https://stream.echo6.co/videos/watch/e469bb57-631f-4320-9401-3dc08674e75b Using a dip oscillator to test the tuned circuit in an RFID card. Though the picture isn't very clear, you can see that the meter needle dips when the RFID's resonant frequency is tuned in on the dip oscillator. The RFIDs tested here use HF frequencies around 13 MHz. Note that some use lower and higher frequencies so may not be detectable in the range covered by most dip oscillators. PS: If you liked this video please consider supporting Amateur Radio VK3YE by: Subscribing on YouTube,, Checking my books page at https://books.vk3ye.com, Shopping on Amazon via: https://amzn.to/3iiDQXv, or, Shopping on eBay via: https://ebay.us/i9DuWP (then if you buy something I'll get a small commission at no cost to you) Sat, 09 May 2026 07:09:08 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://stream.echo6.co https://stream.echo6.co/client/assets/images/icons/icon-512x512.png https://stream.echo6.co/videos/watch/e469bb57-631f-4320-9401-3dc08674e75b All rights reserved, unless otherwise specified in the terms specified at https://stream.echo6.co/about and potential licenses granted by each content's rightholder.