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Jon Elson <elson@pico-systems.com>: Mar 14 01:41PM -0500 On Thu, 14 Mar 2019 11:04:55 +0000, N_Cook wrote:   > TO18 size of can but inerference fit? mounted in a brass mount with > lens, no type number seen. > Actively passing 60mA drops 1.3V and DVM-D test shows 1V one way, so Is this a laser or just an LED? 60 mA sounds to me like it might be a laser, and fairly powerful.   1979? Hmmm, probably NOT a laser at that date, and hitting such an old LED with such current would be pretty hard on it, unless the pulses were short and the duty cycle low.   Possibly heating the whole assembly might make the emitter slide out. I doubt these would be interference fit, as that could easily damage the emitter. Likely, a TO-18 package had a fairly wide dimensional tolerance. So, I'm guessing they used some kind of glue to hold it in place.   Jon

N_Cook <diverse@tcp.co.uk>: Mar 15 12:38PM On 14/03/2019 18:41, Jon Elson wrote: > emitter. Likely, a TO-18 package had a fairly wide dimensional tolerance. > So, I'm guessing they used some kind of glue to hold it in place.   > Jon   No type number found, but at least the likely failure mechanism found, manufacturing flaw waiting to happe, although all well butchered now. Not a TO18 device fitted to a brass barrel. Heat and freezer spray made no difference. So decided to dremmel 0.5mm grinding disc a slot in the brass to relieve the pressure. Firstly it was gold plated copper , not brass and no TO18 device, just a ring of something containing brown epoxy and the pins , so looking like TO18 can. The GaAs die .4mm or so square sitting on plated Cu "top hat" heatsink/plinth, inner diameter of 10mm and outer diameter of 15mm. Interference fit to that ledge, dislodged in trying to force open the slot in the copper, machined Al barrel 13mm long. Machined to a cone inside with pin-hole at end, taking an unsupported length of bare fibre optic approx 8mm long, presumably was cemented to the die. Then a lens fitted over the other end of the fibre over the outer end of the internal cone. So with resonant mechanical vibration from carriage at some point , thermal or g-shock stress , or just post fibre manufacture internal fibre stress-relief over time, the fibre could break from the die and end up 0.2mm off-axis , so IR in the cone recess and next to none in the fibre,so to the outside world no optical output. As no make/number perhaps an early run, just post prototype, before someone twigged the built in self-destruct design flaw.

Look165 <look165@numericable.fr>: Mar 15 01:43PM +0100 Maybe can be a UV LED !   N_Cook a écrit le 14/03/2019 à 12:04 :

N_Cook <diverse@tcp.co.uk>: Mar 15 01:34PM On 15/03/2019 12:43, Look165 wrote: > Maybe can be a UV LED !   Specifications in the user manual say IR 910nm and another contemporaneous (1979) source says the same.

tubeguy@myshop.com: Mar 15 03:23AM -0500 I never remember the numbers, so i will just describe it.   CB and low power ham radios use one type. TV antennas use the other.   Both coax is about the same diameter and looks alike on the outside.   I have a police scanner. It has an ext. antenna connector on the rear that is one of those "Motorola jacks" (same as the ant. connectors on car radios).   I used to use a CB (car type) antenna on my roof, for the scanner. It used the CB coax with them big connectors on the end. When I moved, that antenna got left behind.   I recently dug out that scanner again, and have it connected to my homemade weather radio outside antenna. But this weather antenna has the TV style coax with F connectors.   I dont yet have an adaptor for F connector to the Motorola jack, but found one on ebay and am waiting for it to arrive.   My question is whether it matters which coax is used? My weather radio works fine as it is. I did try the scanner using alligator clips to connect the antenna and i do get a signal.   I dont know how well that antenna, made specifically for 162.xx mhz will work on the UHF scanner bands, but I have gotten 155.xx VHF signals well, even with the alligator clip mess.....

tabbypurr@gmail.com: Mar 15 01:39AM -0700 > I dont know how well that antenna, made specifically for 162.xx mhz will > work on the UHF scanner bands, but I have gotten 155.xx VHF signals > well, even with the alligator clip mess.....   50 & 75 ohm. Each is optimised for its own job. Loss & power handling differ, and there's impedance matching to what you're using. There's also wide variation in frequency response with co-ax, some is only good for baseband. Some is well screened, some less so.     NT

Look165 <look165@numericable.fr>: Mar 15 10:43AM +0100 The cable must match the impedances at both ends and these impedances must be the same. Personally, I recommend shielded cable (signal+alu shield+ground return).

Fox's Mercantile <jdangus@att.net>: Mar 15 08:11AM -0500 > I never remember the numbers, so i will just describe it.   > CB and low power ham radios use one type. > TV antennas use the other.   Communication radios tend to use 50 ohm coax. RG-58 1/4", RG-8X 5/16" and RG-8 RG-213 1/2" (Roughly)   TV and most CCTV stuff use 75 ohm coax. RG-59 and RG-6 5/16" and RG-11 1/2"   > Both coax is about the same diameter and looks alike on the outside.   The 75 ohm is noticeably thicker.   > that is one of those "Motorola jacks" (same as the ant. connectors on > car radios).   > My question is whether it matters which coax is used?   It doesn't make much if any difference. Don't let people wind you up about impedance matching on receive antennas.   > I dont know how well that antenna, made specifically for 162.xx mhz will > work on the UHF scanner bands   Generally, UHF is 3 times the VHF frequencies. What looks like a 1/4 wave whip antenna (16-18")on VHF will look like 3/4 wave on UHF. And will work just fine.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

tubeguy@myshop.com: Mar 15 03:24AM -0500 I have a box of 18 gauge solder that says it has 5 cores. Putting one core in solder that thin seems impossible. and this has five. How do they make it?

Rheilly Phoull <rheilly@bigslong.com>: Mar 15 04:37PM +0800 > I have a box of 18 gauge solder that says it has 5 cores. Putting one > core in solder that thin seems impossible. and this has five. How do > they make it?   Google "Extrusion"

whit3rd <whit3rd@gmail.com>: Mar 15 03:25AM -0700 > I have a box of 18 gauge solder that says it has 5 cores. Putting one > core in solder that thin seems impossible. and this has five. How do > they make it?   A lot like putting stripes on toothpaste, which is also clearly impossible.

Mike Coon <gravity@mjcoon.plus.com>: Mar 15 11:31AM In article <bPWdnZHwTrXd-RbBnZ2dnUU7-WmdnZ2d@westnet.com.au>, rheilly@bigslong.com says... > > core in solder that thin seems impossible. and this has five. How do > > they make it?   > Google "Extrusion"   Or try https://en.wikipedia.org/wiki/Rock_(confectionery)   Mike.

John Robertson <spam@flippers.com>: Mar 14 10:13AM -0700 > The basic message is: Be Careful. Be Aware.   > Peter Wieck > Melrose Park, PA   I appreciate your annual awareness posts Peter, even if others want to drift out of perspective.   John ;-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

John Robertson <spam@flippers.com>: Mar 14 10:16AM -0700 > Its all sugar, and in moderation, no worse than starch, alcohol, apples, oranges, cherries and cantaloupe.   > Peter Wieck > Melrose Park, PA   Or wine...   John ;-#)# (who should really learn not to post after imbibing a few glasses of a nice red merlot or cab-merlot in the evening)   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

makolber@yahoo.com: Mar 14 12:49PM -0700 > Don't forget hurricane season is upon us. I don't know how people survive connecting a generator with those suicide cords, but they look like a Darwin award waiting to happen.   running a generator indoors is a great thing.....   you will have electricity for the rest of your life!   m

bruce2bowser@gmail.com: Mar 14 06:57PM -0700 > Tabby:   > I, too, can describe any of dozens of catastrophic conditions combined with a fundamental lack of common sense that will give bad results. Such a list would run to the point where eyes start to glaze over, and the basic message will be lost.   > The basic message is: Be Careful. Be Aware.   Do poisonous snakes like curling up in old radio speakers in barns?

"pfjw@aol.com" <peterwieck33@gmail.com>: Mar 15 04:21AM -0700 > Do poisonous snakes like curling up in old radio speakers in barns?   For that, three things would have to happen:   a) That there are poisonous snakes in the area. b) That they are tolerant of humans and human odors. c) That there is sufficient prey in the immediate area that they should go there in the first place.   Here in the US, and specifically, here in the mid-Atlantic area, there are poisonous snakes - being Eastern Diamondbacks (exceedingly rare),Timber Rattlesnakes, and Massasauga Rattlesnakes (rare) and copperheads. Of the four, only the copperhead will be found near human habitation, and then, only if near water of some nature. Each and every one is far more afraid of people than we should be of them. And, only the copperhead is aggressive when approached. The others, only when cornered.   In my many years in this area, I have had to kill only one (1) rattlesnake (Timber), as it had take up residence on a favorite walking path for us and for our dogs and despite much encouragement over several weeks, would not be moved. That our neighbor, on whose property it lived, also had small children made the task easier.   Now, black snakes, racers and any of several other non-poisonous snakes are quite happy to reside near and with humans - we are filthy creatures in their eyes and bring lots of good food/vermin with us. And, the state of ignorance being what it is, there are those who would mistake a corn snake for a copperhead.   https://cdn.shopify.com/s/files/1/0109/0052/products/image_2ee976b1-14c2-4b56-ab18-ab673b1573da_large.jpg?v=1546024104     http://www.herpnet.net/Iowa-Herpetology/wp-content/uploads/2018/03/copperhead_New_1-Van-Buren.jpg   This is not to suggest it would never happen, but that snake in that speaker is far more likely to be a harmless variety than one poisonous - at least here in the US in pit-viper territory. Coral snakes (Southeast and Southwest) would almost never be seen, and almost never be found anywhere near humans. Their needs are so specific as to make that barn radio speaker physically untenable.   Peter Wieck Melrose Park, PA

makolber@yahoo.com: Mar 14 12:52PM -0700 On Thursday, March 14, 2019 at 12:20:27 PM UTC-4, bitrex wrote: > On 03/14/2019 08:26 AM, pfjw@aol.com wrote:   > >> Behringer is known as the "Pep Boys"of studio equipment.   A mechanical impact to the knob may be a common factor that damaged both channels of the pot. m

bitrex <user@example.net>: Mar 14 12:20PM -0400 > I would be more inclined to use "Harbor Freight" for comparison. Pep Boys does stock a great deal of OEM equipment, as well as the cheap stuff. Harbor Freight does not.   > Peter Wieck > Melrose Park, PA   Eh, I think they get ragged on unfairly sometimes. It's not an otherwise cheaply made box, the enclosure is solid heavy steel enclosure, massive toroidal power transformer, linear power supply with conservatively-rated parts, the pots are Alps, the soldering-work looks great (compared to some truly awful crap I've seen from China.) It's essentially a solid-state EQ with a over-drivable tube exciter stage prior to it going into the four parametric bands I think it sounds quite nice strapped across the output of a mixer with some bass and treble boost and the "honky" mid-range cut a bit before going into a PC's ADC for recording lil jam sessions.   They're all pushing 20 years old tho stuff just breaks sometimes.   The most reliable piece of studio gear I have probably is my Behringer MX602 line mixer, running most every day for 19 years and all it's needed so far is a replacement headphone volume pot

bitrex <user@example.net>: Mar 14 10:36PM -0400 > A mechanical impact to the knob may be a common factor that damaged both channels of the pot.   > m   I think we might have our suspect, here. I took a closer look at the pots and I overlooked it initially. It's subtle but the metal housings of both have some slight bending/warping that the other, more recessed pots don't. Looks very much like impact damage to me.   I'll swap them out and see what happens.

bitrex <user@example.net>: Mar 14 10:38PM -0400 On 03/14/2019 10:36 PM, bitrex wrote: > of both have some slight bending/warping that the other, more recessed > pots don't. Looks very much like impact damage to me.   > I'll swap them out and see what happens.   Like it was in a rack that tipped over forward onto the floor or something, and those two big knobs that jut out took the brunt of it.

bitrex <user@example.net>: Mar 14 10:45PM -0400 > A mechanical impact to the knob may be a common factor that damaged both channels of the pot.   > m   Mmmhmm. I've pulled 'em and opened them up and the phenolic contact boards inside are both cracked right in half.   That'll do it.

tabbypurr@gmail.com: Mar 15 01:32AM -0700 On Friday, 15 March 2019 02:45:19 UTC, bitrex wrote:   > Mmmhmm. I've pulled 'em and opened them up and the phenolic contact > boards inside are both cracked right in half.   > That'll do it.   transplant time.     NT

"Gareth Magennis" <soundserviceleeds@outlook.com>: Mar 14 10:09PM "Phil Allison" wrote in message news:c50a4e27-7cc1-41d9-8e65-5396dfd8addf@googlegroups.com...     > Maybe wire a switch in series with R74 and let the negative grid bias > go way up to cut the tubes off.   ** A switch in the supply to the output tube's screens works well - assuming beam tubes or power pentodes are in use.   Only a few mA need be switched at idle and no electros to discharge.     ..... Phil       ************************************     This seems to be a very simple and elegant solution, yet I have never seen it in use.   Is there a reason this has not been more widely used?       Gareth.

charlescoquet135@gmail.com: Mar 14 11:39AM -0700 On Tuesday, October 15, 1996 at 3:00:00 AM UTC-4, Paul Atwell wrote:

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