THE GREAT MULLARD MAGIC BLOG — TWIN TRIODE

Well, we're going to talk about the ECC81 twin triode today, originally designed for TV applications, yes, that's right - TV!!!!     All the other valves we have discussed in this World Series of blog entries had been designed for use at the then used British TV frequency bands of 45 - 70 MHz.  However, other countries used carrier frequencies at a much higher range within the 100 - 300MHz region at which a low noise level high grade triode would be needed so enter stage left.... the ECC81.  The ECC81 was great because it was inherently a 'low...