31-07-2015, 02:43 PM
I’ve had a look at 4 different neutrodyne capacitors and included a pic – they read (from left to right in the pic)
.75pF – 29pF
.7pF – 15pF
.9pF – 25pF
.3pF – 6pF
As Mike said earlier the neutrodyne was a type of radio using a technique patented by a chap called Hazeltine. He came up with the idea of neutralizing a triodes grid plate capacity while designing a receiver for the navy in 1919. The neutrodyne circuit was shown in the Radio news in May 1923 – see page 29 of the pdf.
The interstage coils are wound so the secondary voltage opposes the primary voltage, and is coupled back to the grid by the neutralizing capacitor which is adjusted so the grid plate capacitance is nulled out.
A good read is a book called ‘Behind the front panel’ by David Rutland.
.75pF – 29pF
.7pF – 15pF
.9pF – 25pF
.3pF – 6pF
As Mike said earlier the neutrodyne was a type of radio using a technique patented by a chap called Hazeltine. He came up with the idea of neutralizing a triodes grid plate capacity while designing a receiver for the navy in 1919. The neutrodyne circuit was shown in the Radio news in May 1923 – see page 29 of the pdf.
The interstage coils are wound so the secondary voltage opposes the primary voltage, and is coupled back to the grid by the neutralizing capacitor which is adjusted so the grid plate capacitance is nulled out.
A good read is a book called ‘Behind the front panel’ by David Rutland.
