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Old April 20th 04, 04:19 PM
Irv Finkleman
 
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Irv Finkleman wrote:

I should have added that the Twin Lead was the cheapest stuff available as
I just tried it for an experiment! It was a 60 foot run as well!

Irv

--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada
  #52   Report Post  
Old April 20th 04, 05:16 PM
Cecil Moore
 
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Irv Finkleman wrote:
I used 300 ohm TV twin lead for years. Why the concern about 600 ohms? It
really doesn't matter unless you have a 600 Ohm feedpoint. The losses are
still very low regardless of conditions, and as for dirty or rain, I had
some up from 1983 to 1996 -- and never noticed any changes. When I took
the antenna down the twinlead was as good as new and I used it for other
things.


Here's the 600 ohm concern. A dipole's feedpoint is likely to vary from
about 60 ohms min to about 6000 ohms max. With 300 ohm line, the SWR varies
from 5:1 to 20:1. With 600 ohm line, the SWR is relatively constant
at 10:1, i.e. 600 ohm line gives more consistent SWRs over the entire
HF range than does 300 ohm line - just my two cents.
--
73, Cecil http://www.qsl.net/w5dxp



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  #53   Report Post  
Old April 20th 04, 07:06 PM
zeno
 
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Hi Richard,

My beginner's understanding is that I would have a better multi-band
antenna utilizing a balanced feedline than with coax. I had seen a couple
of recommendations by doing internet searches. Several operators spoke
highly of the ~540' loop with balanced feed. I have a nice old 250W
Johnson matchbox on hand. Again, my beginner's understanding, the more
wire=the better, so I figured this long loop would be a good antenna for
"all" bands.

I am just now setting up a station for the first time. I need to think I
know what I am doing long enough to simply put something into action for
fear I will spend forever in a complex endless decision making matrix. I
enjoy trips to the hardware store and the junkyard, I haven't even been
on the air yet......(or at least since 1953....).

I figure antenna concerns are first, a good ground, then I need to think
about some serious equipment. This can be a bit overwhelming. Ihis next
Sat. I will be going to a local hamfest (my first one), hopefully to meet
some locals and make friends (mentor's, Elmers, etc.), also to track down
the guy with the bow and arrow who can get a line up my Eucalyptus tree
(165'+) for another possible antenna in an alternate shack on the
property......

actually, now that I think of it, my whole involvement in ham radio at
this moment (besides the fun of studying for the exams last month) is
dreaming of antenna farm.

just the other night while listening to some local maniacs on 3840, now I
realize I need to get my Extra if I want to be able to chime in at that
frequency.....those guys last night almost shattered my naive expectation
that hams are always gentlmen, a pursuit of integrity I personaly fully
intend to promote in my own operating demeanor. Apparently there is some
"famous" AM talk show host involved with that little late night net.....
shame on them....

Great, now I have a shopping mission.....go out and buy the Extra exam
book.....I do actually enjoy studying and learning.....

Now....a trip to the junk yard to find an old fashion DPDT Knife switch
I can mount on the wall so I can switch my incoming balanced line from
the Johnson to the Kenwood tuner....


help!.....


73

Bill (KG6UHM)



Richard Clark wrote:

On Tue, 20 Apr 2004 06:23:13 GMT, zeno wrote:

Any recommendations on a specific type of commercially made window
(ladder) line? I see that it comes in a variety of configurations
and slight differences in Z.

This feed line will be for a full wave 160m loop.


Hi Bill,

You repeatedly characterize this as 160M and given the size and height
- Why do you think you need ladder line when it will in all
probability fit quite nicely into a coax?

In free space, it may show as much as 140 Ohms R; however, within the
cold embrace of earth only 50 feet away, you will barely muster 35
Ohms at resonance.

73's
Richard Clark, KB7QHC


  #54   Report Post  
Old April 20th 04, 07:09 PM
zeno
 
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Hi Cecil,

I will check that out.

While playing around with wire last night, seriously, the diy that
looked like it would work best was the sample I put together with some
#10 bare copper!

I have been known to end up doing things the hard way, and overdoing
things....

so why not this #10 bare copper ladder line?

73,

Bill

Cecil Moore wrote:

zeno wrote:
Any recommendations on a specific type of commercially made window
(ladder) line? I see that it comes in a variety of configurations
and slight differences in Z.


I use Wireman #554, #14, stranded, copper-clad steel. It's
virtually indestructible. http://www.thewireman.com
--
73, Cecil http://www.qsl.net/w5dxp

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  #55   Report Post  
Old April 20th 04, 07:17 PM
zeno
 
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Hi Irv,

The 300 ohm TV line I am sure works, but it does not appeal to my tendency to
want to make everything "industrial strength" as if we were all going to live
for ever. I am finding it difficult at the moment to resist the idea of
making my ladder line out of #10 bare copper, thus insuring I will have a
*&^%$#@!!!!! time up on top of a ladder yelling and screaming things like
("why do I always make things so difficult) hi hi. Actually I think that the
#10 bare copper ladder line with my secret hardware store insight spacers
will look impressive.... (who am I trying to impress is the question) I need
to get my butt on the air otherwise I be only a "theoretical" ham.....

Secret hardware store spacer insight: the 4" uv/pvc ferrules that come with
the gutter spikes!....no I didn't say gutter snipes.....hi

73

everyone was working this guy in Lithuania on 20m this morning....can't wait
to get in there...... fun.....


Bill

Irv Finkleman wrote:

zeno wrote:

I tried practicing making some diy ladder line...


I am now thinking: how bad could those commercially manufactured
window lines be?

Any recommendations on a specific type of commercially made window
(ladder) line?


I used 300 ohm TV twin lead for years. Why the concern about 600 ohms? It
really doesn't matter unless you have a 600 Ohm feedpoint. The losses are
still very low regardless of conditions, and as for dirty or rain, I had
some up from 1983 to 1996 -- and never noticed any changes. When I took
the antenna down the twinlead was as good as new and I used it for other
things.

Irv VE6BP

--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada




  #56   Report Post  
Old April 20th 04, 10:38 PM
Irv Finkleman
 
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Cecil Moore wrote:

Irv Finkleman wrote:
I used 300 ohm TV twin lead for years. Why the concern about 600 ohms? It
really doesn't matter unless you have a 600 Ohm feedpoint. The losses are
still very low regardless of conditions, and as for dirty or rain, I had
some up from 1983 to 1996 -- and never noticed any changes. When I took
the antenna down the twinlead was as good as new and I used it for other
things.


Here's the 600 ohm concern. A dipole's feedpoint is likely to vary from
about 60 ohms min to about 6000 ohms max. With 300 ohm line, the SWR varies
from 5:1 to 20:1. With 600 ohm line, the SWR is relatively constant
at 10:1, i.e. 600 ohm line gives more consistent SWRs over the entire
HF range than does 300 ohm line - just my two cents.
--
73, Cecil http://www.qsl.net/w5dxp

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Understood, Cecil, but when the SWR losses are of so little concern
then the SWR consistency becomes likewise, at least IMHO.

Irv

--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada
  #57   Report Post  
Old April 20th 04, 11:38 PM
JGBOYLES
 
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Understood, Cecil, but when the SWR losses are of so little concern
then the SWR consistency becomes likewise, at least IMHO


Hi Irv, Excellent point! Although I am sure Cecil put it in there as
Point/Counterpoint.
73 Gary N4AST
  #58   Report Post  
Old April 21st 04, 01:25 AM
Cecil Moore
 
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zeno wrote:
so why not this #10 bare copper ladder line?


For one thing, it is overkill. And if it is solid,
it is subject to failure from fatigue. Many, many
hams have had trouble with breakage of solid wire
ladder-line.
--
73, Cecil http://www.qsl.net/w5dxp



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  #59   Report Post  
Old April 21st 04, 02:00 AM
Cecil Moore
 
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JGBOYLES wrote:

Understood, Cecil, but when the SWR losses are of so little concern
then the SWR consistency becomes likewise, at least IMHO


Hi Irv, Excellent point! Although I am sure Cecil put it in there as
Point/Counterpoint.


If the SWR on 300 ohm twinlead is 5:1, the impedance at the current
maximum point is 60 ohms. If the SWR on 300 ohm line is 20:1, the
impedance at the current maximum point is 150 ohms (3:1 SWR).

If the SWR on 600 ohm line is 10:1, the impedance at the current
maximum point is 60 ohms NO MATTER WHAT THE ANTENNA IMPEDANCE.
The impedance at the current maximum point for a 6000 ohm antenna
fed with 600 ohm line is the same as the impedance at the current
maximum point for a 60 ohm antenna fed with 600 ohm line. That's
a definite '+' in my book. I like 60 ohms better than 150 ohms.
--
73, Cecil http://www.qsl.net/w5dxp



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  #60   Report Post  
Old April 21st 04, 04:20 AM
zeno
 
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Hi Cecil,

The only reason I was considering #10 solid wire was because it
would absolutely hold its shape with a minimum of spacers. Aside
from the fact that it is electrically overkill, you are saying that
even wire that thick could possible flex enough over time to fatique
and fail? Somehow I got it into my head that the best way to go was
homebrew ladder line, and the only way I could see doing it myself
was with this thick wire, all other wires were too messy somehow.

I checked the #554 that you suggested and it is rated for full
power. I didn't realize that #14 wire could handle that (guess I
have AC wiring in mind and not RF). So you have come to the
conclusion that this wire is the best way to go for balanced feed
line all things considered? (weather, dirt, etc.) Maybe I should
just use that and move on from this obsession about making my own
ladder line. I'll tell you that #10 was going to look cool in a
kind of science fiction movie laboratory kind of way..... It is hard
to get off that track, but maybe I am not being very practical...

I see that Radio Works also has this #14 copper-clad for about the
same price, he says that the actual impedance is approx. 390 ohms.


Now I am wondering how I got onto this do it yourself homebrew
ladder line obsession in the first place, I think it was some folks
complaining about how erratic it was with the rainy weather and when
it gets dirty, and stories of oldtimers going out and coating it
with bacon fat etc. yuk.....

So you are predicting eventual unhappiness with #10 bare copper wire
ladder line with cute little gutter spike uv/pvc ferrules as
spacers. Why do all those guys make their own ladder line...is it
because the commercial version is nearly 30 cents a foot? Or is
there some other downside they were trying to avoid?


I was going to order some stuff from Radio Works anyway, so I could
just get a chunk of that #14 ladder line......unless .......

Zeno (can't seem to really get away from this nickname....so maybe
Bill will just have to wait in the wings.....)


Cecil Moore wrote:

zeno wrote:
so why not this #10 bare copper ladder line?


For one thing, it is overkill. And if it is solid,
it is subject to failure from fatigue. Many, many
hams have had trouble with breakage of solid wire
ladder-line.
--
73, Cecil http://www.qsl.net/w5dxp

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