On 4/29/2014 3:17 PM, Richard (Rick) Karlquist wrote:
Now if you use a 75 ohm line in a 37.5 ohm system, then that
will have more loss than two 75 ohm lines in parallel in a
37.5 ohm system. That's true but is kind of a corner case.
Right.
73, Jim
_
Topband Reflector Archives
VHF/UHF for the better cables, the cheap stuff even from the big companies
was failing down in HF, we only tested down to 5 MHz and up to 450 MHz.
The good stuff passed at better than 80dB shield effectiveness over the full
range; the CIA and DoD were real fussy about those specs and was also w
On 4/29/2014 3:19 PM, Mike Waters wrote:
I wonder just how much different the loss is?
Simple -- dig up the mfr data sheets. Belden data sheets is on the web.
So is Times.
73, Jim K9YC
_
Topband Reflector Archives - http://www.contesting.com/_topband
Paralleling two
runs of line does not decrease the insertion loss.
That depends. Given the same source and load Z as with the single run, it
does decrease the loss, because the current divides between the two lines.
The condition that does not reduce the loss is the use of two runs of coax
wi
At CATV frequencies or 160m? Or both?
I've heard it said that quad shield only helps at VHF+. I don't know.
73, Mike
www.w0btu.com
On Tue, Apr 29, 2014 at 6:15 PM, Carl wrote:
>
> ... quad shielded RG-6 and RG-11 made a substantial improvement over same
> company dual shield when it came to s
thinner foil and as little as 65%
braid.
Carl
KM1H
- Original Message -
From: "Mike Waters"
To: ; "topband"
Cc: "Owen Duffy"
Sent: Tuesday, April 29, 2014 6:19 PM
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.
I wonder
I wonder just how much different the loss is?
73, Mike
www.w0btu.com
On Tue, Apr 29, 2014 at 5:14 PM, Jim Brown wrote:
> ... most RG59 and RG6 cables are made for CATV and MATV, and those cables
> have Al foil and thin braids, so the loss in the shield is MUCH greater,
> especially in the low M
On 4/29/2014 11:28 AM, Jim Brown wrote:
Paralleling two
runs of line does not decrease the insertion loss.
That depends. Given the same source and load Z as with the single run,
it does decrease the loss, because the current divides between the two
lines. The condition that does not reduce t
On 4/29/2014 2:59 PM, Mike Waters wrote:
His graph showed almost identical, overlapping loss curves for "RG-6/U" and
"RG-213/U" from 1 MHz to almost 100 MHz. I'm 99% sure that Owen's RG-6 had
a solid copper center conductor, and it was something he obtained there in
Australia. I don't know what t
Jim,
On Sun, Apr 27, 2014 at 2:00 AM, Jim Brown wrote:
> On 4/26/2014 8:21 PM, Mike Waters wrote:
>
>> You're right about the loss being all in the copper center conductor, Jim.
>>
>
> AND in the shield. ... It's important to realize that "RG6" and "RG213"
> are no longer specifications for the c
On 4/29/2014 1:39 PM, Carl wrote:
1/2" CATV hardline is about .085 dB/100' at 2 MHz and increasing to a
hair under .4dB at 30 MHz.
The 3/4" chart is well below .1 dB at 2 mHz and doesnt show on the
chart until 5MHz at .11dB/100' and .26dB at 30 MHz.
Thanks, Carl. Makes sense.
73, Jim K9YC
- Original Message -
From: "Jim Brown"
To:
Sent: Tuesday, April 29, 2014 2:28 PM
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.
On 4/29/2014 10:08 AM, Richard (Rick) Karlquist wrote:
The ARRL Antenna Handbook shows about 0.4 dB for 420
On 4/29/2014 10:08 AM, Richard (Rick) Karlquist wrote:
The ARRL Antenna Handbook shows about 0.4 dB for 420
feet of 75 ohm 1/2 inch hardline.
I suspect they are talking about 75 ohm heliax, not the typical CATV
hard line. The CATV hard line I've seen has an Al shield, so I would
expect loss t
; topband
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.
On 4/29/2014 8:49 AM, Milt -- N5IA wrote:
=
The 420 foot long run of paralleled cables dampens the slight mismatch
The calculated loss is a mere 0.2%. The proof is in the pudding. It
73 de Milt, N5IA
On 4/29/2014 8:49 AM, Milt -- N5IA wrote:
=
The 420 foot long run of paralleled cables dampens the slight mismatch
The calculated loss is a mere 0.2%. The proof is in the pudding. It
73 de Milt, N5IA
0.2% is only 0.01 dB, that can't be right. Maybe
you meant 0.2 dB.
The ARRL Antenn
1.880.
The calculated loss is a mere 0.2%. The proof is in the pudding. It works
stupendously well.
73 de Milt, N5IA
-Original Message-
From: k1fz
Sent: Tuesday, April 29, 2014 6:59 AM
To: Carl ; Mike Waters ; topband
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True L
be considered.
73
Bruce-K1FZ
www.qsl.net/k1fz/beveragenotes.html
- Original Message -
From: "Mike Waters"
To: "topband"
Sent: Saturday, April 26, 2014 9:17 PM
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.
Hardline for 160
rom: "Mike Waters"
To: "topband"
Sent: Saturday, April 26, 2014 9:17 PM
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.
Hardline for 160 meters?
I've mostly used hardline where I really needed it, like back when I was
doing weak signal wo
On 4/26/2014 8:21 PM, Mike Waters wrote:
You're right about the loss being all in the copper center conductor, Jim.
AND in the shield. One of the things that gives bigger coax lower loss
is that skin effect has the greater diameter of the shield to work with.
It's important to realize that "
uot;
Sent: Saturday, April 26, 2014 11:21 PM
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.
You're right about the loss being all in the copper center conductor, Jim.
I based that statement on a graph that Owen Duffy had on the old
vk1od.netsite for solid cent
You're right about the loss being all in the copper center conductor, Jim.
I based that statement on a graph that Owen Duffy had on the old
vk1od.netsite for solid center conductor. Perhaps I looked at it
wrong, but I don't
think so.
There were two charts, one for loss and the other for power han
On 4/26/2014 6:17 PM, Mike Waters wrote:
The loss of RG-6 is about the same as RG-213.
Only in an advertising brochure for the RG-6. On 160M, loss is all due
to copper, and there's LOT more copper in RG213 than in any RG6 cables
I've seen. Remember -- the question was about 1,000 ft.
As to
Hardline for 160 meters?
I've mostly used hardline where I really needed it, like back when I was
doing weak signal work on the low end of 144 MHz.
Is 75 ohm CATV-type RG-6 (F-6) coax available where you live? That's what I
use on 160m to feed my inverted-L that is quite a distance from the
opera
I use 9 gauge Al electric fencing wire for elevated radials among my
trees. It is pretty tough stuff, as 3" branches have fallen on it
without anything but a little stretch. it doesn't stretch much with
time either. Now 7.5 cents per foot on Amazon
http://www.amazon.com/Field-Guardian-9-Guag
??
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Richard
(Rick) Karlquist
Sent: Saturday, April 26, 2014 12:43 PM
To: Carl; Rune Øye; topband@contesting.com
Subject: Re: Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.
On 4/26/2014
On 4/26/2014 9:17 AM, Carl wrote:
Shouldnt that line be rotated along its length to maintain balance as
done with OWL Beverages?
Carl
KM1H
A big vertical is omni directional and has high signal levels.
This is in contrast to the beverage which has low signal levels
and tries to null out ce
On 4/26/2014 9:17 AM, Carl wrote:
Shouldnt that line be rotated along its length to maintain balance as
done with OWL Beverages?
Carl
KM1H
A big vertical is omni directional and has high signal levels.
This is in contrast to the beverage which has low signal levels
and tries to null out certa
Shouldnt that line be rotated along its length to maintain balance as done
with OWL Beverages?
Carl
KM1H
- Original Message -
From: "Richard (Rick) Karlquist"
To: "Rune Øye" ;
Sent: Saturday, April 26, 2014 12:10 PM
Subject: Re: Topband: 1000 feet 5/8"
I used to have a 1000 foot long open wire line using
4AWG stranded insulated aluminum wire with an impedance of
450 ohms. At the time, the wire cost $0.15 per foot.
I think 4AWG was the smallest size available in aluminum.
It is much easier to build a transformer
for 450 ohms than 600 ohms, becau
Hello All,
I have moved to new qth and start to plan my 160/80 meter
vertical antenna. I was reading in ON4UN LOW Band DXing book about coax and
loss. John claims he is using 5/8” hardline coax for his TX antenna and suggests
taking care when chosen your coax. My problem is, from TX antenna to
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