{"product_id":"ohm-s-law-power-formulas-slate-coaster-copy","title":"Decibels Power Ratio Slate Coaster","description":"\u003cp\u003eA smart and technical slate coaster for radio enthusiasts, laser engraved with the essential \u003cstrong\u003edecibel power ratio formula\u003c\/strong\u003e: \u003cstrong\u003edB = 10 log₁₀(P₂ ÷ P₁)\u003c\/strong\u003e. This formula is used to compare two power levels, where \u003cstrong\u003eP₁\u003c\/strong\u003e is the input power and \u003cstrong\u003eP₂\u003c\/strong\u003e is the output power. In amateur radio, decibels are used everywhere — from antenna gain and feeder loss to amplifier performance, filters, attenuators, and signal strength comparisons.\u003c\/p\u003e\n\u003cp\u003eFor ham radio operators and short wave listeners, understanding dB makes it much easier to judge what a change in equipment or antenna system really means. A small number of decibels can represent a meaningful change in power or received signal, while larger values quickly show major gain or loss. The engraved gain diagram and S-meter style graphic make this coaster both a useful reference and a great shack accessory. Laser engraved into natural slate, it has a rugged radio-room look that is ideal for an operating desk, workshop, or gift for anyone interested in RF, antennas, and signal performance.\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003eThese coasters are supplied with four soft adhesive feet so they do not mark surfaces. Putting four or six together would make an ideal gift.\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003eProduct Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePrecision laser engraved design\u003c\/li\u003e\n\u003cli\u003eCrafted from natural grey slate\u003c\/li\u003e\n\u003cli\u003e10cm diameter and 4mm thick slate coaster with a rustic bevelled edge\u003c\/li\u003e\n\u003cli\u003eSoft sponge feet included\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003ePlease note slate coasters are not dishwasher safe.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan style=\"text-decoration: underline;\"\u003eDesign Copyright Notice\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAll designs are the intellectual property of Primary 9 Designs and are protected by copyright.\u003c\/p\u003e\n\u003cp\u003eThese products are supplied for\u003cstrong\u003e \u003c\/strong\u003epersonal use only. The designs may not be reproduced, copied, distributed, modified, or used to create products for resale without prior written permission from Primary 9 Designs.\u003c\/p\u003e\n\u003cp\u003ePurchase of this item does not transfer copyright or grant a commercial licence to reproduce or sell the design in any form.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan style=\"text-decoration: underline;\"\u003eLarge Orders\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eLooking to order larger quantities? We are happy to provide bespoke lead time and shipping quotations for bulk orders, schools, clubs, care homes, events and organisations. Please contact us and we'll help find the most cost-effective shipping option for your order.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Primary 9 Designs","offers":[{"title":"Default Title","offer_id":58373166235993,"sku":"4SLT10CR-DBL","price":4.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1007\/9230\/3961\/files\/IMG_3286.jpg?v=1782138908","url":"https:\/\/primary9designs.com\/products\/ohm-s-law-power-formulas-slate-coaster-copy","provider":"Primary 9 Designs","version":"1.0","type":"link"}