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OldGuy <spamfree@nospam.com>: Nov 29 03:35PM -0800 Looking for recommendations for a Grid Dip Meter built or a kit.   --- news://freenews.netfront.net/ - complaints: news@netfront.net ---

Jeff Liebermann <jeffl@cruzio.com>: Nov 29 04:16PM -0800 On Sun, 29 Nov 2015 15:35:20 -0800, OldGuy <spamfree@nospam.com> wrote:   >Looking for recommendations for a Grid Dip Meter built or a kit.   It's now called a GDO (grid dip oscillator). Here's a page of various manufacturers and models: <http://www.n4xy.com/gdos.html>   I have three Heathkit HD-1250 GDO's. Not the best. You can get what might be a clone of a Heathkit HD-1250 from MFJ: <http://www.mfjenterprises.com/Product.php?productid=MFJ-201> Also, check out the sold listings on eBay for approximate pricing: <http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=grid%20dip%20meter&LH_Complete=1&LH_Sold=1&rt=nc&_trksid=p2045573.m1684>   Sorry, no recommendations as all my stuff is ancient.   -- 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

Cursitor Doom <curd@notformail.com>: Nov 30 12:33AM On Sun, 29 Nov 2015 16:16:27 -0800, Jeff Liebermann wrote:   > Sorry, no recommendations as all my stuff is ancient.   So's a lot of my stuff. But there's nothing wrong with old gear IMO it's the quality of it and whether it's in calibration that counts. The only issues with GDOs IME are that they're not too bad for the lower frequency RF stuff, but hopeless for anything higher.

Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Nov 30 01:56AM +0100 On 30.11.15 0:35, OldGuy wrote: > Looking for recommendations for a Grid Dip Meter built or a kit.   > --- news://freenews.netfront.net/ - complaints: news@netfront.net ---   In google (images) about 10 solutions.

Jeff Liebermann <jeffl@cruzio.com>: Nov 29 05:40PM -0800 On Sun, 29 Nov 2015 16:16:27 -0800, Jeff Liebermann <jeffl@cruzio.com> wrote:   This looks very interesting: <http://www.qrpproject.de/UK/dipit.htm> No clue how to purchase one and it's only 1 to 42 MHz.   May 2003 QST article on building a "modern" GDO: <http://www.qsl.net/k8mcr/downloads/Modern_GDO.pdf>   Feb 2013 Circuit Cellar article on building a GDO: <http://circuitcellar.com/wp-content/uploads/2013/01/CC25_ProjCard_Pres_Ball-CC271.pdf>   Goes to 1GHz by changing both the oscillator and the coil with frequency range. See "Plug in Oscillators" section: <http://elm-chan.org/works/ddm/report_e.html>   July 2014 QST. Using an MFJ-259/269 as a GDO: <http://www.ka6wke.net/finished-projects/grid-dip-meter-coils> MFJ sells these as MFJ-66C: <http://www.mfjenterprises.com/Product.php?productid=MFJ-66C>   More: <http://w5dor.com/W5DOR-GridDip.html>   -- 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 Black <et472@ncf.ca>: Nov 29 09:03PM -0500

Michael Black <et472@ncf.ca>: Nov 29 09:17PM -0500

mike <ham789@netzero.net>: Nov 29 07:53PM -0800 On 11/29/2015 6:03 PM, Michael Black wrote: > frequencies, a lot of the coils were shielded. There were GDOs that > worked well at VHF and UHF.   > Michael   Best one I ever used was the tube version of the Millen. I switched to the solid state version and regretted it. Much less sensitive and more fiddly than the tube version. Tunnel dipper was the worst for sensitivity.   If ham swapmeets are any indicator, most GDO's available second hand are missing some or all of the coils.

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Nov 30 10:08AM -0500 On 11/29/2015 06:35 PM, OldGuy wrote: > Looking for recommendations for a Grid Dip Meter built or a kit.   > --- news://freenews.netfront.net/ - complaints: news@netfront.net ---   Find an old Measurements (Boonton) 59 'Megacycle Meter' on eBay. I used to have a Heath 12something that I used for years. On Joerg's recommendation, I got a Measurements 59, and soon afterwards the Heath went in the trash.   The 59 has accurate frequency calibration. Mine is still within 2% over the full range, by actual measurement, and it hasn't been trimmed in a loooong time. It also gives a nice deep dip even with quite weak coupling--much weaker than the Heath, especially on low-Q resonances. I've used it to measure the coupling coefficient of toroidal transformers, for instance. (An ISDN unit had a CC of 0.99986.)   Besides, it has such a nice retro look and feel.   Cheers   Phil Hobbs   -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics   160 North State Road #203 Briarcliff Manor NY 10510   hobbs at electrooptical dot net http://electrooptical.net

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 29 10:47AM -0800 El viernes, 16 de octubre de 2015, 1:54:16 (UTC-3), Phil Allison escribió:   > Those holes need to be de-burred in a drill press.   > Once done and regreased, output devices run cooler and there are no more shut downs.   > ... Phil   Right.   I'm starting to think this is the problem. I checked the trasistors and they are fine, they are the same as in the schematic.   Y removed them from the heatsink, cleaned everything with alcohol (even tried not to touch it with my fingers) and put fresh thermal paste (with isolation) between the metal plate that holds the transitors, between the plate and the heatsink, and between the heatsink and the case, but still the metal plate is hot as hell (can't even touch it) and the heatsink is very hot, but not so much.   I wonder if there is a video on how to do it properly.

"Ralph Mowery" <rmowery28146@earthlink.net>: Nov 29 02:18PM -0500 "Leonardo Capossio" <capossio.leonardo@gmail.com> wrote in message news:14fca79b-407a-43dc-93c7-99e24240bcdf@googlegroups.com... >plate and the heatsink, and between the heatsink and the case, but still >the metal plate is hot ?>as hell (can't even touch it) and the heatsink is >very hot, but not so much.     When putting the paste on, did you use the thinist layer you could ? The paste is not that conductive to heat, just beter than air. The ideal ammount (which probably can not be done) would be to have the metel surfaces touching each other on the high points and just the voids filled with the paste. Less is often beter than more.

dplatt@coop.radagast.org (Dave Platt): Nov 29 12:10PM -0800 In article <14fca79b-407a-43dc-93c7-99e24240bcdf@googlegroups.com>, >fingers) and put fresh thermal paste (with isolation) between the metal plate that holds the transitors, >between the plate and the heatsink, and between the heatsink and the case, but still the metal plate is hot >as hell (can't even touch it) and the heatsink is very hot, but not so much.   You might want to check the metal plate and heatsink for flatness.   If the plate was warped at all, it won't be making good contact with the heatsink - there would be a few small points or lines of good contact, and a significant air-gap everywhere else. Filling the gap with thermal paste won't help very much. Thermal paste helps thermal conductivity only when it's a very thin layer - just thick enough to bridge the occasional thin gap between two surfaces which are otherwise in good direct physical contact. A thick layer may be worse than not having it at all.   CPU overclockers used to (maybe still) "lap" the top of the CPU and the contact surface of the heatsink, in order to get the both as flat as possible. When this is done, the layer of thermal paste between the two is *very* thin... put a tiny dab on one surface, and then spread it out thin-and-even with a single-edged razor blade.   Over-torquing the screws which hold down TO-220 or similar plastic-package transistors to the heatsink can similarly cause problems. Apply too much torque, make the transistor case and tab flex a bit, and you end up pulling most of the case away from the heatsink and thermal transfer gets worse. If your transistor tabs are bent or warped, lapping them might help.   [Lapping of this type can be done with a sheet of wet-and-dry carbide paper, mounted on a flat plate of some sort - a high-quality sheet of plate glass will serve. The usual finishing technique of "start with a coarser grit, then work your way up through the grits until you get to 1000" would be appropriate.]   The fact that the heatsink itself is very hot does suggest that something else may be going amiss... maybe the transistor quiescent bias is too high, or maybe there's a parasitic oscillation taking place. Using a scope (or an old-style grid-dip meter in absorbtion mode) to look for RF where it doesn't belong might be a good idea.

M Philbrook <jamie_ka1lpa@charter.net>: Nov 29 09:02PM -0500 In article <14fca79b-407a-43dc-93c7-99e24240bcdf@googlegroups.com>, capossio.leonardo@gmail.com says...   > I'm starting to think this is the problem. I checked the trasistors and they are fine, they are the same as in the schematic.   > Y removed them from the heatsink, cleaned everything with alcohol (even tried not to touch it with my fingers) and put fresh thermal paste (with isolation) between the metal plate that holds the transitors, between the plate and the heatsink, and between the heatsink and the case, but still the metal plate is hot as hell (can't even touch it) and the heatsink is very hot, but not so much.   > I wonder if there is a video on how to do it properly.   If it's getting hot like that with the amp on and not generating any sound, you have other problems. Put a volt meter on the output in DC mode first, see if you are getting any DC above a few mVs   After that, put the meter in AC mode and see if you are getting AC ripple of a significant level, which you should not be.   Do this in ideal mode, no sound.   Me thinks you have big ISSUES with biasing.     Jamie.

Phil Allison <pallison49@gmail.com>: Nov 29 07:16PM -0800 Leonardo Capossio wrote:     > I'm starting to think this is the problem. I checked the trasistors and they are fine, they are the same as in the schematic.   > Y removed them from the heatsink, cleaned everything with alcohol (even tried not to touch it with my fingers) and put fresh thermal paste (with isolation) between the metal plate that holds the transitors, between the plate and the heatsink, and between the heatsink and the case, but still the metal plate is hot as hell (can't even touch it) and the heatsink is very hot, but not so much.   > I wonder if there is a video on how to do it properly.   ** Two things are not clear:   1. Does the heatsink get very hot whenever the amp is on or do you have to PLAY something ?   2. Have you found and fixed any burs on the holes in the heatsink coupler and or the chassis ?   BTW:   That amp has an odd, non adjustable bias arrangement.   Transistors Q14 and Q 15 should be in thermal contact with the heatsink.     ... Phil

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 30 06:23AM -0800 El domingo, 29 de noviembre de 2015, 16:15:36 (UTC-3), Ralph Mowery wrote: > touching each other on the high points and just the voids filled with the > paste. > Less is often beter than more.   Yes, I used a very thin layer.

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 30 06:29AM -0800 On Monday, November 30, 2015 at 12:16:15 AM UTC-3, Phil Allison wrote:   > ** Two things are not clear:   > 1. Does the heatsink get very hot whenever the amp is on or do you have to PLAY something ?   You have to play for a while at low volumes (10min tops), or play for a minute at the highest volume. In idle, with a plug connected (otherwise the amp mutes), it does not shut down.   > 2. Have you found and fixed any burs on the holes in the heatsink coupler and or the chassis ?   If by burr you mean what is described in this page: "http://www.nmri.go.jp/eng/khirata/metalwork/basic/bari/index_e.html", then I don't see any worrysome burr on the heatsink.   > BTW:   > That amp has an odd, non adjustable bias arrangement.   > Transistors Q14 and Q 15 should be in thermal contact with the heatsink.   They are on the heatsink, but their tab is completely plastic.

N_Cook <diverse@tcp.co.uk>: Nov 30 01:49PM Crackle just like cathode/heater leakage in one of the valves, but active test as perfectly good isolation . This crackle was present on first receipt testing but now with close-handling not the slightest trace - typical symptom of PbFitis , also can be similar "bacon and eggs" crackle . Any known problem area? hopefully not with the DSP chippery. ( just dealing with a Hartke HA3500 with pbfitis , but as 2006 a bit more excusable)

"Dusty" <dusty@mail.not>: Nov 30 03:54AM -0600 > > https://www.radioshack.com/collections/maker-s-t-e-m   > > It doesn't require bashing off the case of a store bought clock and putting it into a case, and calling it home made.   > Heheh... If little Mo made the theremin kit, Obama would have thought the aliens were landing....   It's easy to impress someone who doesn't know anything.   -- .

philo <philo@privacy.net>: Nov 29 06:54PM -0600 On 11/29/2015 9:36 AM, M Philbrook wrote:   > Jamie   yeah...I am presently scanning my old negatives and just came across a photo of me in my shack back in 1971

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ars.k5zyz@gmail.com: Nov 28 04:15PM -0800 On Saturday, April 9, 2011 at 8:10:21 AM UTC-5, Christopher Hall wrote:   > 73 > Chris > VE9ZX   Probably the plate choke. Replace it with the MFJ 10-15197, pie wound, plate choke. Some of the original plate chokes used by Heathkit have resonances out side the bands for which it was originally designed. I used one of the MFJ chokes in my Dentron Clipperton L an made it stable in all bands, including the WARC bands. K5ZYZ

philo <philo@privacy.net>: Nov 28 07:19PM -0600 > On Saturday, April 9, 2011 at 8:10:21 AM UTC-5, Christopher Hall wrote:   LOOK AT THE DATE

M Philbrook <jamie_ka1lpa@charter.net>: Nov 29 10:36AM -0500 In article <n3djl8$vrr$1@dont-email.me>, philo@privacy.net says...   > On 11/28/2015 6:15 PM, ars.k5zyz@gmail.com wrote: > > On Saturday, April 9, 2011 at 8:10:21 AM UTC-5, Christopher Hall wrote:   > LOOK AT THE DATE   Oh slap my ass! :)   At least it was a good read, it brought back memories!     Jamie

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Uyemura Cisco Technical Solution Series IP Telephony Solution Guide Version 2.0 Classical Dynamics of Particles and Systems, 5th Ed, SOLUTIONS MANUAL; Marion, Thornton Classical Dynamics, A Contemporary Approach (Jorge V. Jose) Classical Electrodynamics 2nd ED SOLUTIONS MANUAL; John David Jackson Classical Electrodynamics SOLUTIONS MANUAL; John David Jackson Classical Mechanics (Douglas Gregory) Classical Mechanics 2nd Ed SOLUTIONS MANUAL; Goldstein CMOS Analog Circuit Design, 2ed SOLUTIONS MANUAL; Phillip E. Allen, Douglas R. Holberg CMOS- Circuit Design, Layout, and Simulation, Revised 2nd Ed SOLUTIONS MANUAL; R. Jacob Baker Cmos Digital Integrated Circuits , Sung-Mo Kang,Yusuf Leblebici CMOS Mixed-Signal Circuit Design, 2nd Ed SOLUTIONS MANUAL; R. Jacob Baker CMOS VLSI Design Circuit & Design Perspective 3rd Ed SOLUTIONS MANUAL; Haris & West College Algebra 8th Ed SOLUTIONS MANUAL; Michael Sullivan COLLEGE ALGEBRA AND TRIGONOMETRY 6th E SOLUTIONS MANUAL; Aufmann, Barker, Verity College Geometry A Discovery Approach 2nd E SOLUTIONS MANUAL; David Kay College Physics 10th Edition VOL 1 SOLUTIONS MANUAL; Serway & Vuille

Chuck <ch@dejanews.net>: Nov 28 12:13PM -0600 On Sat, 28 Nov 2015 00:47:50 -0500, Micky <NONONOmisc07@bigfoot.com> wrote:   >>be able to post back for a couple months or more.   >>Thanks and thanks everyone.   >>>Fred One reason those radios have short antennas is the front ends overload near powerful transmitters.   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

c4urs11 <c4urs11@domain.hidden>: Nov 28 05:51PM On Sat, 28 Nov 2015 06:53:26 -0800, sjoerd kaper wrote:   > Zoals in deze video te zien is, probeer ik ook met de rode klem een > grensdraad te koppelen, en met de zwarte klem vast te maken aan de aarde.   Experimenteer eerst de werking van de kabeldetector met een losse draad (bv. een lang netsnoer). Dan weet je beter hoe de detector reageert.   Daarna zou ik ook proberen met de kabel aan de AL klem. Stel dat de onderbreking dichtbij de AR klem zit, dan zend je het meetsignaal maar over een kort stuk draad uit en is het signaal zwakker.   Succes!

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sjoerd kaper <sjoerdkaper@gmail.com>: Nov 28 06:53AM -0800 Hallo,   Zit met een probleem. De Husqvarna automower 330x heeft ergens een kabelbreuk in zijn grensdraad. Het basisstation heeft een controle lampje wat blauw knippert, en de automower zelf meldt dat hij geen verbinding kan krijgen.   Nu is er op internet een filmpje te vinden, waarin een kabel detector gebruikt word. Hier word een kleine spanningsbron aangebracht(sender) en met een 2e apparaatje(reciever) loop je langs de grensdraad, totdat je signaal wegvalt. Zo ziet het erg eenvoudig uit om de kabelbreuk op te zoeken.   https://youtu.be/l1t8XXI_BI4   Heb een soortgelijk apparaatje aangeschaft. Zoals in deze video te zien is, probeer ik ook met de rode klem een grensdraad te koppelen, en met de zwarte klem vast te maken aan de aarde.(de aarde is een ijzeren pen die in de grond zit, heb ook geprobeerd met een schroevendraaier). Met de reciever krijg ik alleen pieptoon dichtbij de basisstation/sender, echter verder opzoek naar de grensdraad valt het geluid vrij meteen weg, en is er niet meer te horen.   Wie kan me helpen door te zeggen wat ik verkeerd doe?   Zie hieronder mijn filmpje   https://youtu.be/8RW5lmA5mCA   dank alvast! Sjoerd

John-Del <ohger1s@aol.com>: Nov 28 04:27AM -0800 On Thursday, November 26, 2015 at 8:15:09 PM UTC-5, jasper smith wrote: > Radio Shack has a home made clock kit. > https://www.radioshack.com/collections/maker-s-t-e-m   > It doesn't require bashing off the case of a store bought clock and putting it into a case, and calling it home made.   Heheh... If little Mo made the theremin kit, Obama would have thought the aliens were landing....

gregz <zekor@comcast.net>: Nov 28 07:48AM > megaphones both with and without this rubber ring on the > edge of the flared horn. Cannot seem to find it nowadays.   > Anyone?   It would only affect top frequency by diffraction. With a good flaring of the mouth, might not do anything with the sharp edge. These things don't have very good highs to begin with.   Greg

thekmanrocks@gmail.com: Nov 28 03:55AM -0800 GS wrote: "- show quoted text - It would only affect top frequency by diffraction. With a good flaring of the mouth, might not do anything with the sharp edge. These things don't have very good highs to begin with.   Greg "   ^^ The BEST explanation by far!! And that diagram I glimpsed a long time ago alluded to this. Thanks.

Micky <NONONOmisc07@bigfoot.com>: Nov 28 12:47AM -0500 On Thu, 19 Nov 2015 04:25:32 -0500, Micky <NONONOmisc07@bigfoot.com> wrote:   >15 inches, if 1/8 wavelengths are useful, is longer than the wire, i'm >pretty sure. (Someday I may find the wire on the floor in the corner >and I'll measure it. )   BTW, a friend just gave me another radio, second hand, that indeed does have a wire about 34 inches coming out the back, so some makers care about this. I think that's what it shows, even if it's not 30.   He bought it at a Goodwill store to dock his iphone or ipad but he says it doesnt' work. I don't have one to test with, but it also doesn't get many radio stations. It's also missing its AM antenna and the only source I have for a plug is maybe my auto burglar alarm from the previous car, which I'm saving for the next car. For the record it's an Imode model IP200A but I don't really plan to fix it   I posted mostly to say that its antenna was 34 inches, not just 15.

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 27 01:13PM -0800 > Is the heat sink hot when the unit shuts down? > Use your hand, if you can't keep your hand on the > Heat sink, its too hot.   It is hot...which makes me wonder. I will make more checks when I get the chance.

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 27 01:45PM -0800 El viernes, 27 de noviembre de 2015, 3:05:29 (UTC-3), Phil Allison escribió:   > It is a PTC "positive temp coefficient" thermistor (aka posistor) with a steep rise in resistance at 100C. The mute circuit in the Fender trips when the PTC device reaches 800 ohms and is rising steeply - so operates with a snap action.   > FYI: "PTC100" is not a part number, but a code used on the schem referring to the parts list.   > ... Phil   That explains a LOT. Thanks.

Phil Allison <pallison49@gmail.com>: Nov 27 07:43PM -0800 Leonardo Capossio wrote:     > That explains a LOT. Thanks.   ** BTW, the NTC10-15 shown in series with the AC power is used as an anti-surge device. It is mounted on the PCB, not inside the transformer.   At room temp it's a 10ohm resistor, falling to 0.2ohms at 5 amps current.   At switch-on it simply adds 10 ohms to the wiring on the primary side, limiting inrush surge currents so the fuse does not blow regularly.     .... Phil

bud-- <null@void.com>: Nov 27 11:20AM -0600 > last areas in the US where one may still get actual 2-phase power. 2-phase, 4-wire > power was developed primarily for heavy motor use in that era when the battle of AC > vs. DC was not yet settled and 3-phase power was barely a gleam in Tesla's Eye.   All multiphase came from Tesla. And AC was widely thought to be useless until Tesla. Tesla had patents for both 2-phase and 3-phase. Tesla patents also covered essentially all possible AC induction motor designs.   It is common to use 480/277V 3-phase wye as the power distribution in large buildings. Transformers from 480/277V to 208/120V are located throughout the building in electrical rooms. Transformers have 3-cores for the 3 phases. Small transformers may be simpler, with 2 cores T-connected (Scott). These cores run at true 2-phase. The disadvantage is the power factor on the cores is screwed up and they have to be derated.   > hot-to-Hot at a nominal 240V and hot-to ground at 120V. Single-phase as only 1/3 of the > total capacity is realized. All this is done in the single-phase transformer at the > sub-station, not the distribution transformer at the pole (vault) in the neighborhood.   For the houses in my area (and probably all of Minneapolis), a single 8kv L-N distribution leg is tapped off from the 13.8kv 3-phase wye distribution. Something like 4 blocks are fed from each tap. A pole mounted transformer feeds 240/120V to something like a block.

M Philbrook <jamie_ka1lpa@charter.net>: Nov 27 03:08PM -0500 In article <zICdnZ-PgMW5i8vLnZ2dnUU7-W2dnZ2d@earthlink.com>, rmowery28146@earthlink.net says...   > I hope that damn 2 phase 220 house wire does not start up again. There is a > true 2 phase and then then there is the split phase 240 that is common in > most of the houses in the US that some try to claim is 2 phase.   Show me the phase difference between your "TRUE" 2 phase and the "FALSE" 2 phase that you seem to know so much about.   I really want to know because I would like to see if you really understand what the term "PHASE" actually means?   Have a bad day..   Jamie

Jon Elson <elson@pico-systems.com>: Nov 27 02:23PM -0600 M Philbrook wrote:   > "FALSE" 2 phase that you seem to know so much about.   > I really want to know because I would like to see if you really > understand what the term "PHASE" actually means? There REALLY WERE, honestly, 2-phase systems in use quite some time ago. They had a 90 degree phase angle between the two phases. They could be delivered in a 3-wire system, looked just like split-phase 120/240, but were apparently commonly set up with 4 wires. The motors were wired with 2 windings in quadrature, and would start without any starting devices (switches, capacitors, etc.) just like a 3-phase motor. It was quickly figured out that 3-phase was slightly better (less torque ripple, for instance) and the 3-phase system took over.   Google "2 phase utility power" and they have an article on it.   Of course, standard residential power in the US is NOT 2-phase, but single- phase.   Jon

"Ralph Mowery" <rmowery28146@earthlink.net>: Nov 27 03:41PM -0500 "M Philbrook" <jamie_ka1lpa@charter.net> wrote in message news:MPG.30c28254915d4f7a989dc9@news.eternal-september.org... > "FALSE" 2 phase that you seem to know so much about.   > I really want to know because I would like to see if you really > understand what the term "PHASE" actually means?   I don't intend to get suckered into a long thread about the difference. All I am going to say is that by definition the 2 phase power is seperated by 90 deg instead of the 180 deg that the more common split phase is as some try to make it .   An easy way to tell is to hook a simple 2 wire iduction motor across the lines. If it starts, it is 2 phase, if not single phase. The single phase motor needs some means of starting such as a capacitor start circuit. That was one of the reasons 2 phase power was used.

"Ralph Mowery" <rmowery28146@earthlink.net>: Nov 27 03:43PM -0500 "Ralph Mowery" <rmowery28146@earthlink.net> wrote in message news:RfednfFowc14IMXLnZ2dnUU7-SOdnZ2d@earthlink.com... > lines. If it starts, it is 2 phase, if not single phase. The single > phase motor needs some means of starting such as a capacitor start > circuit. That was one of the reasons 2 phase power was used.   I ment to say 3 wires , not 2.

M Philbrook <jamie_ka1lpa@charter.net>: Nov 27 04:06PM -0500 In article <RfednfFowc14IMXLnZ2dnUU7-SOdnZ2d@earthlink.com>, rmowery28146@earthlink.net says... > lines. If it starts, it is 2 phase, if not single phase. The single phase > motor needs some means of starting such as a capacitor start circuit. That > was one of the reasons 2 phase power was used.       I thought so.   Jamie

bud-- <null@void.com>: Nov 27 11:58AM -0600 > This lamp was used by Zenith and more than a few other manufacturers in the 1950s/1960s as an indicator lamp (on/off) at about the time that radio manufacturers started to become concerned about user-servicing and hot-chassis radios - something that never really bothered them in the past. The worked on the theory that a neon lamp was far less likely to burn out than the old standby #44 or #47, so that loose fingers were less likely to get nipped. ASIDE: Audio devices held on to incandescent lamps (With specific reference to the 47) well into the 80s, before shifting - very slowly - to LEDs or Fluorescent lamps. But, they had transformers on board to isolate the chassis.   > It is designed to operate at ~120V AC. It _CAN_ operate at ~120V DC, but only one post will light. It will trip (glow) at about 90V +/-.   > Unless there is a voltage dropper in the circuit, it will fail quickly at 220 or 240 V - that is voltages outside of Japan and the Americas. As supplied, it has a 100K resistor in series with the lamp. For conversion to 220V, I have heard values of up to an *additional* 220K in series. Try there and work back if you wish to operate at 220V.   It will fail immediately without a series resistor. As others have said, there is no resistor built into the lamp.   From a 1965 Allied Radio catalog, Chicago Miniature lamp: NE-51 is clear glass tubular, single contact bayonet base. Voltage across the lamp is 65V when operating at the rated 1/25 watt.   A higher voltage is necessary to ionize the neon (which is why a relaxation oscillator works). The voltage is somewhat constant with varying current. At 1/25 watt and 65 volts the current would be 0.6 mA and the series resistor for 120V supply would be 91k (minimum).   There is also a NE-51H that runs at a blinding 1/7 watt (2 mA).

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Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 26 09:04AM -0800 El jueves, 26 de noviembre de 2015, 0:23:16 (UTC-3), Phil Allison escribió:   > ** PTC100 operates the "mute" function of the power amp by shutting off Q7 and so the base voltage to Q8 - which is a 2mA current source for the input pair Q9 & Q10. This results in no current in the driver stage - transistors Q11, Q12 & Q13 and so no amplification.   > .... Phil   That claryfies things a little bit.   The mute coming from the input jacks seems to pull the "mute" point to ground, hence setting the base voltage much lower than 10v+0.7v, and thus shutting down Q7.   Now I don't fully understand how the PTC100 shuts it down. At 25deg the PTC100 has 110ohm, according to some tables, and at 100deg it has a little less than 140ohms. I don't know how to calculate Q6's Q point (Vec or Ie), since Veb/PTC100 seems to control Ie directly (unless the only way out is using Shockley's equation). Also the shut down seems way to abrupt, like Q6 is open, and then suddenly it is a closed switch.

makolber@yahoo.com: Nov 26 08:50PM -0800 Is the heat sink hot when the unit shuts down? Use your hand, if you can't keep your hand on the Heat sink, its too hot.

Phil Allison <pallison49@gmail.com>: Nov 26 10:05PM -0800 Leonardo Capossio wrote:     > > ** PTC100 operates the "mute" function of the power amp by shutting off Q7 and so the base voltage to Q8 - which is a 2mA current source for the input pair Q9 & Q10. This results in no current in the driver stage - transistors Q11, Q12 & Q13 and so no amplification.   > Now I don't fully understand how the PTC100 shuts it down. At 25deg the PTC100 has 110ohm, according to some tables, and at 100deg it has a little less than 140ohms.     ** There is a device called PT100, a platinum resistance sensor that is quite linear and rises about 0.4% for each degree C. The thing on the schem labelled "PTC100" is not one of them. It is a PTC "positive temp coefficient" thermistor (aka posistor) with a steep rise in resistance at 100C. The mute circuit in the Fender trips when the PTC device reaches 800 ohms and is rising steeply - so operates with a snap action.   FYI: "PTC100" is not a part number, but a code used on the schem referring to the parts list.     ... Phil

"jasper smith" <default@isp.net>: Nov 26 07:15PM -0600 Radio Shack has a home made clock kit. https://www.radioshack.com/collections/maker-s-t-e-m   It doesn't require bashing off the case of a store bought clock and putting it into a case, and calling it home made.   That little Muslim's family are planning to sue the school and police for being afraid he had a bomb when he took the bashed up clock to school and called it home made.   Happy Thanksgiving

"Ron D." <Ron.Dozier@gmail.com>: Nov 26 11:09AM -0800 You really need to define what the intended use is. A <$20 component tester kit(bangood,com) could suffice if your need is troubleshooting.   Friends had a Sencore that they were happy with.   I have a handheld HP/agilent.   At work, we had two HO/Agelent LCR meters. We had to characterize devices with a DC bias. It's no match for the little guys.

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daves <f6ceedb9c75b52f7fcc0a55cf0cfbf5d_1026@example.com>: Nov 26 04:37AM I bought a used amp for my 488 rockola. the old amp worked but one channel fuzzy and lower volume than the other side. The used amp hums but works. disconnecting the pickup doesn't change. Maybe the 2 large silver capacitors?   --

N_Cook <diverse@tcp.co.uk>: Nov 26 08:12AM On 26/11/2015 04:37, daves wrote: > fuzzy and lower volume than the other side. The used amp hums but > works. disconnecting the pickup doesn't change. Maybe the 2 large > silver capacitors?   What does AC volts range on a DVM show for the main caps?

dansabrservices@yahoo.com: Nov 25 09:24AM -0800 If there are ultrasonic frequencies being amplified, you wont hear them. But... they will cause the amp to work really hard and generate more heat than usual. This could cause the amp to shutdown due to the heat. Other than using a scope, there is no way to confirm this.   Dan

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 25 09:48AM -0800 El miércoles, 25 de noviembre de 2015, 13:13:52 (UTC-3), Leonardo Capossio escribió:   > Don't have a scope, best I can do is a DMM.   > Just to clariphy, the audio from the amp gets cut abruptly. Everything is working like a charm, the sound isn't fading away or anything, and the suddenly it stops outputting audio. Everything else seems to be working.   > In this case, the only thermally dependent element I see is the PTC100. The circuit surrounding the PT100 seems to be compensating the bias current of the power amp, though I do not understand it fully, if anyone can point to a source that explains how this circuit work it would be great. To me it seems very strange that it abruptly cuts out the sound.   To clarify, the heatsink is working correctly, but I cannot measure the temperature because I don't have anything reliable to do it with.

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 25 09:50AM -0800 > If there are ultrasonic frequencies being amplified, you wont hear them. But... they will cause the amp to work really hard and generate more heat than usual. This could cause the amp to shutdown due to the heat. Other than using a scope, there is no way to confirm this.   > Dan   If there are ultrasonic frequencies (which I cannot measure), then what could cause this ? Where might they be generated ?   The amp is shutting down via the PT100 circuit, that should also do some temperature drift compensation. If I bypass this compensation, would the amp sound very bad ?

jerryrego03@gmail.com: Nov 25 01:18PM -0800 On Wednesday, October 14, 2015 at 10:18:15 AM UTC-5, Leonardo Capossio wrote: > a power amp problem (because fortunately it has a pre-amp out and pwr > amp in)   > Thanks.   Did you check the 42v and -42v once the amp went into the low volume state?

Leonardo Capossio <capossio.leonardo@gmail.com>: Nov 25 06:18PM -0800 > > amp in)   > > Thanks.   > Did you check the 42v and -42v once the amp went into the low volume state?   No, but I don't notice the LED brightness to be down not even a little bit, or the cooler.

Phil Allison <pallison49@gmail.com>: Nov 25 07:23PM -0800 Leonardo Capossio wrote: > current of the power amp, though I do not understand it fully, if > anyone can point to a source that explains how this circuit work it > would be great.     ** PTC100 operates the "mute" function of the power amp by shutting off Q7 and so the base voltage to Q8 - which is a 2mA current source for the input pair Q9 & Q10. This results in no current in the driver stage - transistors Q11, Q12 & Q13 and so no amplification.       .... Phil

OldGuy <nospam@spamnot.com>: Nov 25 11:41AM -0800 Welder is rated 240VAC 60Hz 20A single phase.   How to connect to house 220VAC 60Hz that is two phase 120VAC? House is 20A. 220VAC coming from unused dryer connector.   --- news://freenews.netfront.net/ - complaints: news@netfront.net ---

Jon Elson <jmelson@wustl.edu>: Nov 25 01:59PM -0600 OldGuy wrote:   > House is 20A. > 220VAC coming from unused dryer connector.   > --- news://freenews.netfront.net/ - complaints: news@netfront.net --- Connect the welder to the two "hot" wires and safety ground. It is 220 (or more likely 240-250 V) between the two hot wires of the dryer outlet.   Jon

Tim Wescott <seemywebsite@myfooter.really>: Nov 25 02:01PM -0600 On Wed, 25 Nov 2015 11:41:47 -0800, OldGuy wrote:     > How to connect to house 220VAC 60Hz that is two phase 120VAC? > House is 20A. > 220VAC coming from unused dryer connector.   It's not really two "phase" -- it'll be the typical North American two legs and ground system, where each leg is 120V off of ground, and the two legs (both of which go to the dryer outlet) are 240V from each other.   You say "house is 20A" -- do you mean there's at least a 20A circuit to the dryer? If so -- plug it in and have fun.   --   Tim Wescott Wescott Design Services http://www.wescottdesign.com

"Ralph Mowery" <rmowery28146@earthlink.net>: Nov 25 03:18PM -0500 "OldGuy" <nospam@spamnot.com> wrote in message news:n35304$2cfa$1@adenine.netfront.net...   > How to connect to house 220VAC 60Hz that is two phase 120VAC? > House is 20A. > 220VAC coming from unused dryer connector.   I hope that damn 2 phase 220 house wire does not start up again. There is a true 2 phase and then then there is the split phase 240 that is common in most of the houses in the US that some try to claim is 2 phase.   If the power is comming from a standard 240 volt dryer connector, there will be 3 wires. Two of them are hot and the third is a combination of neutral and ground.   If the welder has only 2 wires and a ground, then hook up the two hot wires of the welder to the two hot wires at the outlet. Then connect the ground/chasses of the welder to the ground/neutral wire of the outlet.

"pfjw@aol.com" <pfjw@aol.com>: Nov 25 12:48PM -0800 On Wednesday, November 25, 2015 at 3:12:24 PM UTC-5, Ralph Mowery wrote:   > I hope that damn 2 phase 220 house wire does not start up again. There is a > true 2 phase and then then there is the split phase 240 that is common in > most of the houses in the US that some try to claim is 2 phase.   OK - I live near Philadelphia - which, together with Baltimore, MD shares one of the last areas in the US where one may still get actual 2-phase power. 2-phase, 4-wire power was developed primarily for heavy motor use in that era when the battle of AC vs. DC was not yet settled and 3-phase power was barely a gleam in Tesla's Eye. (SIDE NOTE: The last DC building in NYC fed from the Pearl Street Station (for ~125 years) went down in 2007.) For whatever reason, both Philadelphia and Baltimore accumulated an inventory of heavy freight elevators that use 2-phase motors to this day, such that the local utilities continue to supply the power to a very few customers in specific locations within each city. I had the privilege of working on several such elevators and heavy water pumps in my youth while working my way through school as an electrician.   NOTE ALSO: some few households at the time also got 2-phase. And both PA and Reading railroad workers living along the rights-of-way got 25-Hz current - used for railroad traction motors, also to this day.   Standard household power in the US is 1/3 of a Delta-connected 3-phase system, being hot-to-Hot at a nominal 240V and hot-to ground at 120V. Single-phase as only 1/3 of the total capacity is realized. All this is done in the single-phase transformer at the sub-station, not the distribution transformer at the pole (vault) in the neighborhood.   Peter Wieck Melrose Park, PA

"Tom Miller" <tmiller11147@verizon.net>: Nov 25 04:00PM -0500 "OldGuy" <nospam@spamnot.com> wrote in message news:n35304$2cfa$1@adenine.netfront.net... > House is 20A. > 220VAC coming from unused dryer connector.   > --- news://freenews.netfront.net/ - complaints: news@netfront.net ---   Your house dryer connection is still single phase but has a neutral if it has four terminals. It will have a L1, a L2, a Neutral, and a Ground terminal. You will want to connect the welder to the L1 and L2 terminals (240 volts) and the Ground. Three wires total. Dryers usually use a 30 amp connector so you will want to find the correct connector and use 30 amp wiring into the welder. Some older dryer connections were just three wire and used the ground as the center tap (for the 120 volt parts of the dryer).   That is the best I can tell you without seeing everything.

"Ralph Mowery" <rmowery28146@earthlink.net>: Nov 25 04:26PM -0500 <pfjw@aol.com> wrote in message news:c88c56ad-89a5-47b0-a599-4ee4dc142dcd@googlegroups.com... On Wednesday, November 25, 2015 at 3:12:24 PM UTC-5, Ralph Mowery wrote:   >>distribution transformer at >>the pole (vault) in the neighborhood.   >>Peter Wieck >>Melrose Park, PA     I know that in some parts of the country you may run into many different kinds of power in the houses, just not too common.   Only reason I mentioned the 2 phase stuff was because of the origional question. I doubt that a house hold dryer would be 2 phase, but who knows ?   I bet it would be difficult for the average home owner to have a house wired with anything but the standard 120/240 system of most of the country and get anything to work.   Living in the south I doubt much if any of that 'odd ball' power was used. About the only "odd" voltage I see is some 208 volts phase to phase with 120 to the neutral instead of the 240 p to p.

Bill Martin <wwm@wwmartin.net>: Nov 25 04:01PM -0800 On 11/25/2015 11:41 AM, OldGuy wrote: > House is 20A. > 220VAC coming from unused dryer connector.   > --- news://freenews.netfront.net/ - complaints: news@netfront.net --- Might want to take a look at the wires going to that dryer connection...there was a period some years ago when Aluminum wire was in vogue for such things as dryers and kitchen stoves. 1960's time frame if I recall right. That's not really a good thing for a welder...and lots of other loads.

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