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amdx <amdx@knology.net>: Apr 26 07:52AM -0500 On 4/24/2021 6:02 PM, micky wrote:   > https://www.amazon.com/0-5-Fail-Safe-Long-Range-Transmitter/dp/B003FO4UHW/ref=sr_1_12_sspa > $120 Mine was cheaper, I guess because it had no RCA inputs, which I > have no use for.      I have the FM transmitter listed above. At one time it quit transmitting.   I could not find any info on the unit at that time.   Here's the schematic as I drew it on my unit manufactured in 2011. May or may not be correct or complete.   > https://www.dropbox.com/s/8sjv8u3xlsdsg3d/FM%20TRansmitter%20Schematic%20Updated%20schematic%20Latest.jpg?dl=0 Here's a picture of the PCB.   > https://www.dropbox.com/s/o1vuhbgjcyndo3b/FM%20Transmitter%20amp%20section..jpg?dl=0 F1 is the output transistor, it went defective on my unit.  I changed it and that fixed it. Check the voltages, at the output MosFet   If they don't match what I have on my schematic, it would be suspect. I used part # RDO1MUS1.   > https://www.mitsubishielectric.com/semiconductors/content/product/hf/sirfpowermosfet/siliconrfdiscrete/siliconrfdiscrete_lv4/rd01mus1.pdf You will also notice when it's working properly, that the 100 ohm resistor in the L/H power switching circuit runs hot, (I think in low power mode).   It is just poor design it is a 0.5 watt resistor dissipating 0.59 watts.   But 10 years of often hours of daily use and it is still fine. So you can ignore that.                                      Hope that helps, Mikek     -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

amdx <amdx@knology.net>: Apr 26 07:57AM -0500 On 4/26/2021 7:52 AM, amdx wrote:   > But 10 years of often hours of daily use and it is still fine. So you > can ignore that.   >                                    Hope that helps, Mikek   BTW, I bought one in 2011 and paid $114, I bought another in 2017 and paid $69.   The first one I repaired and is still working, the second one is working fine.                                                  Mikek         -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

"Peter W." <peterwieck33@gmail.com>: Apr 26 08:10AM -0700 First, I have a legacy Ramsey FM100B that I built from a kit almost 20 years ago. It has performed flawlessly throughout that time. Sadly, it is no longer made, although they do, occasionally, show up on eBay. Ramsey continues to support them.   Second, there is a LOT of Chinese Junque out there that is awfully cheap, and that is no better than it should be at the price. Those that I have come across have had nice extruded cases, and looked pretty simple. But have not performed anywhere as nicely as the Ramsey.   Third, I suspect that the unit you have that has failed has done so (in rank order) because of a connector failure (antenna, power or input), or because of a failed critical component - because, did I mention, they are cheap.   Fourth, you will notice that the Rangemaster is "FCC Certified". In the world of Part-15 FM transmitters, that does mean something.   You get what you pay for.   Peter Wieck Melrose Park, PA

whit3rd <whit3rd@gmail.com>: Apr 25 10:47PM -0700 On Saturday, April 24, 2021 at 8:15:17 PM UTC-7, Ed Vance wrote:   > I went through the Set Up procedure and had it scan the TV Channels > but the set still didn't let me see the Stations that I had been > able to watch before the Power failed that time.   Two odd possibilities, are that the station might have gone off-the-air during your scan, or that the TV has a restricted tuning range because its varactor bias supply has been misadjusted.   More likely, your antenna isn't picking up all the stations, and could use adjusting. If you still have a converter box, some of those have signal strength indicators (and you can see if the converter scans and finds the same stations, or a different subset. If a converter picks up more stations than the TV on the same antenna... then the TV might need an antenna booster amplifier.

Rheilly Phoull <rheilly@bigslong.com>: Apr 26 07:09AM +0800 On 25/04/2021 8:14 pm, Edward Hernandez wrote: >> the 3 groups in series or connecting 3 cells in series first to >> obtain 6 volts, 2amp per set and connecting the set in parallel?   > This question sounds suspiciously like a homework problem.   As do many :-(

Jason Bowers <jbbowersnospam@aol.com>: Apr 25 01:47PM -0400 The last time I did any serious HF radio adjustments I had a large and heavy 100 Mhz oscilloscope as well as an HP 1 Ghz spectrum analyzer. Due to finances and lack of interest, those items, along with several others, were sold about twenty years ago.   Recently, my interest has been rekindled somewhat and I am thinking about getting on 10 meters once the solar cycle begins to favor the upper HF more consistently. The problem is that my 10 meter radios have been in storage for about twenty years. Some were bought used and I have no idea how clean/ dirty transmitter/ receiver stages are not to mention transmitter output spectrum and modulation. I came across an HTX-100 recently, for example, where someone had removed the "do not adjust" sticker on the bandpass filter. Not good. So, being on a limited budget, I have been looking at these test equipment pieces:   https://www.amazon.com/Portable-TinySA-Spectrum-Frequency-Generator/dp/B08FB5XT7B?tag=worradfor-20   https://www.amazon.com/YEAPOOK-Handheld-Oscilloscope-Professional-Bandwidth/dp/B07XBL4BTL?tag=worradfor-20   I'm hoping that I would be able to check out and adjust spectrum output using the SA for anything up to 30 Mhz as well as checking out radio internals with the scope up to 30 Mhz (as well as viewing output SSB waveforms). So, I would appreciate any feedback on the above units. Thanks in advance.

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dplatt@coop.radagast.org (Dave Platt): Apr 23 12:21PM -0700 In article <39r38gdhf1kr84cetqq9p9e8a5fclrnd74@4ax.com>, >However minidisk uses magnetic recording and playback similar >to a floppy disk. The laser is only used when recording to heat >the disk and thus allow it to be altered by the magnetic write head.   All of the information I've found on Minidisc, says that it works the other way around.   During recording, the laser operates at high power, heating up the magneto-optic layer on the disc above its Curie point. The fluctuating magnetic field from the write head is "captured" by the MO layer as it cools back below the Curie point.   During playback, the laser is used (at low power) to sense the magnetic orientation of the MO layer by sensing changes in the polarization of the reflected laser beam (via the Faraday effect). When playing pre-recorded discs (made more like CDs) the laser is sensing reflectivity differences rather than polarization.   References: https://www.minidisc.org/minidisc_faq.html (item 9) as well as The Great Font Of Dubious Knowledge (a.k.a. Wikipedia).   For more detail, you can take a look at the original Minidisc patent: http://www.minidisc.org/patents/pdfs/US05244705.pdf - the basic descriptions of the recording and playback processes are at the bottom of column 9 and the first part of column 9, on pages 15 and 16.   The technical advantage of this dual approach is that the magnetic head doesn't have to "fly" at an extremely low height over the surface of the disc. In a hard drive, the gap between head and media is truly tiny... much smaller than the diameter of a human hair, and often smaller than a particle of tobacco smoke. It has to be this close, in order to be able to read and write very-tiny bits. That would be very hard to pull off successfuly for a removable medium like MD.   With MD, the write head can be larger, and further away from the surface. It produces a fairly broad area of magnetic field, but this affects the material only in the tiny area being heated by the laser (and cooling down immediately thereafter).

Lucifer <LuciferMorningstar@bigpond.com>: Apr 24 11:22AM +1000 On Fri, 23 Apr 2021 12:21:11 -0700, dplatt@coop.radagast.org (Dave Platt) wrote:   >surface. It produces a fairly broad area of magnetic field, but this >affects the material only in the tiny area being heated by the laser >(and cooling down immediately thereafter).   Thank you so much for that. I had the wrong idea of operation. However, looking at my minidisk recorder playing the magnetic is actually touching the disk and the head moves across the disk when I select a different track.   Now I know how minidisk works I can take a different approach to fixing mine.   Thank you again.

"ohg...@gmail.com" <ohger1s@gmail.com>: Apr 23 11:04AM -0700 On Friday, April 23, 2021 at 11:47:47 AM UTC-4, Peter W. wrote: > Don't get me started on Harbor Freight.... > Peter Wieck > Melrose Park, PA     *resisting* *temptation* *of* *getting* *Peter* *started* *on* *Harbor* *Freight* ....

Cydrome Leader <presence@MUNGEpanix.com>: Apr 23 07:31PM > Hi Group, any recommendations for a good DMM, preferably a Fluke. under a $100.. are the ones made in China reliable.??? what kind do you use.???   What is the end use?

John Robertson <spam@flippers.com>: Apr 23 12:41PM -0700 >> Peter Wieck >> Melrose Park, PA   > *resisting* *temptation* *of* *getting* *Peter* *started* *on* *Harbor* *Freight* ....   "resistance is futile"   ('42' and all that)   John ;-#)#

Phil Allison <pallison49@gmail.com>: Apr 23 05:07PM -0700 Ralph Mowery wrote: =================   > I have a Fluke t100 that is made as an electricians test meter. I have > put it across some 240 volt circuits while set on ohms and no effect to > the meter.   ** That is not unusual, it is easy to protect the ohms ranges of a DMM from voltages up to 240VAC. Along with being ( almost) drop proof, it is one of the great benefits of DMMs compared with analogue types.   The main safety features of a good multimeter are that the 4mm plugs are self shrounding and the battery compartment needs a tool to access. Goes a long at toward preventing accidental contact with dangerous voltages.   Meters with unfused *high current* ranges are a hazard around car batteries and the like, as the leads can smoke, burn or even explode. Not likely at all with mains power as gross overload trips breakers *instantly*.   .... Phil

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Stu jaxon <stankowalski02@gmail.com>: Apr 22 05:55PM -0700 Hi Group, any recommendations for a good DMM, preferably a Fluke. under a $100.. are the ones made in China reliable.??? what kind do you use.???

Rheilly Phoull <rheilly@bigslong.com>: Apr 23 01:42PM +0800 On 23/04/2021 8:55 am, Stu jaxon wrote: > Hi Group, any recommendations for a good DMM, preferably a Fluke. under a $100.. are the ones made in China reliable.??? what kind do you use.???   Does Fluke make any that sell below $100 ?

"Peter W." <peterwieck33@gmail.com>: Apr 23 03:44AM -0700 > Does Fluke make any that sell below $100 ?   Used, perhaps.   And it would depend on the use and the need. My fluke, purchased new over 20 years ago, meets my needs nicely. But it is strictly for hobby purposes, and the occasional bit of troubleshooting around the house and various appliances and such. However, I very much appreciate that it is an accurate and reliable device, and made in the USA.   If one wishes to purchase a used DMM of any nature, please be sure that you are able to kick the tires prior to purchase. The better the scope, the more than might be wrong with it.   Peter Wieck Melrose Park, PA

Ralph Mowery <rmowery42@charter.net>: Apr 23 09:49AM -0400 In article <511c3a4d-8319-4ec2-86a0-6a0b8a1a0d6fn@googlegroups.com>, peterwieck33@gmail.com says...   > > Does Fluke make any that sell below $100 ?   > Used, perhaps.   > And it would depend on the use and the need. My fluke, purchased new over 20 years ago, meets my needs nicely. But it is strictly for hobby purposes, and the occasional bit of troubleshooting around the house and various appliances and such. However, I very much appreciate that it is an accurate and reliable device, and made in the USA.   > If one wishes to purchase a used DMM of any nature, please be sure that you are able to kick the tires prior to purchase. The better the scope, the more than might be wrong with it.   Fluke sells a few meters for under $ 100. I am not sure of the quality or how accurate they are. When buying a meter you need to know what features and how accurate you want them to be. If I don't care about much accuracery , I often just grab my old Simpson 260 analog meter.   I have 2 of the Fluke 87 meters that cost several hundred each. I also have a few of the 'free' Harbor Freight meters that are in various places around the house. They are good enough for some testing.   There does seem to be a few meters around that are good enough for the hobbist and home owner.

Andy Burns <usenet@andyburns.uk>: Apr 23 03:10PM +0100 Ralph Mowery wrote:   > Fluke sells a few meters for under $ 100. I am not sure of the quality > or how accurate they are.   They sell a few low-end models such as 12E, 17B, which I think are intended for sale only in China, but of course they turn up here in the UK on eBay etc, from just under to just over £100, e.g.   <https://ebay.co.uk/itm/Fluke/274104889982>   Personally I went for a Brymen 789.   Joe Smith on youtube does some pretty stressful tests on multimeters   <https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg/videos>

Adrian Caspersz <email@here.invalid>: Apr 23 03:35PM +0100 On 23/04/2021 01:55, Stu jaxon wrote: > Hi Group, any recommendations for a good DMM, preferably a Fluke. under a $100.. are the ones made in China reliable.??? what kind do you use.???   CAT III Measurement category minimum, with a decent set of leads. A manufacturer that will stand behind their safety certification as well as calibration.   Country of manufacture doesn't matter.   Ye want something that is not going to vaporise in a deadly fireball when placed across mains.   I have a few cheap DMM meters, of worth less than $10. They go nowhere near 240V.   -- Adrian C

Aoli <Aoli@Aoli.com>: Apr 23 07:41AM -0700 Personally I like the free DMM give away with purchase at Harbor Freight. Plenty of features including a transistor tester built in and accurate enough. Unfortunately they have stopped the free stuff. The only problems with the HF DMM is that the internal 9V battery requires a screw driver to open the case and replace the battery. So I have to buy a screw driver at HF. LOL   P.S. I had a Fluke DMM and it totally died. And not that old either. Very disappointing.

Ralph Mowery <rmowery42@charter.net>: Apr 23 11:28AM -0400 In article <s5umbi$uu0$1@gioia.aioe.org>, Aoli@Aoli.com says...   > P.S. I had a Fluke DMM and it totally died. And not that old either. > Very disappointing.   You should have gotten the 'free' screwdriver set. I have several of them.   It all depends on what one wants to do with the meters. For low voltage testing that does not need to be too accurate the HF meters are ok. The ones I have are within 5 % or less than the Fluke meters I have . I just don't like to put them on any thing over about 50 volts where there is plenty of current avaliable like the house wiring. I have a couple of good Fluke meters for that.   There seems to be plenty of DMMs out for less than $ 100. See if you can find one that is CAT rated. That is meters certified to be safe is you have them set for ohms or amps and put them across a voltage source. The meter may never work again,but an internal fuse will blow and make it safe . Some of the cheap meters may not do this but arc over internally and the leads melt in your hands and may put you across the voltage. Seeing some of the Fluke safety videos will make you think about that.   I have a Fluke t100 that is made as an electricians test meter. I have put it across some 240 volt circuits while set on ohms and no effect to the meter. Did that at work a lot on purpose for some tests.

Ralph Mowery <rmowery42@charter.net>: Apr 23 11:33AM -0400 In article <ieg49fF7ppnU1@mid.individual.net>, email@here.invalid says... > when placed across mains.   > I have a few cheap DMM meters, of worth less than $10. They go nowhere > near 240V.   I agree. I have several of the 'free' HF meters. They are fine for what they are. I don't put them across anything above 50 volts that is capable of supplying more than an amp.   For serious work I have a couple of the Fluke 87 meters and the good old trusty Simpson 260 and Amprobe analog meters.

"Peter W." <peterwieck33@gmail.com>: Apr 23 08:47AM -0700 Don't get me started on Harbor Freight....   Peter Wieck Melrose Park, PA

John Robertson <spam@flippers.com>: Apr 23 09:37AM -0700 On 2021/04/23 7:10 a.m., Andy Burns wrote:   > Personally I went for a Brymen 789.   > Joe Smith on youtube does some pretty stressful tests on multimeters   > <https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg/videos>   He has a great meter test box, nice work!   John :-#)#

Reinhard Zwirner <reinhard.zwirner@t-online.de>: Apr 16 07:09PM +0200 rbowman schrieb: >> They look like they are connected to transisors, but they have the 3 >> vertical lines, one of which in each set has a left-point arrow.   > https://byjus.com/physics/mosfet/   Umm.   <https://www.bilder-hochladen.net/files/big/12b4-yj-6269.jpg>   Somehow worried   Reinhard

mjmcl <mcl182@ipns.com>: Apr 22 07:50PM -0700 On 4/20/21 4:05 PM, bob prohaska wrote:   > handy is xoscope, available via apt on RasPiOS. It's installed, but > the man page gives no hint what sort of sound device, or general purpose > A/D converters, are supported.     visual analyser works on FreeBSD with WINE, but you're limited to soundcard/chip bandwidth and line level input voltages.

bob prohaska <bp@www.zefox.net>: Apr 23 02:51AM > From what I understand, most people who have tried both, prefer a > standalone scope over a PC based one.   Understood completely, if this were for routine use I'd agree. But, mine is a once-in-a-blue-moon use case. > money. The Rigol DS1054Z seems to be available for around $450. That > is a four-channel, 50 MHz scope. It can easily be hacked for 100 MHz > bandwidth.   That's better than I need by a wide margin, but it's tempting 8-)   Thanks for writing,   bob prohaska

John Robertson <spam@flippers.com>: Apr 22 10:39AM -0700 On 2021/04/21 9:04 p.m., bitrex wrote: >> The problem is the system doesn't work well...   >> John ;-#)#   > What's a "Wall-o-Matic"?   Commonly called "Booth Boxes" or "Wall-Boxes" these used to be (and still are in a few places) jukebox remote controls that displayed a list of the songs available and a coin acceptor and push button system to make your remote selection on the in-house jukebox.   Not unlike a dial phone in many ways - used a pair of steppers - one for the letter (up to twenty) and a second for the number (up to ten) to make a selection of one of up to two hundred songs.   Some photos here:   https://www.smbaker.com/converting-a-seeburg-3wa-wallbox-into-a-remote-for-a-modern-music-player   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

John Robertson <spam@flippers.com>: Apr 22 10:41AM -0700 >> Relevant schematic is on page 5128 (pg 16 or the PDF).   > Yikes. The tube pins all go to off-page connectors, so it's not easy.   The off page connections are mostly switches. I'll find the wiring layout diagram and post it a bit later...   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

John Robertson <spam@flippers.com>: Apr 22 10:43AM -0700 >> https://www.flippers.com/pdfs/Seeburg_V200_Pg_5113-5143_B&W.pdf   >> Relevant schematic is on page 5128 (pg 16 or the PDF).   > Yikes. The tube pins all go to off-page connectors, so it's not easy.   From the service manual - the sequence of operations guide:   https://www.flippers.com/pdfs/Seeburg_V200_Pg_139-154_Colour.pdf   John :-#)#     -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

John Robertson <spam@flippers.com>: Apr 22 10:48AM -0700 On 2021/04/22 6:35 a.m., bitrex wrote:   > So I still think the reason they end up malfunctioning in service is > that the gas is escaping or being absorbed by the glass and reducing the > operating temperature of the cathode may extend their life.   Not unlike He-Ne laser tubes out-gassing He through the glass and failing back when LaserDisk players were somewhat popular (80s).   John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

John Robertson <spam@flippers.com>: Apr 22 10:53AM -0700 On 2021/04/22 2:04 a.m., piglet wrote:   > Possible fets could be BSS126 or LND150 and SCR with sensitive gates > X0402NF or BT149G.   > piglet   Yes, that might work - at least as a starting point. Need to poke at the values a bit and keep the patent design in mind too - I suspect the sensitive gate SCR didn't exist then.   Thanks!   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

bitrex <user@example.net>: Apr 22 02:25PM -0400 On 4/22/2021 1:53 PM, John Robertson wrote: > sensitive gate SCR didn't exist then.   > Thanks!   > John :-#)#   Could use an optocoupler to level-shift the trigger pulse and a PIC...that's not much fun either, though...

Bill Martin <wwm@wwmartin.net>: Apr 22 03:52PM -0700 On 4/21/21 11:43 PM, bitrex wrote:   >> Another says it's xenon:   >> <http://phylab.fudan.edu.cn/lib/exe/fetch.php?media=exp:ajp000701.pdf>   > I think it must be xenon, the first one is just wrong   Nah, they are just xenon-phobic :-)

DecadentLinuxUserNumeroUno@decadence.org: Apr 23 01:09AM > Sounds like you have something to prove.   Your pschologist attitude is not matched by your education. Stay out of the personal assessment opinion crap.

bitrex <user@example.net>: Apr 22 09:35PM -0400 >> Sounds like you have something to prove.   > Your pschologist attitude is not matched by your education. Stay out > of the personal assessment opinion crap.   Have you given your inner child a hug today, though

Lucifer <LuciferMorningstar@bigpond.com>: Apr 23 07:47AM +1000 On Tue, 20 Apr 2021 18:09:04 -0700, dplatt@coop.radagast.org (Dave Platt) wrote:     >At a guess, I'd suspect that it might be any of the typical faults >which can develop in any laser-optical-based disc recording and >playback system:   Thank you for your reply. However minidisk uses magnetic recording and playback similar to a floppy disk. The laser is only used when recording to heat the disk and thus allow it to be altered by the magnetic write head.     >Power-supply problems e.g. deteriorating filter capacitors, loose >cables, intermittent contacts, etc. can also be a problem as these >devices age.   I would say those things are OK as it plays a disk I recorded but not disks recorded on another machine. I'm thinking it's out of alignment.   >None of the above is at all specific to your recorder model. If >you're serious about trying to fix it, I'd suggest getting the >model-specific service manual   That's a good idea.

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