[Elecraft] KAT 500 and open wire

[Victor Rosenthal 4X6GP]

When I used to use ladder line I noticed a significant detuning effect 
when wet. It was worse with older line, probably because the weathering 
made the water more likely to stick. I never tried to measure the loss.

I tried waxing the line with automotive wax and saw an improvement. But 
I don't know how long it would have lasted, since I switched to other 
feedlines.

Today I'm using homemade open wire line, no. 12 (2 mm dia) spaced 4.5 
inches (11.4 cm). Insulators are cut from black irrigation hose. Wire is 
ultra flexible type from The Wireman.

It works great with no noticeable weather effects. It's very easy to 
make: I made a jig from a piece of tubing to cut the insulators to the 
same length. The jig has holes to drill near the ends of the insulators; 
then I snipped a cut from the edge to the hole to enable the wire to 
snap in. The holes are just big enough to grip the wire but to let me 
slip the insulators a bit to get them in the right place. In a few 
locations I made insulators out of fiberglass that could be attached to 
brackets to hold the line in place.

73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/
On 19 Jan 2019 16:45, Bob McGraw K4TAX wrote:
> I didn't measure significant increase in loss with clean water i.e. tap 
> water sprayed on the entire length of the line from a hose.  I did make 
> a solution of dish washing detergent and water and , using a spray 
> bottle, sprayed that on the line.  This caused much more water to cling 
> to the line.   While the loss did not appreciably increase, I did notice 
> the electrical length of the line changed a measurable amount. 
> Measurements were made such that the line was operating at its 
> characteristic impedance.  The source was the tracking generator in my 
> Spectrum Analyzer, sweeping 1 MHz to 50 MHz.
> 
> 73
> 
> Bob, K4TAX
> 
> 
> On 1/18/2019 11:56 PM, Walter Underwood wrote:
>>> On Jan 18, 2019, at 6:08 PM, Al Lorona <alorona at sbcglobal.net> wrote:
>>>
>>> Thing 1 is that, clearly, water really messes up window line's loss. 
>>> However, I'm guessing that a/ in a place like southern California, 
>>> where perpetual drought is the new normal; ...
>> Clean water isn’t a problem. Dirty water is a big problem.
>>
>> When I first moved to the SF Bay area in the early 1980s, I was 
>> surprised by the number of power outages, compared to where I grew up 
>> in Louisiana with heavy weather. The first light rain would be 
>> accompanied by outages. With six or more rainless summer months, dust 
>> and grit would accumulate on the power line insulators. The first 
>> light rain would create conductive mud and trip breakers. So perpetual 
>> drought is just a way to build up more dust on the line.
>>
>> I think we take coaxial cable for granted. It was a brilliant 
>> invention and a real gift to people who love radio. Maybe I’ll start 
>> celebrating December 8th as Coaxial Cable Day.
>>
>> https://www.wired.com/2009/12/1208coaxial-cable-patent/
>>
>> wunder
>> K6WRU
>> Walter Underwood
>> CM87wj
>> http://observer.wunderwood.org/ (my blog)
>>
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