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Jeff Liebermann <jeffl@cruzio.com>: Jul 26 09:05AM -0700 On Mon, 25 Jul 2016 16:31:01 +0000 (UTC), Aardvarks   >Heh heh. Yeah, if I only had a hot air SMT desoldering station, I could >change my MAC address too. :)   I bought mine on eBay for about $80. However, it's not quite as easy as reading all the data from the original chip, editing it, and putting it back. Many such eeproms have protected areas that can't be directly read. My luck in dealing with these has been dismal. Fortunately, such chips are priced a little higher than ordinary eeproms, making their use in price conscious consumer hardware rather limited. Some details: <https://www.maximintegrated.com/en/app-notes/index.mvp/id/3771>   >OK. But that's a lot of work to just get free WiFi from a WISP, and still >more has to be done so as not to get caught (which, I state, would be >virtually impossible and certainly not worth the $100/month WiFi fee).   Suggestions: When looking at costs, I try to annualize the numbers. To many financially marginal users, $1200/year is well worth the effort and would subsidize a fairly substantial collection of electronic burglar and reverse engineering tools.   >Yup. That was my point to the guy, nospam, who accused me of stealing my >WISP just because I knew enough about WISP to spout the words reasonably >coherently.   Oddly, I have the opposite problem. Because I know too much about wireless (and cellular) security, readers automatically assume that I spend my evenings in front of a computah, merrily hacking my way into as many systems as possible. This is hardly that case, but it does improve my otherwise lackluster and boring image.   >What I do know is that it wouldn't be easy for me, and even for you,   If it were easy, it would not be fun.   >This makes sense that the protocols they are all starting to use (except >Loren, and Herman was *always* using the new protocols) are for >communication reasons, and not for security.   Yep. Because these protocols often do not show up on Wi-Fi sniffer, finder, and site survey programs, they present a serious interference potential. I've been told that some have 802.11b compatible beacons, but I haven't seen any.   >Luckily, most of these guys are very nice guys (except Dave over by you who >is only exceeded in crassness by Brett, his Arizona support guy who has an >utterly amazing lack of customer service support skills.   Although we haven't talked in a long time, I don't have any problems with Brett. No clue on the rest of the company. Several friends and customers use their mesh wireless service. I don't hear any complaints, so I presume it mostly works.   >have fiber-optic backhauls, so, the way "I" understand it (I'm just a >customer though) is that they aren't limited by their backhaul but by the >number of access points they set up and their painting coverage.   The limiting factor is what I call "air time" or how much time it takes to send something. Since wireless is a shared medium, only one transmitter can use the bandwidth at a time. If that transmitter happens to be running extremely slow due or is spewing junk, there will not be enough "air time" to service the rest of the channel users. Details if you need them.   Incidentally, mountain tops tend to have fiber backhauls because that's all the telcos will provide these days. Copper is so 20th century and so unreliable.     >Wow, Jeff. Interesting picture. I've seen the insides of your routers, and >lots of your test equipment over the years, but that 1975 picture sure did >look beatnik hippy to me!   I used a bad title. It was really about 1970. I was scheduled to renew my drivers license and needed a suitable disguise. I shaved off the beard but kept the mustache after the license arrived. The common description was "motorcycle thug", not beatnik.   >Is that a park-ranger uniform? Big Basin?   Nope. I was cheap and tended to wear military surplus clothes, much to the irritation of my father, who owned a factory in the L.A. garment district. At the time, the industry was pushing "polyester blend" crap. I wanted cotton and the only way to get it at affordable prices was military surplus. I think I had about 20 identical shirts. I still do much the same thing today, but no more military surplus clothes.   >best but there was never the necessary SNR headroom of a half dozen to a >dozen decibels. I didn't even think about ACKS but the radio does >automatically adjust for distance.   It adjusts, but only to a point. If the timeout is less than the flight time, it will retry BEFORE the ACK is received. Many outdoor radios have a "long distance" check box in the settings to increase the timeout. Few home wireless routers have this feature.   >They told me that you can try, but the firmware won't let you, even though >it might *report* that it's over the legal limit.   Ignoring the legal limit, cranking up the power output to unreasonable levels usually causes the output stage to go non-linear. This is not a good thing and will produce distortion and errors. Better lower power and linear, than higher power and distorted. I found some photos where someone demonstrated this on a WRT54G, but can't locate the URL right now.   >figured we could transmit a strong signal to the Starbucks AP, but without >a far better antenna, the signal from Starbucks would never get back in >sufficient 6 to 10 decibel strength over the noise to us.   That would probably be the major limitation. However, it won't be because of insufficient RF from Starbucks. It will be because even the narrowest beamwidth dish antenna at your end, will pickup hundreds of other wi-fi devices along the line of sight. Starbucks signal will be buried under the interference.   Try Fing on your iphone or Android device at the local wi-fi hot spot: <https://play.google.com/store/apps/details?id=com.overlook.android.fing&hl=en> It will give you a list of what is connected to the local wireless router. If you look through the list, you'll also get a list of wireless cards and devices, which can usually be helpful in identifying the hardware. It's quite common to find desktops and outdoor client bridge radios, which are not what one would expect to see at Starbucks. I know one local hot spot that routinely has between one and three Ubiquiti radios connected.   Gone to replace the LNBF on a C band dish for the 4th(?) time. It's not tower work but still slightly dangerous.   -- 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

N_Cook <diverse@tcp.co.uk>: Jul 26 11:23AM +0100 As though a thermal protect measure is cutting in falsely, but all valve. 10 minutes at gig level, longer at practise level, initially looses bass and then over a couple of minutes vol drops to uselessly low. Switch off ,cool down, and fine again. I'll check with a variac, to simulate gradual loss of DC, but is that the symptom sequence of loss of DC to a valve amp, lose bass then lose vol. Valves have been swapped out , but not the rectifier bottle, likely suspect?, a saggy 2x4007 lump will go in there initially to check that. A hot-air gun looks a promising tool. No hum reported, unlikely a major cap problem,a minor cap problem, surely not a Tx problem

Phil Allison <pallison49@gmail.com>: Jul 26 04:45AM -0700 Nutcase Kook wrote:     ** The model number is wrong or incomplete.   There ain't no " JTM 1982 "   The number 1982 refers to a Quad box.   Maybe it's a JTM45 re-issue.       .... Phil

N_Cook <diverse@tcp.co.uk>: Jul 26 12:47PM +0100 With 8V 400Hz over 8R dummy load, no drop off seen after 10 mins. Preheated rect bottle with low setting hot air and 10V over 8R, and short bursts of extra directed heating and a see-sawing of output, then over 10 seconds or so extreme swinging down to 1V or so and over 10V or so repetitively, tremolo type speed. At least I've shown there is a problem unlike the other 2 "repair" people who've looked at this amp, returned without fixing it . Next step to repeat with hot air, monitoring the DC and then try SS rect

N_Cook <diverse@tcp.co.uk>: Jul 26 03:01PM +0100 Could not repeat while monitoring the HT. So as I can't believe an electrode or 2 failure,or whatever, in the GZ34 had cured itself by my external and internal heating, just a coincidence and some other problem? With original failure returning immediately to full volume, without cooling down, might suggest a "cured" internal problem. I tried heating the pcb with hot air and no return to failure mode. So valve test the GZ and the other valves, put a saggy SS dual rect in there after checking the GZ valve base. Some heavy prolonged testing and return to owner with fingers crossed?

frank <frank@invalid.net>: Jul 25 07:07PM Hi all, I'm repairing this old PAL test pattern generator. The worst problem is mechanic so far: all the presets push-buttons for VHF and UHF are blocked. I have removed the whole RF generator assembly out of the instrument but now, I'm not understanding how to access the internal mechanism of every preset so I can clean it. It seems that the whole assembly has to be taken apart to reach the rotating parts. There's only a very bad quality service manual on the net and it doesn't have mechanical diagrams it seems. Does anyone know better? Thanks in advance Frank IZ8DWF

N_Cook <diverse@tcp.co.uk>: Jul 25 09:18PM +0100 On 25/07/2016 20:07, frank wrote: > Does anyone know better? > Thanks in advance > Frank IZ8DWF   I pulled the complete pm5507 manual off the shelf, probably 1966. No exploded views or dismantling details

frank <frank@invalid.net>: Jul 26 08:09AM > On 25/07/2016 20:07, frank wrote:   > I pulled the complete pm5507 manual off the shelf, probably 1966. > No exploded views or dismantling details   thanks for trying! I'm going to spray the mechanics from outside and hope it will unlock the presets. I've found on the manual how to align the tuning mechanism after removing one (or both) the RF assemblies, but I'd rather avoid doing that. All the electronics appear mostly OK, probably a lot of the old electrolitics will need to be replaced. Frank

frank <frank@invalid.net>: Jul 26 01:15PM > preset so I can clean it. It seems that the whole assembly has to be taken > apart to reach the rotating parts. There's only a very bad quality service > manual on the net and it doesn't have mechanical diagrams it seems.   I could unlock all the presets. There's enough room from the top of the mechanism to spray on all the screws and unlock the tuners. A bottom plate can be removed to better access the 4 rightmost tuners. After that, the knobs have to be freed from the shaft as it turns out that they need to slide in and out to allow both tuning and latching of the presets. If they don't slide, it's impossible to latch the preset in the IN position. Now there's one final problem, the knobs look too short! If I install the knobs again, the presets don't latch anymore, the internal shaft has not enough room to extend far enough to allow the mechanism to reach the latching position. This is really puzzling, how can this happen? The knobs are the only platic parts, so I guess they might have shrank just a little. I may have to try working the internal end with a drill bit to make the necessary clearance. This repair is requiring lots of time so far.   Frank

N_Cook <diverse@tcp.co.uk>: Jul 21 09:26PM +0100 > look up the data sheet for the active devices on the board.   > often the data sheet will have schematics for example applications and often the UUT is pretty much exactly like the app notes.   > M   Perhaps the supervisor IC, nothing of use on driver http://datasheet.octopart.com/STW11NM80-STMicroelectronics-datasheet-24223.pdf

"Gareth Magennis" <soundserviceleeds@outlook.com>: Jul 21 09:51PM +0100 Failure of this cap blew the PCB mounted mains fuse, rendering the unit dead and requiring repair, so this is definitely a known issue.     Gareth.

"Gareth Magennis" <soundserviceleeds@outlook.com>: Jul 21 09:32PM +0100 wrote in message news:24311c0a-ea31-4180-8dd8-16e7cb545f72@googlegroups.com...     > > the three paralleled resistors which are very low ohmage and I guess > > current sense at ground, the other goes to the first pin of the > > transformer which is at high HT.   another way to figure it our is this...   look up the data sheet for the active devices on the board.   often the data sheet will have schematics for example applications and often the UUT is pretty much exactly like the app notes.   M               Cheers, I am being a bit lazy, but you do tend to learn a few things by asking questions here as well :)   http://www.farnell.com/datasheets/87884.pdf?_ga=1.33261950.1327271115.1429123757   Page 2 - the cap is probably a small bypass cap not on the schematic on the transformer HT winding to ground.       Thing is, this component looks like the achilles heel in this particular design, unless duff components were sourced. Else something else is blowing the component.       Gareth.

N_Cook <diverse@tcp.co.uk>: Jul 21 09:38PM +0100 On 21/07/2016 21:32, Gareth Magennis wrote:   > Gareth.   The Rs and C connected to CS pin3 of the supervisor?   http://www.onsemi.com/pub_link/Collateral/NCP1203-D.PDF

"Gareth Magennis" <soundserviceleeds@outlook.com>: Jul 21 07:31PM +0100 Hi,   can't find any schematics for this module - its a Bang & Olufsun combined SMPS/Class D audio amp PCB.   The one I have has the exact same fault as this one: http://forum.recordere.dk/uploads/36113/icepower3.jpg     Blown cap (presumably), but no way of finding out what it was. There are other photos on the Interweb of this board which show the unmarked device not blown up.   There's about 330v DC across the remains, and my amp module still works without it.       This is in a powered Studio Monitor Sub, seems these modules are reasonably popular in this kind of thing - B&O would not sell these to the public, though I read on a forum while Googling today that they might now, but are prohibitively expensive.     Any smart guesses what I should be putting in there? One end goes to the three paralleled resistors which are very low ohmage and I guess current sense at ground, the other goes to the first pin of the transformer which is at high HT.     Cheers,     Gareth.

N_Cook <diverse@tcp.co.uk>: Jul 21 12:09PM +0100 Stock fault ? Phones o/p but no sp o/p. Both pcb traces to the main bridge rects fried. 2xLM3886 seem ok cold DVM "test". Both main caps good ESR and capacity, diodes test ok. Both main caps bowed ends and one with brownish dried "wax" at the cross, presumably electrolyte but no hole seen. All the caps on the PA are Xunda, don't remember seeing that name before, suspect? presumably China. Main caps are radial Xunda RK series, 3300uF,50V 105 deg C, the supposed glue to the pcb has (heat?)failed and they can flop around on axial-type gauge of terminals, not snap-in.

c4urs11 <c4urs11@domain.hidden>: Jul 21 08:42PM On Thu, 21 Jul 2016 16:30:56 -0400, Ralph Mowery wrote:   > CCIR Mainly countries of or were of the British Empire   It would be troublesome to image the Empire calling it then "Comité Consultatif International des Radiocommunications".   Cheers

Ralph Mowery <rmowery28146@earthlink.net>: Jul 21 04:30PM -0400 In article <KL9kz.5883$zu3.1431@fx21.iad>, Chipbee40_SpamNo@yahoo.com says...   > Amplitude of the input signal has no effect as long as its large enough > to register.   > TIA.   The JIS, CCIR, and DIN are standards set by different countries.   JIA Japan CCIR Mainly countries of or were of the British Empire DIN Germany   You probably will not be able to adjust for all 3 countries standars at once.       --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

JC <Chipbee40_SpamNo@yahoo.com>: Jul 21 04:36PM -0400 On 7/21/2016 4:30 PM, Ralph Mowery wrote:   > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus   This is the Leader LFM-3160, there is a switch for each JIS, CCIR, DIN.

JC <Chipbee40_SpamNo@yahoo.com>: Jul 21 05:47PM -0400 On 7/21/2016 5:37 PM, Bob wrote:   >> TIA.   > Are you sure the modulation is a since wave (See Phils post above). This looks like a peak to average of a square wave pulse. I would try an actual analog generator with low distortion (in the 4 hz tone also) modulated and calibrated like Phil suggested. One way to check if I am correct is to listen to the tone and see if its frequency smoothly goes up and down or just snaps between high and low points. If it is hard to hear set the mod rate to 1 hz instead of 4.   > ...Bob   Yes, a possibility but I tried a square wave and I still get JIS giving half the value of CCIR/DIN. A.Audition seems to generate a decent waveform, I'm monitoring the signal on a scope so I know what I'm inputting.

"Michael A. Terrell" <mike.terrell@earthlink.net>: Jul 21 01:53PM -0400 John Robertson wrote:   > Did the Senco company get sued out of business by the widows?     I've heard that they changed their name to Sencore in 1957.

"Gareth Magennis" <soundserviceleeds@outlook.com>: Jul 19 10:37PM +0100 Christopher, can you perhaps leave "Jesus" out of your threads? It's very irritating.     Cheers,     Gareth.

jurb6006@gmail.com: Jul 25 11:55AM -0700 >" Sorry, I posted to the wrong repair group! > Mikek "   HA, have you noticed the off topic posts around here lately ?

amdx <nojunk@knology.net>: Jul 19 08:41PM -0500 I have 13 chest type freezers, a couple of upright freezers and a two Ice Machines having to do with my business. The freezers are not always in use, so are shut off until needed. I have one or two that will leak out if the are shutoff, so we no long shut them off, we either leave them on when empty or move items in from another freezer that we can shut off.   Question one)   Explain to my why the freezer will leak refrigerant when it is off but not on.   Question two)   Sometimes when I go to restart a freezer after it is off for a few weeks or month, it does not want to start. The breaker in the compressor just keeps cycling. Usually after enough time passes It finally starts and will run fine from then on. Why?   Question three)   I would like to get enough education to be able to add refrigerant when a freezer needs it. The electrical part I have a good handle on, I have gauges and have no problem installing a Piercing type Shrader Valve. I need to know how to decide if a problem is caused by low refrigerant, I'm not one to just do something because that's what I know, I want to troubleshoot and come to a logical conclusion.   Has anyone seen a good video that helped or a book that is focused on home freezer?   Help is appreciated.   I have a brother in law that does refrigeration and he usually fixes things when needed. He never charges me enough and I don't like to have him do it because of that.   Mikek

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