https://stream.echo6.co/videos/watch/469c0881-6a1e-48c0-95be-5709155030c6 The inbuilt free-running VFO in the Bitx40 isn't the most stable. This video shows how with few parts you can add a ceramic resonator VXO and obtain better stability. Tuning is also easier as the range can be split into several segments. Bitx40 original circuit at http://www.hfsigs.com/bitx40v3_circuit.html My review of the Bitx40 https://www.youtube.com/watch?v=1EvA6Q6C2rE Note: Bitx40s now come with a DDS frequency synthesiser. However this is on a separate board and you can still do this modification and use the synthesiser for another project. 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) Sun, 03 May 2026 23:26:08 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/469c0881-6a1e-48c0-95be-5709155030c6 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.