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 HRO-7 HRO7 Radio Receiver Manual Shortwave ham $10.49 Read more National NC-57B NC57B Radio Receiver Manual $10.49 Read more National Company the 600-Watt Transmitter HAM Manual $9.99 Read more National NC-300 NC300 Radio Receiver Manual $10.49 Read more