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DaveC <not@home.cow>: Nov 18 09:00AM -0800 > By the way, PVC=Vinyl, oil > and chemical resistant or otherwise.   > RL   Insulation is rarely PVC-only––that would be plumbing pipe. It's the plasticizers mixed with the PVC that make it flexible and may not be oil-resistant. Wash that in a petroleum product and the plasticizers give up the ghost.

DaveC <not@home.cow>: Nov 18 09:41AM -0800 > cover your standard PVC sheathed multicore. VTN-200 shrink is chemical > and oil resistant and easily available. eg. Ebay # 251726064642 Might be > an idea NOT to shrink it as it is more flexible unshrunk.   That's a great idea. I'll check it out.   Thanks.

DecadentLinuxUserNumeroUno <DLU1@DecadentLinuxUser.org>: Nov 18 12:51PM -0500 >> an idea NOT to shrink it as it is more flexible unshrunk.   >That's a great idea. I'll check it out.   >Thanks.   Shrinking the right size choice can be flexible, but also then becomes THICKER, as in a better armor against abrasion.

JC <Chipbee40_SpamNo@yahoo.com>: Nov 18 01:19PM -0500 On 11/18/2015 12:51 PM, DecadentLinuxUserNumeroUno wrote:   >> Thanks.   > Shrinking the right size choice can be flexible, but also then becomes > THICKER, as in a better armor against abrasion.   Good point, choose the diameter carefully depending on whether you intend to shrink it or not.

DecadentLinuxUserNumeroUno <DLU1@DecadentLinuxUser.org>: Nov 18 01:38PM -0500 On Wed, 18 Nov 2015 13:19:42 -0500, JC <Chipbee40_SpamNo@yahoo.com> Gave us:   >> THICKER, as in a better armor against abrasion.   >Good point, choose the diameter carefully depending on whether you >intend to shrink it or not.   Depending on whether you want the item you are shrinking over to be grasped tightly by the shrink or not.   I have shrank tubing over a ferrite rod and noticed that a poor choice results in a bit of magnetostriction. I choose one that fully shrinks but still does not quite 'grasp' the rod. I get multiple benefits. No more magnetostriction and a thicker spacing from the rod to my subsequent winding, resulting in less parasitic capacitance and a better antenna/inductor/transformer, etc.

legg <legg@nospam.magma.ca>: Nov 18 03:39PM -0500 >plasticizers mixed with the PVC that make it flexible and may not be >oil-resistant. Wash that in a petroleum product and the plasticizers give up >the ghost.   The spec sheet for either Alpha or Lapp products will list the degree of resistance to oil or chemicals. I don't know what you go by, but gasoline and other solvents don't tend to hang around - they may sometimes be intentionally used in cleaning, but only under 'user beware' conditions. Both mfrs sell on-line. Alpha will cut.   Mogami has made superior products for a long time before being purchased by OKI. I doubt quality has suffered, but they do not and have never addressed industrial environmental requirements - that's not their market.   Get off the pot.   RL

MJC <gravity@mjcoon.plus.com>: Nov 19 09:12AM In article <punp4bd0sg9d573f682t30erftq5p6jq7j@4ax.com>, legg@nospam.magma.ca says... > gasoline and other solvents don't tend to hang around - they may > sometimes be intentionally used in cleaning, but only under 'user > beware' conditions. Both mfrs sell on-line. Alpha will cut.   Good point... The ends of the shrink shroud will have to be protected to ensure that the oil does not get inside. Otherwise it will "hang around" doing its worst!   Mike.

DaveC <not@home.cow>: Nov 19 08:25AM -0800 > ensure that the oil does not get inside. Otherwise it will "hang > around" doing its worst!   > Mike.   I will put RTV in the end of the shrink and apply heat. Shrink-n-seal. All this will be well inside the multipin connector so will be clamped with strain relief.   Thanks.

N_Cook <diverse@tcp.co.uk>: Nov 19 11:25AM On 18/11/2015 14:52, N_Cook wrote: > thin walled aluminium pcb stand-off cylinder, that would normally take a > long bolt, slid over those 4 and then epoxied in aswell. > Anyone been here before, or better idea?   4 equal overlengths of .7mm stainless steel wire. Equal to check all are seated in properly and 20mm overlength to be able to lightly clamp off. 4mm back, 45 degree bend on the end of each. Dry run they nestled in splayed, and cylinder slid over ok. With a, pin introduce epoxy in each of the holes, then drop of epoxy on each angled wire end and insert, while finger-clamp holding the other main lengths together. Slide the cylinder over, pull the wires as a group lightly , wrt the cylinder, checking right and true and clamp off. A ring of epoxy around the join of cylinder to the actuating plastic block in the switch. First bit of epoxying done. When cured , dribble more epoxy down the cylinder and when cured , grind off the excess. I'll take a pic after the first epoxying is cured.

N_Cook <diverse@tcp.co.uk>: Nov 19 02:34PM Alps 309F type of switch http://diverse.4mg.com/alps309f.jpg

N_Cook <diverse@tcp.co.uk>: Nov 18 07:51PM On 17/11/2015 16:03, N_Cook wrote: > how much extra noticeable hum? > Was it just to save the cost of closing the chassis, at both ends, with > expensive full thickness steel?   Hot air and the remnants of that foil soon came off. Masked off the edges and sprayed the nickel spray on the cabinet sides. When wet , the point contact across a diagonal , 6 or 8 inches, >30M, 20K after 1hr, 90R after 3 hr, 30R after 6hr. So hopefully by tomorrow and distributed ground contact along 3 edges will be sufficient. For safety reasons that foil had to go. I suppose the proper way round this notorious problem is, strip of the foil, depth stopped fly cuttter, router, end mill or whatever and then full thickness metal sheet set in the recess.

N_Cook <diverse@tcp.co.uk>: Nov 19 11:26AM down to 15R after 20 hours

isw <isw@witzend.com>: Nov 18 08:44PM -0800 Since I don't use the garage for a car, I don't need to open it very often. But when I do, I have to push the button on the remote anywhere up to a dozen times before the door opens. Once it's open, it will close and open first time every time. Until I close the door and leave it alone for a few days. Then it's back to the same old tricks.     I've checked the battery, resoldered everything that looked even slightly suspect (along with some that looked fine, just because) and replaced the PCB-located switch. I also did a reset on the codes and started over (it's a "learning" device, not the kind with a bunch of little switches).   Sadly, I do not have any RF test gear to see if the remote is actually transmitting.   Other than via the overhead door, access to the garage is through a rental unit, so being inside when I try the thing "fresh" is not an option.   Suggestions?   Isaac

Clifford Heath <no.spam@please.net>: Nov 19 04:14PM +1100 On 19/11/15 15:44, isw wrote:   > Other than via the overhead door, access to the garage is through a > rental unit, so being inside when I try the thing "fresh" is not an > option.   Most systems use a rolling code that moves through a predetermined pseudo-random sequence, where the sequence is determined by the secret key. The receiver remembers recent codes used, and can detect whether the code just received is correct in any sequence for the known remotes. After it has received the neighbour's remotes or other in-band signals with incorrect codes, it takes more repetitions of correct code sequences before it's willing to unlock.   <https://en.wikipedia.org/wiki/Rolling_code>   Clifford Heath.

Micky <NONONOmisc07@bigfoot.com>: Nov 19 04:32AM -0500 >Since I don't use the garage for a car, I don't need to open it very >often. But when I do, I have to push the button on the remote anywhere >up to a dozen times before the door opens.   I barely understood your post or the reply, but what happens if you push the remote once (or maybe twice) and wait the same length of time that it would take you to push the button those dozen times?   IOW, is it responding to the first push but taking forever to do it, or to the last push?

N_Cook <diverse@tcp.co.uk>: Nov 19 11:24AM On 19/11/2015 05:14, Clifford Heath wrote: > sequences before it's willing to unlock.   > <https://en.wikipedia.org/wiki/Rolling_code>   > Clifford Heath.   I never realised it was that straightforward. Never having researched it, I'd thought is was some impenetrable immensly complex , uC software, pseudo-random number sequencing and varying the seeds for different makes and individual matched send/rec combinations.

Fred McKenzie <fmmck@aol.com>: Nov 18 02:28PM -0500 In article <239f41c2-5923-4e39-8aa5-4b0abcc51ba3@googlegroups.com>,   > When would it be appropiate to use > a half-wavelength or quarter as the > dimension of the antenna being built?   KMan-   Perhaps I was mistaken in saying a quarter wave wire was "ideal". My main point was that the length was a compromise to begin with, so is not critical.   Relative to the body of the receiver, a half wave wire fed from one end has a high impedance. A quarter wave wire has a relatively low impedance. How the wire connects to the receiver would determine which would be best.   Suppose the radio has a coil and capacitor parallel-tuned circuit with one side connected to the body of the receiver. If the wire connects to the other "high impedance" side of the tuned circuit, a half wave might be better. If the wire connects to a tap on the coil, or to a smaller coil wound over the first, a quarter wave might be better.   I suspect the typical table radio with a wire coming out the back, has the wire connected to a relatively high impedance point. In other words, the designer may not have put that much thought into it.   I have an old Heathkit receiver that has a balanced 300 Ohm input for its FM tuner. A 75 Ohm unbalanced antenna could be connected between one of the 300 Ohm terminals and ground. I use a single wire connected to one terminal, and can pick up many stations.   Fred

isw <isw@witzend.com>: Nov 18 08:48PM -0800 In article <fmmck-57B336.14285318112015@5ad64b5e.bb.sky.com>,   > Perhaps I was mistaken in saying a quarter wave wire was "ideal". My > main point was that the length was a compromise to begin with, so is not > critical.   Interestingly, if the input is a *very high* impedance (a FET gate, say), then the antenna length almost does not matter -- if the impedance were truly infinite, then a point antenna would be fine. The E-field will induce the same voltage in the antenna no matter how long or short it is.   Impedance matching is only important when the input needs power, not just voltage.   Isaac

Micky <NONONOmisc07@bigfoot.com>: Nov 19 04:25AM -0500 On Tue, 17 Nov 2015 12:59:43 -0500, Fred McKenzie <fmmck@aol.com> wrote:     >Micky-   >As others have stated, it is not critical. For nearby stations, it may >work without the wire!   Yes, there's a local station, WYPR 88.1 Baltimore, that just about every radio gets.     >Suppose the FM band covers the range of 88 to 108 MHz. The middle of >the band would be 98 MHz. A wavelength would be 300/98 = 3.06 Meters. >A quarter wavelength would be 76.5 CM or 30.1 inches.   30 inches is a lot longer than the wire was. I'm glad I asked. Even 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. )   Besides 88.1t there are two other stations, I only get easily on the car radio (no matter what car I have) and on a 250 dollar table radio (KLH maybe), but not on some fancy digital tuner/preamp. Some other table radios get one or both, at least if tuned perfectly, and it doesn't seem to matter how expensive they are, so I've taken to buying used radios for $3 to see if they will get those stations.   (But this radio I bought new for my mother because it had digital tuning and I thought it would make it easier to change stations. )   Anyhow, the stations I want are in DC, maybe 35 miles away, on 88.5 (WAMU) and 90.1 (C-Span) so I think I'll use 88.5 in your formula above and see how that goes. Maybe I'll trim a little off until I reach the 90.1 length.   Several projects ahead of this, no space on the work bench, so I won't be able to post back for a couple months or more.   Thanks and thanks everyone.

"Ian Field" <gangprobing.alien@ntlworld.com>: Nov 18 06:10PM "(PeteCresswell)" <x@y.Invalid> wrote in message news:r5an4b9em61pq6b3mhksjdjnms3tsc6k6k@4ax.com...   > Looks like the crossover point happens after about 20 days and the > regular ones need re-charging on a monthly basis to assure 50% capacity > when needed.   Nickel chemistry might be on the way out, precisely because of self discharge.   An ever increasing number of cordless devices are appearing on the market with lithium instead of nickel.

Jeff Liebermann <jeffl@cruzio.com>: Nov 18 11:59AM -0800 On Wed, 18 Nov 2015 18:10:28 -0000, "Ian Field" >discharge.   >An ever increasing number of cordless devices are appearing on the market >with lithium instead of nickel.   Yep, and there's a problem. If you charge to 100% and leave it there, the LiIon battery slowly deteriorates. See Fig 5 at: <http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries> That's one reason you don't see any LiIon UPS/SPS battery backup power system. There are plenty of retrofit kits and replacement batteries, but nothing from the OEM's. Same with cordless phones, electric shavers, and other devices that run permanently on chargers. About the only way to do it is to use a battery that's about twice the calculated capacity ma-hr, and only charge it to 50% of capacity.     -- 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

pedro <me@privacy.net>: Nov 19 02:05PM +0800 On Wed, 18 Nov 2015 11:59:37 -0800, Jeff Liebermann <jeffl@cruzio.com> wrote:   >Yep, and there's a problem. If you charge to 100% and leave it there, >the LiIon battery slowly deteriorates. See Fig 5 at: ><http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries>   Yup. The two classical Li-Ion deterioration factors are temp and SOC - in each case, the higher it is the higher the deterioration.   >shavers, and other devices that run permanently on chargers. About >the only way to do it is to use a battery that's about twice the >calculated capacity ma-hr, and only charge it to 50% of capacity.   When we were doing Li-Ion capacity/cycling testing (in association with charger design) we tried moving from the cell manufacturer's "specified terminating voltage for full spec capacity" (4v20) to 4v10.   We found that we were achieving between 85% and 90% of the 4v20 capacity. We didn't have enough lifetime to waste doing deterioration testing for 4v10, but I'm sure that the average always-plugged-in laptop would get double the battery lifetime (cycles, years) at 4v10 terminating voltage with only that commensurate loss of run time.   It's a pity manufacturers of laptops, smartphones etc are obsessed with maximising run-time as a selling spec.

mike <ham789@netzero.net>: Nov 19 01:03AM -0800 On 11/18/2015 10:05 PM, pedro wrote: > terminating voltage with only that commensurate loss of run time.   > It's a pity manufacturers of laptops, smartphones etc are obsessed > with maximising run-time as a selling spec.   Well...offer a laptop with less battery life than the competition and see what happens to your market share. It's not manufacturers, it's customers who are obsessed with run-time. If you're gonna get a new smartphone every two years, do you really want to trade run-time for a battery that lasts 10 years instead of three?   What would be interesting is a customer available parameter that traded battery life for run-time.   So, what was the termination voltage in your final charger design?

cgwebb@itmco.net: Nov 18 07:58PM -0800 On Friday, April 11, 1997 at 3:00:00 AM UTC-4, Michael Kevin Drummey wrote: > if this is to blame (possibly surplus or obsolete stock)   > Thanks in anticipation.   > M.Drummey   probable the emf diode

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