Continuing from a previous post linked below about adding a ground plane for HT antenna testing I ran the following 3 Diamond and 1 Pryme, VHF/UHF antennas.
Diamond RH3
Diamond RHF10
Diamond RH519
Pryme RD-98
Sweep from 143 MHz to 455 MHz and 1010 data points. The calibration was done at the antenna attachment point, which included a short cable from the VNAnano to the antenna attachment point.
Each antenna was a different length starting with the shortest in the list above.
Sweeping each antenna with and without the 12” disk in place shows that impact was at the VHF frequency as expected. Surprisingly “grabbing” the base of the antenna had a better sweep response without the disk than when in place.
Sweeps are compressed for visual data because of the sweep bandwidth, but markers are placed at the ‘sweet spot’ for each band of interest and numbers are in the box next to the Smith Chart. In general I would say the shorter antennas had the “better” sweep for their intended function.
All of this is my exercise in applied learning with what I have available limited by cost and configuration. All the supplied information may be seriously flawed by the setup and environmental configuration.
The attachments are png screen captures and for me I could zoom in to read details. I’m not sure if others interested in the details will be able to read or zoom. Looks like it might be better to copy files out to display than inline with the post.
It’s been an interesting ‘shelter-in-place’ morning.
forums.radioreference.com
Diamond RH3
Diamond RHF10
Diamond RH519
Pryme RD-98
Sweep from 143 MHz to 455 MHz and 1010 data points. The calibration was done at the antenna attachment point, which included a short cable from the VNAnano to the antenna attachment point.
Each antenna was a different length starting with the shortest in the list above.
Sweeping each antenna with and without the 12” disk in place shows that impact was at the VHF frequency as expected. Surprisingly “grabbing” the base of the antenna had a better sweep response without the disk than when in place.
Sweeps are compressed for visual data because of the sweep bandwidth, but markers are placed at the ‘sweet spot’ for each band of interest and numbers are in the box next to the Smith Chart. In general I would say the shorter antennas had the “better” sweep for their intended function.
All of this is my exercise in applied learning with what I have available limited by cost and configuration. All the supplied information may be seriously flawed by the setup and environmental configuration.
The attachments are png screen captures and for me I could zoom in to read details. I’m not sure if others interested in the details will be able to read or zoom. Looks like it might be better to copy files out to display than inline with the post.
It’s been an interesting ‘shelter-in-place’ morning.
To Disk or Not to Disk...
This is a journey that started a number of years back when I moved from one city to the next one over. Keeping what I was normal scanning and adding to my Favorites List the results were not the best. In hopes of improving the reception I built what you see “In the Beginning”. Bulkhead female...
