[TowerTalk] Replies from the Cushcraft 2 element 40 Question

Brent Childers prosper@airmail.net
Thu, 20 Feb 1997 21:57:21 -0600

Thanks to everyone who responded to my question.  Glad to see that there are
a couple places to start looking for stuff.  Hopefully if all goes well, I
will be finished this spring.

73 to all and thanks for taking the time to reply.


and now the replies

Hi, Brent --

     I would recommend the RTV used for aquariums since it doesn't outgas
solvent like the regular ones do.  OTOH I don't know if it makes any
difference.  The solvent is an acid that MAY cause electrical continuity
problems.  Or it may not.

    I asked Dave how he came up with all the materials for his custom 402CD
and he told me it was just stuff he had laying around!  So now all you have
to do is come up with his junkbox stuff.  Great.

73,  Steve  K7LXC

Try calling AIN Plastics for a catalog.  They will have just about anything
you are looking for in their 200+ pages, and have about the best prices I've

                AIN Plastics of Florida         (800) 282-2710
                AIN Plastics of Ohio             (800) 575-4246


I rebuilt our 40-2CD using 'QHS specs.  For the caulking, I used regular 
outdoor window sealer.  I also covered the exposed part of the coax (used to
to the driven element) with the sealant.  At least this way, corrosion can't 
work its way down into the coax.  (I didn't cover the lugs, just the wire(s).)

I can't help much with the fiberglass.  We have an industrial supplier right 
down the street from us, and I was able to purchase the 3/4 inch fiberglass
They don't carry the 1-7/8 inch fiberglass rod, so a treated dowel was used. 
 'Course, we don't have the same weather up here as you down there.
Staining the dowel
and covering it with a couple of coats of polyurethane won't do it?

For the boom to mast and element plates, I purchased 1/4 inch T6-6061 
aluminum plate and cut it to form.  A word of advise; I found the original
element U-bolts are not truly long enough to make it through both the driven
boom plate and the 
additional plate.
If you go with strengthening this particular plate, you'll need to purchase 
longer ones.   The industrial supply store near us carried S/S types, but
I've no 
doubt a place like Home Depot carries them as well.

If you can't find a local source for the aluminum plate, might I suggest you 

Davidson Aluminum & Metal
330 Roberts St.
East Hartford, CT
(860) 289-0211

Order Location:
Davidson Aluminum & Metal Corp.
100 W Industry Court
Deer Park NY  11729

This is the source we used.

By the way, we'll be "Leesonizing" our other 40-2CD antenna early this 
spring.  The plan  works  real well.  During our last real bad snow storm,
the "Leesonized" 
40-2CD was as straight  as can be, while the other antennas bowed (just a
bit) under the 
weight of all the heavy, wet snow.  We have atop our 120 foot Rohn a
Cushcraft 20-2CD and the 
Leesonized 40-2CD.
The elements on the 20 have their normal sag, while the 40 stays straight!

I hope this is of assistance to you.


Joe, NJ1Q
W1AW Station Manager


I asked Randy, K5ZD, about his use of plastic tubing. He told me that he
too could not find the correct size, and simply bought the size closest
but too large.  He then cut a slit in the tubing and squeezed it in.

I called Texas Towers and asked Gerald Williamson (K5GW, the founder) if
they had a kit made up, priced, and ready to ship.  Frankly, I was
astonished when he said no and listed as one of the reasons: "We'd have
to post it and try to see that the list doesn't get lost."  Talk about
externalizing your costs!

Fred Hopengarten, K1VR


Point your search engine at Lightning Bolt Quads, I found them to have a
huge assortment of fiberglass rod, tube, and other neat things for
antennas.  Their prices are reasonable as well.



1. For rivets, I chose aluminum instead of stainless, which QHS* recommends.
My basis for this is that I don't think the strength is needed - I still
have the hose clamps in place. On the other hand, I was concerned about
corrosion, and AL-stainless is a notoriously bad combo. I asked QHS* about
this but lost his answer. It's been up a year - we'll see if it's OK.

2. I used short pieces of EMT in the boom ends. I can't remember all the
dimensions, but it fit pretty tightly and provided support. If you're
going to pin the elements so they don't rotate, I don't think the U-bolts
need to be as tight.

3. For the center section, I wanted to use a 3 foot length of thick-wall
2" OD aluminum tubing, but couldn't get it in time. It would add some weight,
but be very strong.

-Tony, K1KP, fisher@hp-and2.an.hp.com

* yes, I know 'QHS is now some other call. He'll always be QHS to me...



Sometime ago I was given the following information as a source of
Fiberglass products:

	Alan Bond Fiberglass Products
	221 Greencrest Ct.
	Marietta, GA 30068-3825

At the time I was in need of fiberglass tubing for making insulating
sections for a vertical array. I found the tubing elsewhere, so I haven't
tried the above source.

For plastics (Lexan, Delrin, etc) try Cadillac Plastics:

For silicone RTV, I use the local Dow Corning dealer, Applied Technology
Corp. Check your area. My favorites are 732 standard clear silicone
adheasive(about $3/80z tube: like bathtub caulk) and 734 clear flowable
silicone adheasive (about $8/8oz tube: flows like molassas, fills hard to
reach places, excellent for potting baluns, exposed connectors, etc. cures
like regular RTV). Dow also has types designed for electrical service. Try
here for info.


Hope this info helps.

Bill N4ALG


I purchased a set of quad spreaders from Allen Bond, DBA Max Gain Systems,
at Dayton last. I'm very satisfied with them. At that time, he gave me
the following email address (haven't verified lately):


-Tony, K1KP, fisher@hp-and2.an.hp.com


Hi Brent.

Don't know if this will help or not, but Glenn, W0GJ (ex WA0PUJ), told me 
about a place in WS that is able to supply fiberglass rods.  The nameand 
address of the company is Ultra inc, 3276 N. Weil St, Milwaukee, WS 
53212.  Phone number is 414-771-4747.  

Hope this helps.

Bob, W9UI.

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