4-400A, Tube 4-400A; Röhre 4-400A ID21383, Transmitting Tetr | Radiomuseum.org
Eimac 4-400A Tetrode Tube Spec Sheet
A 500 Watt Output 4-400A Linear Amplifier For 600 Meters
RCA 4-400A Vacuum Tube High Power Tetrode Transmitting Tube - Etsy Denmark
4-400A 4-400 Eimac Electron Tube Valve | eBay
A 500 Watt Output 4-400A Linear Amplifier For 600 Meters
Varian Eimac 4-400A Made in USA 8438 Tube Ham Radio Transceiver Amp Amplifier | eBay
4-400A-EI Transmitting Tube, Glass Envelope, MFR: Eimac (N.O.S.), 90 day or 2200 hrs, prorated
4-400A / 8438 | TubeDepot.com
Eimac 4 -400a | Reverb Canada
Vacuum Tubes: Transmitting & Receiving: "4"
Eimac 4-400A Jan-cim-4-400A Made in USA 6039 Electron Tube Untested w/ Socket | eBay
4-400A, Tube 4-400A; Röhre 4-400A ID21383, Transmitting Tetr | Radiomuseum.org
4-400A - Richardson Electronics - Electron Tube
Amplifier Construction
Grounded-grid tetrode kilowatt
Eimac 4-400A Grounded Grid RF Amplifier Collins 30K-1 Cabinet From 1947 - YouTube
4-400A Amperex Transmitting Tube NEW - Max-Gain Systems
4-1000A - Wikipedia
4-400A-EI Transmitting Tube, Glass Envelope, MFR: Eimac (N.O.S.), 90 day or 2200 hrs, prorated
4-400C vacuum electron tube, 4-400G, 4-400A, 5F23 equivalents, glass tube 4 -400
A 500 Watt Output 4-400A Linear Amplifier For 600 Meters
A 4-400A amplifier for c.w., s.s.b. or a.m.
Eimac 4-400A power tetrode vacuum tube — Calisphere
