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"Michael A. Terrell" <mike.terrell@earthlink.net>: Mar 16 01:29AM -0400 >> want nto this business need to know that there are more than five >> volts in the world.   > They need 4 or 5 years of union electrical school. It sure helped me.     Did it teach you how to wire the HV power supply in a high power TV transmitter? Have you ever worked with 10 KV shielded cable? Years ago I was installing a TV transmitter when the local building inspector told me that I had to hire a local wire monkey. There was no one in tea area that did industrial level work, so I showed him the HV cable and asked which of the GOBs was bonded and insured for $1 million to cover any damage to the equipment.   I showed him the table covered with the factory installation and asked him to read the top left corner where it said "Electrician, connect power here". All of the switchgear was bolted to a 4'x10' sheet of 1/4" steel plate. He insisted that it had to be taken out and screwed to a sheet of 1/2" plywood. There was over a ton of transformers and switches that would have snapped plywood into pieces. He was not qualified to inspect anything bigger that a small store or one of the thousands of Condos in the area. He had no idea who the FCC was, or what a FCC Construction Permit was. He was as clueless about the FAA permit for the tower or the lighting requirements.   Then I handed him my copy of the NEC and asked him to show me the relevant sections for industrial and studio wiring. He tossed it on the table, cursed me out and said he would be right back with a 'Cease and Desist Order to stop work on the new TV station. He never came back.     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

bruce2bowser@gmail.com: Mar 16 09:16AM -0700 Michael Terrell wrote:   > Did it teach you how to wire the HV power supply in a > high power TV >transmitter? Have you ever worked with 10 KV shielded cable?   No, no. I've mostly just driven around a van or truck with supplies here and there. I have wired up one or two places behind walls, roughed-in a few panels, outlets, etc.. and finished them, maybe. But, no. I haven't recently gone into radios, TVs or anything else and bothered anything.

Micky <NONONOmisc07@bigfoot.com>: Mar 16 02:57PM +0200 How can it keep charged in use, but be unable to recharge?   I spent an hour on the Android phone with a friend, and because we kept getting dicsonnected on whatsapp and also on Skype, the phone's screen was on all the time, but I was plugged into a small cubicle charger the whole time, and the phone charge stayed at 77% the whole time.   Then the phone call ended, I closed the light, but left the phone on, and let it finish charging for an hour. But after an hour or more, it was still at 77%.   How can that be?   Later I was able to recharge the battery fully, use some and recharge over and over up until now. Using a different cable. But if the cable were bad, how to account for the first paragraph??

Pat <pat@nospam.us>: Mar 16 11:12AM -0400 On Thu, 16 Mar 2017 14:57:53 +0200, Micky <NONONOmisc07@bigfoot.com> wrote:     >Later I was able to recharge the battery fully, use some and recharge >over and over up until now. Using a different cable. But if the >cable were bad, how to account for the first paragraph??   Any chance one of those apps didn't really shut down due to a bug? Or maybe the charge indicator is (was) out of calibration. Or maybe something was sensed as too hot (the battery? the charger?) and didn't work until it cooled down. Just wild guesses.   Pat

bruce2bowser@gmail.com: Mar 16 09:01AM -0700 On Thu, 16 Mar 2017 14:57:53 +0200, Micky <NONONO...@bigfoot.com> wrote: - hide quoted text -     >Later I was able to recharge the battery fully, use some and recharge >over and over up until now. Using a different cable. But if the >cable were bad, how to account for the first paragraph??   Whenever I have state-of-the-art questions about computer software/hardware, I try to visit the PC Gaming or PC Magazine websites.

Jeff Liebermann <jeffl@cruzio.com>: Mar 15 08:48PM -0700 On Wed, 15 Mar 2017 07:33:45 -0700 (PDT), "Ron D."   >The generator probably has a 50 ohm output. If it's >an FM radio, the input is likely 75 ohms. So, you >do need a matching transformer.   Nope. Most of my test equipment is 50 ohms. However, I also work with 75 ohm devices and antennas. Transformers do not have a very flat frequency response. If I need a flat frequency response from DC to many GHz, I use a minimum loss pad: <https://www.maximintegrated.com/en/app-notes/index.mvp/id/972> <https://www.minicircuits.com/WebStore/dashboard.html?model=BMP-5075R%2B> <https://www.minicircuits.com/pdfs/BMP-5075R+.pdf> <https://www.pasternack.com/matching-pads-category.aspx> <http://www.comm-connect.com/8006.html> etc... Figure on 5.71dB loss. The technique also works for 50 to 300, 50 to 600 ohms, and other impedances.   >It also depends where you want to put the adapters.   Yep. Coax adapters are fun: <http://802.11junk.com/jeffl/antennas/connector-loss/Adapter%20Colluge.jpg>   More: <http://ham-radio.com/k6sti/match.htm> <https://www.microwaves101.com/encyclopedias/l-pads#minloss>   -- 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

"Michael A. Terrell" <mike.terrell@earthlink.net>: Mar 16 01:58AM -0400 Jeff Liebermann wrote:   > More: > <http://ham-radio.com/k6sti/match.htm> > <https://www.microwaves101.com/encyclopedias/l-pads#minloss>     I have used some of the six hole ferrite beads to make transformers. six turns, tapped at the fifth turn. The 1.2 turns ratio, squared is a 1.44:1 impedance ratio. These are the same beads used for CATV line taps and broadband splitters.   They convert 75 ohms to 52 ohms. I put some into some old Blonder Tongue inline attenuator housings with an F connect on the 75 ohm end and a BNC connector on the 52 ohm end. (52.0833 Ohms) They were handy to use a TV FSM as a 50 ohm RF millivoltmeter. Now, I have some precision attenuators, and a Boonton 9200 RF Millivoltmeter ans different feedthrough terminators.. :)     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

Phil Allison <pallison49@gmail.com>: Mar 16 12:25AM -0700 Ron D. wrote:   > Honestly, we havent; the foggiest of what you want to do.   ** The dopey OP has one of these:   https://elektrotanya.com/PREVIEWS/38933510/23432455/eico/eico_320_150k-34mhz_am_signalgenerator_1956_sch.pdf_1.png   The output Z is anyone's guess.   He only wants to use it for old, tube AM radios.   IMO use no cable at all, just let it radiate via a length of wire.     .... Phil

gregz <zekor@comcast.net>: Mar 16 08:19AM >>>> So what is normally used?   >>> I use RG-58c/u for 50 ohm test leads. The stranded center wire is >>> more flexible than the rather stiff RG-58a/u.   A/U is stranded center too. Rg58 is solid. Au cu difference seems to be outer covering difference.   Greg

"Michael A. Terrell" <mike.terrell@earthlink.net>: Mar 16 01:45AM -0400 > recall trying to unsolder some IC chips, and ruining them every time. > Then spending days or weeks trying to locate replacement parts, > because they are factory numbers that can't just simply be purchased.     SMD is easier to work with than old point to point wired chassis. I am in my mid 60s, and I have had poor eyesight all my life. I worked with SMD boards daily at Microdyne. I now have a nice B&L Stereozoom 4 boom microscope for my projects now that I'm retired. I purchased an adapter to be able to record video from the microscope, so that I can post video of the techniques I use.   You need the right tools and some practice to work with the small parts. I routinely removed and replaced 288 pin ICs without damaging the PCB or to IC.   ASIC (Application Specific Integrated Circuits) are what you referred to as "can't just simply be purchased". They only make sense for products built by the millions, or for unlimited budget high end industrial electronics.   A lot of what you think are unavailable is because you don't know actual part numbers, VS what they have room to mare a component with.     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

"Michael A. Terrell" <mike.terrell@earthlink.net>: Mar 16 01:13AM -0400 Benderthe.evilrobot wrote: > USB stick into a computer.   > Maybe an old tower case with no front sockets and stashed under the > desk......................................     Maybe a webcam used as a security camera, or any of hundreds of other USB devices. That's why it's called the 'Universal Serial Bus'. This computer came with eight USB ports, then I added a card with another four to eliminate an external hub.   I also have a long USB to USB cable made to transfer files from one PC to another. It replaced the old Laplink cable that used the Parallel ports.   Here is a handy program that helps you identify registered USB devices that have been connected to your computer   32 bit: http://www.nirsoft.net/utils/usbdeview.zip   64 bit: http://www.nirsoft.net/utils/usbdeview-x64.zip   -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

davidahoneycutt@gmail.com: Mar 15 03:25PM -0700 Hello Group, I am looking for a replacement motherboard for my Tektronix 2215a oscilloscope. Any thoughts and suggestions will be appreciated.

Foxs Mercantile <jdangus@att.net>: Mar 15 06:34PM -0500 > I am looking for a replacement motherboard for my Tektronix > 2215a oscilloscope. > Any thoughts and suggestions will be appreciated.   Depends on what you're willing to pay. You can buy a complete scope for $100 or so. <http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2057872.m570.l1313.TR1.TRC0.A0.H0.Xtektronix+2215a.TRS0&_nkw=tektronix+2215a&_sacat=0>     -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com

"David Farber" <farberbear.unspam@aol.com>: Mar 15 02:52PM -0700 I'm servicing a JVC RX-807V receiver. After about 5 minutes of warm up, the left channel starts to get distorted. Injecting a sine wave into the tape input shows the top half of the wave is getting clipped. This only happens when the SEA equalizer is enabled. Intermittently, the same problem will happen on the other channel. When I tested it extensively last night, it was only the left channel having the problem. I've narrowed the problem down to the ENC-093 pc board. You can have a look at the schematic here. https://www.elektrotanya.com/jvc_rx-807vtn.pdf/download.html   I took some voltage measurements of IC 503 which is a dual op-amp:   Before the left channel starts clipping, pins 2 and 3 are about 2.0 and 2.4 volts respectively. Pin 1, the output, is at 3.0 volts. When the clipping happens, pins 2 and 3 are about 6.7 volts, and pin 1 is at 12.0 volts. The working channel has its own interesting measurements. Pins 5 and 6 are about -4.0 volts and pin 7 is about -4.5 volts (there is no distortion with these measurements in the right channel.) The input to both channels is clean at IC503 even when the output is distorted. I want to replace IC 503 but before I do, I'd like to know.   What is the function of the JFET, Q553? the source(?) goes directly to pin 6 which is the inverting input of the right channel of IC503. I would think that since this is a stereo receiver that there would be some symmetry to the opposite inverting input, pin 2, of IC503 but instead pin 2 is wired back to the drain of Q553 through an RC network. The gate of Q553 is -10 volts instead of +10 volts because Q551 and Q552 apparently are switched off. I believe there is an error in the schematic that shows C516 connected to pin 6 of IC503 rather than pin 7.   Thanks for your replies.   --   David Farber Los Osos, CA

MyToshiba <MyToshiba@ToshibaProblems.COM>: Mar 15 10:03AM -0700 My Toshiba TV remembers things like favorites but will not remember my setting of Daylight Savings Time so the next time I hit the remote Power button I am reset back. Is there something else I need to do ?

John Robertson <spam@flippers.com>: Mar 15 11:01AM -0700 On 2017/03/15 10:03 AM, MyToshiba wrote: > My Toshiba TV remembers things like favorites but will not remember my > setting of Daylight Savings Time so the next time I hit the remote Power > button I am reset back. Is there something else I need to do ?   <rant> Complain to your State Senator (US) or MP/MLA (Canada) about Daylight Savings! Really, who needs it? Waste of time and resources. </rant>   John

Ralph Mowery <rmowery28146@earthlink.net>: Mar 15 02:02PM -0400 In article <oabs4a$cd0$1@gioia.aioe.org>, MyToshiba@ToshibaProblems.COM says...   > My Toshiba TV remembers things like favorites but will not remember my > setting of Daylight Savings Time so the next time I hit the remote Power > button I am reset back. Is there something else I need to do ?   Wild guess here.   Some devices are set for an automatic time change. Not sure if yours is that way or not. You may be able to disable the automatic part.   The day the time changes had been moved by the government several times over the years and yours may not be the current one. In a month or two it may self correct to the fall change.

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