Hello all. I may be aquiring one of those RCA VICTOR R32's with that almost space age rf chassis with the symetrically laid out UX226 tubes.Weird! Anyways I was reading about the method of neutralizing the 4 rf stages and using a dummy UX226 with an open filament etc. and was just wondering what this is exactly.I have read about aligning receivers and adjusting capacitors or coils and I know this is the same thing sort of but what is with the dummy UX226 etc. and has anyone done this with this or similiar model? Any info expanding on this topic will be appreciated.

The neutralizing circuit was developed by Prof. Hazeltine, probably in the 1920s - when triodes, with large inter-electrode capacitance were used for RF amplification in tuned-radio-frequency sets. Neutralizing is a form of feedback that counteracts the oscillation and howling caused by the capacitance. More info here: http://www.philcoradio.com/tech/neutral.htm

Neutralizing isn't the same as IF or other types of alignment. TRFs don't have an IF - and no alignment is required if each RF stage is tuned separately. (If the tuners are ganged together, then each tuner needs to be synchronized with the others.)

:The neutralizing circuit was developed by Prof. Hazeltine, probably in the 1920s - when triodes, with large inter-electrode capacitance were used for RF amplification in tuned-radio-frequency sets. Neutralizing is a form of feedback that counteracts the oscillation and howling caused by the capacitance. More info here: http://www.philcoradio.com/tech/neutral.htm
:
:Neutralizing isn't the same as IF or other types of alignment. TRFs don't have an IF - and no alignment is required if each RF stage is tuned separately. (If the tuners are ganged together, then each tuner needs to be synchronized with the others.)
:You know,that is really interesting! Thankyou Doug,I will look more into that.

Here's Prof. Hazeltine's 1923 neutrodyn patent: http://www.google.com/patents?id=xshYAAAAEBAJ&printsec=abstract&zoom=4&source=gbs_overview_r&cad=0#v=onepage&q=&f=false

Like most patents, this one is not written to make it all that easy to understand.

The neutrodyne circuit became obsolete with the advent of pentode tubes (with low plate-to-grid capacitence) and superhet radios.