It is relatively easy to do that comparison for yourself if you already have the second edition of the K7LXC/N0AX "Tribander Test Report." The K7LXC/N0AX report includes all of the raw data for both
This is a complete red herring ... within limits ELEMENT SPACING DOES NOT ENTER INTO EITHER GAIN OR F/B IF THE ELEMENTS ARE PROPERLY TUNED FOR THEIR POSITION IN THE ARRAY. It is an easy job to run a
Gain does not double with as boom length doubles ... never did, never will. If it did a Hy-gain 105BA would have 3 dB more gain that a 204BA. The actual increase from doubling the boom length is in
Mike, I would bet that the switching supply is shutting down because of a highly capacitive load and very high current peaks. The stepper motors operate on square wave drive. The controller is feedin
Not so much capacitance although it will be significant - I would not rule out transmission line effects. Each closely coupled pair will have a Z of about 100 Ohms and a velocity factor down around
Not true ... the vertical beam will always miss the "ground gain" and will lag the horizontal antenna by three to six dB. Over salt water the vertical beam will have more gain at lower take off angl
Even at 20 meters, 150 feet or more is a bit out of reach for most people. However, your statement is correct at heights that begin to approach free space conditions (5 to 10 wavelength). With those
Bob, That's complete nonsense unless you are comparing something like a 60 foot boom monobander. YO shows a 1 dB advantage for the 4 element over the 205CA because the 205CA gives up gain to maintain
Bob, Obviously you have not done the work. I have just rerun the models of the BV205, Hy-Gain 205 and the 4 element SteppIR in YO and the results are unequivocal. Both the Hy-Gain and BV designs give
Yes, you will see a significant difference in F/R ... the five element, 32 foot boom will provide 20 to 25 dB across 28.00 to 28.80. However the gain difference will be less than .3 dB. 73, ... Joe,
John, Frank and Gerald are giving you the best advice. I would not even consider using the 1200 on a temporary AB-577 with something as large as the C-31XR on it. The 2100 is a realistic minimum for
Bill, Here is a copy from an old e-mail by K2AV concerning hybrid Philystran/steel guy configurations. I hope it helps. An effective compromise for you would be 45' of Philystran for the top guy, 33'
One doesn't have to buy a book to be aware of that. The information is widely discussed by those who know the antenna. 73, ... Joe, W4TV _______________________________________________ _____________
Results will not be similar to the "Moxon." The Moxon uses the tails to force current (increase coupling) between the two elements. It is the extra coupling that increases current in particularly th
The A103 manual is available on the Cushcraft web site - look in "Tech Library -> Installation Manuals" The A103 is not the same as the A743. Trap TK in the A744/743 kit is resonant on 20 meters. The
Tashjian as adopted the new standard for wind load that specifies peak wind speed (gusts). US Tower is still using the older "60 second average" wind ratings. If I recall correctly, the 85 MPH gust r
Florida EMA's trailer towers only come out after the fact - they don't need to deal with real weather. There is an Aluma Tower out back of AES in Orlando. I've seen it many times and it definitely f
Absolutely correct ... $900K is generous. On a good day, $900K would be 8 to 10 times gross margin on $600K in annual sales. Debt service on $2.7 million is more than expected gross margin on sales!
I don't think any of us are being optimistic ... we're all saying the $2.7M asking price is far from reality. Since there is no real estate or large fixed capital base, depending on assumptions for
Jim, The BN-86 is a standard voltage balun; trifilar winding on a ferrite rod. Common failure mode is due to excessive voltage and arc over at high SWR. If I recall correctly the worst case is using