[TenTec] Wet ladderline

Scott Harwood scotthsr at earthlink.net
Wed Aug 14 08:53:39 EDT 2013


Good advice, Bob.  I run my 600 ohm insulated open wire line straight into a balanced tuner in the shack.  It works fine.  I related the story a few weeks ago how a contractor tied the line to an aluminum gutter with cable ties to get it out of the way and there was no decrease in performance.  He tied it perpendicular to the gutter, which backs up what you were saying about towers.

Scott K4VWK


-----Original Message-----
>From: Bob McGraw - K4TAX <RMcGraw at Blomand.net>
>Sent: Aug 14, 2013 8:01 AM
>To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
>Subject: Re: [TenTec] Wet ladderline
>
>As I have professed for years, open wire line is much easier to deal with 
>than the "old wives tails" would lament.   As to windows, just bring it 
>straight to the window sash, straight through and into the station.  As long 
>as the insulation is not broken and the wire or wires do not contact the 
>window sash, be it metal, vinyl or wood, nor the wires shorted at the 
>entrance point, no harm done.  I run the vinyl covered window line through 
>windows, doors, attics, ceilings and such with no issues.  If one needs to 
>bring it down the tower, then stand it off 5x to 10x the spacing of the line 
>from the tower.  This applies to any metal running parallel with the line 
>such as gutters, downspouts and such.  As to running it perpendicular, there 
>is no issue.
>
>73
>Bob, K4TAX
>
>
>----- Original Message ----- 
>From: "Rick - DJ0IP / NJ0IP" <Rick at DJ0IP.de>
>To: "'Discussion of Ten-Tec Equipment'" <tentec at contesting.com>
>Sent: Wednesday, August 14, 2013 1:01 AM
>Subject: Re: [TenTec] Wet ladderline
>
>
>> Joel,
>>
>> I had an experience at Field Day in OKC concerning openwire that 
>> completely
>> surprised me.
>> I have always run openwire as you say, "in the clear", but at FD something
>> funny happened which had curious results.
>>
>> Due to the heat (over 100 deg. F), we set up in an air conditioned 
>> volunteer
>> fire department which had heavy metal doors.
>> We ran all coax and the openwire from our vertical dipole and our 135 ft.
>> doublet through the open door, into the shack.
>>
>> Both openwire fed antennas were pre-tuned before the FD started and charts
>> were made with matchbox pre-sets.
>>
>> At night, somebody closed the door as best he could, to keep the bugs out.
>> The coax's were laying on the ground, stacked vertically on top of each
>> other and squeezed by the door, but he shoved the openwire up over the 
>> metal
>> door, pushed them towards the side and closed the door on them.
>>
>> I was running the CW station on the doublet at the time, but did not 
>> notice
>> the door getting closed AND it did not cause any change to the matchbox
>> settings, nor any apparent loss in ability to work at least one station 
>> per
>> minute.
>>
>> I would have expected it to basically short the two wires of the Wireman
>> Window Line, but apparently nothing changed.
>>
>> I have not made any attempt to repeat that kind of circumstance but it
>> certainly made me wonder.
>> In the past 30 years I've built all kinds of contraptions to enable me to
>> get the openwire in through metal window frames. Maybe I should have just
>> closed the window on the line and used it!
>>
>> 73
>> Rick, DJ0IP
>> P.S.  I think it was one of the boys visiting us from Texas who closed the
>> door on the window line!
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Joel 
>> Hallas
>> Sent: Wednesday, August 14, 2013 4:15 AM
>> To: 'Discussion of Ten-Tec Equipment'
>> Cc: k9yc at arrl.net
>> Subject: Re: [TenTec] Wet ladderline
>>
>> Bob,
>>
>> Good observations, and I have also seen European HF broadcast curtain 
>> arrays
>> using our friends, the open wire line. It works as well today as it did in
>> 1930.
>>
>> The key thing about such line is that, unlike coax, the fields are not 
>> just
>> "between" the conductors, but surround them at 2-3 times the spacing. Put
>> lossy stuff (such as terra firma) within that region and you warm worms.
>> Both our ARRL measurements (2009) and Steve Hunt's recent data confirm 
>> high
>> attenuation (up to 10 dB/ 100 ft, as I recall) of window (or open wire) 
>> line
>> laying on the ground.
>>
>> This may come up more at Field Day locations than at other times, but keep
>> it in mind.
>>
>> Regards, Joel Hallas, W1ZR
>> Westport, CT
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Bwana Bob
>> Sent: Tuesday, August 13, 2013 10:02 PM
>> To: Discussion of Ten-Tec Equipment
>> Cc: k9yc at arrl.net
>> Subject: Re: [TenTec] Wet ladderline
>>
>> I like LMR400. We ordered spools of it along with N connectors for the
>> workplace when we rebuilt our GPS antenna distribution system. We have
>> preamps built into the antennas and in the splitter, but the coax runs 
>> from
>> the antennas are about 100 ft and at 1.5 GHz, LMR400 works very reliably.
>> The system we replaced used RG-213, which was marginal.  Some hams say 
>> that
>> LMR400 is noisy, and they buy Belden 9913. I think that's an urban myth, 
>> and
>> I hear that water can get into the 9913 because it is mostly air 
>> dielectric.
>> To each his own.
>>
>> I have to laugh about the idea of burying  open wire or window line. The
>> whole idea of using window or ladder line today is to reduce dielectric
>> losses by making sure that most of the dielectric between the conductors 
>> is
>> air, so that attenuation under a high SWR will be minimal.  Now replace 
>> the
>> air with a  lossy dielectric like dirt and see what happens.
>> In 1991 I found myself in a foreign land. The hotels were in a line on the
>> beach and a couple of blocks in were several embassies. I amused myself by
>> walking around spotting antennas. Except for one big log periodic, all of
>> the embassy rooftops sported dipoles fed with good old
>> 600 ohm ladder line.
>>
>>                 73,
>>
>>                 Bob WB2VUF
>>
>> On 8/13/2013 11:41 AM, Mike Bryce wrote:
>>> You're right, Jim,
>>>
>>> I ordered the LMR400 and had a bit of worry about how well the copper
>>> clad
>> would hold up to the soldering iron.
>>>
>>> seemed to work okay, but that stuff sure is hard to work with.
>>>
>>>
>>> Mike Bryce, WB8VGE
>>>   the heathkit shop
>>> SunLight energy systems
>>> J e e p
>>> o|||||||o
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Aug 13, 2013, at 3:19 AM, Jim Brown wrote:
>>>
>>>> LMR400UF (Ultraflex) has stranded copper center. :LMR400 has copper
>>>> clad
>> Al. Two different cables.
>>>>
>>>> 73, Jim K9YC
>>>>
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>>
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