I have a Philco Model 511 that has been completely restored electronically. This model has three controls, a volume control on the left, a tuning control in the middle, and a third control on the right which Philco designates a "Range Control". I'm confused about the operation and use of this control and the position in which this control should be placed when the set is aligned and when it is nutralized. I sure hope some one here can help me with this. Any information will be sincerely appreciated.
Thanks, Robert
Thanks Richard for the link to the very interesting Philco history site. The discussion did give me enough information to look up the patent online and it did explain the controls use and operation to my satisfaction. For the record, the patent number is 1,866,462 and was issued to W. H. Grimditch et al (the "et al" being David P. Earnshaw) on July 5, 1932 and was assigned to Philco. I am still not sure what position the control should be in when the set is aligned and I have seen no references to this, so maybe it's not important. I would assume that it should be near full clockwise. Also, I'm still confused as to alignment frequency. I realize that the information on this site indicates that both alignment and neutralization should be done at 1300KC but I have some copies of factory literature that seem to indicat that alignment should be done at 700KC and neutralization at 1200/1400KC. This seems reasonable to me since the sensitivity of this radio seems to decrease at the lower frequencys. I'd sure appreciate some advice on this.
Thanks Robert
That small variable cap is not critical to the alignment of this TRF.
It's used to help in "tuning" or matching the antenna to the radio during use.
Hi Robert,
Used the procedure on Ron's site to align and neutralize my 511 years ago. Remember using a tube with heat shrink on filament pin for neutralization. Guess I'm someone who does not over think things. My radio is original and the procedure did make a nice improvement in reception. Richard
http://philcoradio.com/tech/neutral.htm