Gregg: The 87,000 is the stress in pounds per square inch required for the metal to yield. You need to know the cross sectional configuration of your mast, (OD and wall thickness) and calculate what
I believe the Prosistel design was changed in the last year or so. The version I have (about 8 months old) has the motor sticking straight out from the rotor housing, at right angle to the axis of ro
The Third Order Intercept concept is a theoretical point that is projected as the intercept of the third order products from two equal level tones (slope = 3:1) and the fundamental of the tones (slop
Jeff: It is possible to design a foundation that can just sit on the ground and resist the over turning moment (OTM) of the tower/antennas. The soil underneath must support the compression forces tha
With elevated radials operating at 180 kHz, the radials were probably a form of Litz wire, a multi-strand wire that has each strand insulated from the other. Such wire is necessary to get low loss at
Jake: You might consider the AIM-4170 Antenna Analyzer from Array Solutions. It is (to my knowledge) the only reasonably priced antenna analyzer that provides correctly signed reactance (X) in an imp
Bill: I too have been following your exploits, both here and on the SteppIR reflector. I still believe the issue is related to the power supply. As Mike M. pointed out, the motor drive is via current
Dick makes some good points. Cable capacitance and shunt capacitance of supressors will both increase the transient (and over-all average) current drawn from the power supply. A previous similar prob
Between 204BA & SteppIR 4El, it will be a valid horse race on 20 (although the SteppIR may beat you when a P5 shows up 180 deg away from where you both are looking). SteppIR will very likely do much
Jerry, K4SAV: Your transient measurement is a very good clue. It appears to me the 12V drop represents the power supply voltge regulator response time to the current surge due to the antenna tuning.
Greg: Take a look at Heights Towers, they have a fold-over mechanism that works very well. I have an 80 ft tower that folds from the base using a motor driven jackscrew. MY tower is rated at 35 sq ft
I am showing my age, Steve. The RS stds became TIA standards quite some time back, but old habits are hard to break. I was using it in reference to wind loadings, not structural design details. The U
Here is where I got my equipment ground bar. It was reasonably priced, about $50 + shipping as I recall. It comes tapped for 12-24 about every inch, and available in many lengths, in 1 ft increments.
Kim: I question the accuracy of the impedance measurement. If it was an accurate value at the base of the tower, you should have found a good match at around 200pfd of series capacitance. Z = R+jX =
It appears you had a lemon. Welding of Aluminum is not something for the casual do-it-yourselfer. The process requires special equipment (Heliarc) to fuse the aluminum in a non-oxidizing environment
I can confirm Richard's experience. I have had a 78 ft version (counting the 5 ft fold-over stand) for over 5 years. It works very well. You can fold it over or raise it in about 15 minutes. I have a