I'm not sure but I think people would like to see a real world performance comparison between your design and what many may recall from an original ST2.There
There are no such test results for the ST2, so why is it SO VITAL that I produce test results against something the original manufacture did not produce publicly?
For the live of me I can’t see all this controversy over comparing the reception capabilities of two similar omni-directional antennas. I am in complete agreement with budrousa.
I could run the required test at my home with only one piece of specialized equipment: a 1 GHz Spectrum Analyzer or a Test Receiver. Here’s how.
Antenna 1 is an original, out-of-the box ST2, of which I understand numerous exist. Antenna B is “ a design copy of the ST2".
1. Mount both antennas identically on separate 10 foot pools on the peak of my roof, say at least 10 feet apart.
2. Run two identical in every way (length, connectors) cables down to my den.
3. Connect the two cables to the two inputs of a 1 GHz coaxial switch with the output connected to the measurement instrument set to read power in dBm.
4. With antenna A selected, tune to a frequency to be measured. Record the frequency and dBm.
5. Switch to antenna B. Record the power.
6. Compare the two readings to determine which antenna is “best” at that frequency
7. Repeat steps 4 through 6 for chosen frequencies.
8. Display results as a table or graph.
Frequencies should be chosen across the 25 MHz to 1GHz spectrum. I’d do so my using a scanner to select signals.
1. No prior knowledge is required of either antennas characteristics. This is a COMPARISON under IDENTICAL CONDITIONS.
2. The type of signal is immaterial
Well that's interesting. The title of this thread is-While it is a design copy of the ST2 it is NOT an ST2.
I don't get it? You offered to have it tested! Were your test results sour or something? You were full steam ahead, until it came time to release test results. Then the "Test results" page got locked down/removed, for whatever reason. So you forgot to add an counterpoise, ok, no big deal, add it in, and test her out some more, no need to get argumentative and defensive. **We WANT a great antenna!**There are no such test results for the ST2, so why is it SO VITAL that I produce test results against something the original manufacture did not produce publicly?
The bigger the distance the bigger the difference in reception. When you have a diversity system that uses several antennas connected to several receivers that receive the same frequency, it selects the antenna that have the best signal and you try to seperate the antennas as much as possible to create a bigger difference in reception of a signal.For omni-directional basically 0 gain antennas, 10 feet should be no problem. What the heck, make it 30 feet apart! In anticipation of another potential objection, pick signals as close to broadside to a line between the two masts as possible.
I'd suspect he either had a poor test result or the actual testing cost way more than he was expecting depending on how professional the testing lab is. He's possibly making design changes now based on test results.All this is true, UBBE, but looking back in the pages here, he supposedly had sent an original ST-2, AND the "Searcher I" off for "Professional testing".
This is a very positive act for him to do. But now, we are wanting to see what the results were, it is somehow not important anymore.
To do as prcguy suggests, as I understand it, would require running all the frequencies on antenna A, taking it down and mounting antenna B. By the time you have run all the necessary frequencies on A and changed to B, mucho time has passed (hours, next day?). Who knows what the field strength at a given test frequency from its source will be then compared to what it was earlier, due to atmospherics, etc. Using over-the-air signals REQUIRES taking readings with both antennas at the flip of a switch to insure the same the same field strength is sampled.
For omni-directional basically 0 gain antennas, 10 feet should be no problem. What the heck, make it 30 feet apart! In anticipation of another potential objection, pick signals as close to broadside to a line between the two masts as possible.
What I suggested was I simple test that would give satisfactory results. To do as proguy suggests would require an anechoic chamber good down to 40 MHz where you have the ability to recreate a given field strength at any time. Oh, the $$$$$$!