sci.electronics.repair@googlegroups.com

Google Groups

blisca <blisca@tiscali.it>: Jul 01 05:36PM +0200 Hi to all the people here   I bought the old preamplifier,i remember it as pretty silent,and the "apparent" S/N ratio is further increased by the proprietary noise gate called "H.U.S.H." This is a good pic of the board ,found on a website https://images.reverb.com/image/upload/s--oH5vkrFt--/a_exif,c_limit,e_unsharp_mask:80,f_auto,fl_progressive,g_south,h_620,q_90,w_620/v1497562015/pq4p7tei1daqvapl3ygx.jpg I'm finding it a bit too noisy,and this noise sounds as "digital noise",more than white noise..it sounds like the frequencies composing the noise are related to the activity of the segments digits of the display.Adding a piece of wire as antenna to the resistors between IC driver and display increases some particular frequency to the heared noise,confirming my impression . I tried shorting ground points with good cables,it does not change anything. I tried adding some metallic shield with minimal or null impact. I ask your opinion about the decoupling capacitors,they are 1uF ceramic capacitors,with relatively long leads.Do yout think that it is worth replacing them?Maybe with SMD capacitor directly to IC VDD and GND? Another idea is to replace the displays with new ones more efficient,needing much less current,and then ,to increase the resistor values,less current=>less noise,but i still dont know if such display exists. I would like to know your opinion. Thanks for your time Diego   --- Questa email è stata esaminata alla ricerca di virus da AVG. http://www.avg.com

gregz <zekor@comcast.net>: Jul 01 08:12AM > The forum is mostly about CNC machines, but also covers other aspects > of machining. For example: > <https://www.cnczone.com/forums/benchtop-machines/86146-rust-prevention.html>   Been a long time since I used it, LPS3 dries waxy. I hardly ever see LPS 1,2,3 in stores.   Greg

Fox's Mercantile <jdangus@att.net>: Jul 01 06:08AM -0500 On 7/1/19 3:12 AM, gregz wrote: > Been a long time since I used it, LPS3 dries waxy. I hardly ever see LPS > 1,2,3 in stores.   That's because they only stock what sells. And what sells to the knuckle dragging morons is WD-40.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Jeff Liebermann <jeffl@cruzio.com>: Jun 30 11:56AM -0700 >will clean the stuff that may appear in the bell jar as being evacuated >so as not to contaminate the vacuum pump.   >Got links would be helpful   Are you sure that a water bubbler is what you want? If you draw down to a reasonable vacuum, the water will boil (without heating). My guess(tm) is that you're looking for a vacuum filter, trap, drier or scrubber which removes water and other contaminants from the air sucked out of the bell jar before they can wreck your vacuum pump. This article gives an overview of available filters: <http://www.mainpress.com/nederlands/dossier_pompen/pdf/vacuumcontamination.pdf> <https://www.google.com/search?q=vacuum+pump+filter+drier> Also, if you have large amounts of water involved, you may need a refrigerated condenser to get rid of the water.         -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann <jeffl@cruzio.com>: Jun 30 11:39AM -0700 On Sun, 30 Jun 2019 06:07:08 -0700 (PDT), Jeff Urban >>has proper external speakers and better bass/treble controls.   >Bass and treble ? I have a design that will blow your mind. >If your public email is good I'll send you the print. Once I find it.   My email in the signature works. However, please don't send me your design. I'm not into audio (pro or prosumer) and really don't have the time to look at it, analyze it with LTSpice, critique it, build it, or test it. Good luck with your design. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.