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"David Farber" <farberbear.unspam@aol.com>: Mar 01 07:26PM -0800 I have an intermittent Shure wireless UT2 mic/transmitter. The user said that tapping on the mic when it wasn't working would restore its operation but now even that doesn't help. I would like to have look inside but I don't see a simple way of opening it. I removed the windscreen and there is a label that says, "Caution do not attempt to open or turn. Warranty will be voided." I wanted to know if turning the microphone will damage the wiring going to it or if that warning is just telling you to, "Keep out!."   I found some disassembly instructions here that did not mention anything about "turning" the mic as dangerous. https://shure.custhelp.com/app/answers/detail/a_id/3447/~/disassembly-of-a-handheld-transmitter%3A-t-series-and-others   Thanks for your reply. -- David Farber Los Osos, CA

Phil Allison <pallison49@gmail.com>: Mar 01 07:55PM -0800 David Farber wrote:   > I found some disassembly instructions here that did not mention anything > about "turning" the mic as dangerous.   > https://shure.custhelp.com/app/answers/detail/a_id/3447/~/disassembly-of-a-handheld-transmitter%3A-t-series-and-others     ** The head screws off easily and holds the mic capsule, normally an SM58.   The main electronics are trapped under a large C-clip:   http://i.ebayimg.com/00/s/MTU0OFgxNjAw/z/EMkAAOSwUuFWxVdj/$_1.JPG   The instructions you cited seem accurate but may well be not needed.   COS you have NOT said if just the audio cuts out or the RF carrier stops.   You do have the receiver, don't you ?   More info please.       .... Phil

"David Farber" <farberbear.unspam@aol.com>: Mar 01 08:34PM -0800 Phil Allison wrote:   > You do have the receiver, don't you ?   > More info please.   > .... Phil   Hi Phil,   I have the UT4 receiver. The green power l.e.d. illumintates on both the mic and the receiver but neither of the antenna receiver lights (A or B) illuminate. The mute switch on the mic seems a little wonky. There is a lot resistance (physical) moving it to the mute position and almost no resistance moving it back to the "on" position. Does enabling the mute switch turn off the RF?   Thanks for your reply. -- David Farber Los Osos, CA

Phil Allison <pallison49@gmail.com>: Mar 01 08:38PM -0800 David Farber wrote:   > label that says, "Caution do not attempt to open or turn. Warranty will be > voided." I wanted to know if turning the microphone will damage the wiring > going to it or if that warning is just telling you to, "Keep out!."   ** Hang on a mo - you are trying to take apart the Cartridge Assembly - right ?   1. Put the wind shield back on.   2. Run the transmitter and see if it outputs a carrier.   3. If 2 is OK, connect an audio signal ( via a cap) to the "AUD IN" terminal on the transmitter and see if you can hear it coming out the receiver.   4. If 4 is OK, the capsule is the problem. 5. There is an SMD board that is a pre-amp for the SM58 capsule - removing it is tricky but IIRC the capsule is attached to it.   Shure consider it to be non repairable, but you may as well have a go if it is the problem. In your case it might be a bad solder joint on the 58 capsule itself.     .... Phil

Phil Allison <pallison49@gmail.com>: Mar 01 08:49PM -0800 David Farber wrote:   > I have the UT4 receiver. The green power l.e.d. illumintates on both the mic > and the receiver but neither of the antenna receiver lights (A or B) > illuminate.   ** So no RF OR maybe the frequency is off.   Do you have a frequency counter that works at UHF ?   If so, use that to see if there is a carrier and at what frequency - just hold the mic right next to a short antenna plugged into the input.     > resistance (physical) moving it to the mute position and almost no > resistance moving it back to the "on" position. Does enabling the mute > switch turn off the RF?   ** No, it just mutes the audio.   Last one of these beasts I saw had a problem with the frequency synthesiser inside the mic handle. It was outputting a carrier frequency the receiver did not work on. Off by only 100kHz from one of the available ones, but that was enough - plus the buttons on the mic did nothing to change that frequency.   The local Shure agents supplied a new mic at trade price to my customer, cos that had no way to fix it either.     .... Phil

"David Farber" <farberbear.unspam@aol.com>: Mar 01 09:11PM -0800 Phil Allison wrote:   > The local Shure agents supplied a new mic at trade price to my > customer, cos that had no way to fix it either.   > .... Phil   I have a frequency counter... a Heathkit I built around 1982 I believe its upper range is 30MHz. I was thinking if I could open up the transmitter, maybe there was some minor physical damaged caused by some rough handling around the mute switch area. Getting back to the disassembly question, can I just unscrew the mic capsule? I don't want to force it but if it's ok to safely remove it that way, then I'd like to get to the internal circuitry.   Just to make sure you understand which mic/transmitter I have, you can see a picture of it here. http://www.shure.com/user-guides/us_pro_ut_wireless_en_ug.pdf on page 6, Figure 5.. I do not see any "AUD IN" on the transmitter.   Thanks for your reply. .-- David Farber Los Osos, CA

Phil Allison <pallison49@gmail.com>: Mar 01 09:24PM -0800 David Farber wrote:   > > customer, cos that had no way to fix it either.   > I have a frequency counter... a Heathkit I built around 1982 I believe its > upper range is 30MHz.   ** No use at all.     > I was thinking if I could open up the transmitter, > maybe there was some minor physical damaged caused by some rough handling > around the mute switch area.   ** The mute switch doe not stop RF.   > Getting back to the disassembly question, can I > just unscrew the mic capsule? I don't want to force it but if it's ok to > safely remove it that way, then I'd like to get to the internal circuitry.   ** The head should unscrew easily, then the C-clip as previously stated.   Be CAREFULL, the buttons that operate the switches are FRAGILE.   BTW:   Do you know the mic's frequency ??   The handbook gives tables for code letters and actual frequencies. Do you have a radio scanner that covers the UHF band ??   You MUST have a counter or a radio scanner or you cannot service radio mics.       .... Phil

"David Farber" <farberbear.unspam@aol.com>: Mar 01 10:09PM -0800 Phil Allison wrote:   > You MUST have a counter or a radio scanner or you cannot service > radio mics.   > .... Phil   I do have a scanner. It's a Bearcat BC125AT. It will receive analog only. I do no plan on making a habit out of servicing radio mics but this is for a charity.   There is a label near the battery that says, 623.350 MHz FM. According to my scanner's user manual the upper limit of the UHF band is 512 MHz. I'm guessing that's not going to work.   Thanks for your reply. -- David Farber Los Osos, CA

"Michael A. Terrell" <mike.terrell@earthlink.net>: Mar 01 01:26PM -0500 >> "It all about raising up the plate supply voltage while keeping the screen supply under 400V - plus matching the load correctly. "   > Seems to me to would have to load is pretty heavily, not just to get the power, but also to try to keep the plate volage down. If you go to 2X 700 volts, it might not be a matter of the tubes, it might be the tubes sockets.     They used a lot of ceramic tube sockets in transmitters. :)       -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

Michael Black <et472@ncf.ca>: Mar 01 01:54PM -0500

oldschool@tubes.com: Mar 01 01:33PM -0600 >> They used a lot of ceramic tube sockets in transmitters. :)   >ANd the really good tubes had plate caps.   > Michael   I can relate to using ceramic sockets, because the standard ones would likely burn up from such high voltages. * What are the standard sockets made out of anyhow????   Considering the closeness of the tube socket pins, I could see where there could be arcing between pins at voltages that are or exceed 1000V. Plate caps eliminate that problem. However, I would assume that the wire going to those plate caps would need to have insulation capable of the voltage, and where they go thru the chassis, would need grommets that can handle the voltage too. Not to mention the connections below the chassis such as terminal strips.   I have not worked with any voltages exceeding 1000V (except the HV in the old tv sets). But since I am on a farm, I know what an electric fencer can do. If a fence wire gets too close to a tree (for example), it will snap and shoot a spark a half inch long, or longer. Most of those fencers are around 5000 V. Those fence wires are all run on porcelin insultors. (although there are now plastic ones that work as well).   I have felt them fences far too many times too..... I have been literally knocked down from them more than once, if I was well grounded.... NOT FUN. :(   Fortunately those fencers do not kill a person or animal (or we would not use them, since livestock are expensive and dead people are not a good thing). The voltage is high, but the current is low. (and it pulses).   Anyhow, while I have not done it, I am sure building transmitters (or anything else) using those high voltages, require special components and wiring, which in itself requires special knowledge.

Ralph Mowery <rmowery28146@earthlink.net>: Mar 01 03:36PM -0500 In article <t37ebcpgloi0idj7v42jksdni0v7jd9277@4ax.com>, oldschool@tubes.com says...   > Anyhow, while I have not done it, I am sure building transmitters (or > anything else) using those high voltages, require special components and > wiring, which in itself requires special knowledge.   I have 2 amplifiers for my ham radios. Both have about 2700 volts on the plates of the tubes. The current drawn by the tubes is almost one amp. I have worked on them several times. To do that I make sure the capacitors have fully discharged by watching the voltmeter on the amps go near zero. When I take the cover off, vurey carefully, I then short the capacitors to ground to make sure the volt meter is not giving a false reading. The voltage and current is not like a fence charger. It will dump a lot of current into you and often kill. Fence chargers are more like a static electricity shock, lots of voltage,but little current. They are made to shock and not to kill.   It does take some special insulated wire for the amps and other high voltage items. Most common wires are insulated for around 600 volts or even 300 volts. That 2700 volts will often burn through wire insulated like that . Only 'good' thing about it,is that it will not jump much of an air gap. However with RF applied the operaing voltages inside the amp is somewhat greater and can arc a short distance.   Most of the tubes operate with less than 500 volts on the pins with the higher voltage going to the cap on the plates. Ceramic is often used because of the heat on the pins of the tubes. The filiments get hot and direct transfer heat, and the heat of the plate is radiated to some extent. Afer all, if an amp is putting out 1000 watts it is using close to 1500 to 2000 watts to do it. That is almost as much as some of the smaller 'bathroom' portable electric heaters put out.

Phil Allison <pallison49@gmail.com>: Mar 01 03:15PM -0800 > >"It all about raising up the plate supply voltage while keeping the > >screen supply under 400V - plus matching the load correctly. "   > Seems to me to would have to load is pretty heavily, not just to get the power, but also to try to keep the plate volage down.   ** The load impedance is doubled, since the max tube current cannot increase.   Double voltage into double load = double the power.     > > If you go to 2X 700 volts, it might not be a matter of the tubes, > >it might be the tubes sockets.   ** Most sockets can handle the extra voltage.   > What does limiting the G2 do ?   ** Keeps the screen current within limits.   Having the screens glowing bright is the biggest killer of power tubes.     .... Phil

jurb6006@gmail.com: Mar 01 07:38PM -0800 >"** The load impedance is doubled, since the max tube current cannot increase.   Double voltage into double load = double the power. "   I think you got this fucked up somehow. When the load impedance is halved then the power is doubled. I'll put it down as a typing error unless you argue the point.   What's more, double the voltage into the same load if four times the power, not two.   >"Having the screens glowing bright is the biggest killer of power tubes."   Perhaps you are older and thus have more knowledge then I on some of this. From what I understood from the old days, tubes (valves) generally break down due to the cathode nit being able to put out current, and that is where all the current comes from.   However of course there can be other failure modes. Are you saying that some sort of arc or leakage is damaging the valve ? If so I would like your explanation of this failure mode.

Clifford Heath <no.spam@please.net>: Mar 02 03:05PM +1100 >> "** The load impedance is doubled, since the max tube current cannot increase.   > Double voltage into double load = double the power. "   > I think you got this fucked up somehow. When the load impedance is halved then the power is doubled.   Phil meant "double the load impedance". Not half. If you do that and double the voltage, current is the same, so power is only doubled.   Clifford Heath.

Phil Allison <pallison49@gmail.com>: Mar 01 08:11PM -0800 > >"** The load impedance is doubled, since the max tube current cannot increase.   > Double voltage into double load = double the power.   > I think you got this fucked up somehow.   ** Like hell I did.   Try reading it AGAIN !!!   IF you double the voltage into double the load, the CURRENT stays the same.   But double the voltage at the same current is TWICE the power.   Power = V x I     > current, and that is where all the current comes from.   > However of course there can be other failure modes. Are you saying > that some sort of arc or leakage is damaging the valve ?   ** Any data sheet will quote max screen dissipation - usually only a few watts.   The fine steel wire will glow red or even white if the rating is exceeded.   Then guess what happens ??   If the screen supply voltage is too high, it take excessive current whenever the plate voltage swings low under load.   Data sheets reveal this as an increase in AVERAGE screen current at max signal.   Screen dissipation = V x I average.       .... Phil

ohger1s@gmail.com: Mar 01 01:10PM -0800 Looking for a datasheet for an O2micro device OZ9908BGN This is a 32 pin DIP SMD package.   There are datasheets on-line but all of them are so low resolution that the pin callouts cannot be read.   I've tried two dozen downloads and they're always the same. I'll even be thrilled to have the schematic of *any* LED driver (TV use them) circuit that uses this chip.

"pfjw@aol.com" <pfjw@aol.com>: Mar 01 01:52PM -0800 I suggest you call Mouser or DigiKey, or another supplier that stocks this device and ask them to scan you a high-res datasheet. Better yet, the manufacturer if they have either e-mail or a US rep.   I have found Mouser very helpful to this end.   Peter Wieck Melrose Park, PA

jurb6006@gmail.com: Mar 01 07:48PM -0800 I have to second this. The people who sell them want you to know EVERYTHING about them.

jurb6006@gmail.com: Mar 01 07:19PM -0800 Yeah, and if you read your inbox you would know that most of Usenet is dropping you, and that includes paying members.   You just made all the links we had unusable, just like that ? FUCK YOU.   You people just fucked yourselves really good. Don't even try to get into this business anymore. i can get hosting for the little bit I use for about three bucks a year. You will never be able to compete with that.   And your "noreply" are a fucking joke, you really think that I think you can't read this ? You are not playing with kids here.   Sorry, I am going to have to give some schlameal like five bucks a year now. Big fucking deal.

oldschool@tubes.com: Mar 01 01:59PM -0600 This video is worth watching....   https://www.youtube.com/watch?v=C3_-2fUm6y0   1000 Watts audio at Full Power.....   (Lets see you do this with a solid state amp) :)

Phil Allison <pallison49@gmail.com>: Mar 01 04:59PM -0800 > This video is worth watching....   > https://www.youtube.com/watch?v=C3_-2fUm6y0   > 1000 Watts audio at Full Power.....     ** The blue glow is caused by *fluorescence* - fast electrons striking the glass of the tube excite minerals on the surface.   Cerenkov radiation is a very different thing, happening only with particles that are travelling close to the speed of light.     .... Phil

Stijn De Jong <stijndekonlng@nlnet.nl>: Mar 01 06:33PM I was hiking today and my phone switched from reporting EDGE and then HSPA and then HSPA+ when I started wondering what practical significance to a user these terms might be.   Have you ever needed to know this information? Has it been useful to you?   HSPA http://i.cubeupload.com/QxYc3v.jpg HSPA http://i.cubeupload.com/mTTuMA.jpg HSPA+ http://i.cubeupload.com/RXx4QM.jpg   Other terms that pop up in those screenshots are: http://i.cubeupload.com/QxYc3v.jpg 2.5G (this is the only one that was 2.5G) RXLEV (none of the others had an RXLEV field) SDR (what does the "R" mean for example?)   http://i.cubeupload.com/mTTuMA.jpg http://i.cubeupload.com/RXx4QM.jpg 3.5G (the two hspa ones showed also as 3.5G) PSC (the two hspa ones showed also a PSC)   The main question is whether you've ever had a need for this type of information?

"pfjw@aol.com" <pfjw@aol.com>: Mar 01 12:04PM -0800 The troll is back. PLEASE DO NOT FEED THE TROLL.

Stijn De Jong <stijndekonlng@nlnet.nl>: Mar 01 06:25PM On Wed, 01 Mar 2017 00:48:31 -0500, micky wrote:   > I just searched on the subject in my list of posts (another advantage of > off-line readers.) Then I looked for the day an date.   That works also. Especially since it was very recent, so everything is up to date.   > But from the post you referred me to, I found 4 that sound quite nice. > However I'm like a duck, and I like most whatever I have imprinted on, > so I'm startign with the one I looked at in this thread.   The cost of freeware is finding a good one. If I had to recommend a single program, it would be the one you chose.   It reports more information than I understand, but what matters most is the signal strength coupled with the exact micro or femto tower you're using (bearing in mind all the neighbors have them also so you wouldn't know whose you're connecting to if you don't know the unique cell tower cellid.   >>The goal is for each user to improve upon the tribal knowledge of all.   > I'll try to do my share.   The main confusion I have, especially since I don't do cellular data at home, is the functional practical significance of all these acronyms: EDGE http://i.cubeupload.com/QxYc3v.jpg HSPA http://i.cubeupload.com/mTTuMA.jpg HSPA+ http://i.cubeupload.com/RXx4QM.jpg > I've only installed network Cell Info Lite and it has more information > that I can absorb. Phone and wifi. And it knows all about both sim > acrds etc.   I only have one SIM card, so that's nice that it tells you what you need for both, especially if they use different carriers.   > On map, it has a red line that I t hought would point toward the tower, > but it points** towards a strictly residential area.   That whole online-database tower-map stuff is crowd-sourced data, which may or may not be accurate. It's all that the iOS users can do, so, it's certainly better than absolutely nothing, but if you have an Android phone, you can obtain the exact cell tower ID, which if you want to know where it is, and if it's a major tower (not someone's home femtocell like I have), then it will be on a map somewhere.   You have to be very careful about the open-source tower databases though because they don't locate the tower - they locate the *average* of all the cellphones that report that tower to the app developers.   Again, it's all that the iOS people have, but if you have an Android phone, you have the real tower id (which you can get the location from more reliably from carrier maps).   > towers right next to the supermarket I go to about 4 blocks away, I > figured one was mine, but it is ignoring both of them. Sometime I will > take the phone over there and see what it says.   Bear in mind from the tower ID, in some cases, you can figure out exactly which sector antenna you're connected to! They have three sectors, alpha is north, beta is southeast, and delta is southwest. Each carrier uses a different system, but it's documented somewhere how to figure out which sector antenna you're connected to (if it is a sector antenna) just from the cell tower id.

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