21-05-2013, 05:09 PM
(This post was last modified: 21-05-2013, 05:40 PM by Radio Fixer.)
Really impressive engineering.
How's this for tracking with no adjustments made by me. Well the coils are the best and the trimmers are a mechanical work of art, being coaxial tubes over a ceramic former, so I didn't adjust any of the RF. I set the dial mechanics up to achieve a correct pointer setting at 550m. After a few iterations between this and 250m the pointer was amazingly accurate at almost any setting. It was almost spot on at 550m, dead on at 450m and 350m, half of a small division (about 1/16”) out at 250m and one small division low at 200m. On LW I only checked for R4 and the 1500m marker, or 200kHz. This peaked at 199kHz with the signal generator and frequency counter.
And that was all adjusted back in 1934!
Here's a pic of the coaxial trimmers from my 834C and one I actually took apart! the gap between the tubes would need someone like Colin to measure it! Tiny it is, mere thou. Boy! they were fantastic engineers.
And finally heres a couple of pics of the 634A tuning gang (on a French web site somewhere, why he took it apart I don't know but I was over the moon to get a look).
[attachment=8011]
Gary
How's this for tracking with no adjustments made by me. Well the coils are the best and the trimmers are a mechanical work of art, being coaxial tubes over a ceramic former, so I didn't adjust any of the RF. I set the dial mechanics up to achieve a correct pointer setting at 550m. After a few iterations between this and 250m the pointer was amazingly accurate at almost any setting. It was almost spot on at 550m, dead on at 450m and 350m, half of a small division (about 1/16”) out at 250m and one small division low at 200m. On LW I only checked for R4 and the 1500m marker, or 200kHz. This peaked at 199kHz with the signal generator and frequency counter.
And that was all adjusted back in 1934!
Here's a pic of the coaxial trimmers from my 834C and one I actually took apart! the gap between the tubes would need someone like Colin to measure it! Tiny it is, mere thou. Boy! they were fantastic engineers.
And finally heres a couple of pics of the 634A tuning gang (on a French web site somewhere, why he took it apart I don't know but I was over the moon to get a look).
[attachment=8011]
Gary
