Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

Discord ! 

tautech beat me to it!   

Discord is live, even if the patrons aren't...   

[Robert763]

I've brought various sulfated lead acid batteries back usind high voltage and low current. The trick is not to try and rush it. C100 or less is about the current to use . Never force more power than C10 x Vnom into a sulphated battery. e.g. a 12V 5AH (c10xV = 6W) and initial constant current voltage is 60V  so 100mA maximum current. This rule of thumb is based on a good battery being able to dissipate C10 x nominal voltage when float charged and msot of the de-sulfation power being dissipated in the resistenace of the sulphate rather than chemical conversion. 

[tautech]

I've brought various sulfated lead acid batteries back usind high voltage and low current. The trick is not to try and rush it. C100 or less is about the current to use . Never force more power than C10 x Vnom into a sulphated battery. e.g. a 12V 5AH (c10xV = 6W) and initial constant current voltage is 60V  so 100mA maximum current. This rule of thumb is based on a good battery being able to dissipate C10 x nominal voltage when float charged and msot of the de-sulfation power being dissipated in the resistenace of the sulphate rather than chemical conversion.

Some interest info here:
https://www.eevblog.com/forum/repair/attempt-rejuvenating-old-gel-cell-lead-acid-batteries-with-a-bench-supply/

[Robert763]

Yep, lot's of opinions and ideas. All I can say is what I have done. Note that some batteries will take up to about 10 times their nominal terminal voltage before any current will flow. It takes days and you will be lucky if you get 50% capacity back. I reserve it for odd batteries that are hard to replace.

[SilverSolder]

Yep, lot's of opinions and ideas. All I can say is what I have done. Note that some batteries will take up to about 10 times their nominal terminal voltage before any current will flow. It takes days and you will be lucky if you get 50% capacity back. I reserve it for odd batteries that are hard to replace.

I imagine that once the sulfation is penetrated by the high voltage, it is easier for the current to go through the "cleaned" areas than continuing to drill through the sulfate - so it is very difficult to remove all of it. 

[tautech]

Yep, lot's of opinions and ideas. All I can say is what I have done. Note that some batteries will take up to about 10 times their nominal terminal voltage before any current will flow. It takes days and you will be lucky if you get 50% capacity back. I reserve it for odd batteries that are hard to replace.

I imagine that once the sulfation is penetrated by the high voltage, it is easier for the current to go through the "cleaned" areas than continuing to drill through the sulfate - so it is very difficult to remove all of it.

You can't.
There's 3 levels of plate sulphation in a LA battery and the most complex is impossible to remove other than by physical means. Once they get that far they're toast.
Far better to perform periodic battery maintenance..............

[Neomys Sapiens]

Together with the 8060A I got an AVO Multiminor and a Hung Chang toy. The Hung Chang is never coming close to being used; it's down right dangerous.  The Multiminor looks superficially OK, but is as of yet untested; my plan is to assess it this weekend. In the repair queue I've also got a Model 7 Avometer that looks OK from the outside but is somehow broken; no reaction on any range is detected.

None of these will be turned into a lamp.

 

As far as the telephone; I've got an Asterisk PABX at home where one of my Grandstream ATAs has support for pulse dialling, including the Swedish system where -- properly -- 0 is less than 1.

0 < 1. Cool and makes sense. But how many pulses does 0 generate? Less than 1?

I know you're trying to pull my leg, but, just to be explicit:

The swedish system is:

Digit	Pulses
0	1
1	2
2	3

...et cetera up to 9.

But this would mean, that on the old phone with the dialing scale it goes like 0, 1, 2, ... 9 and not as in Germany from 1, 2, 3, ... 9, 0

Example: the famous W48

Where things became interesting in those times were when you could dial a DOPPELNULL (11 Imp.) or a DREIFACHNULL (12Imp) . With the Doppelnull, you could pose as an emergency dialler (Notrufgeber) of choice, with the Dreifachnull you got into the Waehlpruefnetz.

[beanflying]

Meanwhile in shopping issues in 'Stralia  The big Goannas are just downright scary if you get bailed up by one in the bush like Snakes 'normally' they run but not always.

[med6753]

Everything there either stings, bites, or kills you. 

[Brumby]

I know this is a bit off topic, but can someone tell me why - in this day and age - I can get a single monitor KVM switch for under $50, but if I want a second monitor switched as well, prices shoot to the $200-$300 range?

Makes me want to get 2 cheapies and see if I can slave one off the other.

[vk6zgo]

Everything there either stings, bites, or kills you. 

Unlike the USA, we don't have big, furry things that eat you!
I guess a feral pig could have a good try, though........

[Cubdriver]

I know this is a bit off topic, but can someone tell me why - in this day and age - I can get a single monitor KVM switch for under $50, but if I want a second monitor switched as well, prices shoot to the $200-$300 range?

Makes me want to get 2 cheapies and see if I can slave one off the other.

Try finding one that can do three DisplayPort monitors.  Easy to find one to switch one monitor between four computers, but next to nothing to switch thee or more monitors between multiple computers.  You'd think it would be common, given the popularity of multiple monitor systems.

-Pat

[McBryce]

Corona-times.. home-office..

Need my car for a trip next monday. Didn't move it for ~6 months. Battery measured ~1,7V.   
[I really need to disconnect the battery when leaving the car unused for longer periods of time..]

What could I do?
Two-point strategy:
1. trying to reanimate the dead battery (takes the whole weekend).
2. buying a spare battery to be sure the car can be moved.. (buying a car battery on a Saturday in covid times is pricey, don't ask...)

2. was done quickly at a local shop.   

1. is still in progress but seems to bring back the battery (52Ah):
First try: Special car battery charger with 14.6V but practically no current draw.   
Second try: HP 6643A at 35V, 5A, CC mode: Battery started at ~26V, went down and settled at ~11.9V after 4h.
After the voltage had dropped to under 12V I noticed that the HP6643A put out loads of heat.
So I switched to my HP 6632B at 14.4V, 4A, CC mode to charge the battery from that ~11.9V to 14.3V at 0.7A now after roughly 11h.
Seems to have lost some capacity (charging isn't lossless..), put in ~55Ah.

Will test tomorrow by putting it back into the car and check voltage while starting the motor etc. Curious..   

For measuring the battery's voltage I used one of my 34401 DMMs at 6 1/2 digit resolution.      

I've been "taking my car for a walk" once a month for the last year+. I charge it for a few hours before hand (6A - 13.8V) and then go for a 20Km drive. I'm still on the same tank of petrol that I filled in Feb. 2020! but the battery seems to be holding up.

McBryce.

[tautech]

I've been "taking my car for a walk" once a month for the last year+. I charge it for a few hours before hand (6A - 13.8V) and then go for a 20Km drive. I'm still on the same tank of petrol that I filled in Feb. 2020! but the battery seems to be holding up.

McBryce.

Too low as modern LA construction can handle to 14.5V.
~14.2V is a safe level to set for most any starting battery.

[tautech]

Unlike the USA, we don't have big, furry things that eat you!

Really, no redheads in Oz ?   

[beanflying]

Furry New Zealand things  Red Heads the world over are still far more scary 

[tautech]

Baaaaaaaaaaaaaaaaaaaad joke. 

[mansaxel]

Everything there either stings, bites, orand kills you. 

FTFY, HTH, HAND

[Martin.M]

the Hantek Software, specially the Win Drivers Setup, is a nightmare.
But now, .. 

[mansaxel]

I know this is a bit off topic, but can someone tell me why - in this day and age - I can get a single monitor KVM switch for under $50, but if I want a second monitor switched as well, prices shoot to the $200-$300 range?

Makes me want to get 2 cheapies and see if I can slave one off the other.

Try finding one that can do three DisplayPort monitors.  Easy to find one to switch one monitor between four computers, but next to nothing to switch thee or more monitors between multiple computers.  You'd think it would be common, given the popularity of multiple monitor systems.

-Pat

It's the same with HDMI in/out on A/V amps and separate matrices, et c. "4 in, 2 out" seems to be the only size they come, at least in current resolutions. I suspect there's a very convenient SoC style solution in that particular form factor.

This is without having opened anything up and looked; Because I'm in the market for a matrix and have been doing the equivalent of window shopping to find something not expensive and large enough to fit my needs.

Same with Bluetooth headsets; there's an abundance of upscale models that can pair to two hosts, with the intention of doing "computer + phone", and I've got one, a Jabra. Very good, excellent noise cancelling, OK sound quality, pretty sturdy, et c. But I've got two phones and a computer, and 3-relation headsets simply don't exist. Again, I suspect a SoC / reference design that stops at 2.

[bd139]

Best solution is buy a Mac and magic touchpad. Then run everything headless and use RDP to windows, ssh to Linux. Then you can triple swipe between as many computers as you need to  . Basically my Mac is a KVM.

[bd139]

Something TE related. Found a new knob for the TQ D755. Works nicely although it’s from the other side of the fence:

[mansaxel]

Best solution is buy a Mac and magic touchpad. Then run everything headless and use RDP to windows, ssh to Linux. Then you can triple swipe between as many computers as you need to  . Basically my Mac is a KVM.

Yes, this is the best way as long as you don't need the full graphics performance. Most of my unixy machines have never had a monitor attached; they're VM's and as soon as I've got GSSAPI-ssh login going on them I never look at their graphics output unless there's a problem rebooting them, and then only in the vmware remote console thingy.

[bd139]

Same. RDP isn’t too bad for graphics if you’re on the LAN. Don’t expect to play games but CAD is fine.

[McBryce]

I've been "taking my car for a walk" once a month for the last year+. I charge it for a few hours before hand (6A - 13.8V) and then go for a 20Km drive. I'm still on the same tank of petrol that I filled in Feb. 2020! but the battery seems to be holding up.

McBryce.

Too low as modern LA construction can handle to 14.5V.
~14.2V is a safe level to set for most any starting battery.

That's what the charger puts out. I don't have an option to change it, it's a standard no-frills car battery charger, not a desk supply. The goal is only to raise the charge before I start the car, the alternator should be doing the complete charging while I drive around.

McBryce.