- What can I buy at Walmart for dial string? - 3 Updates
- Radial X2-AC Safety Capacitors (Question) - 3 Updates
- SMD capacitors - 3 Updates
| "Michael A. Terrell" <mike.terrell@earthlink.net>: Aug 29 07:15PM -0400 Tim R wrote: >> Best think to do is check with each manufacturer and pick by diameter not pound weight. > Yes, that's what I'm trying to explain. That kastking is called braid but it's the modern stuff, not the old cheap line. > It's okay for fishing but you absolutely don't want to put it in a radio at any strength or diameter. It's super slippery, hard to tie a knot that will hold, and it has no abrasion resistance. But it's diameter is tiny so fish don't see it, and it casts very well. You also want to be close to the original diameter. If it is much larger, it can bind and wear out faster, or just jam on the main tuning shaft. If it is smaller, it won't have enough friction to work properly. -- Never piss off an Engineer! They don't get mad. They don't get even. They go for over unity! ;-) |
| Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Aug 30 03:35PM +1000 On 29/08/2017 5:54 PM, rickman wrote: > from ebay without buying from the most expensive seller and then he gets > mad when people express frustration in trying to help him. > What is wrong with this guy Oldschool? **He is one of the most astonishingly stupid people I've run across. -- Trevor Wilson www.rageaudio.com.au |
| Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Aug 30 03:36PM +1000 On 28/08/2017 9:42 PM, John-Del wrote: >> addresses of people who are ham radio operators. Maybe they can provide >> some real help, since it's obvious I wont get it here. > You should probably take Trevor's offer as "free" seems to be as low as he's willing to go (unless he throws in a Super "Shammy" if you order now!!). **Dunno what I was thinking. I should have offered to pay him to take the stuff. -- Trevor Wilson www.rageaudio.com.au |
| "Michael A. Terrell" <mike.terrell@earthlink.net>: Aug 29 07:12PM -0400 >> 2.828 is the peak to peak factor on a RMS sine wave. That is >> 1.414 volts peak, on each side of zero > Erm... no. Firstly 275v ac is 389v dc peak, so a 389v dc rating. Secondly the 2 ratings are not comparable, even after conversion to dc. The 600v cap has no fusing and most likely no double layer safety feature, the 275v ac one has both. Think again. You have a negative and a positive peak, not just a single peak. You have to add them together. That is why the original DC cap was 600V, not 300V. -- Never piss off an Engineer! They don't get mad. They don't get even. They go for over unity! ;-) |
| Ralph Mowery <rmowery28146@earthlink.net>: Aug 29 08:02PM -0400 In article <_oydnUQN6YdVaTjEnZ2dnUU7-cnNnZ2d@earthlink.com>, mike.terrell@earthlink.net says... > Think again. You have a negative and a positive peak, not just a > single peak. You have to add them together. That is why the original DC > cap was 600V, not 300V. While there is a positive and negative peak, the capacitor only charges to the peak and not p to p. The charge reverses at each half cycle. |
| tabbypurr@gmail.com: Aug 29 05:46PM -0700 On Wednesday, 30 August 2017 00:12:17 UTC+1, Michael Terrell wrote: > Think again. You have a negative and a positive peak, not just a > single peak. You have to add them together. That is why the original DC > cap was 600V, not 300V. 275v ac = 389v peak, which can be withstood by a 389v rated capacitor. The reason they used 600v was to improve safety & reliability. However time showed that it wasn't good enough. X & Y caps are much better attempts to address the failure/safety issues. NT |
| "Ian Field" <gangprobing.alien1@virginmedia.com>: Aug 29 10:23PM +0100 "Ralph Mowery" <rmowery28146@earthlink.net> wrote in message news:MPG.340e4bcbb44ddece989997@news.east.earthlink.net... > they are probably the same material, so the larger ones won't be > ploarized either. I did notice the voltage on them is only 10 volts > instead of 25 and 50 like the others. The lower voltage ratings are probably tantalum, polarity is *VERY* important. Don't be fooled by large capacitance values - I've seen a brochure for MLCC capacitors up to 180uF. SMD tantalum caps are usually encapsulated (after a fashion) and usually have markings. SMD ceramics are rarely encapsulated and rarely have any markings. Sometimes I've encountered MELF round glass encapsulated MLCC caps on high end equipment. |
| Ralph Mowery <rmowery28146@earthlink.net>: Aug 29 05:55PM -0400 In article <kXkpB.728842$YV4.539839@fx18.am4>, gangprobing.alien1 @virginmedia.com says... > SMD ceramics are rarely encapsulated and rarely have any markings. Sometimes > I've encountered MELF round glass encapsulated MLCC caps on high end > equipment. Yes, the polarity is very important if the capacitor has one. I have not installed any of thse backwards to see what happens as of yet. I have seen the old aluminum and tantalum one blow over the years. I am not used to seeing capacitors ( other than large AC and speaker crossover) much over 1 uF. I can see why they don't mark most of the SMD, just no room but with micro printing there may be a way but it would cost. Even buying them from Digikey and Mouser they are very inexpensive compaired to the old point to point components. As mentioned, been working with components for over 50 years,but just started with the SMD in the last year. Could not justify the items it took to do that for just a hobby. Now they have came down a lot. Like the China hot air rework station for about $ 60 and a $ 200 microscope. The hot air station is probably no where near good enough for regular shop work,but good enough for hobby,and if it breaks, the replacement is not that much. I am learning a lot about the capacitors with the help here. |
| tabbypurr@gmail.com: Aug 29 05:44PM -0700 On Tuesday, 29 August 2017 22:55:42 UTC+1, Ralph Mowery wrote: > shop work,but good enough for hobby,and if it breaks, the replacement is > not that much. > I am learning a lot about the capacitors with the help here. I've seen SMDs where one end is a bit pointed to indicate polarity. If there's really nothing to indicate polarity it's most likely nonpolar. Hook one up & see, not that hard. NT |
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