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N_Cook <diverse@tcp.co.uk>: Feb 07 03:55PM A fused piece of 1.5mm pcb trace, warmed up laquer and then a clean break, no smoke staining. I make that about 4 amps carrying capacity for 5 deg C rise along 25mm assuming 2oz board. Anyway this is the main trace between earth bond point and common of the secondaries and the speaker lines, all of which is 20 amp wiring. Another 20A line from this bond point to the input pcb and no heavy wires out from that pcb. So 1/4 inch spade connections to the wiring off the ps board, but on the board just this thin trace to the earth bond wire. Just about goes with the "6 transistor" radio component placement and 2 fudged, topside only, rework replacement components, ie using the cut stubs of the original leads to solder replacements to

N_Cook <diverse@tcp.co.uk>: Feb 07 09:59AM I suspect they deliberately used non-matching threads,ie cross-threaded, despite disassembly ideograph of a screw on the pcb overlay and red nail-varnish anti-shake lock. Even 2 minutes of soldering iron tip on the head will not free the locking . And of course buried deep in the case surrounded by all sorts, that block access, to grind flat blade slots in the screw heads or pairs of flats for mole-grips etc. Before grinding off the heads of these screws , any ideas to try.? Good mechanical holding of this pcb is via a large bolt through the main bridge rect, that came away easily, then glue on the shanks of the original screws would do for remounting. The retaining pillars for these pcb screws are welded to the case bottom. Before attacking wiht a grinder I'll try an impact driver, but that is guaranteed to butcher the cross-head slot. It might be easier to grind through the pillars as better access for that angle, not decided yet. Then sleeve over the existing half pillar for reassemble and glue to stop any rattling.

N_Cook <diverse@tcp.co.uk>: Feb 07 10:30AM Going by the slight hex shape under the case, these pillars must be Hank Bush (TM) press fitted pillars , not welded. Rather than silicon wafer colateral damage possibility from impact driver shock, I'll try grinding into the base of one of those pillars, to free the pillar with pcb screw. That keeps grinding dust out of the elctronics. Then reassembly may be just countersunk head screw into the pillar at the other end.

N_Cook <diverse@tcp.co.uk>: Feb 07 11:30AM That worked surprisingly well, just hoping the punch through shock of each pillar moving impulsively did not do any electronic damage. Not seen the pillars yet as will be marking the 30/40 or so headers and crimps and photoing before disconnecting that rat's nest. So method used. Clearly mark the hex shadow in the outer case paint. Dremmel and .5mm grinding disc (no breakage) 3 cuts diametrically to the corners of the hex, about 3 minutes per pillar . The centre will then take a 3mm ball bearing. Then use a board over the amp and a clamp to squash between board and ball. The ball punches through leaving a small disk on the end of the pillar which hopefully will grind off easily when I get the now loose pcb out of the case. The cuts reduce the metal and allow seating of the ball. Another impossible task in my portfolio, still learning about all this stuff.

N_Cook <diverse@tcp.co.uk>: Feb 07 01:15PM Incompetent or deliberate filling the tapped pillars with proper threadlock before screwing in , correct threads, then blinder blobs of antishake lacquer on the heads. Needs more than 50W soldering iron, due to heatsinking of the steel casing via the pillars.

Bruce Esquibel <bje@ripco.com>: Feb 07 01:10PM > and many people using antennas that are UHF only. WMEU is a low-power > Class D station, but it transmits from the Willis (Sears) tower and has > pretty good range.   Thanks for passing that tidbit along, you are correct.   -bruce bje@ripco.com

oldschool@tubes.com: Feb 06 10:55PM -0600 Last night it began getting cold in my house. I went to the thermostat and found out the Digital readout was blank. I pushed the UP button and the furnace did not turn on. I popped it off the wall and found two AAA batteries. Of course this is 3am and there are no stores open closer than a 25 mile drive (I live in a rural area).   Then I remembred that my small LED flashlite has AAA batteries, so I used those. The thermostat had alkaline batts, but the ones in the flashlite were carbon-zinc, but they worked fine and I had heat again.   That thermostat was installed in here about 4 years ago, when I had some furnace work done. I never knew it even had batteries, thinking it was powered from the transformer on the furnace. It's NOT a programmable t-stat, so aside from the digital readout, it's nothing more than a plain thermostat.   I never knew those thermostats would completely fail to start the furnace when the batteries went dead. Apparently so.   Now that I know it has batteries, I will replace them yearly, but I'm actually thinking about replacing that t-stat with a standard analog one. The last thing I need is for the pipes to freeze because the batteries failed, when I was not at home. (Even new batteries can be bad). There is no advantage to having a digital readout for me. I hardly ever change the temperture anyhow.   My question is how does this sort of thermostat switch the furnace on and off? Is it a semiconductor type of switch or what?   Yea, I did buy some new alkaline batteries today and put those in this thermostat.   (I still think the best Thermostats made were those old round Honeywell ones with the mercury switch. They lasted decades and never needed any repairs. So much for so called "improved technology").

gregz <zekor@comcast.net>: Feb 07 08:39AM > (I still think the best Thermostats made were those old round Honeywell > ones with the mercury switch. They lasted decades and never needed any > repairs. So much for so called "improved technology").   I had at least one fancy stat that ran off Line with battery backup. Most I've seen have a two way mechanical relay of some sort except the one that ran on line I think. The digital ones have better accuracy with less temp swing, and some have adjustable swings. I don't like the many that limit cycles. By the way, I've had a few electronic types go bad. The mechanicals are fairly reliable.   Greg

Look165 <look165@numericable.fr>: Feb 07 10:30AM +0100 Mercury is prohibited because of environmental considerations.   Coould you precise the exact failure ?   Are the batteries in the right position ?   Did you check them with a meter ?

oldschool@tubes.com: Feb 07 03:58AM -0600 On Tue, 7 Feb 2017 10:30:19 +0100, Look165 <look165@numericable.fr> wrote:   >Mercury is prohibited because of environmental considerations.   Yep, but there are lots of them still around. I know I have several of them in my shop, if I can remember where I put them.   >Coould you precise the exact failure ?   >Are the batteries in the right position ?   >Did you check them with a meter ?   I said it works now, since I replaced the batteries. No need to check anything more. I am just wondering how this thing is switched.   By the way, I got a surprise. I found a manual for it on the Honeywell site, and it IS a programmable 'stat. After having it for 4 years, I found this out.... Not that it matters, I dont live on a schedule and I dont like it cool when I'm sleeping. I just keep it at 68 deg all the time. Once and awhile I may raise it a few degrees when I take a bath, othrsise it stays the same.   When that guy installed it, all he told me was to use the up / down arrows to set the desired temp, and press the HOLD button to keep it at that temp. He never told me it was programmable or gave me a manual. But now that I have the .PDF manual, I know what it does, and I did set the correct time on it, which I never knew how to do, nor did I really care, since I got plenty of clocks.   I still might replace it with an analog 'stat. Knowing this could cause a loss of heat, just because of batteries, makes me uncomfortable. Normally I am home in the winter, but like when I visited distant relatives and stayed overnight for Christmas, I could have ended up with frozen pipes if the battery failed. I dont like that idea....   ---

Jeff Liebermann <jeffl@cruzio.com>: Feb 06 09:51AM -0800 >>wireless link will get you internet.   >No, they are Amish. Almost all my neighbors are Amish, except for one >very old retired farmer who I doubt even knows what the internet is.   The modern equivalent of the Amish are people who claim to be "electro-sensitive". A former lady friend was like that. I didn't recognize the similarity until now. Thanks for the hint.   >climb a tree, or even stand on top of a full hay wagon full of hay. But >if I go another 50 or 70 feet higher (up the private road), I can easily >see town.   I suspect that the aesthetics of a 50ft radio tower would be a show stopper with the local planning department. However, if you can get past that, you would end up with a radio tower with one end of a 2.4 or 5GHz wireless bridge with the other end in town with someone who has high speed internet. Ideally, the backhaul from the tower to your house would be buried cable or fiber, but can also be wireless. More commonly, there's a 2nd wireless radio on the tower to distribute internet to the neighbors, but that doesn't seem to be a requirement here.   >You lost me, when you started talking about "point to point wireless >link, and WISP".   WISP is "Wireless Internet Service Provider". It's just like a conventional cable or telco service providers, but without the wires. Instead of you building the tower and negotiating for sharing broadband, the WISP does this for you.   Point to point wireless is basically a wireless bridge. I'll spare you the details, but here's an example: <http://www.ebay.com/itm/122182834424> Think of it as an ethernet network extension cord without wires.   >semi-usable signal on the roof, I thought about putting a yagi antenna >on my tv antenna tower and running that into the house. Part of my >problem is having a house with metal siding and roof.   The legality of some of those boosters are questionable. They're also expensive. I have one made by zBoost. Of course, I couldn't resist tearing it apart and looking inside: <http://802.11junk.com/jeffl/zBoost/>   >The cell company in the area said they were >planning to build a new tower. (But from what I have heard from the >locals, they said that same thing 10 years ago). Nothing has changed.   I had a talk last year with the local Verizon engineer about new site construction. He casually mentioned that they typically have about 2,000 new sites in progress at any time in Northern California. That doesn't mean they're building these sites, just at some step in the process, such as getting approvals from the local councils, boards, and agencies. If they meet any resistance from citizens groups, that site goes to the bottom of the list, and they continue working on those where the locals want a cell site installed. He mentioned that there were several sites where the locals offered to subsidize the construction in order to get cellular service. I suspect your cellular company meet some resistance from the local Amish, and just walked away.   >I hate having to cope with dialup, and worse yet, I can not establish a >decent connection using my US RObotics modem on any computer with >Windows XP.   I used that combination for many years until I was able to get DSL. It should work. I wrote this during that era to test phone lines using USR modems: <http://members.cruzio.com/~jeffl/aty11/aty11.htm>   >I may be emailing you soon....   I was afraid that might happen.   -- 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

Chuck <ch@dejanews.net>: Feb 06 01:50PM -0600 >the capacitance changes as temperature changes. Some capacitors change >very little (for example C0G ceramics), others change a LOT (Z5U >ceramics). The 470pf polystyrene capacitors used in the mpx circuits of many receivers in the 1970s used to fail all the time.   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

"Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com>: Feb 06 07:57PM <oldschool@tubes.com> wrote in message news:957f9chh7874ipnges7e90a80v5idod4k5@4ax.com... > the top vent hole. I also recall that the speaker magnet was an > electro-magnet and was also used as a choke for the power supply. Those > were some of the oldest things I worked on.   AFAICR: the one with the paper reservoir cap was a regen.

"Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com>: Feb 06 08:03PM "Jim Mueller" <wrongname@nospam.com> wrote in message news:5897ad0a$0$59611$c3e8da3$460562f1@news.astraweb.com... > No, polystyrene capacitors have LOWER maximum temperature capability than > most other capacitors; that is one of their limitations. But they have > very low leakage, last forever if not mistreated, and are cheap.   Apparently the tempco of polystyrene is a good match for pot cores.   I've seen polystyrene crack/craze with age - I didn't investigate whether performance was impaired.   Polystyrene is pretty much the most vulnerable to solvents there is - fortunately, most de fluxing solvents were banned to protect the ozone layer.

Spare Change <noncompliant@notcompliant.zgq>: Feb 06 09:54PM -0800 On Feb 2, 2017, oldschool@tubes.com wrote   > Why should someone replace ALL the capacitors on old Tube equipment?   <https://en.wikipedia.org/wiki/Glowing_plate#Common_Occurrences>   Several causes listed are caused by shorted or leaking capacitors. It's a tube killer.

M Philbrook <jamie_ka1lpa@charter.net>: Feb 06 06:54PM -0500 In article <92111d01-b7f6-4fd9-abc9-2dbf7bf37469@googlegroups.com>, avagadro7@gmail.com says...   > Consolidated   > 14(41)UL 1007/1569 105C CSA TR64 30C FT1 BLUE   > for example, other spools state differently but same batch MO   PLL lock just out of reach ?   jamie

Spare Change <noncompliant@notcompliant.zgq>: Feb 06 12:25PM -0800 BZW6-26, 26v TVS unidirectional diode, through-hole, obsolete, n/a.   The original datasheet says that the 600W peak pulse power is measured over 10/1000 uS waveform, but the 100A forward surge current is spec'd over 1/2 cycle of 60 Hz sine:   http://diotec.com/tl_files/diotec/files/pdf/datasheets/bzw065v8   All replacements I see, the surge current is nowhere near 100A or is spec'd at 10/1000 uS waveform.   Surely the original isn't all that unique a part...? Anyone know of a direct replacement?   Thanks, Dave

Winfield Hill <hill@rowland.harvard.edu>: Feb 06 12:47PM -0800 Spare Change wrote... >at 10/1000 uS waveform.   >Surely the original isn't all that unique a part...? Anyone know of a >direct replacement?   Fagor (my TVS favorite) uses the same spec. So does ST. Try the -28 version for distributor inventory. Fagor's slightly larger 5kp version, 8.7 x 9 mm, is rated for 500A surge. There are larger ones available.     -- Thanks, - Win

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