Guest caselogic Posted February 26, 2007 Report Share Posted February 26, 2007 Hi allpresently rebuilding a pair of AL115's, which are rare over here in the UK. Anyway, the crossover is a minimal affair - 2 inductors and 2 capacitors (one is an electrolytic, the other a disc ceramic). The electrolytics I have measured as 8.8uf (marked 8uf), but the disc ceramics just will not give a reliable reading, and I can not make sense of the markings. Anyone got any idea what value they are? Also, given the discrepancy of the measured/marked values, do I go with actual or marked? Thanks. Link to comment Share on other sites More sharing options...
dynaco_dan Posted February 26, 2007 Report Share Posted February 26, 2007 Hi there;Can you post a photo of the small caps markings, please. Link to comment Share on other sites More sharing options...
Guest caselogic Posted February 26, 2007 Report Share Posted February 26, 2007 Hi Vernthe markings on one side are: CF3A Made in Mexicoon the other side it says 50v (obvious) then X135. Could this be the value - 1.3uf - seems a strange value and quite high for a ceramic.Andrew Link to comment Share on other sites More sharing options...
Carlspeak Posted February 26, 2007 Report Share Posted February 26, 2007 >Hi all>>presently rebuilding a pair of AL115's, which are rare over>here in the UK. Anyway, the crossover is a minimal affair - 2>inductors and 2 capacitors (one is an electrolytic, the other>a disc ceramic). The electrolytics I have measured as 8.8uf>(marked 8uf), but the disc ceramics just will not give a>reliable reading, and I can not make sense of the markings.>Anyone got any idea what value they are? Also, given the>discrepancy of the measured/marked values, do I go with actual>or marked? Thanks.Go with the marked values. Those are the design values. Besides, what you measured is within the typical plus/minus 10%.A pic of the disc ceramic would help as Vern suggests. If you are adventurous, you can also cut one of the cap leads you should then be able to get a reading. It could be very low (It's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
Guest caselogic Posted February 26, 2007 Report Share Posted February 26, 2007 Hi allplease find attached images of both sides of the cap, and the crossover - which leaves a little bit to be desired!Andrew Link to comment Share on other sites More sharing options...
dynaco_dan Posted February 27, 2007 Report Share Posted February 27, 2007 Hi there;I may be wrong but I believe that the 135 is 13,500 pf.Possibly just to add different flavour to the driver.It appears to be in series with the larger cap as well, which would lessen the capacitance, a slight tad, I believe.I would wait for a techie to respond for more precise advice....I just went back for another looksee.I now see that you had clipped it off of the second terminal so that it is across the tweeter, not in series with the larger elect cap.Sorry, this one is now beyond me. Link to comment Share on other sites More sharing options...
Guest GranPa Posted February 28, 2007 Report Share Posted February 28, 2007 What looks to be a ceramic disk capacitor, is a polyswitch fuse.The value is 1.35 amps, which will open at 2.7 amps, and close backwhen it cools down. PE #071-264 Link to comment Share on other sites More sharing options...
Guest GranPa Posted February 28, 2007 Report Share Posted February 28, 2007 Another source would be MCM# 28-60R135, or check any electronics supplier's "fusing" section. Best of luck. Link to comment Share on other sites More sharing options...
Guest caselogic Posted February 28, 2007 Report Share Posted February 28, 2007 Ah, brilliant. Mnay Thanks.That explains why I couldn't get a reading on my capacitor meter! Link to comment Share on other sites More sharing options...
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