Hi All, I've been in several discussions with some local contesters/DXers over the High Frequency Terrain Assessment (HFTA) software included with the ARRL antenna book. I have used the program mysel
They way I understand the data is this: Data was collected that shows the angles of the incoming signals for the desired area over the opening. Yes you can go too high for the highbands if you want t
I'm not an engineer, or antenna designer...just a contester and kind of an "appliance op". Back in Florida, I used antenna stacking programs and did not concern myself with HFTA since most of Florida
WU2X wrote: He had purposefully chosen 78 feet over even higher heights because HFTA showed that higher heights actually raised his angle of radiation towards Europe. ..... Take off angle from irregu
Scott - Yes, I think you can go too high. Why do I say this? First, I believe in the basic method used in the HFTA program, having produced a similar computer program for my personal use in about 198
I developed an analysis techniques which correlates an antenna's vertical response with the Angle-of-Arrival statistics published by ARRL. Basically it gives you a "figure of merit" for an antenna at
Count me among those who find HFTA to be quite useful in predicting the relative advantage/disadvantage of various mounting heights for horizontal antennas based on terrain data AND propagation data.
Steve, I published substantially the same method in the US National Contest Journal in January 2001, with a correction in the September/October issue to incorporate the point about applying the weigh
Pete, How interesting - I was certainly unaware of your prior work. As you can see from my web site I came at this in the context of Hexbeam - I was continually being asked "what's the best height".
Hi Pete, I agree that arrival angle statistics generated with models using isotropic antennas produce an unrealistic bias towards very low angles (much less than 5 degrees). In the real world, only o
At the 2004 Dayton antenna forum a presentation was given by N6BV. See http://www.kkn.net/dayton2004/N6BV-Dayton-2004.pdf 73, Bert K2BA --Original Message-- From: Steve Hunt [mailto:steve@karinya.net
Without passing judgment on the usefulness of HFTA, let me tell you my story... I live on a hilltop, with a net dropoff of 400 feet in the first quarter mile, in every direction except west. The drop
Hi All, Yeah so largely anecdotal / empirical evidence seems to say HFTA generally seems to coincide with the results observed in the real world. I was more curious about the technical reasons why HF
As an EE, I learned long ago that I will learn far more from finding many points on any curve than only one or two. It's far easier to understand the elephant with observations through many widely sp
Jim's making sense too - I always use 1-meter data from the USGS seamless database, so it makes no sense to enter fractional meters or feet in the terrain profile. 73, Pete __________________________