed the the article* that got me going on this subject.  It's 
interesting to note that to my knowledge, loss in tuners had never been 
mentioned in any ARRL publications before this correspondence. Shortly 
thereafter, "/How to Evaluate Your Antenna Tuner" /was published in 1995.  
Coincidence I'm sure.


BTW, any ARRL publication before 1994 with charts of transmission line loss that 
include open-wire line is incorrect.  It's easily seen by inspection, but 
apparenty I was to first to inspect it. Dean and I hashed out a correct 
attenuation chart.


Wes  N7WS

* "/The Lure of the Ladder Line", QST, /December 1993, pp. 70-71




: On 8/4/2016 11:08 AM, Ken G Kopp wrote:

As usual, Jim is correct ...

I have Lou Varney's original article.  The G5RV was designed as a 20M
--ONLY-- antenna.  It's now achieved some kind of cult ... read voodoo ...
status. (;-)

If one has an antenna that is partially fed with balanced line that's then
directly (!) spliced to a specific length of coax and then still requires a
tuner, why not run the balanced line directly to the tuner ... assuming it
has a balun ... or provide one at the tuner?

This same argument would apply to Varney's design for a 20M only dipole.

Maybe he didn't have a tuner of any kind, and wanted to use coax feed line
because there was a coax connector on his rig. (;-)

73

K0PP


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

[Elecraft] OT:. G5RV's

[Ken G Kopp]

As usual, Jim is correct ...

I have Lou Varney's original article.  The G5RV was designed as a 20M
--ONLY-- antenna.  It's now achieved some kind of cult ... read voodoo ...
status. (;-)

If one has an antenna that is partially fed with balanced line that's then
directly (!) spliced to a specific length of coax and then still requires a
tuner, why not run the balanced line directly to the tuner ... assuming it
has a balun ... or provide one at the tuner?

This same argument would apply to Varney's design for a 20M only dipole.

Maybe he didn't have a tuner of any kind, and wanted to use coax feed line
because there was a coax connector on his rig. (;-)

73

K0PP
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Re: [Elecraft] OT: G5RV's and variants

[Tom H Childers]

Thank you Eric.

Here is an antenna reflector link anten...@mailman.qth.net.

73,
Tom
Amateur Radio Operator N5GE
ARRL Lifetime Member
QCWA Lifetime Member

On Thu, 14 Feb 2013 14:40:51 -0800, Eric Swartz - WA6HHQ, Elecraft
e...@elecraft.com wrote:

Let's wrap up the G5RV OT discussion by the end of today in the interest 
of keeping list volume under control for others.

73,

Eric
List modulator
elecraft.com


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[Barry LaZar]

Ron,
I've modeled my antennas using EZNEC. What I've found is that the 
horizontal pattern  is more sensitive to conductor length on dipoles. 
Electrical height determines vertical angle of arrival. For NVIS work on 
40 30' high is good; double that for 80. However,as you get higher than 
1/4 wave the lobes start to lay down. there is an exception to this and 
that is a null that is created at the horizon that can occur when you 
get to certain heights between 1-2 wavelengths above ground. It's part 
of an interference pattern.


The Carolina Windoms are really interesting affairs. they are 
designed to have radiation from a part of the feed near the dipole. I've 
chosen to use an18' radiation length on my 66 footer. This allows a 
little better radiation at the horizon on the lower frequencies with a 
small impact on ten. However, at 22' things got crazy, so, 18' became 
the magic number.


Using these configurations for a fair number of years I find that 
this seems to work. I do reach out and touch people when band conditions 
are in good shape, and in the present iteration, the antenna is at about 
40' on one end and about 30 feet on the other. This is not by design but 
rather by aim and the slope of the ground. I do run both QRP, ~5 Watts 
and QRO, 100 Watts.


What I do and what I say about antennas are NOT absolute. These are 
good guides that can be tailored for specific locations. The only 
important thing to remember, IMHO, is antenna tuners take care of many 
bad estimates and low loss feed lines mask many mistakes.


73,
Barry
K3NDM



On 2/14/2013 1:29 AM, Ron D'Eau Claire wrote:

If you like to use it for chasing DX on 10 meters, you'll get better results
with a slightly shorter radiator - something about 42 feet overall. That's
because a longer antenna generates a big lobe pointing straight up on 10
meters  - not very helpful for DX-ing on that band. At 42 feet the main
lobes are still down near the horizon on 10 meters.

At 42 feet, the efficiency is excellent down as low as 40 meters.

73, Ron AC7AC

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of k3...@comcast.net
Sent: Wednesday, February 13, 2013 5:37 PM
To: Ken G Kopp
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] OT: G5RV's and variants

From my experience, hams misunderstand antennas more than anything else
they have as a part of their station. What I've been able to discover for
the popularity of the G5RV is that you have an all band antenna in just
102'. The other issues have to do with the concept of resonance in an
antenna system and the need for it.

I guess I'm just not smart enough to worry about all of the issues. My
approach has been to just hang up 132' or 66' of wire fed in the center with
open wire to a 4:1 balun near the house. My transition into the house is
either something like LMR-240 or LMR-400 to my tuner. I can use this
configuration either 80-10 or 40-10. Resonance? I really don't worry about
it too much as my tuner can address the issue for me thereby making my
transmitter happy. I don't worry about losses either. With low loss feeds,
there is little loss, even at 10 meters, with SWRs as high as 10:1.
Simplicity is key here.

The antenna that I now have up is roughly equivalent to a 40 meter Carolina
Windom, modified. My thinking on this gets a little convoluted, but it
works. For a new installation with the room, I would suggest the center fed
dipole with low loss feeds into a good tuner. And, oh yes, get it up as high
as possible.

73,
Barry
K3NDM

- Original Message -
From: Ken G Kopp kengk...@gmail.com
To: elecraft@mailman.qth.net
Sent: Wednesday, February 13, 2013 6:06:25 PM
Subject: [Elecraft] OT: G5RV's and variants

It's already been pointed out that the original article by G5RV indicated
that the antenna was for 20M only.
I have the original article in my files.

I've always wondered why builders of the antenna simply don't make an
open-wire fed Zepp and stop there.
Why add a magic length of coax ... without any kind of impedance matching
... to what would otherwise be a Zepp? Yes, the length of the coax portion
of the feeder acts as an impedance transformer ... on 20M.
On other bands, all bets are off. (:-)

The antenna requires an antenna tuner to operate on bands other than 20M.
Many tuners contain a balun so one has the option of either coax or balanced
line feeders. Why not avoid the coax-to-balanced line splice with it's
almost certain mismatch losses and connect the balanced line portion of the
G5RV's feeder directly to the tuner? If the tuner as no internal balun, one
can be made or purchased.

I once knew a local who actually coiled the coax portion of his G5RV's feed
system behind his desk and then connected it to his tuner. The end of the
balanced portion was within inches of his tuner's balanced line connections.


The G5RV certainly qualifies as a cult antenna.

73!

Ken Kopp - K0PP

Re: [Elecraft] OT: G5RV's and variants

[Terry Schieler]

Interesting observation, Ken.  After seeing a upsurge of interest in G5RV 
antennas discussed on various ham radio reflectors (and noting that the 
interest seems most enthusiastic among newly-minted hams), I honestly feel that 
the recommendations from one new ham to the next seems to be based on 
trumped-up theory that the G5RV is an all-band antenna.  Almost every new ham 
would like an inexpensive, easy-to-build, low profile antenna for all bands.  
While we know that the G5RV *can* be made to work OK on several bands with a 
tuner, I feel that this new found G5RV interest is a self perpetuating rumor 
spreading like a bad cold among newcomers.  No one seems to want to explore the 
technical issues at hand.

Nice to know that someone has saved the original article.

73,

Terry, W0FM




-Original Message-
From: Ken G Kopp [mailto:kengk...@gmail.com] 
Sent: Wednesday, February 13, 2013 5:06 PM
To: elecraft@mailman.qth.net
Subject: [Elecraft] OT: G5RV's and variants

It's already been pointed out that the original article by G5RV indicated that 
the antenna was for 20M only.
I have the original article in my files.

I've always wondered why builders of the antenna simply don't make an open-wire 
fed Zepp and stop there.
Why add a magic length of coax ... without any kind of impedance matching ... 
to what would otherwise be a Zepp?  Yes, the length of the coax portion of the 
feeder acts as an impedance transformer ... on 20M.
On other bands, all bets are off. (:-)

The antenna requires an antenna tuner to operate on bands other than 20M.  Many 
tuners contain a balun so one has the option of either coax or balanced line 
feeders.  Why not avoid the coax-to-balanced line splice with it's almost 
certain mismatch losses and connect the balanced line portion of the G5RV's 
feeder directly to the tuner?  If the tuner as no internal balun, one can be 
made or purchased.

I once knew a local who actually coiled the coax portion of his G5RV's feed 
system behind his desk and then connected it to his tuner.  The end of the 
balanced portion was within inches of his tuner's balanced line connections.

The G5RV certainly qualifies as a cult antenna.

73!

Ken Kopp - K0PP


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[Elecraft K3]

There is a reason that the G5RV is a good beginner's first antenna, IMO.  It is 
relatively easy to install.

Of course the same size antenna performs better as a doublet fed with balanced 
line, but I had a lot of trouble with balanced line when I was starting out.  I 
didn't know enough to get usable matches.  Feedline length, routing and balun 
issues, while simple for me to solve now, were just too much for me to solve in 
the beginning.

The G5RV got me on 10, 12, 15, 17, 20, 40, 60 and 80 all at once.  Admittedly 
not very well on all, but I made contacts on all those bands.

Another country heard from,

73 de Eric, KG6MZS 

 
 I've always wondered why builders of the antenna simply don't make an 
 open-wire fed Zepp and stop there.

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[hawley, charles j jr]

Yes sure...
Kurt N. Sterba who once wrote an article in World Radio about how he connected 
two shopping carts to the end of his coax and worked the world.
So working this or that is very unimpressive. Have you ever been he a QSO and 
turned the power down from a 100 watts to 1 watt and were still Q5?

Sent from my iPad
Chuck, KE9UW 
(Jack for BMW motorcycles)

On Feb 14, 2013, at 2:38 PM, Elecraft K3 k...@hollywoodtitle.com wrote:

 There is a reason that the G5RV is a good beginner's first antenna, IMO.  It 
 is relatively easy to install.
 
 Of course the same size antenna performs better as a doublet fed with 
 balanced line, but I had a lot of trouble with balanced line when I was 
 starting out.  I didn't know enough to get usable matches.  Feedline length, 
 routing and balun issues, while simple for me to solve now, were just too 
 much for me to solve in the beginning.
 
 The G5RV got me on 10, 12, 15, 17, 20, 40, 60 and 80 all at once.  Admittedly 
 not very well on all, but I made contacts on all those bands.
 
 Another country heard from,
 
 73 de Eric, KG6MZS 
 
 
 I've always wondered why builders of the antenna simply don't make an 
 open-wire fed Zepp and stop there.
 
 __
 Elecraft mailing list
 Home: http://mailman.qth.net/mailman/listinfo/elecraft
 Help: http://mailman.qth.net/mmfaq.htm
 Post: mailto:Elecraft@mailman.qth.net
 
 This list hosted by: http://www.qsl.net
 Please help support this email list: http://www.qsl.net/donate.html
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[Eric Swartz - WA6HHQ, Elecraft]

Let's wrap up the G5RV OT discussion by the end of today in the interest 
of keeping list volume under control for others.


73,

Eric
List modulator
elecraft.com


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[Don Wilhelm]

I have always been amused by the antenna adverts that say things like I 
worked 100 countries in 6 hours or some such nonsense.
Those type ads never give radiation patterns or any other meaningful 
data that can be used to compare with other antennas.


That does not mean that the ads were mis-leading, but the fact that 
however many contacts were made is really meaningless.


The fact is that any antenna will radiate and can make contacts unless 
it is rolled up and sitting on a shelf in the basement.


73,
Don W3FPR

On 2/14/2013 4:03 PM, hawley, charles j jr wrote:

Yes sure...
Kurt N. Sterba who once wrote an article in World Radio about how he connected 
two shopping carts to the end of his coax and worked the world.
So working this or that is very unimpressive. Have you ever been he a QSO and 
turned the power down from a 100 watts to 1 watt and were still Q5?




__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[David Cutter]

A 66ft off-centre-fed dipole works better than the 105ft G5RV worked on 
multiple bands.


Remember, however, that when Louis Varney designed his antenna (aerial in 
those days, probably) we all had valve (tube) transmitters which could cope 
with the wide variation in impedance.  My only matching unit was for top 
band.  I didn't use a matching unit for the other bands until I had a 
transistor rig.


David
G3UNA



There is a reason that the G5RV is a good beginner's first antenna, IMO. 
It is relatively easy to install.


Of course the same size antenna performs better as a doublet fed with 
balanced line, but I had a lot of trouble with balanced line when I was 
starting out.  I didn't know enough to get usable matches.  Feedline 
length, routing and balun issues, while simple for me to solve now, were 
just too much for me to solve in the beginning.


The G5RV got me on 10, 12, 15, 17, 20, 40, 60 and 80 all at once. 
Admittedly not very well on all, but I made contacts on all those bands.


Another country heard from,

73 de Eric, KG6MZS



I've always wondered why builders of the antenna simply don't make an 
open-wire fed Zepp and stop there.



__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[Dale Putnam]

. Have you ever been he a QSO and turned the power down from a 100 watts to 1 
watt and were still Q5?
 As a matter of fact, YES! emphatically, most of the time actually... and even 
 more of the time I start at 5 and then turn it downon 40-30-20 
 especially, and on 160 and 80, I find that happening less.. but it does 
 happen. And the antennae here are all wire.just wire, and nothing but the 
 wiare..
Have a great day, 
 
 
--...   ...--
Dale - WC7S in Wy
 
 

  
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[EMD]

My 2 cents,

As a relatively new ham lacking any real world skills with regards to making
antenna's, the G5RV has worked for me.  I am very limited in time, I am not
normally home more than 10 days a month so my spare time is limited.   But I
still have some time to enjoy the hobby and personally I would rather spend
what time I have getting on the air.  That being said the G5RV has done what
it promised, I have made contacts on 80 through 10 meters and I always am
able to tune any band with less than 1.5 SWR using the K2's internal tuner. 
I am only running 10 watts and have made contacts as far away as the Ukraine
from my east coast QTH so it seems to getting out.  I'm sure there are
better antenna's and some day I would like to have something more than the
G5RV but for now it works for me.  Anyhow I don't really understand why the
G5RV is so controversial.  

Respectfully submitted,

73's
Ed K3ENV



--
View this message in context: 
http://elecraft.365791.n2.nabble.com/OT-G5RV-s-and-variants-tp7569905p7569962.html
Sent from the Elecraft mailing list archive at Nabble.com.
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[k3ndm]

From my experience, hams misunderstand antennas more than anything else they 
have as a part of their station. What I've been able to discover for the 
popularity of the G5RV is that you have an all band antenna in just 102'. 
The other issues have to do with the concept of resonance in an antenna system 
and the need for it. 

I guess I'm just not smart enough to worry about all of the issues. My approach 
has been to just hang up 132' or 66' of wire fed in the center with open wire 
to a 4:1 balun near the house. My transition into the house is either something 
like LMR-240 or LMR-400 to my tuner. I can use this configuration either 80-10 
or 40-10. Resonance? I really don't worry about it too much as my tuner can 
address the issue for me thereby making my transmitter happy. I don't worry 
about losses either. With low loss feeds, there is little loss, even at 10 
meters, with SWRs as high as 10:1. Simplicity is key here. 

The antenna that I now have up is roughly equivalent to a 40 meter Carolina 
Windom, modified. My thinking on this gets a little convoluted, but it works. 
For a new installation with the room, I would suggest the center fed dipole 
with low loss feeds into a good tuner. And, oh yes, get it up as high as 
possible. 

73, 
Barry 
K3NDM 

- Original Message -
From: Ken G Kopp kengk...@gmail.com 
To: elecraft@mailman.qth.net 
Sent: Wednesday, February 13, 2013 6:06:25 PM 
Subject: [Elecraft] OT: G5RV's and variants 

It's already been pointed out that the original article 
by G5RV indicated that the antenna was for 20M only. 
I have the original article in my files. 

I've always wondered why builders of the antenna 
simply don't make an open-wire fed Zepp and stop there. 
Why add a magic length of coax ... without any kind 
of impedance matching ... to what would otherwise be 
a Zepp? Yes, the length of the coax portion of the 
feeder acts as an impedance transformer ... on 20M. 
On other bands, all bets are off. (:-) 

The antenna requires an antenna tuner to operate on 
bands other than 20M. Many tuners contain a balun 
so one has the option of either coax or balanced line 
feeders. Why not avoid the coax-to-balanced line splice 
with it's almost certain mismatch losses and connect the 
balanced line portion of the G5RV's feeder directly to the 
tuner? If the tuner as no internal balun, one can be made 
or purchased. 

I once knew a local who actually coiled the coax portion 
of his G5RV's feed system behind his desk and then 
connected it to his tuner. The end of the balanced portion 
was within inches of his tuner's balanced line connections. 

The G5RV certainly qualifies as a cult antenna. 

73! 

Ken Kopp - K0PP 
__ 
Elecraft mailing list 
Home: http://mailman.qth.net/mailman/listinfo/elecraft 
Help: http://mailman.qth.net/mmfaq.htm 
Post: mailto:Elecraft@mailman.qth.net 

This list hosted by: http://www.qsl.net 
Please help support this email list: http://www.qsl.net/donate.html 
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's and variants

[Ron D'Eau Claire]

If you like to use it for chasing DX on 10 meters, you'll get better results
with a slightly shorter radiator - something about 42 feet overall. That's
because a longer antenna generates a big lobe pointing straight up on 10
meters  - not very helpful for DX-ing on that band. At 42 feet the main
lobes are still down near the horizon on 10 meters. 

At 42 feet, the efficiency is excellent down as low as 40 meters. 

73, Ron AC7AC

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of k3...@comcast.net
Sent: Wednesday, February 13, 2013 5:37 PM
To: Ken G Kopp
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] OT: G5RV's and variants

From my experience, hams misunderstand antennas more than anything else
they have as a part of their station. What I've been able to discover for
the popularity of the G5RV is that you have an all band antenna in just
102'. The other issues have to do with the concept of resonance in an
antenna system and the need for it. 

I guess I'm just not smart enough to worry about all of the issues. My
approach has been to just hang up 132' or 66' of wire fed in the center with
open wire to a 4:1 balun near the house. My transition into the house is
either something like LMR-240 or LMR-400 to my tuner. I can use this
configuration either 80-10 or 40-10. Resonance? I really don't worry about
it too much as my tuner can address the issue for me thereby making my
transmitter happy. I don't worry about losses either. With low loss feeds,
there is little loss, even at 10 meters, with SWRs as high as 10:1.
Simplicity is key here. 

The antenna that I now have up is roughly equivalent to a 40 meter Carolina
Windom, modified. My thinking on this gets a little convoluted, but it
works. For a new installation with the room, I would suggest the center fed
dipole with low loss feeds into a good tuner. And, oh yes, get it up as high
as possible. 

73,
Barry
K3NDM 

- Original Message -
From: Ken G Kopp kengk...@gmail.com
To: elecraft@mailman.qth.net
Sent: Wednesday, February 13, 2013 6:06:25 PM
Subject: [Elecraft] OT: G5RV's and variants 

It's already been pointed out that the original article by G5RV indicated
that the antenna was for 20M only. 
I have the original article in my files. 

I've always wondered why builders of the antenna simply don't make an
open-wire fed Zepp and stop there. 
Why add a magic length of coax ... without any kind of impedance matching
... to what would otherwise be a Zepp? Yes, the length of the coax portion
of the feeder acts as an impedance transformer ... on 20M. 
On other bands, all bets are off. (:-) 

The antenna requires an antenna tuner to operate on bands other than 20M.
Many tuners contain a balun so one has the option of either coax or balanced
line feeders. Why not avoid the coax-to-balanced line splice with it's
almost certain mismatch losses and connect the balanced line portion of the
G5RV's feeder directly to the tuner? If the tuner as no internal balun, one
can be made or purchased. 

I once knew a local who actually coiled the coax portion of his G5RV's feed
system behind his desk and then connected it to his tuner. The end of the
balanced portion was within inches of his tuner's balanced line connections.


The G5RV certainly qualifies as a cult antenna. 

73! 

Ken Kopp - K0PP
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net 

This list hosted by: http://www.qsl.net Please help support this email list:
http://www.qsl.net/donate.html
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's antenna

[Kim Bottles]

I am with Ken on this one. 

I use a 130 foot classic Zepp with 600 ohm ladder line to a balun and then a 
short coax line to the K-3 with internal tuner. It tunes very nicely on all HF 
bands 160 to 10. (Yes, even 160.)

Kim - K7IM

-Original Message-
From: Ken G Kopp [mailto:kengk...@gmail.com] 
Sent: Friday, March 09, 2012 6:54 PM
To: elecraft@mailman.qth.net
Subject: [Elecraft] OT: G5RV's antenna

I have Varney's (G5RV) original article.  The antenna was designed for -only- 
20M .  Since then it's taken on the proverbial life of it's own and become 
somewhat of a cult antenna, as is the case with the Carolina Windom.

Why would one start with a perfectly good balanced-line fed Zepp, cobble a 
piece of special-length coax onto the end of that balanced line so that the 
antenna becomes something else, and then have to use an antenna tuner to make 
the thing work?

Since the antenna requires a tuner, why not connect the balanced line to a 
balanced tuner ... or one with a balun ... and enjoy all the virtues of a 
classic Zepp?

73!

Ken Kopp - K0PP
elecraftcov...@gmail.com

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's antenna

[Kim Bottles]

OK, I amend my post to say 130 foot doublet.

Kim - K7IM

-Original Message-
From: Ron D'Eau Claire [mailto:r...@cobi.biz] 
Sent: Friday, March 09, 2012 8:09 PM
To: 'Ken G Kopp'; d...@w3fpr.com
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] OT: G5RV's antenna

The feeder was exactly 1/4 wavelength long so it transformed the very high 
impedance at the end of the radiator to a very low impedance at the rig in the 
Zeppelin, minimizing RF in the Shack issues. 

Since the radiator was 1/2 wavelength long, very little current flowed from the 
feeder into the radiator. It was a voltage loop. That meant that, although 
the other side of the feeder was terminated in an insulator, the currents along 
the feed line were well balanced. Most radiomen of the time considered that the 
leakage current into the insulator closely matched the current into the 
radiator so the balance was very good indeed. 

The next step, coming back to Don's comment, was to connect two Zepps back to 
back for some additional gain. Extending the radiators beyond 1/2 wavelength 
enhanced this effect and, since it was now a center fed antenna, feedline 
imbalance was no longer a danger, hence the popularity of the extended double 
Zepp.

I am always careful to call my center fed wires a doublet to avoid confusion 
but many Hams today incorrectly call any wire fed at the center with open wire 
line a Zepp. 

Feeding a traditional Zepp only minimizes feed line radiation when the radiator 
is exactly 1/2 wavelength. (The feeder can be any length if you can deal with 
the feed point impedance at the rig end.) However, many Hams have reported 
excellent results with Zepps with not-1/2-wave long radiators. In those cases 
the feed line is also part of the radiating antenna. That can be good when the 
feeder is in the clear and less so if it's not. The same is true of most off 
center fed antennas.

73,  

Ron AC7AC

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Ken G Kopp
Sent: Friday, March 09, 2012 7:34 PM
To: d...@w3fpr.com
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] OT: G5RV's antenna

Yes Don, I knew when I used the term classic Zepp that I was taking a bit of 
liberty with the term.  The original Zepp was indeed end-fed from the cabin of 
a Zepplin.  I've often wondered how long the feeder actually was.
They may have been closer to a simple end-fed wire.

I'd also noted the concept repeated in the J-pole.

We old ops have certain advantages ...

73!  Ken

On Sat, Mar 10, 2012 at 3:23 AM, Don Wilhelm w3...@embarqmail.com wrote:
 Ken,

 I will agree with all until I got to the end of your post - classic zepp
 The original (and classic)  Zepp antenna was a 1/2 wave wire fed 
 through a 1/4 wave transmission line connected to the end that was 
 trailed behind lighter-than-air aircraft (Zepplin).  If you look at 
 the J-pole, and turn it horizontally, you will see exactly the same 
 thing - a 1/4 wave transmission line with one side connected to a 1/2
wavelength radiator.

 I am not sure how the Zepp term became associated with any kind of 
 center fed dipoles, but it has in ham circles, and I find it confusing
 - there is the Center Fed Zepp (2 halfwaves in phase) antenna, and 
 then there is the Extended Center Fed Zepp (5/8 wavelength each side 
 of center), and then there is the classic Zepp that is the antenna 
 designed for trailing the aircraft.  So we must be careful to explain 
 which kind of Zepp antenna we are referring to when we write Zepp
 There is a lot of difference.

 73,
 Don W3FPR


__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Elecraft] OT: G5RV's antenna

[Ken G Kopp]

I have Varney's (G5RV) original article.  The antenna was designed
for -only- 20M .  Since then it's taken on the proverbial life of it's
own and become somewhat of a cult antenna, as is the case with
the Carolina Windom.

Why would one start with a perfectly good balanced-line fed Zepp,
cobble a piece of special-length coax onto the end of that balanced
line so that the antenna becomes something else, and then have to
use an antenna tuner to make the thing work?

Since the antenna requires a tuner, why not connect the balanced line
to a balanced tuner ... or one with a balun ... and enjoy all the virtues
of a classic Zepp?

73!

Ken Kopp - K0PP
elecraftcov...@gmail.com
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's antenna

[Don Wilhelm]

Ken,

I will agree with all until I got to the end of your post - classic zepp
The original (and classic)  Zepp antenna was a 1/2 wave wire fed through 
a 1/4 wave transmission line connected to the end that was trailed 
behind lighter-than-air aircraft (Zepplin).  If you look at the J-pole, 
and turn it horizontally, you will see exactly the same thing - a 1/4 
wave transmission line with one side connected to a 1/2 wavelength radiator.

I am not sure how the Zepp term became associated with any kind of 
center fed dipoles, but it has in ham circles, and I find it confusing - 
there is the Center Fed Zepp (2 halfwaves in phase) antenna, and then 
there is the Extended Center Fed Zepp (5/8 wavelength each side of 
center), and then there is the classic Zepp that is the antenna 
designed for trailing the aircraft.  So we must be careful to explain 
which kind of Zepp antenna we are referring to when we write Zepp  
There is a lot of difference.

73,
Don W3FPR

On 3/9/2012 9:53 PM, Ken G Kopp wrote:
 I have Varney's (G5RV) original article.  The antenna was designed
 for -only- 20M .  Since then it's taken on the proverbial life of it's
 own and become somewhat of a cult antenna, as is the case with
 the Carolina Windom.

 Why would one start with a perfectly good balanced-line fed Zepp,
 cobble a piece of special-length coax onto the end of that balanced
 line so that the antenna becomes something else, and then have to
 use an antenna tuner to make the thing work?

 Since the antenna requires a tuner, why not connect the balanced line
 to a balanced tuner ... or one with a balun ... and enjoy all the virtues
 of a classic Zepp?

 73!

 Ken Kopp - K0PP
 elecraftcov...@gmail.com
 __
 Elecraft mailing list
 Home: http://mailman.qth.net/mailman/listinfo/elecraft
 Help: http://mailman.qth.net/mmfaq.htm
 Post: mailto:Elecraft@mailman.qth.net

 This list hosted by: http://www.qsl.net
 Please help support this email list: http://www.qsl.net/donate.html

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's antenna

[Ken G Kopp]

Yes Don, I knew when I used the term classic Zepp that I was taking
a bit of liberty with the term.  The original Zepp was indeed end-fed from
the cabin of a Zepplin.  I've often wondered how long the feeder actually
was.  They may have been closer to a simple end-fed wire.

I'd also noted the concept repeated in the J-pole.

We old ops have certain advantages ...

73!  Ken

On Sat, Mar 10, 2012 at 3:23 AM, Don Wilhelm w3...@embarqmail.com wrote:
 Ken,

 I will agree with all until I got to the end of your post - classic zepp
 The original (and classic)  Zepp antenna was a 1/2 wave wire fed through
 a 1/4 wave transmission line connected to the end that was trailed
 behind lighter-than-air aircraft (Zepplin).  If you look at the J-pole,
 and turn it horizontally, you will see exactly the same thing - a 1/4
 wave transmission line with one side connected to a 1/2 wavelength radiator.

 I am not sure how the Zepp term became associated with any kind of
 center fed dipoles, but it has in ham circles, and I find it confusing -
 there is the Center Fed Zepp (2 halfwaves in phase) antenna, and then
 there is the Extended Center Fed Zepp (5/8 wavelength each side of
 center), and then there is the classic Zepp that is the antenna
 designed for trailing the aircraft.  So we must be careful to explain
 which kind of Zepp antenna we are referring to when we write Zepp
 There is a lot of difference.

 73,
 Don W3FPR

 On 3/9/2012 9:53 PM, Ken G Kopp wrote:
 I have Varney's (G5RV) original article.  The antenna was designed
 for -only- 20M .  Since then it's taken on the proverbial life of it's
 own and become somewhat of a cult antenna, as is the case with
 the Carolina Windom.

 Why would one start with a perfectly good balanced-line fed Zepp,
 cobble a piece of special-length coax onto the end of that balanced
 line so that the antenna becomes something else, and then have to
 use an antenna tuner to make the thing work?

 Since the antenna requires a tuner, why not connect the balanced line
 to a balanced tuner ... or one with a balun ... and enjoy all the virtues
 of a classic Zepp?

 73!

 Ken Kopp - K0PP
 elecraftcov...@gmail.com
 __
 Elecraft mailing list
 Home: http://mailman.qth.net/mailman/listinfo/elecraft
 Help: http://mailman.qth.net/mmfaq.htm
 Post: mailto:Elecraft@mailman.qth.net

 This list hosted by: http://www.qsl.net
 Please help support this email list: http://www.qsl.net/donate.html

 __
 Elecraft mailing list
 Home: http://mailman.qth.net/mailman/listinfo/elecraft
 Help: http://mailman.qth.net/mmfaq.htm
 Post: mailto:Elecraft@mailman.qth.net

 This list hosted by: http://www.qsl.net
 Please help support this email list: http://www.qsl.net/donate.html
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Re: [Elecraft] OT: G5RV's antenna

[Ron D'Eau Claire]

The feeder was exactly 1/4 wavelength long so it transformed the very high
impedance at the end of the radiator to a very low impedance at the rig in
the Zeppelin, minimizing RF in the Shack issues. 

Since the radiator was 1/2 wavelength long, very little current flowed from
the feeder into the radiator. It was a voltage loop. That meant that,
although the other side of the feeder was terminated in an insulator, the
currents along the feed line were well balanced. Most radiomen of the time
considered that the leakage current into the insulator closely matched the
current into the radiator so the balance was very good indeed. 

The next step, coming back to Don's comment, was to connect two Zepps back
to back for some additional gain. Extending the radiators beyond 1/2
wavelength enhanced this effect and, since it was now a center fed antenna,
feedline imbalance was no longer a danger, hence the popularity of the
extended double Zepp.

I am always careful to call my center fed wires a doublet to avoid
confusion but many Hams today incorrectly call any wire fed at the center
with open wire line a Zepp. 

Feeding a traditional Zepp only minimizes feed line radiation when the
radiator is exactly 1/2 wavelength. (The feeder can be any length if you can
deal with the feed point impedance at the rig end.) However, many Hams have
reported excellent results with Zepps with not-1/2-wave long radiators. In
those cases the feed line is also part of the radiating antenna. That can be
good when the feeder is in the clear and less so if it's not. The same is
true of most off center fed antennas.

73,  

Ron AC7AC

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Ken G Kopp
Sent: Friday, March 09, 2012 7:34 PM
To: d...@w3fpr.com
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] OT: G5RV's antenna

Yes Don, I knew when I used the term classic Zepp that I was taking a bit
of liberty with the term.  The original Zepp was indeed end-fed from the
cabin of a Zepplin.  I've often wondered how long the feeder actually was.
They may have been closer to a simple end-fed wire.

I'd also noted the concept repeated in the J-pole.

We old ops have certain advantages ...

73!  Ken

On Sat, Mar 10, 2012 at 3:23 AM, Don Wilhelm w3...@embarqmail.com wrote:
 Ken,

 I will agree with all until I got to the end of your post - classic zepp
 The original (and classic)  Zepp antenna was a 1/2 wave wire fed 
 through a 1/4 wave transmission line connected to the end that was 
 trailed behind lighter-than-air aircraft (Zepplin).  If you look at 
 the J-pole, and turn it horizontally, you will see exactly the same 
 thing - a 1/4 wave transmission line with one side connected to a 1/2
wavelength radiator.

 I am not sure how the Zepp term became associated with any kind of 
 center fed dipoles, but it has in ham circles, and I find it confusing 
 - there is the Center Fed Zepp (2 halfwaves in phase) antenna, and 
 then there is the Extended Center Fed Zepp (5/8 wavelength each side 
 of center), and then there is the classic Zepp that is the antenna 
 designed for trailing the aircraft.  So we must be careful to explain 
 which kind of Zepp antenna we are referring to when we write Zepp
 There is a lot of difference.

 73,
 Don W3FPR

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html