https://stream.echo6.co/videos/watch/d7aedc3c-87c9-4d08-94c1-73d30b439cf5 A mailbag replacement custom LED display for the Agilent 53131A VFD display frequency counter. www.hubequip.net Oven oscillator upgrade: https://www.youtube.com/watch?v=KmZwAjmzHx8 Playlist of related videos! https://www.youtube.com/playlist?list=PLvOlSehNtuHupdUJVYdRnihTTQ_Tw7MHt Forum thread on the display: https://www.eevblog.com/forum/testgear/hp-agilent-53131a-53132a-vfd-to-led-conversion/ Forum: https://www.eevblog.com/forum/blog/eevblog-1669-agilent-u53131a-vfd-to-led-display-upgrade-mailbag/ How VFD Displays work: https://www.youtube.com/watch?v=gZIRPJt69sM Web Site: http://www.eevblog.com Hardware Store: https://eevblog.store/ Merch Store: https://eevblog.dashery.com/ If you find my videos useful you may consider supporting the EEVblog on Patreon: http://www.patreon.com/eevblog Or with crypto: BTC: 33BsprBQNBtHuVzVwDmqWkpDjYnCouwASM ETH: 0x68114e40ff4dcdd384750500501e20acf3875f8c BCH: 35n9KBPw9T7M3NGzpS3t4nUYEf9HbRmkm4 USDC: 0x68114e40ff4dcdd384750500501e20acf3875f8c LTC: MJfK57ujxy55su4XicVGQc9wcEJf6mAoXF Other channels: EEVblog2: http://www.youtube.com/EEVblog2 EEVdiscover: https://www.youtube.com/eevdiscover #ElectronicsCreators #Mailbag Wed, 15 Apr 2026 11:28:58 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/d7aedc3c-87c9-4d08-94c1-73d30b439cf5 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.