Check the listing for details. SCHEMATIC ONLY 41 PENTODE BALLOON TUBE SHORTWAVE/AM BCDST. REGEN RECEIVER. Condition: New. Listed at 16.95 USD. This listing is for a full schematic only of the 41 Glow-Bulb Regenerative Receiver that you see in the photos. All parts values are specified, but no assembly or construction manual is included in this listing. However, general operating instructions for a regenerative receiver are included, along with several pages of examples for coil data, for long wave, am and shortwave bands. You should have some previous technical experience before attempting to build this radio. You will need high impedance (2 to 4k ohms) headphones for this radio (not included). The piezo element headsets, like the ones you see in the photos, will also work well. I have this same radio on another listing, which comes with a piezo headset. The circuit uses either a rare 1930's 41 pentode tube, plus a one transistor, built-in headphone amplifier. These tubes are pricey and getting hard to come by, but the nostalgic appearance is well worth it. The radio works great, with good headphone volume. The spectrum coverage is continuous, from about 540 khz to 15.8 mhz--using several plug-in coils. Power requirements are 6 to 7 volts dc for the filament and 20 to 30 volts dc for the regen amp circuit. Please do not use ac voltage for the filament. This is a big no for regen radios, as it will inject ac hum into the audio. You do not need a separate power source for the transistor amp. You will need a wire antenna at least 25 ft. long and a good earth ground. You'll pick up more stations with a longer antenna, 50 to 100' in length. I'm able to copy tons of stations in the early evening and early morning hours, including stations on the amateur radio bands. The fine tuning control will allow you to clarify ssb and cw signals. Controls are main and fine tuning, antenna coupling and regen setting. These power pentode tubes make great regen receivers and the added one stage transistor amp gives you plenty of headphone volume. I CAN SEND THIS SCHEMATIC TO YOU AS A PDF FILE, OR IT CAN BE MAILED FIRST CLASS USPS, YOUR CHOICE. MAILING TO THE UNITED STATES ONLY.