I just ordered $30 in caps to redo a radio and I had to violate some of the rules I was taught in High School relating to replacing capacitors. Ok we where all taught you can always replace a part with a part with higher voltage, capacitance, tighter tolerances or higher heat rating than the original just never lower than the original!
For some reason I seem to recall being taught in radio circuits that one should ideally try to keep capacitance and all other values not counting voltage to not more than 130% of origanal part. Outside of tuning high end audio circuit and very tightly defined high tuned audio circuits in a radio like a split band audio compressor I can not think of why the above advice I learned in High School would apply to a CB or Export radio. Since my electronics education is limited to what I learned in High School I was hoping someone could explain the above to me as it applies to a CB or Export radio. I might just have remember it incorrectly. I did try google'ing this but got no where.
My second question has to do with extremely long life 5000 hour Aluminum Organic Polymer Capacitors. In the past I would replace the 6.3V and 10V caps in a CB with a cap that was at least a 16V. Often the capacitance was at least 3X-10X greater with out actually trying to increase it. This always solved the 6.3V and 10V cap failures no matter if they where Electrolytic failing or tantalum failing. I was thinking about trying some AOP caps from Panasonic to replace these caps with. I can get much closer to the OEM values and get a 5000 hour rating. Any reason other than cost that I should avoid this? I plan on keeping these radio's I am going to recap until I die assuming nothing else happen to them to destroy them so the capacitor cost is not a huge deal for me in this situation I am not selling these.
Third and final question. The capacitor in the Mechanical/Crystal Filter in radio's goes bad like all caps do. A lot of them used electrolytic under the tin embedded in epoxy. To me this seems like the PERFECT place to install Aluminum Organic Polymer Caps because of the 5000+ hour rating you can get. I know Uniden on their in-house built filters used the classic orange diped ceramics along the outside edge of their shrink wrapped package so is it safe to assume that the type of capacitor used here does not matter much? What I mean is that as long as the value is right I could use Silver Mica, AOP's, Electrolytics, Ceramic Disc etc????
Thanks guys for your time. I truly appreciate the experience and knowledge. I also hope someone else learns and benefits from the advice you give me!
For some reason I seem to recall being taught in radio circuits that one should ideally try to keep capacitance and all other values not counting voltage to not more than 130% of origanal part. Outside of tuning high end audio circuit and very tightly defined high tuned audio circuits in a radio like a split band audio compressor I can not think of why the above advice I learned in High School would apply to a CB or Export radio. Since my electronics education is limited to what I learned in High School I was hoping someone could explain the above to me as it applies to a CB or Export radio. I might just have remember it incorrectly. I did try google'ing this but got no where.
My second question has to do with extremely long life 5000 hour Aluminum Organic Polymer Capacitors. In the past I would replace the 6.3V and 10V caps in a CB with a cap that was at least a 16V. Often the capacitance was at least 3X-10X greater with out actually trying to increase it. This always solved the 6.3V and 10V cap failures no matter if they where Electrolytic failing or tantalum failing. I was thinking about trying some AOP caps from Panasonic to replace these caps with. I can get much closer to the OEM values and get a 5000 hour rating. Any reason other than cost that I should avoid this? I plan on keeping these radio's I am going to recap until I die assuming nothing else happen to them to destroy them so the capacitor cost is not a huge deal for me in this situation I am not selling these.
Third and final question. The capacitor in the Mechanical/Crystal Filter in radio's goes bad like all caps do. A lot of them used electrolytic under the tin embedded in epoxy. To me this seems like the PERFECT place to install Aluminum Organic Polymer Caps because of the 5000+ hour rating you can get. I know Uniden on their in-house built filters used the classic orange diped ceramics along the outside edge of their shrink wrapped package so is it safe to assume that the type of capacitor used here does not matter much? What I mean is that as long as the value is right I could use Silver Mica, AOP's, Electrolytics, Ceramic Disc etc????
Thanks guys for your time. I truly appreciate the experience and knowledge. I also hope someone else learns and benefits from the advice you give me!
