{"type_number":"E810F","canonical_url":"https://tubeofile.com/tubes/E810F","manufacturer":"Philips","tube_type_key":"ss_pentode","tube_type_display_name":"Small Signal Pentode","base_name":"Noval","description":"Philips SQ (Special Quality) frame-grid pentode for use as a wideband amplifier in professional equipment. Exceptionally high transconductance (~50 mA/V) at 35 mA anode current, with low noise and excellent vibration resistance. Designed for measurement instruments, oscilloscopes, and professional audio. The frame-grid construction gives very tight parameter spread and long life (10,000 hours rated). Indirect heating, Noval (B9A) base.","is_directly_heated":false,"completeness":"high","notes":["SQ (Special Quality) designation indicates tighter parameter tolerances, longer rated life, and enhanced mechanical ruggedness compared to standard production valves.","Frame-grid construction: the control grid uses a precision-wound frame grid giving very high and consistent transconductance. Two g1 pins (4 and 5) are provided for low-inductance grid connection at VHF.","Suppressor grid (g3, pin 9) is internally connected to the cathode.","The datasheet specifies the anode supply voltage (Vba) rather than anode voltage (Va) directly; at the recommended operating point (Vba=135V, Rk=360Ω, Ia=35mA), the actual anode voltage is approximately 135 - (35 × 0.360) = 122V.","Heater current: Philips datasheet specifies 340 mA (Column I). Radiomuseum lists 0.34 A. End-of-life range (Column III) is 320-360 mA.","Triode-strapped estimates: mu ≈ 57 (from datasheet amplification factor g2/g1), gm ≈ 50 mA/V, ra ≈ 1140 Ω. No manufacturer triode-strapped data exists; these are derived from pentode parameters. Not in Schlangen's triode-strapped reference.","Philips datasheet 722 1337-1341, dated 8.8.1962, marked 'Tentative data'.","Rg1_max depends on bias method: 0.2 MΩ (fixed bias), 0.6 MΩ (Rk=47Ω), 3.5 MΩ (Rk=360Ω)."],"references":["https://frank.pocnet.net/sheets/030/e/E810F.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=E810F","radiomuseum":"https://www.radiomuseum.org/tubes/tube_e810f.html"},"raw_equivalents":["7788","CV5809"],"equivalents":[],"similar":[{"type_number":"E282F","reason":"Philips frame-grid pentode in same family — listed as equivalent by Brans but different pinout (Magnoval base), not pin-for-pin compatible","has_detail_page":false},{"type_number":"PF86","reason":"Philips pentode listed as equivalent by Brans — different heater voltage (P-series = 300 mA series heater), not pin-for-pin compatible","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Internal Connection (shield)","function_code":"ia","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Heater","function_code":"h","notes":null},{"pin_number":"4","function":"Control Grid (g1)","function_code":"g1","notes":null},{"pin_number":"5","function":"Control Grid (g1, second connection)","function_code":"g1","notes":null},{"pin_number":"6","function":"Screen Grid (g2)","function_code":"g2","notes":null},{"pin_number":"7","function":"Anode","function_code":"a","notes":null},{"pin_number":"8","function":"Cathode","function_code":"k","notes":null},{"pin_number":"9","function":"Suppressor Grid (g3, internally connected to cathode)","function_code":"g3","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"6.3","numeric_value":"6.3","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"0.34","numeric_value":"0.34","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"ss_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"250","numeric_value":"250","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"200","numeric_value":"200","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"5","numeric_value":"5","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"1","numeric_value":"1","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"50","numeric_value":"50","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"100","numeric_value":"100","unit":"V","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"3.5","numeric_value":"3.5","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"135","numeric_value":"135","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"165","numeric_value":"165","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"+12.5","numeric_value":"12.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"35","numeric_value":"35","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"5.0","numeric_value":"5","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"42000","numeric_value":"42000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"50","numeric_value":"50","unit":"mA/V","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"0.036","numeric_value":"0.036","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"0.060","numeric_value":"0.06","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"0.060","numeric_value":"0.06","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"14.5","numeric_value":"14.5","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"3.5","numeric_value":"3.5","unit":"pF","param_group":"capacitances"},{"key":"Rn","display_name":"Equivalent Noise Resistance","value":"110","numeric_value":"110","unit":"Ω","param_group":"noise_rf"}]},{"section_number":2,"section_label":"Triode Strapped (estimated)","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"200","numeric_value":"200","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"5","numeric_value":"5","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"50","numeric_value":"50","unit":"mA","param_group":"absolute_max"},{"key":"ra","display_name":"Anode Resistance","value":"1140","numeric_value":"1140","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"50","numeric_value":"50","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"57","numeric_value":"57","unit":"—","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T19:06:46.706Z"}