National Horizon 20 HiFi Amplifier Manual Sorry, this product cannot be purchased. $8.99 Category: National Description Description For sale is reprint of National Horizon 20 HiFi Amplifier Manual. Manual is 8 pages Includes Part List and Circuit Diagram. Manual also includes 2 Service Bulletins Hi-Fi-8 and Hi-Fi-9 Related products NATIONAL Model HRO-5A1 Radio Receiver manual $10.49 Read more National NCL-2000 NCL 2000 Linear Amplifier Manual $10.49 Read more National NC-183 NC183 Radio Receiver Manual $11.99 Read more National NC-108 NC108 Receiver Manual $7.49 Read more