I want to remember (when money was tight) that regular lamp cord happen to be
70 - 75 ohms. The dielectric might not be that good though.
Hans - N2JFS
-----Original Message-----
From: n8de <n8de@thepoint.net>
To: Herbert Schoenbohm <herbert.schoenbohm@gmail.com>
Cc: towertalk <towertalk@contesting.com>
Sent: Mon, Apr 13, 2015 1:02 pm
Subject: Re: [TowerTalk] 75 or 70 Ohm twinlead or ladderline cable - does
it exist?
In the 70's, there was a product named 'Saucerline' .. which had
circular
plastic insulators which were donut-shaped. It was 75 ohm
line.
73
Don
N8DE
Quoting Herbert Schoenbohm
<herbert.schoenbohm@gmail.com>:
> Telephone C drop wire may work in your case
and it is very strong. I
> believe the characteristic impedance is 70
ohms.
>
> On 3/24/2014 4:15 PM, jpk5lad@cox.net wrote:
>> From where I'm
sitting, I can see a run of Kilowatt Twinlead
>> running up the wall, into
the attic
>> and to standoffs going up the tower. I've used it for years to
>> feed two of my top guy anchors,
>> insulated off to be fed at the top.
This KW twinlead was not 75
>> ohm but was actually 300
>> ohm. When I
owned a ham store in the 70s, I bought it from Dentron
>> in a 100'
length.
>> Dentron offered both the 450 ohm window line and the 300 ohm KW
>> Twinlead through their
>> dealers.
>> .
>> I do remember (I'm from the
1957 era) both a lighter duty 75 ohm
>> twinlead and a much,
>> much
heavier 75 ohm twinlead although I don't recall ever using it.
>> Perhaps
they were both
>> spec'ed at 72 ohms, it's been too many years to remember that
>> particular detail.
>>
>> Around our neck of the woods, I believe only the
300 ohm heavy and
>> thick twinlead was
>> referred to as "Kilowatt
Twinlead."
>>
>> Just musings from another old timer.
>>
>> 73,
>> Jim -
K5LAD
>>
>>
>>
>> On 24 Mar 2014 at 12:45, Jim Brown wrote:
>>
>>> On
3/24/2014 11:36 AM, Drax Felton wrote:
>>>> It's 72 ohm twin lead. Also known
as zip line.
>>> That's a new one on me, and I've been at this since 1955. Back
then, and
>>> for several decades thereafter, Belden and Amphenol made a
product
>>> commonly called "Kilowatt Twinlead," which was a pair of AWG
#13
>>> stranded copper conductors spaced apart by 2-3 conductor diameters by
a
>>> rather beefy dielectric. My old Belden catalog from 1971 says it's
part
>>> number 8210, is 72 ohms Zo, 0.67 Vp. I actually have several
hundred
>>> feet, what's left from a 250 ft spool that I bought "new old stock"
at
>>> the Milwaukee hamfest sometime in the 70s, figuring that I'd
someday
>>> find a use for it. 25 years later, I did, and it fed an 80/40
dipole
>>> that I also loaded as a Tee vertical on 160M.
>>>
>>> I also have
some junk lengths of the Amphenol product, which looks a bit
>>> less robust.
Both products have been discontinued for several decades.
>>>
>>> Last I
looked (about 7 years ago), I think I remember DXE was selling a
>>> window
line that they described as 100 ohms.
>>>
>>> 73, Jim K9YC
>>>
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>>
>>
>>
===============================
>> Life is like a football ---
>> It ain't
round ... It'll bounce funny on ya.
>>
>>
http://www.hayseed.net/~jpk5lad/
>>
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