10-16-2017, 09:55 PM
I went through and started to change out some of the out of tolerance resistors. All caps have been replaced but I'm still get okay reception on lower stations like 710 and 770 but as I go up on the dial I'm getting nothing but static. There is quite a lot of static (white noise). At this rate, any part that I've changed has not improved the reception.
I aligned the radio using an Eico 324 and everything is peaked per the manual. I did get some increase on the voltage of the 6a8 tube and they've come up to were they should be (pin 3 176 vdc, pin 4 105vdc). Prior to some parts replacement, those voltages were about -30vdc. All the other voltages look fairly good. The Plate on the 6K5 is about +15v higher than the schematics call for. The 6K7 is also showing about +10v higher on the Plate as well.
At this point, with the exception of a couple of resistors that are slightly out of tolerance, I'm at a loss with this one at the moment. I do get more gain if I touch the grid cap of the 6a8 tube, but it only increases the gain and doesn't clean up the static noise. Grounding the radio seems to help but only on the lower stations. The tubes did test good and I have a couple NOS in there as well.
Any suggestions?
I aligned the radio using an Eico 324 and everything is peaked per the manual. I did get some increase on the voltage of the 6a8 tube and they've come up to were they should be (pin 3 176 vdc, pin 4 105vdc). Prior to some parts replacement, those voltages were about -30vdc. All the other voltages look fairly good. The Plate on the 6K5 is about +15v higher than the schematics call for. The 6K7 is also showing about +10v higher on the Plate as well.
At this point, with the exception of a couple of resistors that are slightly out of tolerance, I'm at a loss with this one at the moment. I do get more gain if I touch the grid cap of the 6a8 tube, but it only increases the gain and doesn't clean up the static noise. Grounding the radio seems to help but only on the lower stations. The tubes did test good and I have a couple NOS in there as well.
Any suggestions?