Products > Test Equipment
Test Equipment Anonymous (TEA) group therapy thread
bd139:
--- Quote from: mnementh on July 01, 2022, 03:25:11 pm ---
--- Quote from: bd139 on July 01, 2022, 05:12:33 am ---
--- Quote from: Cerebus on July 01, 2022, 03:05:54 am ---Talking of ginger and white cats. About 30 minutes ago the living room curtains twitched and about five feet off the ground a furry ginger and white face poked through them. We're not on the ground floor, and we don't have a ginger and white cat. Window now shut to keep the furry burglar out.
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Had that with a tabby cat here a few months back. Was just sitting at the desk and it came and brushed my leg. I crapped myself as we don’t have a cat :-DD. I shovelled it back out of the window it came from.
As much as I hate cats, the poor bugger was hit by a car a couple of weeks back and didn’t make it :(
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Better watch out bd... we might start thinking you actually have a soul or summat... you know, something left that hasn't been eaten by all your redheads... >:D
mnem
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If it's any consolation, I only spent about 3 seconds in that state of mind and my mind immediately turned into this dude and the possibilities of murdering my neighbour with a flying cat at 2AM at the window.
mnementh:
--- Quote from: AVGresponding on July 01, 2022, 05:28:19 am ---
--- Quote from: Cubdriver on July 01, 2022, 02:40:04 am ---
--- Quote from: Zucca on July 01, 2022, 01:39:19 am ---Interesting the first comment....
--- Quote ---I like to solder all my lugs on for an even better connection. And in the example at the end where you cut through the 4 - 0 lug, you chose a location where it had not been crimped thereby showing an uncrimped gap inside. Not a nice demonstration. Solder has always been superior to crimp, throughout the history of cable lug use. Not sure where you went to school but we actually tested crimped vs soldered connections for resistance and noticed failures in current draw tests. The solder, when done correctly always produced better results than crimps when done correctly. In most applications, either will suffice. However, for pure results solder wins. Silver based solder is 5% more conductive than copper (copper 100%, silver 105% using copper as the standard conductor). Heating wire tends to distort the insulator so care must be used. I like to use a wet rag to cover the insulation near the end or an cooling paste which is available from most HVAC wholesalers. Silver requires a bit more heat than propane, though so most opt for the crimp. We're talking about the purest method here...in real life and in most situations the crimp will suffice. Its important to know the composition of the lug being used as well. Some are made of aluminum while some are copper and other's copper with a tinned coating. Best to choose one with copper, either bare or tinned, since aluminum tends to oxidize over time which creates friction within the lug. I've seen 'em glowing red like a toaster element from bad connection. I got about 50 years experience in this subject.
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Purely from a resistive point of view that may be true, but overall I don’t think it is - solder will wick into the wire, and turn at least some of it, right where it emerges from the terminal, effectively into a solid conductor - right where it’s anchored and going to be subjected to the most stress. What breaks first when subjected to vibration - solid wire, or stranded wire?
Properly made crimps are mechanically sound, more resistant to vibration than soldered ones, and gas tight.
https://workmanship.nasa.gov/lib/insp/2%20books/links/sections/201%20General%20Requirements.html#:~:text=Crimping%20is%20an%20efficient%20and,design%20application%20and%20connectivity%20requirements.
I’ll stick with crimping, thankyouveryplease…
-Pat
Edit to add: copied from the first paragraph of the link above:
Crimped Terminations
Crimping is an efficient and highly reliable method to assemble and terminate conductors, and typically provides a stronger, more reliable termination method than that achieved by soldering.
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No. Just no.
Solder joints are more difficult to do correctly, but when done so are almost always the better choice. The vibration point is a good one, but not really applicable for a home solar PV installation, unless you live directly above a seriously active tectonic fault zone.
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I tend to agree... having done gazillions of soldered lugs personally. I'll make a exception for crimping a solderable lug if one does a crimp right at the end of the lug (or a couple mm inboard if it's a lug with no flare), then fill the shoulder with solder. The crimp will ensure you don't have to worry about the solder wicking up the cable.
mnem
Look! I contributed something positive to the discussion! :-+
mnementh:
--- Quote from: Zucca on July 01, 2022, 12:41:25 pm ---
--- Quote from: Messtechniker on July 01, 2022, 12:20:12 pm ---What kind of soldering (station?) are you using for thick cables? Our everyday 80 W soldering station wont cut it, right?
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You need napalm...
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Even on 4-aught lugs, a propane torch is more than enough. You dip the stripped end in rosin flux, heat the lug right around the back of the shoulder, then when the flux smoke starts shooting out the hole, you start feeding in solder. Reheat as needed to finish the solder joint.
Some will tell you to feed solder until you see it drip out the back; I look for solder to be just starting to wick right at the end of the lug but still mostly copper, as I always finish with heavy-thickness heat-shrink, preferably the sealant-impregnated kind.
Y'all can argue aboot that one if you like... IMO, if your wires are breaking at the solder joint due to vibration, it means you haven't properly applied your D-straps close enough to the end of the wire to support it as it needs.
mnem
:bullshit:
AVGresponding:
Yeah, if your application has major vibration issues you should really be taking extra care with cable routing and strain relief.
Robert763:
So I finally got around to trying out the recently purchased R&S FSH-Z1 power sensor that goes with my FSH3 SA.
All looked good so what to use as a reference power source? First thing I grabbed was an old HP 435A power meter.
As most will know these have a built in 0dBm (1mW) reference at 50 MHz. As this was an old meter that I'd never tested before I did a basic check to make sure there was no DC on the output using the trusty Fluke 8060A There wasn't any DC but switching the meter to AC showed 2.5V RMS at 50Hz :scared:. I'm gussing the main smoothing cap(s) have gone. I think that 435A will become a donor.
So I set up the R&S CMS-33 comms test set as a source.
All looks good. There is a ~0.5dB difference from the set output setting but this is well within the the specification of the CMS-33.
So we need a third measurement or refence to find exactly what is Watt.
Enter the HP 432A and not one but two 478A thermistor sensors (about £20,000 worth at current Keysight list prices)
Bill, Dave and the two Doctors would be happy - perfect agreement :-DMM. Test at -5dBm shown I did check other points.
More interstingly, while the FSH-Z1 is specified for 10MHz to 8GHz some testing shows that it is perfectly good all the way down to 500kHz 8)
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