Prohibited bands
The 600 MHz Service Band: Illegal to Operate
Quick answer
Operating a wireless microphone in 617 to 652 MHz or 663 to 698 MHz is illegal in the United States. That spectrum was auctioned to mobile carriers in the 600 MHz incentive auction. Equipment tuned only to those ranges cannot be made legal and is worthless secondhand.
This is the page to read before you accept a donated rack of wireless receivers or bid on a bargain on an auction site. The 600 MHz incentive auction moved mobile carriers into spectrum that wireless microphones used for decades, and the transition finished in 2020. The equipment still powers up. The audio still sounds fine on the bench. None of that matters, because the transmitter is now sitting in a licensed mobile network and using it is an offence. Check any purchase against the legal band list and read buying used church sound equipment before money changes hands.
On this page
What the 600 MHz band plan looks like now
The auctioned spectrum is split into a downlink block and an uplink block with a gap between them, in the usual way a mobile network is arranged. The two blocks are what is closed to microphones, and they are not adjacent, which is why the prohibited range is quoted as two numbers rather than one.
Two blocks totalling 70 MHz, at 617 to 652 MHz and 663 to 698 MHz, are licensed mobile spectrum and illegal for microphones.
| Range | What it is now | Status for a church |
|---|---|---|
| 614 to 616 MHz | Guard band segment left open for microphones | Legal at 20 mW |
| 617 to 652 MHz | 600 MHz service band downlink, mobile carriers | Illegal to operate |
| 652 to 663 MHz | Duplex gap between the mobile blocks | Tightly restricted. Not a band to buy equipment for. |
| 663 to 698 MHz | 600 MHz service band uplink, mobile carriers | Illegal to operate |
| 698 to 806 MHz | 700 MHz band, public safety and mobile | Prohibited since 2010 |
The downlink block carries the tower transmitting to handsets, so it is loud and easy to detect. The uplink block carries handsets transmitting to the tower, which is where a microphone is most likely to be noticed as interference by the carrier.
Why the gear cannot be rescued
People reasonably ask whether a firmware update can move a receiver down into legal spectrum. Almost never. A wireless receiver front end is tuned by physical filters and oscillator components chosen for a specific range, typically a span of 24 to 56 MHz. Software can select a frequency inside that span. It cannot move the span. A system built for 653 to 698 MHz has no path to 500 MHz, whatever the menu appears to offer.
The manufacturer rebate and trade-in programmes that ran during the transition have closed. That means a donated rack of 600 MHz systems is a disposal job rather than a gift, and it is worth saying so kindly but clearly to the donor. What has value is the capsules and the accessories: a Beta 58A capsule, a lavalier element or a set of body pack belt clips will fit current systems from the same manufacturer even when the radio underneath is scrap.
How to check a system before you buy it
- Read the tuning range in megahertz, not the band letter. Band letters vary by manufacturer and by product generation, and the same letter has meant different ranges at different times. The printed megahertz range on the receiver rear panel is the fact. Anything whose range sits above 616 MHz is a problem.
- Power the receiver up and read the display. The frequency the previous owner left it on tells you where the system has been living. A display reading 662.500 MHz is a system that was in use illegally or has been in a cupboard since the transition.
- Check every transmitter, not just the receiver. Body packs and handhelds have their own tuning ranges and they must match. A legal receiver paired with a 600 MHz transmitter is a half a system, not a bargain.
- Ask what television channels are open at your address. A legal system is still useless if its 24 MHz tuning range happens to sit entirely on top of the only two occupied television channels in your market. Check before you buy, not after.
- Price the batteries and the spares into the deal. Discontinued platforms run out of body pack antennas, belt clips and charging docks. Run the numbers in the wireless battery calculator before deciding a used system is cheaper than a new one.
What to buy instead
Replacements start at about $330 per channel and the money buys spectrum you are allowed to use. If your channel count is above about six, spend the difference on digital, because digital is what makes the remaining spectrum hold a modern channel plan. See the full roundup for the reasoning by church size.
Shure BLX24/SM58 Wireless Microphone System - 14-Hour Battery Life, 300 ft Range, UHF
$389.00 Specs and sizingThe common landing place for a church replacing dead 600 MHz channels. Up to twelve compatible channels per band, a capsule everyone already knows, and a price a committee can approve four of.
Best for: Replacing two to four analog channels
Check price on Amazon
Shure SLXD24D/SM58 Dual Wireless Vocal System - H55 Band
$1,649.00 Specs and sizingTwo digital receivers in one rack unit that coordinate their own frequencies, which matters when you are rebuilding a plan from scratch in less spectrum than you used to have.
Best for: Rebuilding a six to twelve channel system
Check price on Amazon
Audio-Technica ATW-1102 Wireless Handheld Microphone System
$349.95 Specs and sizingA 2.4 GHz digital system, so no future television auction can strand it. The trade is about 100 feet of range and sharing the band with the building Wi-Fi.
Best for: A small church that never wants this conversation again
Check price on AmazonWhat about 652 to 663 MHz?
The eleven megahertz between the two mobile blocks is the duplex gap in the 600 MHz plan, and it is tightly restricted. It is not a free band, it is not an equivalent of the 614 to 616 MHz segment that churches can simply move into, and no mainstream church wireless product is sold to operate there. Treat it as unavailable. The practical planning rule for a church is simple and has the virtue of being easy to remember: everything at or above 617 MHz is off the table, and 616 MHz is the top of the world.
How we chose
We did not test these products in person and we never claim to. Picks are researched from manufacturer specification sheets and operator manuals, FCC rules where spectrum is involved, published standards, warranty terms, and the recurring themes in verified owner reviews. Every pick is matched to a real room size, seat count or input list rather than to a price bracket, and it is placed in the tier where its capability actually belongs. Where a product is wrong for most churches we say so on the page.
Sources
Frequently asked questions
Is it illegal to use a 600 MHz wireless microphone in a church?
Yes. Operating in 617 to 652 MHz or 663 to 698 MHz is prohibited in the United States because that spectrum was auctioned to mobile carriers and is now licensed to them. The prohibition applies at any power level, licensed or unlicensed, in every market. There is no exception for small congregations, rural locations or occasional use.
Can a firmware update move my system into legal spectrum?
Almost never. A receiver front end is tuned by physical filter and oscillator components chosen for a span of roughly 24 to 56 MHz. Software selects a frequency inside that span but cannot move the span itself. If the printed tuning range sits above 616 MHz, the hardware has nowhere legal to go and no update will change that.
Someone offered to donate 600 MHz wireless systems. Should we take them?
Not for the radios. Say so kindly and clearly, because the donor almost certainly does not know. The capsules and accessories may still be worth having, since a Beta 58A capsule or a lavalier element often fits current systems from the same manufacturer. The receivers and transmitters themselves are a disposal job rather than a gift.
What happens if we keep using ours anyway?
You are transmitting inside a licensed mobile carrier network. The carrier has both the motivation and the equipment to locate interference, and enforcement is a matter for the FCC rather than for the carrier. Beyond the legal exposure, the practical result is poor, because a live 600 MHz network in your market will sit on top of your microphone every Sunday.
How do I tell which band my system is in?
Read the megahertz tuning range printed on the receiver rear panel. Band letters are unreliable, because the same letter has meant different ranges across manufacturers and product generations. Then power the receiver up and read the frequency on the display. Anything at or above 617 MHz means the system is out, whatever the letter says.
What does a replacement cost per channel?
Between about $330 and $800 per channel for analog or entry digital systems, and $700 to $1,650 per channel for dense digital installations. Settle your channel count before you shortlist anything, because the count moves the total far more than the brand does. Count in-ear monitor transmitters in the same plan, since they use the same spectrum.
Researched, not professional advice. This page is compiled from published manufacturer specifications, operator manuals, FCC rules, published standards and owner-review consensus, not hands-on testing. Sound system design, rigging loudspeakers overhead, and any electrical work are jobs for a qualified professional: have flown loudspeakers and their attachment points signed off by a structural engineer or a certified rigger, and have all wiring done by a licensed electrician to your local code. Wireless microphone rules change, so confirm the current FCC position before buying. As an Amazon Associate we earn from qualifying purchases.