Safe Distances for QRO HF Antennas
This page has been replaced by a newer and more complete RF.Guru guide.
This Article Has Been Updated
Important update: The information that was previously published on this page is now outdated. RF-exposure guidance for HF antennas is a topic where simplified tables, antenna height, duty cycle, near-field behavior, grounding, feedline current, and local regulations all matter. Because of that, we have replaced the older article with a more complete and technically refined version.
The new article expands the topic from QRP through 100 W stations and QRO operation, explains the limits of simplified safe-distance tables, and gives a more careful interpretation of FCC-style screening values, ICNIRP-based considerations, low-HF near-field behavior, and practical antenna installation risks.
For the most accurate and up-to-date RF.Guru guidance on this subject, please continue here:
RF Safe Distance Guide for Common HF Antennas
Why This Page Was Replaced
RF exposure around HF antennas is easy to oversimplify. A table may be useful as a first-pass screening tool, but it is not a full near-field model of every real antenna installation. Low antennas, house-mounted loops, end-fed wires, loaded antennas, feedlines with common-mode current, balconies, roofs, and nearby conductive structures can all change the practical exposure situation.
The updated guide therefore gives a better engineering framework instead of presenting separation distances as universal “safe distances.” It explains what the numbers mean, when they are useful, and when a more detailed evaluation is needed.
What the New Guide Covers
- QRP, 100 W, 500 W, 1 kW, 1.5 kW, 2.5 kW, and 5 kW screening examples
- General-public versus controlled exposure
- Duty cycle, transmit-time fraction, and average power
- Why upper HF can require larger separation distances
- Why low-HF near-field behavior needs extra care
- Practical notes for verticals, dipoles, loops, loaded antennas, and end-fed antennas
- The difference between RF-exposure distance and safe-to-touch distance
- Why grounding, bonding, and common-mode chokes help, but do not replace an exposure evaluation
Mini-FAQ
Is the old article wrong?
The older article was too simplified for the way this subject should be explained. The new version gives a more complete and technically careful treatment.
Should I still use the old table?
No. Use the updated guide instead. It gives better context, clearer assumptions, and broader coverage from QRP to QRO.
Does the new guide replace a legal compliance assessment?
No. It is engineering guidance. Your local rules, antenna geometry, power level, operating mode, and access conditions still determine the correct assessment method.
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