Actually, the current UST wet stamp calculations for my about to be installed HDX589 has a base 5'6" sq by 9' deep. (10yds of concrete) MA-550 at 3.5 x 3.5 x 5' is 2.3 yds so that is a VERY big diffe
All the numbers are in the 589 "Structural Analysis Report" 12/15/2010. Leave out whatever you like AYOR. That's what makes lawyers rich. Do not presume there are big safety margins in this design fo
One more implementation alternative to add to the stack: Place the rivets at 90 degrees to each other, two sets of two offset along the element at 1/2 the rivet spacing. The theory is the same as usi
Just buy enough (I don't know how much is enough, but seem to qualify) and McMaster will mail you one of their awesome yellow catalogs. However, the web site is very good so if you know what you want
"Adhesive lined" heat shrink is available from lots of sources - Mouser, Digi-Key, even West Marine. http://www.mouser.com/Search/Refine.aspx?Keyword=adhesive+lined+heat http://onlinecatalog.digikey.
So, my lawyer talked to County Counsel and resulting fee was zero for the "planning review". All that I paid was the building permit fee. Lesson - read the codes relative to what you want to do. Unde
I have a "new" but 20 year old TH7DX acquired from a ham that never put it up. Since the BN-86 factory balun is universally declared "unfit", exactly what is it inside? I'm prone to replace it with a
I've decide the price-performance-safety-no sweat of rental boom lifts (e.g. Genie lift, JLG Lift) are a winner. Around here 40 footers go for about $220 a day plus $50 for the round trip delivery/pi
My impression is that commercial tower climbers aren't cheap, so what are the usual climber and helper rates from a tower maintenance company? What do they require for pre-climb tower inspection, cer
Tin-lead solder was used for more than 40 years for potable water copper plumbing inside structures. It has now been replaced (by code) with lead free solder to remove lead as a potential trace water
Top loading the 43' will increase its radiation resistance and thereby the efficiency. DX Eng has some top hats in their catalog. Some of the Antenna Compendiums have articles. It's an interesting qu
I recently rewired a TV van 45' air operated mast. These use a Nycoil coiled nylon hose to hold the many control and coax cables to the mast head (15 cables were in the 1.5" ID Nycoil replaced). Nyco
Nylon 3 strand will elongate about 50% before breakage. That property is great for anchoring or towing but awful for guying or lifting. The energy that can be stored in a piece of nylon rope is impre
A few comments and a question. Having about 2 miles of wire fencing at my ranch, I've learned that most of the farm store "hi-tensile" wire is import junk. It stretches and stretches. So my ranch han
Use a large enough nylon rope (5/8 - 3/4") and you might be ok. However, think about what the rope tension becomes as a section of tower gets out of vertical. It is impossible to pull a horizontal po
Another choice for conduit is SDR35 (or SDR26 with a heavier wall) PVC pipe which in 4" and up diameters can be had with rubber gaskets. No glue involved. Check with your local pipe suppliers as it i
Here are a few numbers from a 20 minute modeling exercise with EZNEC 43' vertical modeled as a 1.75' diameter conductor and adding 4 top load wires at 47 deg angle to ground each 13.5' long and a per
I just rebuilt one of these. Certainly the bearing races and balls need cleaned and regreased. A synthetic grease that is TFE loaded is what I used - "Superlube" by Synco. The rotator I rebuilt was s
There are two 1000' spools of Commscope 1/2" hardline and DIN connectors on ebay now at attractive opening bids, search for SFX500* The loss specs are in between LMR400 and LMR600. Grant KZ1W _______
For those not familiar with ExpressPCB, here is the deal - three double sided plated thru hole boards 2.5" x 3.8" delivered in about 3-4 days for $51. free layout and schematic entry tools, decent li