March 28, 2022 at 11:41 am #18371
I’m working on a Crosley 181 and have replaced most of the resistors that were out but I’m confused over the two resistors in the photo.
#1 is a 30K not sure the wattage but I assume 3 watt. One end soldered to chassis ground and the other end connected to #2 resistor then on to Pin 3 of the 2A7 tube.
#2 is a 25k resistor of unknown wattage that is connected to end of the 30K resistor that goes to the 2A7 and the other end Y’s with one side going to the 20K (red) resistor and the other end of the Y going to one of the IF tuning condensers.
My problem is that there are no 30K or 25K resistors on the parts list. I’m assuming that these two resistors are Parts #21/22, the 15,000-10,000 ohm resistors but my schematic reading abilities are still very limited.
I’m not sure what values these 2 resistors should have and the enclosed schematic and parts list does not mention any wattages for the resistors so I’m at a bit of a standstill here and would appreciate any input from those with far more knowledge and experience.
Attachments:March 28, 2022 at 5:39 pm #18373Ralph SpracklinCVRS Member
You did not say which transformer your Radio runs on. Could be any of three Power Transformers. 110 Volt, 60 Cycle; 110 Volt, 25 Cycle; or 250 Volt.
This Schematic has done things in a different manner than most schematics. And as well their method of numbering the tubes on the schematics, is something else. Also it seems that the Heavy Black Line through the center of the schematic, represents chassis ground. I’m just thinking that different Power Transformers could be the reason for the different values on R21 and R22.. Does this Radio work since you re-capped it and replaced some of the resistors?
And also did you take a reading with your meter, on those two Resistors?? Some of those radios were made for the European Market.
RalphMarch 29, 2022 at 6:27 am #18374
This radio has the 110 volt 60 cycle transformer and both resistors tested at 25K which is much higher then they should be if they are Parts #21-22. The radio does not work now. It has what I think is referred to as, birdies and squeals, no stations picked up.
Not quite sure how to proceed. I do have some 15K 5 watt resistors. Not sure if substituting them is an option.March 29, 2022 at 8:36 am #18375Ralph SpracklinCVRS Member
Does those two resistors look original in regards to installation?? Physically, to me they look like the original resistors of that time period. If they are original, they must have worked properly as one time. I would look elsewhere for the problem of birding-whistling. Are any of the tube shields missing?? A bad AVC Capacitor or a problem with parallel wiring can sometimes cause the same problems. Even a micro-phonic vacuum tube. Tap the tubes lightly to see if there are any changes in the sound.
March 29, 2022 at 10:06 am #18381
- This reply was modified 4 months, 1 week ago by Ralph Spracklin.
Yes Ralph the orange one appears to be an original dogbone but not the dark grey one #2. All the resistors I previously replaced were dogbones so I think it may have been a replacement.
All the tube shields are there and I’ll do some checking on the other items you mentioned to check before I replace either of the resistors.
Thanks again for the input, much appreciated. It may be a couple of days before I get back to you. I’m just on my way out of town for a couple of days.
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