The AM Forum

Open wire feeders have once again become popular with radio amateurs. "Ladder line" has become a common ham radio term.  Antenna tuners with balanced output, produced by major manufacturers are widely available.  Articles frequently appear in QST and other ham publications using OWL, and there is in-depth discussion of tuned and untuned balanced line in the handbooks.  There are many articles describing ways to laboriously fabricate spreaders, using everything from PVC pipe, hair curlers to plastic coat hangers.  New Old Stock commercial spreaders such as the ceramic ones made by EF Johnson go for top dollar at hamfests and on ePay.

With all this interest in open wire amongst amateurs, why is it that about the only thing available on the commercial market is that crappy "window line" garbage, which is nothing but heavy duty TV ribbon with rectangular holes punched in the plastic dielectric, the only possible exception being the W7FG open wire  line? No-one seems to be offering pre-manufactured spreaders for making one's own line, and they certainly do not appear in any of the major appliance distributors' catalogues, such as Texas Towers, HRO, AES, etc.

The W7FG stuff costs little more than it would to make it from scratch.   With PVC pipe and all sorts of synthetic subs for the old heavy ceramic spreaders, there's probably little/no demand for it.

why do it right when you can sell crap.
I'm set for life with Johnson spreaders

This is something I have noticed too.  Presently I have an RG-213 coax feed to my single 75 Meter dipole.  I took down the G5RV after my crappy MFJ-tuner roller inductor complained heavily at the added power from the Henry amp.  I'm a slow poke at projects due to other commitments so the homebrew balanced tuner is still a bit up the road for me.  In the mean time, I am considering throwing up a parallel 40 and maybe a 20 meter dipole under the existing 75 meter fed off of the same feedline. 

This has brought me to a similar conclusion, since I will need spreaders on the dipoles to do this.  I'm trying to avoid pvc simply because it will look odd having some white pipe sections floating above my yard.  The dipole is made from 14 gauge solid wire with black insulation and is really nearly invisible unless you look for it. 

I saw a post from a couple years back where Don, K4KYV built open line with acrylic plexiglass spreaders.  Since I have a large sheet of that which was bought for the large homebrew inductor on the tuner project, I'm thinking of making some spreaders from that.  If that stuff is good enough for high power tuner coils, it should be good enough for antenna spreaders too.  Jetstream makes a "fan dipole kit" that includes a 1:1 choke balun and some sort of antenna spreaders and you provide the wire but I already have the W2DU 1:1 choke and ceramic insulators so I'm not spending the 80 bucks on that!

http://www.jetstream-usa.com/jtfan.shtml

BTW, one of the best things I bought recently is a little bench top drill press from Harbor Freight.  I had an expired coupon from Flying magazine for 39.95 when regularly 79.95 and they actually accepted it and honored it!  Looks like I might be putting it too use on the plexiglass.  First I have some branches to remove (or maybe the entire tree) because the darn thing is in the way!

The explanation is simple...There's no money to be made manufacturing and selling OWL spreaders.....I think we are lucky that they still make the window line crap...I thought about asking the pottery class at the community college or an independent potter to make up a few but I never acted on it.....

C'mon guys!

Both the Wireman and Davis RF sell poly "#14 copperweld window line".

Made from 14 gauge stranded copperweld spaced maybe 1-1/4".  I've got a run of the stuff up 100' on the side of the tower and it's lasted 10 years now with no degradation, and it takes full bore power. I have never smoked it, and it's taken 100 MPH+ winds.

It's way more rugged than open wire fashioned from Johnson insulators and soft copper wire.

Seriously.

C'mon guys!

Both the Wireman and Davis RF sell poly "#14 copperweld window line".

Made from 14 gauge stranded copperweld spaced maybe 1-1/4".  I've got a run of the stuff up 100' on the side of the tower and it's lasted 10 years now with no degradation, and it takes full bore power. I have never smoked it, and it's taken 100 MPH+ winds. The poly insulation is as good today as it was years ago. No cracking, no degradation in our southwestern sun.

It's way more rugged than open wire fashioned from Johnson insulators and soft copper wire. I was a good friend of Gary,loved the dude, but the W7FG line is light duty stuff made from insulated #16 stranded soft copper. The Wireman and Davis RF line is 10x better and stronger. I refused to endorse the W7FG line in a past magazine article. I had a sample, it was lightweight stuff and I smoked it with a pair of 304s.It actually caught on fire, XYL freaked out, had to spray the tower down with the garden hose.

It's prolly OK if matched at 100-500 watts, but don't try to run a crusher or BC transmitter into it.

Seriously. What it is. Nothing smaller than #14.

Spreaders don't have to be made of heavy, brittle, expensive ceramic.  Plexiglass works well, and I suspect polycarbonate would be still better.  Polycarbonate rod stock (http://www.k-mac-plastics.net/polycarbonate-rod.htm)  is available commercially and inexpensive.  The going price for EFJ ceramic spreaders would suggest that money could be made mass producing good, durable spreaders.

I have some 6" clear plastic spreaders made by  Bud, n.o.s. still in the box. I have made my own using plexiglass rods.  Many hams who would be willing to make up good open wire line if they had the spreaders don't have the drill press and other shop tools required to make them out of blank rod stock.

I don't have the answer for you Don. Seems like a commonly sought after item based upon many conversations I have had on the air. Some enterprising guy with simple tools and skills could make a few bucks on the side cranking them out.

I followed a recent thread at EHam regarding this. The first poster mentioned that he used electric fence insulators which are designed to handle high voltage and are UV resistant. They are 4 inches in length and apparently come in packages of 100 for around 5 bucks. All you would need to do is notch the ends and use a hot glue gun to fasten the wire on each side in place. Looks interesting, but I have not confirmed that price at any place online. There were a few other clever methods mentioned in the thread.

http://www.eham.net/articles/23413

As always, when I cruise any building supply houses I keep an eye out for (cheap) material that would work out well.

I recall a small story in QST circa early 70s, about 2 paragraphs. It was about a rural ham who made his own open wire line by whittling a large number of wooden spreaders and boiling them in paraffin wax. According to the story it took him many months to complete the project. A caption quoted him as saying, "It just goes to show what a poor man can accomplish". An accompanying photo revealed that the ham was a black man dressed in ragged overalls standing outside a log cabin with his more prosperous white ham radio club president posed alongside. At the time, I thought the story was very odd on several levels, since boatanchors were uncool and open wire line was considered old-fashioned.

http://www.youtube.com/watch?v=qzFKGB6qkXs


Check out the above link to homebrew "ink pen open line"  N4LQ has a novel
idea to homebrew true open line

Don, here's a perfect opportunity for you to start a small manufacturing business creating a product for others sharing your radio hobby.  You can design them, fabricate them from plastic, and sell them, "factory-direct".  You'll be doing something you enjoy and providing a needed product.  And, I'm sure it will be XYL-approved if money comes into the household.  

Personally, I derived a great deal of self-satisfaction in fabricating my own spreaders from discarded plastic test strips gleaned from the dumpster at my former place of employment.  I enjoy making something useful out of discarded stuff.  The test strips were 5" long so I cut them in half (for 2.5" line spacing), drilled 2 - 0.11" holes at each end.  Then I used 2 black (UV resistant) cable ties to secure the 12 AWG solid copper conductors to each end of the spreaders.  I spaced them 19" apart.  I used epoxy to reinforce the cable tie bond.  

Eric

I think the last posts explain it well enough.  Most folks who want to use OWL have the homebrew bug so instead of purchasing spreaders or line, they make their own.  

It's a case of perceived value, if I can make a thing, I will pay a lot less for it no matter how nicely done it may be by the other guy, since "I could do that myself".

I always figured it was cooler to have built a station from items not normally used in radio, like cake pans or bread board for chassis, Home made open wire line, spark-plug lightning gaps, etc.  I think is shows true understanding of the art if you can create functional equipment from whats available whether it's radio parts or not.

Ain't cheap but they are the real McCoy...

http://www.daburn.com/10-62feederspreaderinsulators.aspx

Wow, What a great idea this guy has! I'm definitely going to try it with the next antenna and feedline project I do. Not only are the materials readily available, but it looks like it'd be very secure as well. The only drawback may be the initial cost of the pens that will lend themselves as standoffs. i guess it wouldn't be to bad if you don't need a lot of feedline.

Last year I made 100' of 600 ohm openwire feeders using 1/4" polycarbonate stock, and the job came out pretty good. it's not perfect, but so far I haven't had any problems with using the aforementioned as spreader material.

For anyone wanting to use 450 ohm ladderline, I stumbled across a novel idea. Someone gave me a few hundred old 35mm film spools that lend themselves rather nicely to make up hb spreaders with.  Just slip your wire through each side, add some hot glue from a hot glue gun, and you'll have yourself a nifty piece of hb transmission line! Just a FYI for anyone out there who may have the material and the willingness to give it a try. it worked fB for me!

Those look very similar to the old EF Johnson ones.  I have seen similar prices for EFJ's at hamfests.  The ham radio appliance outlets ought to carry them, if the company supplies 3rd party dealers.  That price would probably include the markup.

I would still make my own, but I suspect there would be a ham market for them.  I'd have to look in some of my old catalogues, but I am almost willing to bet that the pre-WW2 price for  the EFJ ones, when corrected for inflation of the dollarette, would be about the same as or even more than the Daburns.

Those are 2 inch spreaders at 3.92 each minimum 25!! Quite a hit to the wallet!  The 6 inch spreaders are 5.45 each minimum 25!!  I think I'll be drilling some plexiglass! ;)

when you start making 600 ohm line that will handle the limit easily..and survive the WX...Let me know....I'm in ...I want some

wifey is a lampworker, meaning she likes to make decorative glass beads.

I could probably talk her into blowing some glass for open wire spreaders. She could even put a desired call sign in them or some other such desired customization. she could make them in color, like red or cobalt blue.   8) 

guess some form of Pyrex ® would be the glass of choice. Extreme buzzardly-ness.

Cant do ceramic, thats a whole nother level of heat. ::)

In case you haven't noticed, nobody makes anything anymore.

That may be a bit strong, but you get the idea.

We are a plug and play culture and hams are no different.

js

Keep checking e-pay. Quite often the mil spec and other batches of the real deal show up and go cheaply.
 I keep the e-pay search terms for "insulator" very broad and plow through the many results. I have found some rare and obscure stuff that way.
I was going to mention the "pen trick" but some one mentioned it already.

Looks like this place has plenty of open wire spreaders.

http://www.surplussales.com/antennas/Antennas-9.html (http://www.surplussales.com/antennas/Antennas-9.html)

I know of another source where prices may be better but I need to find it again on my computer.

I have some of those little 2" spreaders, and use them with #10 copperweld.  My proposed open wire line from the dawg house to the shack will be made with #8 copperweld, because I have a big spool of it and have run out of #10.  None of the EFJ spreaders will take wire that big.  I have seen some 6" long brown glazed ceramic spreaders, about 1" in diameter, with a groove large enough to accommodate #8,  but not recently.  I would pay $5.50 each for enough of those to build the line, but don't think I would need 25.

I'll probably order some 3/4" or 1" polycarbonate rod stock and make my own.  That stuff seems almost indestructible and supposedly is an excellent rf dielectric, better than plexiglass.

Now, what about standoff insulators to affix the open wire line run to the poles that will support it?  I had thought of ceramic electric fence insulators, but the metal nail that  runs through the ceramic insulator would probably cause breakdown with rf voltage. I need something mechanically sturdy that would attach to a metal or wooden cross bar, but leave a long insulative path between the feeder wires and any metal or lossy wood.

Don,

I've got 25 new glazed ceramic Birnbach 262's nib, yours if you want em. these are about 2" wide. when the wifey gets home with the camera I'll take  some pix and post em for ye.


hmmm here's a resource I've never seen before.

http://www.r-infinity.com/Companies/Catalogs.htm

Thanks, Derb.

Shoot me the photos and I'll let you know if I can use them.

Here is one source of polycarbonate rod.  Looks like cost per spreader wouldn't be a terribly lot cheaper than the ready-made ceramic ones.
http://www.k-mac-plastics.net/polycarbonate-rod.htm

Electrical characteristics (http://www.k-mac-plastics.net/data%20sheets/alh13695.pdf)

here they are. i think the box cost me a entire dollar.

that's solid #8 copper lying in that groove.

Don, use these bad boys with that #8 and you'll never have to worry about trespassers again..

Derb,

I already have some extra copies of those.  I thought you meant standoffs to mount on the support poles.  Thanks anyway, but I  don't need any more 2" spreaders.

ok gotcha. I have some of those too but not enough for the distance you're gonna run.

Here's a guy who makes repros of NOS parts; coil forms, sockets, etc. He's considering a run of ceramic beehive insulators. He might be persuaded to do ceramic spreaders.

http://sites.google.com/site/kshamradioparts/ (http://sites.google.com/site/kshamradioparts/)

At Dayton last year someone, either the Wireman or Radioworks was going to make and sell spreaders.  But for an insulated support interface between the wires and a post, something would probably be cooked up with PVC, a saw, and a hot glue gun.


Rob

http://sites.google.com/site/kshamradioparts/home/ladder-line-spacer (http://sites.google.com/site/kshamradioparts/home/ladder-line-spacer)

Huh, interesting, he ALREADY makes 'em!

(http://sites.google.com/site/kshamradioparts/home/ladder-line-spacer/spacer%20pic.jpg)

If I may be so bold as to shamelessly flog my own merchandise: we have been making and selling black polycarbonate clip-on 84mm. wire spreaders in South Africa for about 2 months now. Shipping to the US is certainly possible, but how economical that is would depend on order size etc.

Details: http://www.instantladderline.co.za.

Hope this helps. :-)

73 Frank ZS6TMV

Hello, welcome to the BB.

Nice spreaders, do you think you could put on your web pages the dimensions in inches for us in the US?


I'm too dumb to figure that out ??? ??? ???

Terry.......

84/25.4(mm per inch) = 3.307"
just shy of 3 3/8"

You mean 3⅜"?

That's what I meant but my fingers didn't listen!

I just got a reply back from Frank this morning.

I may order 250 of them since it doesn't add much to the total. I'll have plenty of extras, since I'm going to need less that 100 ft of line....

<snip>



They are produced locally in South Africa.

>  I'd like a quote on shipping for quantities of
> 100 and 250 to Minneapolis, MN USA.

If delivery via surface mail is acceptable (airmail from South Africa
to the US would be very expensive) your order would come to this:


For 100 wire spreaders:

100 spreaders:          $ 9.50
Postage (surface mail): $21.60
                       ----------
Total amount due:       $31.10


For 250 wire spreaders:

250 spreaders           $20.75
Postage (surface mail): $26.00
                       ----------
Total amount due:       $46.75


If you are interested in ordering, you can pay via my Paypal account
if the Netherlands. (When I migrated from the Netherlands to South
Africa seven years ago I kept my Dutch paypal account, since online
transactions into South Africa are a pain, and very expensive.) Your
order will be dispatched upon receipt of payment, and you will receive
a notification of this, as well as the estimated time to delivery
(which for surface mail could be three to four weeks). You will be
provided with a tracking number if the SA postal service provides one
for international shipments (I am not sure that they do but I will
inquire).

> Greg Cotton N0WEK
> 5227 33rd. Ave. South
> Minneapolis, MN 55417

Will this be your preferred delivery address?

I'm hoping to hear from you soon!


73,

Frank ZS6TMV / PA3GMP
Cell: 082-294-2648
Highveld repeater (near Jo'burg): 145.7875MHz

========================================================
Instant Ladder Line clip-on wire spreaders
info@instantladderline.co.za
www.instantladderline.co.za
====================

Looks to me like we want to get the quatity right up to the weight limit on the postal side to minimize the cost of the postage vs. the part!!

$26bux for the postage and <$26 for the part(s)!!

I'm in on this... I'll take 250 spreaders or some similar amount, assuming we can beat back the postage devil??

                         _-_-bear

Now, after I have opened my BFM (big fat mouth) it seems to me that there could be a problem with these under ice loading conditions, as there is a slight offset of the spreader vs. the clip part. It might be a better product if the clip (ends) were rotated 90 degrees so that the faced outwards.

The other thing is that they will tend to rock up and down under wind conditions, with the offset... might not be an issue...

I guess one could alternate the direction that the spreaders are clipped on to the wires so that the line would "S" not "C" under ice loading... maybe it's not really an issue... dunno.

The other thing is, and I do not know if it is practical but molding out of polyester might be better, as it is far less UV and weather sensitive. Polypropylene line dies pretty quickly in the outside elements, but again maybe this is a non-isssue.

                      _-_-bear

Frank says he uses polycarbonate, not polypropylene.  It's the same stuff as Lexan. I have heard conflicting reports about its UV resistance, but the opaque black should suffer less damage in any case.  Some people say they have made antenna insulators out of crystal clear Lexan, which have lasted 30 years or more.  It's supposed to be more rugged mechanically than plexiglass.  I used corrugated polycarbonate sheeting designed to cover car-ports for the roof on the dawg-house, and the stuff seems indestructible. I could beat it with a hammer and it would pop back into shape with barely perceptible dents. It has survived at least one summer in the sun with no visible deterioration.

Have you seen this stuff Ladder Snap?
http://www.73cnc.com/73cnc/laddersnap.html

The sky lights and side windows in my Super Cub are made from Lexan.....They have withstood sitting outside in the long days of Alaskan summers for 12 years with no problems..

I used that 450 Ohm window line on an  antenna I put up in 1989. 20 years later it was still fine after enduring two decades of ice, rain, nor'easters, etc. Finally, the antenna was destroyed in a powerful nor'easter that struck this area in March of 2010 with hurricane force winds.

I am putting up a new antenna and I am debating whether to go with window line again or, to build some true ladder line. I am tempted  to go with real ladder line, although, wiindow line has served me well in the past.

Last time I build a stretch of ladder line I used sections of PVC tube with notches cut into the ends as spreaders.

I believe that in the old days they used wooden spreaders  that were  soaked in paraffin or creosote. Is anyone familiar with this ?

Not sure which product ur thinking about Don, but here is the South African one:

http://www.instantladderline.co.za/specs.html

    *  Material: polypropylene with UV blocker
    * Weight: 2.5 grams
    * Outer dimensions: 98.5 x 14.5 x 5.5mm
    * Wire spacing (conductor centre to conductor centre): 84mm.
    * Usable wire diameter, insulated, including insulation: ± 2 - 3.5 mm.
    * Usable wire diameter, bare: ± 2 - 2.5 mm.
    * Recommended spacing between spreaders: ± 50cm.

                            _-_-bear

His are rather big bucks.

Those are cheap compared to his tuning knobs and custom plate caps; nice stuff, but REALLY pricey!

Unfortunately, yes. And that's via surface mail!

Having a reseller in the US somewhere would probably be much more economical, but right now just mailing the stuff overseas is the only option for me. Which is a pain, because the problem with high shipping costs works both ways: whenever South African hams want to order something from sellers in the US (say, on Ebay or similar deals) we have the same problem with high postage.

73 Frank ZS6TMV

No, Frank says he's using polypropylene. :-) With a UV blocker that is capable of dealing with the South African sun - and its relatively high UV levels that make short work of any plastic with insufficient UV resistance.

73 Frank ZS6TMV

The clips grip the wire tightly enough so that I personally have never seen one move of its own accord in any weather conditions I've ever experienced. But your mileage may vary - I have never lived in a country with tornado's or tropical storms. :-) However I am sure the shape won't be a significant issue.

On a similar note (and I have to be honest here): I am also not sure how the material will behave at, say, 20 or 30 degrees below freezing point, not having experienced this at any of my QTH's, either.

That's what the UV blocker in the plastic is for. Unprotected PP is indeed not very UV resistant and tends to crack, crumble, flake and otherwise deteriorate fairly quickly (six to 24 months depending on climate and UV levels).

73 Frank ZS6TMV

I must have mis-read.  I could have sworn he said polycarbonate, but Frank says it is polypropylene.

Even polycarbonate has to have UV protection.  I notice in the catalogues for plastic products it states whether or not it is protected on one side or both.  But I have heard numerous stories of antenna insulators made from Lexan lasting in the sun for years.  Apparently the UV protection is applied to the surface.  In that case, whenever it is cut, unprotected plastic is exposed.

Maybe some products have UV protection built into the material.

Plexiglass is inherently UV resistant.  It was developed during WW2 as a shatter resistant material for use in aircraft windows. Interestingly, it still shattered upon severe impact, such as bullet hits.  Small pieces sometimes embedded in the eyes of personnel on the planes, but it was discovered that years later, the embedded shards of plastic had caused no ill effects from the body trying to reject the foreign material, so plexiglass was successfully used to make artifical lens implants following cataract surgery. 

I'm not sure if the same material is still in use, since to-day's surgery uses a flexible plastic lens that is rolled up into a cylinder, inserted through a tiny incision, and fully deployed inside the eye, kind of like building a model ship inside a bottle. Before installing the implant, the clouded natural lens is pulverised and then sucked out through a hollow needle.

I'm trying not to drift too far off topic here, but I'm sort of guessing that the material properties of ladder line spreaders and other mechanical parts could be considered relevant. :-)

To keep a long story short, almost all plastics are susceptible to degradation over time. This is, in a nutshell, mainly due to three factors.

The first is inherent chemical instability in the material itself, which causes the molecule to break down into smaller fractions over time. Good quality plastics do not exhibit this property to any appreciable degree, but bad ones might. In some cases this property is even considered desirable, e.g. when materials have to be bio-degradable.

The second is the influence of chemicals. Well-known examples are rubber and plastic washers that crumble when exposed to engine oil, or polycarbonate (and, to a lesser degree, poly-ethylene-therephtalate) that may start to crumble when exposed to gasoline for several days. Because plastics consist of organic compounds, it will generally be organic chemistry (e.g. petrochemicals, especially volatile solvents) that are able to attack them.

The third, and perhaps most important one in this discussion, is exposure to UV. To be exact, this is not really a factor per sé, but UV rather acts as a catalyst that speeds up material degradation due to the first factor above (inherent long-term instability causing the molecule to break down) dramatically, by a factor of tens or hundreds. In other words, if a plastic might take 100 years to break down while kept in the dark and in an inert atmosphere, exposure to UV could speed up that process to take one or two years, or even less, and harmful chemicals would speed up the process even more.

There are two ways to combat this. The most popular ones used in the plastics industry are 1.) to improve chemical stability, and 2.) to prevent UV from wreaking havoc on the material in the first place. Option 1 is difficult, and essentially requires that a plastic be synthesized that exhibits excellent long-term stability even under adverse conditions. Examples of this are Perspex (which is very stable compared to other plastics, albeit still not 100%) and oil and solvent resistant rubbers and plastics for applications that involve petrochemicals.

The second option is the most popular one, and takes the form of a UV blocker or UV absorber. A UV blocker is a pigment that prevents UV from entering all but the topmost surface layer of the material. (That's why black cable ties stand up to UV so much better than the white or semi-transparent ones.) A UV absorber is a dye that absorbs UV and re-radiates it on different wavelengths (usually in the infra-red) similar to fluorescent paints and inks, and the powders with which the inside of a florescent tube has been coated.

Some materials, including plastics (to return to the start of this over-long diatribe) exhibit one or both of these properties naturally. Chemicals that are inherently part of the material's composition may block or absorb/re-radiate UV naturally, which does away with the need to add substances to achieve this. Some have better long-term stability than others. And some have a bit of both.

I have cut some big corners in the above (a text book on plastics and the chemistry of same is hardly called for here) but in a nutshell this is what's happening. Hope it helps. :-)

73 Frank ZS6TMV

A good example of this is the plastic used on older air-core plug-in coils, such as the B&W HDVL series.  First, the plastic shrinks and warps, sometimes enough to warp the coil and break the ceramic bar that holds the banana plugs.  Then it begins to crumble.  As it deteriorates, it becomes lossy at rf.  I have had the insulating support strips on those coils to literally burst into flame while the transmitter was operating. If stored in a moist environment like a cellar, the plastic may even become attacked by fungus.

Those old coils used a substance called celluloid acetate.  Later on, they changed the plastic to polystyrene (Victron), which is an excellent rf insulator and doesn't deteriorate when kept out of sunlight, but UV destroys it in no time.  I once built some open wire spreaders out of the stuff, and they turned to powder within a couple of years.

The self-deterioration was particularly bad with the B&W coils.  I have seen others, made by other manufacturers like National and Bud, that didn't deteriorate so badly with time. They may have used another plastic like polystyrene from the outset.

I was reminded of these again today when I happened to run into Peter - N2IDU on 75 meters. He uses them spaced 2 feet apart in his open wire feedline. He indicated that they are easy to work with and hold up very well. They're very lightweight hollow tubes that you can slot at the ends, or drill holes to pass your wire feeders through. I'd be inclined to slot the ends, jam the wires into the slots, then fill up the ends with my hot glue gun. They come in 4 inch lengths, have a rigid shape, are made of black non-conductive polyethylene, and are designed to insulate conductors in high voltage fence applications. Peter picked his up at a local Tractor Supply store, but they are also available at Agway outlets and some ACE Hardware stores. You can also order them online direct from the manufacturer at the links below. I figure the price is right for some experimenting this spring!

Available in bags of 25 for $4.70 or boxes of 200 for $17.53.

http://www.fishock.com/store/high-tensile-electric-fence/500-540

http://www.fishock.com/store/high-tensile-electric-fence/500-540t

looks like some good stuff for a beverage antenna system.

Another example is the viewfinder of my old LeicaFlex SL camera. A thing of beauty... except for one of the plastic parts in the viewfinder which originally was transparent but is now a hazy shade of brown.

And the natural degradation of organic plastics is still a common phenomenon even today. Last year I took a pair of running shoes out of the closet where they had been stored (in the original box) for two years, only to discover that the soles (originally some kind of supple vinyl rubber or a similar compound) had turned into chewing gum: sticky, soft and gooey. Obviously some chemical reaction, perhaps involving a plasticizer, or else a long-term stability problem with the rubbery compound itself, had taken place and turned a formely firm shoe sole into goop.

Chemicals can also be an issue. Beware the plasticizers used in the transparent sleeves used to store documents in, for example. (You know the type: a page-sized transparent plastic envelope, with or without perforation to put it in a binder.) Not only will these plasticisers, which are somewhat volatile, erase the print on thermal paper (cash slips, fax messages etc.) in short order, but they will also attack many plastics, given enough time. Keep your vintage radio parts away from circuit diagrams and such which have been stored in these sleeves, at least when you store them for any appreciable amount of time. (I'm not suggesting that any contact on the work bench etc. is going to destroy anything, of course - we're talking months of storage time here, at least.)

And then there's what happened to my lawn mower. While on vacation, we had a deal with the neighbours' kid to cut the grass every two weeks or so. He tried to save a few bucks by not putting in real two-stroke fuel/oil mix, but he made up his own by putting some engine oil into regular gasoline. When we came back, literally every rubber gasket and washer, and most of the plastic parts, inside the engine had been destroyed by the engine oil, from the priming bulb to the carb. Aargh.

73 Frank ZS6TMV

Now, that is wierd?? I use Lawn Boy 2-stroke mowers, and have for the last 30+ years. I like the fact that 2-stroke oil has additives to lessen the smoking, but I have used SAE#30 motor oil and regular gasoline most of the time. (Or whatever kind of oil that I have an open container of) I have done small engine repairs for most of my life and NEVER seen that problem. I also usually run them with double the oil in the gas (16:1). (maybe that is why my 1967 LB still runs as good as it did when it was new and I beat the Hell out of it with no mercy)

The gasket materials and rubbers/plastics used in them are made to be impervious to gasoline, so motor oil should have no effect on them. I wonder if he put laquer thinner or tolulene or something else wierd in there?? That stuff is another story, they will disolve plastics and screw up rubber!    

or fuel injector cleaner.
I blew 2 LB's my Dad built. Threw a rod once wide F open and the second rebuild seized the crank when the lower needle bearings got too small and turned about 30 degrees. Dad not pleased.

I used to own a LB with the larger engine (4 HP?) that was self propelled. I'd run my oil at 20 to 1 if not a little richer. I figured a fouled plug or two once in a while was worth the extra  money spent to make it last longer.

Remember a hi-performance two stroke oil called "Klotz"? I believe it was a early synthetic based oil with performance additives in it. I really can't say if it ran any better, but it had the characteristic Klotz oil odor from it.  Ditto with the 1963 Vespa Lambretta 125cc scooter I had. The scooter did run a little better. Can't say the same with the Lawn Boy though......

When I had my perfect 1961 Merc 50 horse outboard tuned up by the local expert I asked him about the oil mix, which in the original manual called for 20 to 1 of regular 30 wt. He said that the engines haven't really changed, that what changed was the oil. Modern 2 stroke oils are designed for that use, which is why they call for 40 or 50 to 1 mix now. He said go ahead and run at 40 to 1 or if it would make me feel better, a little richer. Everything else I've read on the subject agrees.

Well, FWIW, my 67 LB till has the ORIGINAL plug in it!! I have pulled the muffler and cleaned the carbon out of the exhaust ports ONCE!! I usually run it at the high speed setting and dont hesitate to cut wet grass a foot high! It has been an incredible machine and has NEVER been rebuilt!!

I also have a '95 self propelled "commercial series" one as well. It isnt half the mower the '67 is. the older one definately seems to have more BA's than the newer one and it also starts easier. (one pull vs 2 pulls) The only improvement I can see is that it is self propelled and the older one isn't.  The '67 is indestructable!! The only thing I have ever done to it besides an occasional (very occasional) sharpening is to clean the points once, and clean the plug once. Not bad for the 30+ years I have had it!!

Oh, Joe, we used to call KLOTZ "bean oil"!! Used Klotz and Blendzall in 2-stroke dirt bikes back in the good old days...................................

IIRC, werent they 24:1?? I thought I remembered that they used a quart to a 6 gallon tankful of 'olene. Outboard tanks were always 6 gallons, IIRC. They could also get away with it because being water cooled they ran much cooler than the air cooled stuff. The later outboards that used those damned surface gap sparkplugs would not tollerate the extra oil without fouling. I hated them and usualy ended up changing them to J4s or J6s. this helped with continued low speed use. (like crabbing)