Just wondering: If you had a 33 foot horizontal wire, fed at one end with a
ladder line, which was connected to an atu, it would work on 20 metres, but
would it work on 40, 80 and 160metres? TIA.

On Wed, 8 Sep 2004 15:25:35 +0100, "Richard"
wrote:

Just wondering: If you had a 33 foot horizontal wire, fed at one end with a
ladder line, which was connected to an atu, it would work on 20 metres, but
would it work on 40, 80 and 160metres? TIA.

Hi Rich,

It might, but your atu might not. ATUs are not a one-size-fits-all
solution. In fact they fit very few problems that are not already
pretty close (and what you describe above and in other posts is
definitely not close). Maybe two bands will pull in, the others will
not (unless the loss of the ATU adds to the appearance of being
"tuned").

73's
Richard Clark, KB7QHC

"Richard Clark" wrote in message
...
On Wed, 8 Sep 2004 15:25:35 +0100, "Richard"
wrote:

Just wondering: If you had a 33 foot horizontal wire, fed at one end
with a
ladder line, which was connected to an atu, it would work on 20 metres,
but
would it work on 40, 80 and 160metres? TIA.

Hi Rich,

It might, but your atu might not. ATUs are not a one-size-fits-all
solution. In fact they fit very few problems that are not already
pretty close (and what you describe above and in other posts is
definitely not close). Maybe two bands will pull in, the others will
not (unless the loss of the ATU adds to the appearance of being
"tuned").

73's
Richard Clark, KB7QHC

Hi.

I know the zeppalin antenna I described works when the top wire is a half
wavelength or greater. I was just wondering if the set up (ie 10 metre
length of top) might at least be a good as a 20 metre long inverted L (well,
L on it's side) on 40, 80 & 160, using a not very good ground arrangement.

Thing with the zepp is that there is no ground losses. Thing is, ground
losses with inverted L are probably replaced by greater atu losses? And of
course the inverted L would radiate also from the vertical section which
migh be useful. I do wonder of the two arrangements, which would be better.
I wonder also whther I might not get a true balance on the open line when
the top is less than half a wavelength.

On Wed, 8 Sep 2004 20:21:46 +0100, "Richard"
wrote:

I know the zeppalin antenna I described works when the top wire is a half
wavelength or greater.

Hi Rich,

You also need to consider the length of the transmission line (what
makes the Zeppelin work with your rig).

I was just wondering if the set up (ie 10 metre
length of top) might at least be a good as a 20 metre long inverted L (well,
L on it's side) on 40, 80 & 160, using a not very good ground arrangement.

For 160 it is quite short, for 80 somewhat short; but being short is
not a sin in and of itself. What is a sin is what the tuner has to
put up with. Most ATU's only cope with up to 3:1 SWR. A short
antenna may well exceed that. Obtain a copy of EZNEC (using the free
version) and give yourself an education on what to expect.

Thing with the zepp is that there is no ground losses. Thing is, ground
losses with inverted L are probably replaced by greater atu losses? And of
course the inverted L would radiate also from the vertical section which
migh be useful. I do wonder of the two arrangements, which would be better.
I wonder also whther I might not get a true balance on the open line when
the top is less than half a wavelength.

You won't have a true balance unless you are feeding a true balanced
antenna (which a Zepp is not, nor an inverted L).

73's
Richard Clark, KB7QHC

Read up on the topic of linear loading. You can bend that wire back on
itself and increase the total length of wire. There are discussions of this
in ON4UNs Low Band Dxing book. One commercial example is the Cobra
Ultralite at http://www.k1jek.com/.

I use a top center fed L. One side is horizontal and the other side is
vertical. Fed at the top center with ladder line. Cebik has several
articles on his site about center fed Ls. No ground plane, horizontal and
vertical polarization, fewer nulls in the pattern. Very nice

I think the center feds make a lot more sense for multiband operation.

--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64
"Richard" wrote in message
...
Just wondering: If you had a 33 foot horizontal wire, fed at one end with
a
ladder line, which was connected to an atu, it would work on 20 metres,
but
would it work on 40, 80 and 160metres? TIA.

"Craig Buck" wrote

I use a top center fed L. One side is horizontal and the other side is
vertical. Fed at the top center with ladder line. Cebik has several
articles on his site about center fed Ls. No ground plane, horizontal and
vertical polarization, fewer nulls in the pattern. Very nice

I think the center feds make a lot more sense for multiband operation.

--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64

Hi Craig, is that fed with ladder line right out of the tuner? I'm hoping
there is a best-fit arangement from my tuner to an inverted-L with either a
top-fed through a 4:1 balun or end-fed without a balun. In either case the
intention is to cover 2182khz with a 107' 1/4~ L. Any suggestions on the
best arrangement for that work?

Thanks,

Jack
Virginia Beach VA

You can go with ladder line right out of the tuner or to a short piece of
coax to a balun, then to ladder line. I have about ten feet of coax to a
1:1 balun outside. The coax is easier to get out of the house and away from
things that might unbalance the ladder line. Loss on such a short piece of
coax is negligible even at high SWRs on HF.

Whether you use a 4:1 or 1:1 depends on the antenna and feedline. I use a
1:1. Your antenna will be the "right" length so the impedance at the
transmitter end won't be too far off from 70 ohms. A 4:1 balun would be a
mistake as it would lower the impedance making it harder to match the
transmitter.

I have to ask, "Why are you using ladder line?" Usually it is only used
when the antenna has a high SWR and we want to avoid losses in the coax.
You won't have much of a mismatch, if any. I would think you would go with
coax, you might not even need a tuner.
--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64


"Jack Painter" wrote in message
news:UuM%c.173651$Lj.145677@fed1read03...

"Craig Buck" wrote

I use a top center fed L. One side is horizontal and the other side is
vertical. Fed at the top center with ladder line. Cebik has several
articles on his site about center fed Ls. No ground plane, horizontal
and
vertical polarization, fewer nulls in the pattern. Very nice

I think the center feds make a lot more sense for multiband operation.

--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64

Hi Craig, is that fed with ladder line right out of the tuner? I'm hoping
there is a best-fit arangement from my tuner to an inverted-L with either
a
top-fed through a 4:1 balun or end-fed without a balun. In either case the
intention is to cover 2182khz with a 107' 1/4~ L. Any suggestions on the
best arrangement for that work?

Thanks,

Jack
Virginia Beach VA

Thanks Craig - and if you could, please elaborate on these design
considerations:

The antenna is not erected yet - still planning. I would choose a 1:1 balun
if I used one at all with an end-fed inverted-L configuration. But if I
configure the antenna as a sloper (same L-shape) and top-feed at the angle
point, then I thought a 4:1 balun could help make 2182khz tunable on an
antenna with dipole properties that is really too short (would have to be
107' each leg not 107' total, which is about all I can get at that
location). Of those two choices, I had not intended to use ladderline for
either, but would consider it if some benefit was possible. Ideally, the
antenna would be desireable to cover 2-20mhz. No compromse on the 2182 end
is worth the upper bandwidth though, with 5.7 & 8.9 mhz the other
requirements that should not unduly strain a tuner under high tx power. The
antenna would be primarily for 2182 - 4125 khz.. Thanks for any help.

Jack

"Craig Buck" wrote in message
news:Y6O%c.7112$OZ6.5222@okepread06...
You can go with ladder line right out of the tuner or to a short piece of
coax to a balun, then to ladder line. I have about ten feet of coax to a
1:1 balun outside. The coax is easier to get out of the house and away
from
things that might unbalance the ladder line. Loss on such a short piece
of
coax is negligible even at high SWRs on HF.

Whether you use a 4:1 or 1:1 depends on the antenna and feedline. I use a
1:1. Your antenna will be the "right" length so the impedance at the
transmitter end won't be too far off from 70 ohms. A 4:1 balun would be a
mistake as it would lower the impedance making it harder to match the
transmitter.

I have to ask, "Why are you using ladder line?" Usually it is only used
when the antenna has a high SWR and we want to avoid losses in the coax.
You won't have much of a mismatch, if any. I would think you would go
with
coax, you might not even need a tuner.
--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64


"Jack Painter" wrote in message
news:UuM%c.173651$Lj.145677@fed1read03...

"Craig Buck" wrote

I use a top center fed L. One side is horizontal and the other side
is
vertical. Fed at the top center with ladder line. Cebik has several
articles on his site about center fed Ls. No ground plane, horizontal
and
vertical polarization, fewer nulls in the pattern. Very nice

I think the center feds make a lot more sense for multiband operation.

--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64

Hi Craig, is that fed with ladder line right out of the tuner? I'm
hoping
there is a best-fit arangement from my tuner to an inverted-L with
either
a
top-fed through a 4:1 balun or end-fed without a balun. In either case
the
intention is to cover 2182khz with a 107' 1/4~ L. Any suggestions on
the
best arrangement for that work?

Thanks,

Jack
Virginia Beach VA

Craig Buck wrote:
Read up on the topic of linear loading. You can bend that wire back on
itself and increase the total length of wire. There are discussions of
this in ON4UNs Low Band Dxing book. One commercial example is the
Cobra Ultralite at http://www.k1jek.com/.

I use a top center fed L. One side is horizontal and the other side is
vertical. Fed at the top center with ladder line. Cebik has several
articles on his site about center fed Ls. No ground plane, horizontal
and vertical polarization, fewer nulls in the pattern. Very nice

I think the center feds make a lot more sense for multiband operation.

You're absolutely right, Craig... in principle.

But Richard's situation reflects the reality for many British hams whose
house is at one end of a short and narrow rear lot. With neighbors very
close on all sides, we're lucky to have even one mast, so center-fed
antennas are often not very practical for us - they either sag in the
middle or wind up in a very sharp inverted-V configuration.

As a result, we're very much forced towards considering end-fed or
base-fed solutions.

However, I wouldn't go near an end-fed long wire or zepp configuration,
because of the very high risk of feeding the RF return currents into the
mains. Been there, done that, had the doorbell ring!

Living in that situation myself, my best solution has been a 30-33ft
vertical at the far end of the garden, fed against the best ground
system I can manage. This can be fed directly on 7MHz; with an ATU at
the base it is good for 10, 14 and 18MHz, and is usable on the higher
bands too.

Over the years, this system has acquired an auto-ATU at the base, and
has evolved into a guyed tilt-over mast with various quick-change
"accessories" that can be attached at the top. A lightweight 12ft
fishing pole makes a taller vertical, which has slowly crept up to 45ft;
or a selection of horizontal loading wires running back towards the
house at the 33ft level make inverted-L configurations for the lower
bands.

With the auto-ATU, any configuration can easily be loaded on any band.
It won't be optimum on more than one HF band, but it will get you on the
air on *every* band - and that's what counts for most.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

"Ian White, G3SEK" wrote in message
...

But Richard's situation reflects the reality for many British hams whose
house is at one end of a short and narrow rear lot. With neighbors very
close on all sides, we're lucky to have even one mast, so center-fed
antennas are often not very practical for us - they either sag in the
middle or wind up in a very sharp inverted-V configuration.

As a result, we're very much forced towards considering end-fed or
base-fed solutions.


Although center-fed is not totally impossible or out of the question, you
are right, a lot of UK hams have small back lots/gardens and so many of us
do tend to seek verticals or end-fed arrangements with the feed point away
from the house. In my particular case, the problem with a vertical is that
it would practically be surrounded on all sides by either trees or the
house, so I'm not sure if going for a vertical alone would be a good idea,
and that's why I'm considering either an inverted-L or zepp or something
better.


However, I wouldn't go near an end-fed long wire or zepp configuration,
because of the very high risk of feeding the RF return currents into the
mains. Been there, done that, had the doorbell ring!

Noted.

Living in that situation myself, my best solution has been a 30-33ft
vertical at the far end of the garden, fed against the best ground
system I can manage. This can be fed directly on 7MHz; with an ATU at
the base it is good for 10, 14 and 18MHz, and is usable on the higher
bands too.

Yes. Any vertical at my QTH would be about 10 metres away from the house to
the south, and about 2 metres away from tallish conifers to the north. A
vertical would seem to be hemmed in to me. No clear take of in any direction
actually.

The problem with using a center-fed arrangement, is that the most I could
put up in backgarden would be ap 40 metre doublet as per:


x-------------------
| \
| \
| \
| \
| \feedline

back garden

But the feed would be at the top of a 10 metre mast. I would have to have
the feedline go in at an angle.

So one thinks perhaps I need to end-feed as per:

-------------------
|
|
|
|
|
x

back garden

BUT, I could be daring and do this:


/ | \
/ | \
/ house \

back garden front garden

Erect a 40 dipole, feeding at point of small mast on chimney stack of house.
That means half of the antenna ends up in front garden.

Or even put up cobra:
http://www.k1jek.com/index.html
Junior does not do 160 though.