1955 Chevy Radio

The radio repair was quite straight forward, the major problem was one shorted capacitor in the power supply.  I replaced all the paper and electrolytic capacitors with modern Tantalum and Mylar caps.  The other major issue was the switch.  The switch was stuck in the ON position. Which allowed the testing of the radio.

I was quite pleased that the tubes and vibrator worked.  I connected a 13.8V Power supply, speaker and antenna. 

The first station it tuned in was ~  appropriately enough ~ the KFSD AM 1450  "oldies" station in Escondido, CA.  I also was able to tune in the local San Diego talk radio stations as well as Tijuana, BC stations.  The sensitivity was not the greatest but a half a dozen stations could be clearly heard. 

The vibrator buzz can be heard between stations until the AGC takes over on a strong signal.  The selectivity was OK.

As the night time clear channel broadcasters came on many more stations including 640 KFI (Los Angeles) , 680 KNBR + 810 KGO (San Fransisco) and 1160 KSL (Salt Lake City) and XEPRS (Rosarito, Mexico) were all heard.

There seems to be a peak of the vibrator's noise in the upper center of the band, but 680-550kHz stations are heard again with some quieting as the AGC takes over.  It may be my antenna or there is a bypass capacitor not working or soldered correctly.

Besides the shorted capacitor, most of these were simply out of tolerance, or had a significant value change over the last 5 decades!  For example; the 0.002uF was reading 0.008uF  ~ it still was working as these are not used for any critical frequency determining elements, but this tells me there are changes going on to the old paper, wax, and foil and it is only a matter of time that they would fail...