trombo
02-07-2009, 02:34 AM
Updated GH Collinear Rod Reflector Design by John E. Davis
John's work has progressed the GH antenna design in two important areas:
1. John's optimizations provide a better GH design over the entire new UHF band of 470-700Mhz. The gain is amazingly flat over the UHF band-width !!
2. His narrow-band design shows the max GH gain at reduced bandwidth, which is applicable to those seeking reception of specific distant channels. I'm sure this will perk interest in double bay Narrow-band designs for those "hard-to-receive" channels. It has certainly revived my quest for wnpi on Ch 23, and I'll be looking into a double-bay narrow band design....mlord...perhaps there is still hope...
His web page provides Netgain, SWR and F/B results for four collinear rod reflector designs, as well as the design parameters and dwgs, that contain all the info needed to build any of these designs.
For those that want a GH design that covers the entire post 09 UHF band (470 to 700Mhz), these designs are the best, and John has provided four options, from the simplest GH4 to the higher gain GH10 collinear design.
To have a detailed look, here is John's Web Site..
http://www.jedsoft.org/fun/antennas/dtv/gh.html
John's work has progressed the GH antenna design in two important areas:
1. John's optimizations provide a better GH design over the entire new UHF band of 470-700Mhz. The gain is amazingly flat over the UHF band-width !!
2. His narrow-band design shows the max GH gain at reduced bandwidth, which is applicable to those seeking reception of specific distant channels. I'm sure this will perk interest in double bay Narrow-band designs for those "hard-to-receive" channels. It has certainly revived my quest for wnpi on Ch 23, and I'll be looking into a double-bay narrow band design....mlord...perhaps there is still hope...
His web page provides Netgain, SWR and F/B results for four collinear rod reflector designs, as well as the design parameters and dwgs, that contain all the info needed to build any of these designs.
For those that want a GH design that covers the entire post 09 UHF band (470 to 700Mhz), these designs are the best, and John has provided four options, from the simplest GH4 to the higher gain GH10 collinear design.
To have a detailed look, here is John's Web Site..
http://www.jedsoft.org/fun/antennas/dtv/gh.html