Doing replacement electrolytic capacitors in several older short wave radios and a few CBs I have come across some interesting things, mostly by accident. 
op:
I am not fortunate to have a capacitor checker and if I suspect a rig with one or more bad caps, I replace them all. Most of the time the symptoms tell about bad caps. :headbang
Tonight I restored a Cobra 148 GTL to working condition! No receive but good transmit with modulation.... I wanted to find out what electrolytic was causing the problem, so I replaced them one at a time and checked each new cap for the rig coming back to life. This time it was the fourth cap I replaced, a 220µf @ 10 volts. I replaced it with a smaller one in size but it is a 220µf @ 16 volts.... The radio came back to life!
Just wondering what happened I checked the cap with my Fluke DVM and compared it to another new cap. Here is what I found... Checking the new cap with the leads of the DVM in correct polarity and set in ohms scale charged up the cap, the bar meter showed a build up and then it went to about 2675 ohms and slowly fell about an ohm per second. I tried a different value new cap and it did about the same. The bad cap I pulled from the 148 did something different, not a short but the meter went to figures right away of about 60 or so ohms and slowly built up. :glare:
So I was wondering if this is a good way of checking caps the cheap and dirty way? But the Cobra is alive!!
op: I am not fortunate to have a capacitor checker and if I suspect a rig with one or more bad caps, I replace them all. Most of the time the symptoms tell about bad caps. :headbang
Tonight I restored a Cobra 148 GTL to working condition! No receive but good transmit with modulation.... I wanted to find out what electrolytic was causing the problem, so I replaced them one at a time and checked each new cap for the rig coming back to life. This time it was the fourth cap I replaced, a 220µf @ 10 volts. I replaced it with a smaller one in size but it is a 220µf @ 16 volts.... The radio came back to life!
Just wondering what happened I checked the cap with my Fluke DVM and compared it to another new cap. Here is what I found... Checking the new cap with the leads of the DVM in correct polarity and set in ohms scale charged up the cap, the bar meter showed a build up and then it went to about 2675 ohms and slowly fell about an ohm per second. I tried a different value new cap and it did about the same. The bad cap I pulled from the 148 did something different, not a short but the meter went to figures right away of about 60 or so ohms and slowly built up. :glare:
So I was wondering if this is a good way of checking caps the cheap and dirty way? But the Cobra is alive!!
