So I got around to digging up some better info on antennas, and referencing the following sources:
http://www.larsen-antennas.com/docfiles/ASB9/Mobile/MobileSeriesDesignations.pdf
Larsen - Antenna Basic Concepts
http://ndl.ee.ucr.edu/manual.pdf
http://forums.radioreference.com/antennas-coax-forum/175061-gain-antenna.html#post1275243
I believe I get an understanding regarding the 'wave' of an antenna and how it relates to the radiation pattern. But a lot of this seems more tuned with transmission....what about reception?
Considering the image on Page 6 of the ndl.ee.ucr.edu PDF, if that car is transmitting using a 5dbd antenna, thus the signal radiates more towards the horizon, it'll go farther, but not as high, meaning antennas mounted on buildings wouldn't receive signals from the car very well.
But how about the other way around? I.e., what's the usual wave used on the common (if there is such a thing) 800MHz trunked radio system antenna? Are they going to default to some standard, or do they go with different transmitting antenna types depending on the terrain? And thus, what's going to be a good antenna for a car to target that particular setup?
I'm in the DC area, so while driving, I go up and down lots of shallow hilly areas. Not mountainous, but not flat by any means either. I also drive a lot near the Potomac River, so keeping these factors in mind, I'm guessing something in the 3dbd range might be the best. I think this means the Larsen tri-band I currently have is probably all I'll need, but I wanted to get some fact-checking done on my logic to make sure I'm getting this information correctly.
That then leads to my next question. Per Larsen's antenna placement guide, I assume an NMO trunk-lip mount, back-center of the trunk lid against the rear windshield, is going to have some considerable loss? They don't have a mark there for that one, but taking the average of the other listed similar trunk mounts, I would guesstimate I'm still looking at ~2.8-3.4dB of loss? Per that, is a simple mag mount on the roof of the vehicle going to really out-perform an NMO mount? That range of loss implies that's over half of my signal reception. Is an 800MHz-targeted, high-gain antenna going to work better, or do I need a lower-gain? How does this translate into the proper wave-type to get as well?
And I thought understanding all the factors for aperture speed, f/stop, ISO settings, etc.., on DSLR cameras was complicated....
http://www.larsen-antennas.com/docfiles/ASB9/Mobile/MobileSeriesDesignations.pdf
Larsen - Antenna Basic Concepts
http://ndl.ee.ucr.edu/manual.pdf
http://forums.radioreference.com/antennas-coax-forum/175061-gain-antenna.html#post1275243
I believe I get an understanding regarding the 'wave' of an antenna and how it relates to the radiation pattern. But a lot of this seems more tuned with transmission....what about reception?
Considering the image on Page 6 of the ndl.ee.ucr.edu PDF, if that car is transmitting using a 5dbd antenna, thus the signal radiates more towards the horizon, it'll go farther, but not as high, meaning antennas mounted on buildings wouldn't receive signals from the car very well.
But how about the other way around? I.e., what's the usual wave used on the common (if there is such a thing) 800MHz trunked radio system antenna? Are they going to default to some standard, or do they go with different transmitting antenna types depending on the terrain? And thus, what's going to be a good antenna for a car to target that particular setup?
I'm in the DC area, so while driving, I go up and down lots of shallow hilly areas. Not mountainous, but not flat by any means either. I also drive a lot near the Potomac River, so keeping these factors in mind, I'm guessing something in the 3dbd range might be the best. I think this means the Larsen tri-band I currently have is probably all I'll need, but I wanted to get some fact-checking done on my logic to make sure I'm getting this information correctly.
That then leads to my next question. Per Larsen's antenna placement guide, I assume an NMO trunk-lip mount, back-center of the trunk lid against the rear windshield, is going to have some considerable loss? They don't have a mark there for that one, but taking the average of the other listed similar trunk mounts, I would guesstimate I'm still looking at ~2.8-3.4dB of loss? Per that, is a simple mag mount on the roof of the vehicle going to really out-perform an NMO mount? That range of loss implies that's over half of my signal reception. Is an 800MHz-targeted, high-gain antenna going to work better, or do I need a lower-gain? How does this translate into the proper wave-type to get as well?
And I thought understanding all the factors for aperture speed, f/stop, ISO settings, etc.., on DSLR cameras was complicated....