sci.electronics.repair@googlegroups.com

Google Groups

John Robertson <spam@flippers.com>: Feb 28 10:37PM -0800 >> the picture shifts sideways until it loses the lock.   >> John :-#(#   > I wonder if you're describing what we used to call "piecrusting". Most of that was was from leaking HV. Remove the HV rectifier and see if there's any green schmutz in the contacts. Any corrosion will cause arcing.   Sorry, been busy. The diode is soldered directly to the HV leads. So a bad connection is out. The HV probe does not show any obvious signs of jitter, but I suspect that would be the case seeing as the tube is a giant capacitor and would smooth over most noise.   I also pulled the LOPT/Flyback and did both a ring test and a leakage test - it passed both just fine, good ring count, and no appreciable leakage using my old Heathkit R/L/C Bridge Cap checker (1960s - with Magic Eye tube!).   Additional comments in response to other posts on this topic...   Thanks,   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

John Robertson <spam@flippers.com>: Feb 28 10:53PM -0800 On 2017/02/27 8:59 AM, Chuck wrote:   > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus   Hi Chuck,   Thanks for the suggestions - I tried all that and no improvement in the image quality. I used a couple of 1N43 Germanium diodes in place of the AA143s, but (as I said) no change.   The only place I can 'see' a problem is when I monitor the cathode of the picture tube. The horizontal section appears quite stable with no flicker showing on my fast Tectronics scope.   Images:   Video - jitter on screen:   http://www.flippers.com/images/Horizontal_jitter_on_TEC_monitor.MOV   Scope - base of Horizontal drive:   http://www.flippers.com/images/Horizontal-drive-@-base   Scope - base of final video amp:   http://www.flippers.com/images/Base_of_final_video_amp   Schematic - base of final video amp (wrong version of schematic here though):   http://www.flippers.com/images/Base_of_final_video_amp-scope   Appreciate any other suggestions. I haven't yet tried replacing the resistors in the feedback loop, however the jitter doesn't show in the loop...   Thanks!   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

Phil Allison <pallison49@gmail.com>: Feb 28 03:17PM -0800 Michael Terrell wrote:   > > EL34s can also be used the same way to deliver 100W.   > > Guitar amps made by MusicMan and Dynacord are commercial examples.   > He asked about the 6L6,   ** The OP asked about "common audio output tubes" which the original 6L6 is not.   It's an all metal, museum piece.   6L6GCs have been the most common type sold for audio use for decades.       .... Phil

"Michael A. Terrell" <mike.terrell@earthlink.net>: Feb 28 07:39PM -0500 Phil Allison wrote:   > ** The OP asked about "common audio output tubes" which the original 6L6 is not.   > It's an all metal, museum piece.   > 6L6GCs have been the most common type sold for audio use for decades.       Yes, but the 'Amateur radio transmitters' he's talking about are from the '40s and '50s, which were shipped with the original metal 6L6, not the later glass versions. A lot of them were built with W.W. II surplus tubes, of which the 6L6 was readily available as surplus into the '70s.   We aren't talking about stereos or guitar amps. The were audio outputs for radios, or modulators for medium power AM transmitters designed for Amateur radio service. I was servicing these radios back in the '70s. That is four decades ago.     -- 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>: Feb 28 06:08PM -0800 Michael Terrell wrote:   > Yes, but the 'Amateur radio transmitters' he's talking about are from > the '40s and '50s, which were shipped with the original metal 6L6, not > the later glass versions.       ** Read correctly, the OP was not asking about transmitters at all.   The performance of some common tubes for audio output use was his topic.       .... Phil

"Michael A. Terrell" <mike.terrell@earthlink.net>: Mar 01 12:26AM -0500 Phil Allison wrote: >> the later glass versions.   > ** Read correctly, the OP was not asking about transmitters at all.   > The performance of some common tubes for audio output use was his topic.   QUOTE:   I was looking at some old 813 tubes that were once commonly used for Amateur radio transmitters, as the final output tube. While the common audio output tubes like 6L6 and 807 can produce about 25 to 30 watts audio output (per tube), running around 300 to 450 volts plate voltage,   UNQUOTE:   -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

Clifford Heath <no.spam@please.net>: Mar 01 05:18PM +1100 On 01/03/17 16:26, Michael A. Terrell wrote: > audio output tubes like 6L6 and 807 can produce about 25 to 30 watts > audio output (per tube), running around 300 to 450 volts plate voltage,   > UNQUOTE:   So you agree, OP was not asking about transmitters? He also wasn't asking about 6L6's of either type! (though his reference to 30W/tube says he meant 6L6GC).   He was asking about 813 (transmitting) tubes in an audio amp.   Phil was right. Now can we please end this pissing match?

micky <NONONOmisc07@bigfoot.com>: Feb 28 02:40PM -0500 In sci.electronics.repair, on Tue, 28 Feb 2017 05:15:08 +0000 (UTC), >signal from -100 dBm to -50dBm at home using these three free devices from >the carrier: >http://i.cubeupload.com/sSOph0.jpg   These seem to be for LTE.   >I used my Android phone to check exactly which of the three devices worked >best to give me the best cellular signal strength: >http://i.cubeupload.com/HIz95n.jpg   I like this meter. Does it only measure HSPA? If it measures others too, can I install it on my phone? What is it called.     >The three devices are two different types, where this one is a pure >cellular signal booster (the other ties to your router): >http://i.cubeupload.com/NhwUFR.jpg   They also seem to be for LTE??

Stijn De Jong <stijndekonlng@nlnet.nl>: Feb 28 08:38PM On Tue, 28 Feb 2017 14:40:32 -0500, micky wrote:   >>the carrier: >>http://i.cubeupload.com/sSOph0.jpg   > These seem to be for LTE.   When I complained to T-Mobile that my cell signal was around -105 dBm, they sent me the signal booster, which recently died in all the power outages we've been having, so they sent me a second signal booster and what people seem to call a femtocell that connects to the router.   They all seem to be labeled "LTE": https://u.cubeupload.com/sSOph0.jpg   >>http://i.cubeupload.com/HIz95n.jpg   > I like this meter. Does it only measure HSPA? If it measures others > too, can I install it on my phone? What is it called.   I think it measures everything found in the USA. You can refer to this thread for the tools used. From: Stijn De Jong <stijndekoning@nlnet.nl> Newsgroups: comp.mobile.android,misc.phone.mobile.iphone Subject: Which app do you use to scan/debug GSM/CDMA cellular tower signal strength? Date: Thu, 16 Feb 2017 01:52:24 +0000 (UTC) Message-ID: <o830kn$bvh$1@gioia.aioe.org>   If you put that message id into this site, it should pop up: http://al.howardknight.net/   You can find the entire thread here: https://groups.google.com/forum/#!forum/alt.home.repair   Which reports this URL which contains scores of screenshots and recommendations for both Android and iOS devices.   https://groups.google.com/d/msg/comp.mobile.android/PC0ePLqaD5w/HoH7HiLsBwAJ   The goal is for each user to improve upon the tribal knowledge of all.

Stijn De Jong <stijndekonlng@nlnet.nl>: Feb 28 08:51PM On Tue, 28 Feb 2017 20:38:14 +0000 (UTC), Stijn De Jong wrote:   > You can find the entire thread here: > https://groups.google.com/forum/#!forum/alt.home.repair   My mistake.   That was the wrong search url as it was for alt.home.repair: https://groups.google.com/forum/#!forum/alt.home.repair   This is the right url for Android: https://groups.google.com/forum/#!forum/comp.mobile.android   While we're at it, this is the right url for iPad: https://groups.google.com/forum/#!forum/comp.mobile.ipad   And this is the right url for iphones: https://groups.google.com/forum/#!forum/misc.phone.mobile.iphone   You'll find probably a hundred very detailed screenshots in that thread. For example, here are the dramatic results of just one experiment!   http://i.cubeupload.com/jqV5cR.jpg   Without the tools, it's hard to tell exactly which device is doing what: http://i.cubeupload.com/RLxLv5.jpg

Stijn De Jong <stijndekonlng@nlnet.nl>: Feb 28 09:02PM On Tue, 28 Feb 2017 14:40:32 -0500, micky wrote:   >>cellular signal booster (the other ties to your router): >>http://i.cubeupload.com/NhwUFR.jpg   > They also seem to be for LTE??   I'm ignorant of what acronym should I be looking for?   I must confess that I'm not sure what the significance of your question about LTE is, but mostly because I'm pretty ignorant of the various acronyms (EDGE, HSPE, LTE, etc.) even though I see them on my phone at times.   All I know is I asked T-Mobile for better cellular signal (I don't really do data on the phone except on WiFi). They gave me these three devices. https://u.cubeupload.com/sSOph0.jpg   They're all labeled "LTE" but I don't really know what to make of that since they all seem to give me better signal strength in different ways. http://i.cubeupload.com/RU3rGl.jpg   What I find most useful is that I went from -100dBm to -50dBm, which is a jump of about half a million times stronger signal. http://i.cubeupload.com/RUsTGy.jpg   Note that -50dBm is about as good as is humanly possible even if you were standing right in front of a cellular tower.   If someone can give me a quick rundown on what acronyms are important in this endeavor, I'd appreciate it.   Remember, I only asked for them to increase my "cellular signal". I didn't ask for LTE (and I don't use cellular data to any extent).   This survey, for example, at my house, says UMTS (whatever that means): http://i.cubeupload.com/3y52PN.jpg   Yet, this survey, again in the same location, says HSPA (whatever that's telling me): http://i.cubeupload.com/tLTJFw.jpg   So does this survey in the same location: http://i.cubeupload.com/9MCM5S.jpg   And this one too: http://i.cubeupload.com/WA3BwE.jpg   Yet, this survey, same place, just says GSM/CDMA: http://i.cubeupload.com/U1aqb7.jpg   I admit I really don't understand what these acrynyms are trying to tell me since my own surveys shown above show an alphabet soup of acronyms at various times in my tests.   What should I be concluding from all these acrynyms at my one location?

micky <NONONOmisc07@bigfoot.com>: Mar 01 12:48AM -0500 In sci.electronics.repair, on Tue, 28 Feb 2017 20:38:14 +0000 (UTC), >signal strength? > Date: Thu, 16 Feb 2017 01:52:24 +0000 (UTC) > Message-ID: <o830kn$bvh$1@gioia.aioe.org>   Great.   >If you put that message id into this site, it should pop up: > http://al.howardknight.net/   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.   >Which reports this URL which contains scores of screenshots and >recommendations for both Android and iOS devices.   >https://groups.google.com/d/msg/comp.mobile.android/PC0ePLqaD5w/HoH7HiLsBwAJ   That sounds interesting too.   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 goal is for each user to improve upon the tribal knowledge of all.   I'll try to do my share.   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.   And it has an FAQ *and* an online manual. Most apps I see don' thave either. i have to guess at how they work.   On map, it has a red line that I t hought would point toward the tower, but it points** towards a strictly residential area. There are two cell 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.   **It was a long red line but the line got shorter and it added the image of a tower, and there might actually be one there now. There wasn't a few years ago It would only be 7 blocks from the one I know about. Is't that closer than need be? At any rate, I'll go over there and see. It's an apartment complex that might want extra money for permitting a tower.   Thanks. P.s, this was so much fun I may not wait til tomorrow to get a second one.

oldschool@tubes.com: Feb 28 02:24PM -0600 I said I would not order anything from China or anywhere outside of North America. But I placed an order today for some chassis mount RCA phone jacks, from China. Now I am sort of worried.....   I want to build a box so I can swap the output from my computer to several amplifiers, and need at least 8 jacks. Radio Shack wants about $6 for a pair of them, and they only had 2 packages (4 jacks) in the store. I dont plan to make this thing for several weeks, because I have other priorities, so I decided that I can wait a month or so for this package to arrive from China.   I placed the order. 40 jacks for around $8 (with shipping). Cant argue about that price....   After placing the order I was reading the fine print in the ad, and it says "buyer is responsible for all Tariffs and Taxes.... This has me worried. Who will bill me for that? What percentage of the price must I pay? I'd think on an $8 order it would only be a dollar or less, but since this is government, they could charge me $100 or more....   What's the scoop on this?   (If I had read this before placing the order, I would not have placed this order).

JC <Chipbee40_SpamNo@yahoo.com>: Feb 28 03:44PM -0500 > What's the scoop on this?   > (If I had read this before placing the order, I would not have placed > this order).   There are no import duty/taxes into the USA and the Chinese mark stuff low value or gift usually. (Don't tell Trump)

ohger1s@gmail.com: Feb 28 01:16PM -0800 > What's the scoop on this?   > (If I had read this before placing the order, I would not have placed > this order).   Don't worry about it. I've bought thousands of parts from China and never had to pay any duty or tariff.   But then, I don't think I've spent any more than $100 on any given order.

Wayne Chirnside <wc@faux.com>: Feb 28 09:50PM On Tue, 28 Feb 2017 14:24:02 -0600, oldschool wrote:     > What's the scoop on this?   > (If I had read this before placing the order, I would not have placed > this order).   I have used Banggod, Aliexpress and Gearbest and as yet no taxes or tariffs on some 120 orders.

Ralph Mowery <rmowery28146@earthlink.net>: Feb 28 05:17PM -0500 In article <t9mbbc5418km67mllujvn066i1utpo7uma@4ax.com>, oldschool@tubes.com says...   > What's the scoop on this?   > (If I had read this before placing the order, I would not have placed > this order).   Don't worry aoburt it. I have ordered lots of things off Ebay from China. Some parts and some circuit board assemblies. Most of the time it takes about 3 weeks or so to get here. I did have one item that was only about $ 8 including shipping that took about 2 1/2 months, but it got here.   The taxes and whatever are in the price you see on Ebay. You will not be charged mpore at a later date.   It amazes me how they have shipped in some items that only cost about $ 2 or less. To get a 1 st class letter out of the US to another country costs about $ 1.25. China does pick up the out going postage form what I have heard.   So far everything I have ordered has met my expectations. Some simiconductors dont. Friend ordered about $ 25 worth of transistors (about 8 of them) and they were all bad.   While you are looking around on ebay look for a component tester. It is a circuit board with a lcd display. It will have 3 leads and a 9 volt battery terminal. They are usually less than $ 20 and will test about anything you hook to it that will work at 9 volts or less. Best spent money for testing I have ever seen.

Foxs Mercantile <jdangus@att.net>: Feb 28 04:53PM -0600 > What's the scoop on this?   > (If I had read this before placing the order, I would not have placed > this order).   It's Lawyer speak" for cover your ass. The only time I've had problems is buying stuff from Canada and using UPS, where it went into a customs warehouse and customs wanted to rape me on duty fees. Similarly sending stuff to England where the hose the buyer with value added taxes.   I have had ZERO problems with buying stuff from China via eBay or Aliexpress.     -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com

mike <ham789@netzero.net>: Feb 28 09:14PM -0800 On 2/28/2017 2:17 PM, Ralph Mowery wrote: > got here.   > The taxes and whatever are in the price you see on Ebay. You will not > be charged mpore at a later date.   Don't think that's accurate. They specifically say that they aren't responsible. Last I looked, there was a limit for US duty free in this type of transaction and it was something like under $250. Who knows what Trump is gonna do.   > So far everything I have ordered has met my expectations. Some > simiconductors dont. Friend ordered about $ 25 worth of transistors > (about 8 of them) and they were all bad.   I've had very few EBAY items that were what I expected. Most just failed to disclose...others outright misrepresented the product. If the price is very low, it may still be worth it. There are some really cost-effective products, like flashlights, that are WELL short of specification, but still a great value. I don't trust the specs posted for anything.

micky <NONONOmisc07@bigfoot.com>: Feb 28 02:50PM -0500 In sci.electronics.repair, on Mon, 27 Feb 2017 15:36:52 -0800, Jeff >FET), 3Nxxxx = (Dual gate MOSFET), 4N = Optoisolator, etc. That >lasted about 10 years before devices arrived that could not easily be >crammed into the significant numbering scheme.   I agree with you here.   > The JEDEC would have >been better off just starting at 00001 and counting up in sequence. It   I don't agree they would be better off. The system was valuable for many early tubes and I didn't expect it to work forever. so I ignored it when it didn't work. Numbers in sequence would have meant nothing,   OTOH, the relationship between a 6SD6 and a 12SD6 is clear. (I'm not positive those exact tubes existed. It's been a long time.)   And the tubes in my father's battery powered tube radio, with names like 1au4 and 2-something, made it clear how they could run off of batteries. (Unfortunately one of the batteries was iirc 46v, so I couldn't afford to buy another one.) The radio also ran on AC, but was meant for civil emergencies.   Someone, maybe my father, also bought a crystal radio, a 3-inch diameter, 3/4" brown plastic box with holes in one side to listen through, and a green wire with an alligator clip coming out of it. It had a clear plastic rounded fluted tuning knob and only got one station in Indianapolis, the strongest one I think. But one is enough, if we'd ever been without power during an emergency. But I dont' think we ever were.   >would seem that the semiconductor people had not learned the lessons >of tube numbering, and repeated the basic mistakes.   As to 813 etc. I haven't found any all numerica names but I wouldn't have thought the 8 referred to voltage. That I would have taken as some subset of sequential numeric naming.

ohger1s@gmail.com: Feb 28 01:26PM -0800 On Tuesday, February 28, 2017 at 2:50:33 PM UTC-5, micky wrote:   > As to 813 etc. I haven't found any all numerica names but I wouldn't > have thought the 8 referred to voltage. That I would have taken as some > subset of sequential numeric naming.   I suspect the very early tubes were simply numbered in order of development. My old Radiola uses an 80, a 171 and a bunch of 27s. The 27s are 2.5v filaments and the 171 and 80 are 5v.

Foxs Mercantile <jdangus@att.net>: Feb 28 04:49PM -0600 In short, there is no "standard" numbering scheme for American vacuum tubes.   In the "beginning" numbers 01 though 99 were assigned pretty much on a "first come first serve" basis. More confusing were, for example, adding a number to signify manufacturer. For example, the type 27. 127, 227, 327, 427 etc were the same tube but by different manufacturers.   Starting in the '30s, they got together and agreed that the first number would be the filament voltage. 6A7 for example, 6.3 volt filament. 5Y3, 5 volts etc.   An original "idea" of assigning 1 or 2 letters in the middle on a per function basis went to Hell surprisingly fast.   During WWII, the military also came up with VT-nnn numbers that referenced "normal" tubes, such a 27, 80, 6SK7 etc.   Transmitting tubes were different, usually "high numbers" such as the 807, 811, 813, 1625 and so forth.   Then there's the entire gambit of 4-digit "industrial" types. Nominally in the 4000-9000 range.   The only other thing they agreed on was keeping the type the same across different filament voltages. 6BE6 and 12BE6 as an example.   Then of course, a few manufactures came up with their own bastard numbers. Like Taylor TZ-40. "Taylor, Zero bias, 40 watts."                 -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com

Ralph Mowery <rmowery28146@earthlink.net>: Feb 28 05:51PM -0500 In article <c7ef9132-3aab-4577-be9e-248896588a09@googlegroups.com>, ohger1s@gmail.com says... > > have thought the 8 referred to voltage. That I would have taken as some > > subset of sequential numeric naming.   > I suspect the very early tubes were simply numbered in order of development. My old Radiola uses an 80, a 171 and a bunch of 27s. The 27s are 2.5v filaments and the 171 and 80 are 5v.     As with all things they start off with a sysem and as new items are developed that system falls apart. I think tubes were numbered in order to start with. Then they were listed as the first number being the filiment voltage, letters to indicate what type and the last number the number of elements.   Some power tubes started with a number a dash and another several numbers such as a 3-500. That was the number of elements and the plate dissaplation. A 4x150 started the same way. Later it was a 4cx150 that indicated a ceramic seal instead of glass. Then a letter was added to the end to indicate the filiment voltage.   Simiconductors tried the same system. First number the number of junctions. Not sure about the N and the last numbers were just assigned in order. Later some even had dots of colored paint on them This was for the range of gain on them.   Japan tried the same thing with the numbers. One was the number of junctions. leters for the type, RF , AF. Many of them left off the starting 2 on them and yu just had to remember to add that when looking at them.

John Robertson <spam@flippers.com>: Feb 28 03:38PM -0800 >> have thought the 8 referred to voltage. That I would have taken as some >> subset of sequential numeric naming.   > I suspect the very early tubes were simply numbered in order of development. My old Radiola uses an 80, a 171 and a bunch of 27s. The 27s are 2.5v filaments and the 171 and 80 are 5v.   My 1933 RCA/Cunningham Radio Tube Manual agrees. Pg 143: -------------------------------------------------------------- THE NEW TUBE-NUMBERING SYSTEM   Type numbers for new tubes are now being assigned in accordance with the new system adopted in the early part of 1933 by the Radio Manufacturers Association. A new system was required because practically all of the available two and three digit numbers have been utilized.   ... (description of the numbering system, as described above)   While these rules assist to some extent in classifying tubes by filament voltage and function, the significance of the individual symbols will in most cases be inadequate to identify the specific features of a tube. --------------------------------------------------------------------   I love old manuals!   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

"Michael A. Terrell" <mike.terrell@earthlink.net>: Feb 28 07:42PM -0500 micky wrote:   > As to 813 etc. I haven't found any all numerica names but I wouldn't > have thought the 8 referred to voltage. That I would have taken as > some subset of sequential numeric naming.     The 813 is an industrial tube, not a consumer numbered tube.     -- Never piss off an Engineer!   They don't get mad.   They don't get even.   They go for over unity! ;-)

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.