If you want a like comparison of similar Vertical Antennas, there's a booklet published in 2000 that conducted these tests.HF Vertical Performance; Test Methods & Results - Price $20.00
NØAX and K7LXC are at it again - this time it's HF multiband verticals. Now you can read an unbiased report on how they really performed. Antennas tested include the Cushcraft R8, Butternut HF6V, MFJ 1798, Force 12 ZR-3 and V-3, Diamond CP-6, Hustler 6BTV and Gap Titan. It's 64 pages of protocol, data sets and summaries. Presented at the 2000 Dayton Hamvention.
Read a review by recognized antenna expert and published author LB Cebik, W4RNL. See W4RNL's Book Review at
I have this book and the hams attempted to conduct these tests as per each manufactures specs. They did NOT make ground mounted (radial / no radial) verticals vs roof mounted with Elevated radial comparisons. After going through the results, while it gave me some food for thought, yet I'm still researching, reading, and learning.
Also, there's always Antennas by N6LF, Rudy Severns
recent articles / research on verticals.
Check out N6LF articles on …
= QEX article on elevated radial ground systems
= Series of QEX articles on ground system experiments
Answers for Vertical antennas are hardly ever simple black and white, but many shades of gray depending on your QTH, antenna placement location (ground vs Roof), and soil conditions to name a few factors.
Hope this gives you some answers, and / or a direction for a starting point. Good Luck.