Sunday, September 27, 2015

New Beam Antenna Installation at N6QW ~ FINAL INSTALLMENT!

The Final Piece - Post Mortem!

My dream beam is up and operating and I surely can tell the difference! The front to side and front to back attenuation is very evident and I have netted quite a few contacts running 100 watts with my ZIA transceiver on 20 Meters. The signal reports are very good even with crappy band conditions so all and all I am a happy camper.
The cost of this installation --well I stopped counting after $2300. The mast with accessories and delivery was close to $800. The beam with shipping was $500 and the rotator with free shipping was $300. The coax and rotator cables were $250. The US Tower base plate with shipping was about $100. The Home Depot hardware was $100 and the contractor was $200. That is a lot to spend for a beam that ostensibly will be used during the down part of the solar cycle. But given where I am age wise this is probably not  all a bad decision. For about another $1000 I probably could have had a 40 foot tower and a three element beam. But never look back.
Some lessons learned:
  1. The information from the manufacturers is not very good or not even present. SpiderBeam does not have an instruction manual! Given that I am bottom rotating the mast I was told very few are sold for this purpose especially in a fixed location installation thus no manual. I did receive good factory support when I asked about drilling the mast for the bottom mast to rotator adapter and how to route the coax from the beam -- however, this should be standard information and not require emails to the factory.
  2. Yaesu (I am using Model G450) has a standard calibration process for zeroing the rotator so when you are north the beam is actually pointing north. However there are several steps which are not clear and I had to call the factory -- and sort of got "Oh yeah we get calls about that all of the time." So I am not the only one.
  3. I purchased a Mosley custom beam the Model MP-32-N which has the high power driven element from a TA-32 and the lower power reflector from the TA-32- Jr. The instructions are for the most part are OK except for three items. 1) There is an anti-corrosion compound that must be applied to all metal to metal mechanically connected parts. The only place this is mentioned is on the pictorial assembly drawing. The actual assembly instructions about fit Tab A into Slot B are silent on this matter. So if I had not spotted the note on the pictorial drawing my install would have lacked the compound. 2) Routing of the coax from the beam. I called the factory and inquired about a choke balun. I was told that is a really good idea and was given the dimensions. So why is not this just standard practice to say build a choke balun? Actually using the balun facilitates routing of the coax. 3) Where to place the boom to mast bracket? The parts are color coded and one of the final instructions says align the boom to mast bracket with the black index marks on the boom. Mine didn't have such marks and so I called the factory and was told it should be in the middle at the balance point (36 inches). The word balance point rang my bell! The driven element is heavier given the larger traps and size of tubing. So the balance point has to be closer to the driven element. I used a crude mechanism to create a balance structure ( a couple of stacked  1 X1 "'s ) and moved the boom along the balance beam until I found the balance point --which is 28" from the driven element. So why isn't that information in the assembly instructions?
This will be the last post on my antenna and future posts will concentrate on the Simple-ceiver.
Thanks for riding along!
Pete N6QW