[jrbar2]

Hi, I have a Philco 53-954 with a 6AQ6 tube. My schematic shows info for the 954 & 950. The 950 shows it using a 6AQ5. What is the correct tube for my 53-954 ??? Also, the radio plays very well for 10 minutes then it goes nuts with noise. The station is still strong, but the crackling noise is not normal. I can't find what is causing this problem. I hope you can help !! THANK YOU VERY MUCH !!!!!!!!!!!!!!!!!!!
Joe

[Radioroslyn]

Hi Joe and Welcome!!
Looks like it's a 35C5. The 6AQ5 heater current is much higher than the others with these series strung set they need to be the same. If you pop a 35C5 in it you can't hurt it. The 6AQ5 will be a problem and burn out other tubes. As for the noise sounds like you need some new caps or you've got a bad IF can.
GL
Terry

[klondike98]

Looking at the Rider ( http://www.nostalgiaair.org/Resources/784/M0013784.htm )info I think the 6AQ5 label is a typo. That label shows up on the views for parts locations but on the actual wiring schematic it shows a 6AQ6. A 6AQ6 is a twin diode-Hi mu triode while a 6AQ5 is a beam power pentode. The schematic is wired for the twin diode 6AQ6. You can check these tubes out at http://www.nj7p.org/Tube.php

As for the noise--have you changed out all the capacitors?

[klondike98]

Terry I think its the detector tube rather than the output tube that's in question unless I misunderstood what Joe was asking. Joe?

[jrbar2]

THANK YOU VERY MUCH for your help !!! I put in a 35C5 and AM reception was weak/poor. I put the 6AQ6 back & reception was superb. I still get the crackling noise. I did replace all caps & electrolytics. Anything else I should try ??? THANKS !!!! Joe

[Radioroslyn]

If the pin out is the same you could drop in a 12AT6 or 12AV6. I didn't look at the pin out
Terry