I’m a pretty reasonable person, but, the number of e-mails requesting personal support and peddling spam is getting beyond reasonable. With the recent rise in time-consuming e-mails, I have been completely overwhelmed and that has come at a great personal cost.
So before e-mailing me, please consider the following:
- I am not your personal helpdesk. I don’t know everything, I cannot possibly know everything, and I cannot possibly help everyone that comes along with a question.
- I am not a shop – I do not sell products, and I am not interested in selling my items to you.
- I am not a distributor or an importer – I have no interest in becoming a business partner in selling your products.
- I’m not interested in SEO or advertising services or helping you to promote your SEO site which is even less popular than a personal blog such as my own.
- If you have a question, it is often better to post a comment so that everyone can see it and any responses I may wish to offer. That way, as many people benefit as possible.
- If you have a very specific question relating to your circumstances, unfortunately, 99% of the time, this will not interest me. Do not be under the impression that just because I’ve written something on a similar topic that I will suddenly answer every question about the topic that you might have.
- Within every field, there is jargon and technical aspects which can only be adequately explained using the correct terminology. I won’t be involved in lengthy “lessons” in trying to privately educate you about some of these technical aspects. Please take the time to self-educate by spending some time on Google. There’s a lot you (and I) can learn from the internet.
That being said, I am happy to receive e-mails from users when they have something that concerns me – maybe it’s a compliment, maybe it’s some well-reasoned disagreement, maybe it’s some opportunity or something not covered above. I’d be happy to receive offers of products to review, or enquiries about licensing my content. Whatever it may be, please be polite and don’t let this deter you from sending me a message. I’m a reasonable person.
If you send me an impolite e-mail, or one about your specific problem that doesn’t interest me, I will no longer reply. If you are half-reasonable, I might provide you half-a-reply. There are many forums online where many technical minded people are able to better help you with your specific problem.
I honestly don’t care for e-mails that go “you’ve written about this, so you must know this, so please solve my problem”, or “you’re so smart, so this is going to be easy for you”. If you leave a comment, I may or may not reply depending on whether I have any time, or information to contribute.
Just because you leave me a message does not make me in any way obligated to help you. I’m sorry, but I need to live too.
I hope that this will save me enough time so I have a better chance of updating the blog with more interesting, different and exciting experiments.
Now that you’ve read that, if you still wish to e-mail me, my address is (please retype and interpret – don’t copy and paste):
mxex(xatx)xgxoxuxgxhxlxuxix.xcxoxm
For vision impaired, or where the browser does not render the above intelligibly, the address has been read out in the NATO Phonetic Alphabet as an audio recording
Something wrong with your email server config?
Dec 4 via Gmail:
“This is an automatically generated Delivery Status Notification
THIS IS A WARNING MESSAGE ONLY.
YOU DO NOT NEED TO RESEND YOUR MESSAGE.
Delivery to the following recipient has been delayed:
[redacted]
Message will be retried for 2 more day(s)
Technical details of temporary failure:
DNS Error: Address resolution of mail.goughlui.com. failed: Domain name not found”
Thanks mate!
In the transition, I had unfortunately removed an A-record for mail.goughlui.com in the DNS which caused things to become unresolvable. It was working fine earlier because I was still hosting mail through the old hosts, but then they terminated my hosting before my requested end date which caused a bit of a fuss.
With the DNS propagation delays, it might take a day before it’s ultimately fixed. I hope it is. I will keep an eye on it.
Thanks,
Gough
I am looking for a Good Sony AN-LP1 Antenna for my Shortwave Radio. I want it for my Sony CRF-330K Radio. Does anyone have an Antenna for sale?
I’m not tech savvy. Have a 49 plan on iPhone with Lyca but it won’t let me tether to my computer. I need that, what to do??
If you use an iPhone, tethering is controlled by the carrier. There is absolutely NOTHING you can do on your end to enable or disable tethering without the help of the carrier. This is an Apple design decision, and is one of the reasons I don’t use Apple devices in general. Unfortunately, I don’t think Lycamobile offers tethering support for iPhone, so you’ll have to look for a different carrier which supports it. Do make sure you check with the carrier before you buy in – because it’s no good changing to another carrier that doesn’t support tethering either.
– Gough
Hi.
I’ve sent Email about MS-DOS 4.01.
If you didn’t receive my message, can you send Email?
just wondering if a satalite finder could be hacked into a gold or metal detector
Great Read. Keep it up
Congrats on the Thesis. Great read every time I come here. As a techie, I love the analysis you do of everything, really encouraging.
Sir,
This is Nikhil Anjane. I’m an engineering student in 3rd year at K. J. Somaiya Institute of Engineering & Information Technology, Mumbai. I’m currently working on a project which involves the IC-STA8088EXG manufactured by company, STMicroelectronics for positioning applications.
For this reason I need a schematic diagram of this IC which I cannot find anywhere on the internet.
So it would be a great help if you provide me with the schematic of this IC.
Hoping for a positive reply soon.
Thanking You.
I’m sorry but I don’t know why you think I would have such information? I don’t work for STMicroelectronics, let alone design ICs. Schematics for ICs are generally considered the intellectual property of the company and aren’t openly available. Some companies might do some reverse engineering and sell reports for a few thousand US$ and up. The only data available is the public datasheet (http://www.st.com/content/ccc/resource/technical/document/data_brief/55/e9/1e/cb/a6/a2/43/d1/DM00047101.pdf/files/DM00047101.pdf/jcr:content/translations/en.DM00047101.pdf).
– Gough
Hi – read your post on the damaged flash drive repair – glad you could help them! Gives me hope. I am contemplating a DIY on my own Lexar 128G flash drive whose retractable usb port snapped off. Plastic port! Who makes an entire usb AND port out of cheap plastic? In my defense, it was purchased in blister packaging and the offending plastic port was not visible.
I got solder and flux today but I don’t want to screw it up or make it worse, it is so tiny! The circuit board looks different too, doesn’t appear to have a copper layer, but copper wire threaded through the wafer itself. Can you recommend a company that you would send one to? Or have a look at it? I have photos of it.
This has tons of work files with thousands of hours of material, and presentations I need. I know, bad idea to not back it up when so vital, but I was actually leaving a client, literally on my way to get a backup drive. I slipped it into my bag for a minute to get to my car – and the unthinkable happened. When I fished it out at the car to put it away in the protective pouch- the retractable port apparently had not retracted fully and snapped off in my bag. I have some older files backed up, but the newer ones I couldn’t because my laptop memory was maxed out, which is why I was heading to the store for more memory.
To add insult to injury, one file I need for a new client was still open in Photoshop on my laptop so I went to resave it to the laptop c drive – and Windows 7’s infamous ‘no warning’ system update took over and shut everything down and lost it. That was so so unfair. (Really, would it have killed them to give you a 60 second warning? Or let you opt out?) I had files on it for several volunteer projects I was doing in my local community too so that hurts – I donated hundreds of hours to create material – and it is a punch to the gut to look at this flash drive in pieces.
Every drive has a different circuit board layout, and some don’t even have a circuit board at all. Depending on how it is designed, it could be entirely impossible to repair yourself, or you might need other spare components (e.g. cut up a USB lead to get the connector).
As I am in Australia, and I normally solve all my problems by myself, I can’t really recommend anyone by name. That being said, I think recovery might get costly, so maybe it pays to shop around especially if you’re not willing to accidentally damage it beyond repair. Depending on how much you value your data, maybe some companies can offer you a service for a reasonable price.
Yes, automatic update reboots are a pain, but a simple regedit fix (creating the NoAutoRebootWithLoggedOnUsers value) seems to do the trick for me: http://answers.microsoft.com/en-us/windows/forum/all/i-want-to-turn-off-the-automatic-restart-for/88191194-d3e7-428d-a2a5-89e427756ccc?auth=1
I don’t think it’s economical to send it to me, and really, if you were to send it to me, it would be the absolute last-resort, and I will take no responsibility and provide no guarantees especially not knowing further what the unit looks like and what the repair strategy would be like.
– Gough
Hi Gough, I came across your site and your article on the Woomera modem, from searching google. My mother (71 years old) lives in Winton, Queensland (a small outback town) and, as I discovered recently when visiting her, has a Woomera modem. She has the one before the one you wrote about in your article. To be honest I was shocked when I saw it because it looked really old to me and I wondered how it could possibly still function! But it does function and she accesses the internet with it every day. I took a photo of it so that I could show my sons (18 and 27) when I came back (to Melbourne) as they are both tech minded and I thought they would find it interesting that a modem from so long ago is still being used today. I could email you the photo, if you’re interested? Thanks for the well-written article, it was very interesting and informative! Kind regards, Amii
Hi Gough, thank you for your excellent teardowns of laptop battery publications.
I would like to connect 2 laptop batteries in serial then in parallel for tests.
Could you tell me what are the risks to damage the cells or the controller ?
regards,
Jack
Personally speaking, I would not recommend connection of any sort of finished battery packs in series or parallel for a number of reasons as it can cause danger or permanent damage to the cells. If you choose to do any of these experiments, please do so at your own risk. I will not be held responsible for any damage which may occur because of your own doings.
Basically speaking, a properly made laptop battery has an internal charge controller, software-based protection against overdischarge/overcharge/overcurrent, balancing, colomb-counting and I2C/SMBus communications to let the computer know about the charge state and battery capabilities. A properly made laptop battery (with the exception of cheap copies) also has a physical fuse as a last line of defense against controller failures, and likely also a thermal fuse to protect against overheated packs. The 18650-cells they are made from also have a PTC protection on the cell which should go open in case the per-cell draw exceeds a set limit (5-8A normally), and a cell interruptor device in case of overcharge. Despite all these protections, it is known that some times the protections do not work correctly or are absent in the case of cheap copy batteries, and or some protections when activated are irreversible resulting in permanent damage to the pack. Power banks are fairly similar to this, but with the exception that each of the power banks has its own switching (normally) boost converter to push up the voltage and frequently LESS protection around the battery itself.
As each laptop battery itself is a collection of series-parallel sets (e.g. a 9 cell battery is often three sets of three cells in parallel), internal balancing is necessary to make sure that the differences in capacity of each set of cells is accounted for, to prevent a single battery from overcharge and failure by venting with flame. Hence charging with the controller or an external charger with balance connections (e.g. hobby R-C Li-Ion/Poly chargers) is advisable.
If you put several assembled batteries in series, you run the risk that the batteries will inevitably both have a different capacity. Assuming the protection works, the lower capacity battery should shut-down its output once it is depleted, however, the other remaining working battery is still putting out a voltage and if an external load is present, there is a potential that this voltage is enough to damage the MOSFETs which allow the battery to shut down by forcing current through it, heating it up and burning it out. Permanent damage may result. In case of short circuit, the protection level may not be the same on the two batteries – the same result may occur, but with the added potential that any primary protection fuses may permanently blow as well, rendering the pack unusable (at least, not without physically attempting to repair it). If you put a large number of batteries in series, the voltages which are developed may be above the insulation ability of the PCB and breaking ability of fuses/MOSFETs which could result in fires when the protection attempts to open due to striking an arc that is not extinguished. Incorrect connections or even interfacing to the in-cell microcontrollers are also likely to cause trouble – as the I2C bus is referenced to ground and the “ground” of each battery is its own negative terminal, so they can’t blindly be bussed together (as far as I know).
Parallel connection is also problematic, as the cell voltages are likely to differ, especially if the state of charge is different on the batteries. Depending on the protection, the high current flow when batteries of dissimilar voltages “equalize” can permanently damage the controllers or protective MOSFET/fuses. More unusually is that the batteries might get a little confused, as incoming current is usually only experienced when charging, so the controller might oscillate between charge and discharge operation. In case of cell/battery fault, the working battery could dump its charge into the failed battery resulting in high current flow, heat and fire – or protections to trip, but if you parallel a number of batteries, the protection is not designed for the high level of fault current and is likely to fail to trip. Even if all else is fine – the first battery that becomes discharged and falls into protection may immediately “awaken” due to the voltage supplied by the other batteries in parallel, and so the protection may fail to work as intended. To get around this, it’s advisable to at least prevent the batteries from charging each other through the use of an “auctioneering diode” arrangement, but this involves some losses, as well as current limitations of the diode that you choose. Charging under this circumstance is not a realistic possibility.
In short, I highly recommend not doing any of this at all. It can result in dangerous situations which are not obvious until something “happens” – e.g. cell trips out because it empties first, unit switches off, charging occurs, highly inductive load is connected, etc. In the case of power banks, because power converter circuitry is used, they may power-on and off erratically and protections can trip randomly as well. Insulation can be an issue if developing higher voltages in series, and damage from reverse-polarity back-feeding a unit that has switched off could permanently destroy the power converter as well or heat up its MOSFET.
Note that the controllers do NOT have a limit on allowed charging cycles as you mentioned in your e-mail to me. Some merely count cycles, others don’t do it at all, but most of them will report the remaining full-charge capacity to a computer and may shut down the pack permanently when a safety condition is violated – for example, charging has gone too long but the cell did not fully charge, or the pack is so out of balance that it’s likely that there is a cell failure within the pack. When the battery shuts down, it’s trying to keep you safe.
– Gough
Hi Gough, thank you for your excellent lecture. You are exactly right but we poor unexperienced developers try from time to time to make things to work against the technology standards known to experts like you. I have studied personal drone crashes in US for a year, since the date FAA imlemented compulsory registration of small personal drones. Since all flight parameters get registered by black box, I could have done that job remotely, getting flight data logs for analysis. Ts of personal drones crashed already and more may crash tomorrow, but ppl still buy, build personal drones, fly and crash them ( visit diydrones website one day).
Quite recently I was offered Li-Ion packs made of used laptop batteries connected in parallel and large packs of used Li-Ion cells connected in serial and parallel.
I have received images of such Li-Ion packs as attachments, so I will try to send them attached to you via email.
Thank you very much for your expert’s opinion and let me be your student and junior researcher/ developer.
You really deserve to be promoted to Research Professor, as soon as possible.
Thank you once again for your excellent job done so far for the Internet community.
Jack
Interesting to hear that – I have torn apart power banks with mismatched cells that appeared to be harvested “recycled” pulls from old laptop batteries possibly sent to China for recycling. I’ve also found some anomalous cells with Samsung “claimed” branding, but the printing on the sleeve and battery internals differ from genuine Samsung cells.
As a rule of thumb, Li-Ion cells degrade from the date of manufacture. As they age, they invariably get more and more “different” with their remaining capacity. Most manufacturers set 70% or 80% of the initial capacity as the “designed lifetime” because after this point, the degradation can sometimes be very rapid and unpredictable.
Aged “reused” cells in this manner tend to have lower than original capacity, but also more unpredictable cycle life. When you start combining cells (or batteries) that are towards the end of their life like this, aside from the safety implications, you also potentially decrease the reliability of the system as a whole unless special design precautions are taken. As far as I’m aware, the capacity loss on Li-Ion batteries is not “reversible” by any end-user possible means, so things generally only get worse over time.
– Gough
Thank you Dr. Gough
for your kind reply.
Last week I visited a small company refurbishing old laptop batterry packs, replacing old Li-Ion cells to new ones.
I have spent more than 2 hours having a nice chat with a manager of the workshop and telling him about the new GigaFactory by Tesla to manufacture Li-Ion cells for new EVs ( 7,000 cells to make 100kWh energy stored in a single car), he presented me with oversized Li-Ion cells by Headway.
And the largest, highest capacity single Li-Ion cell is rated 100Ah vs.
2.5Ah standard Li-Ion cell.
I would like to import used EV from UK and replace Pb gel batteries with the new by Headway one day.
But my first challenge is to replace Pb gel batteries in my UPS power supplier to Headway oversized cells to get higher capacity and more operation hours in cold start mode (as 12V power bank).
Please let me know your opinion, what makes manufactures of EVs to install and assemble battery packs made of multi-Ts of standard Li-Ion cells if oversized Li-Ion cells are already on the market pretested.
Reference only link to oversized Li-Ion cells by Headway on eBay
(you are free to visit their website to get technical specification)
http://www.ebay.com/sch/i.html?_nkw=headway+lifepo4
The cells you describe are Lithium Iron Phosphate cells (LiFePO4), which are distinctly different from Li-Ion type cells which often are LiCoO2/LiMn2O4/LiNiMnCoO2 chemistry. As compared with Lithium Ion technologies, LiFePO4 cells are much more tolerant of abuse, relaxed in protection requirements, and capable of providing high currents more safely (i.e. less chance of an explosion) whilst also delivering higher cycle life. They are often found in power tool batteries because of these properties, and can be a bit expensive (especially when A123 had the patents for the technology) and rarely found in mass-market electronics due to lower energy density and nominal voltage. The “oversized” cells you describe are ones which are often used in electric bicycles, especially in DIY conversion kits, designed to be “bolted” together. While the cells can be found in prismatic packs which are similar to SLA/gel-cells, they are not exactly a drop-in replacement as they prefer to be charge-terminated rather than sitting on float.
Large cells can be of use, but pricing is often higher as the demand for them is less, and the number of competing suppliers is less. If you buy enough volume, you can conceivably have any pack or configuration of cell you can imagine, just as each mobile phone manufacturer often specifies a different prismatic size for their “latest” flagship devices to make the best use of the volume. The main reason 18650 cells are so often used is because they have become a de-facto standard owing to the large number of places where they “fit in” or are an acceptable compromise in the name of meeting price-point requirements.
That being said, Tesla has a good reason to vertically integrate their business and insulate themselves from the market which could fluctuate in the near future as energy storage systems take off. By producing batteries in-house, they can better optimize their form factors, reduce overheads (e.g. protection requirements due to less cells delivering the same capacity), improve specifications and safety (due to having full control) and regulate their costs.
Direct replacement of Lead Acid with LiFePO4 is possible but not without potential for safety issues and unexpected problems. You really need to know what the operational characteristics of the device are – e.g. maximum currents/voltages/temperatures/vibration/size. In the case of your UPS idea, it is potentially feasible, but I would have to note a few shortcomings of UPSes in general:
– Often their charge rate is not particularly fast, so in case of a depleted pack, it takes a good 10h+ to charge. In the case of “up-rating” the packs for a larger capacity, this only gets worse.
– Batteries are sat on float to maintain charge when not in use. This is not a recommended or permissible condition in the long term to maintain LiFePO4 safety/lifetime.
– Discharge rates can be quite high – Lead-Acid is tolerant of this, LiFePO4 could be damaged if the permissible rate is exceeded, especially when the battery is cold.
– UPSes are generally designed with “low quality” square-wave or “modified sine wave” output which can be harsh on electronics. They also like to beep in cold-start mode, so disabling the buzzer is a good idea. It does have some on-board monitoring, but the voltage-based capacity indication could be incorrect due to differing voltage discharge curves.
– UPSes are often designed with limited, sometimes only just-sufficient levels of heatsinking and can get quite warm under high loads (50%+). They often will run for the 2-7 minutes the battery can provide for at those draws, but if uprating the pack, then it is likely that the inverter might overheat and be damaged.
From my perspective, the main reason such packs are not already more prevalent are several:
– Cost. LiFePO4 batteries aren’t the cheapest on the market, and they need to be carefully watched (more than lead-acid or Ni-MH cells) to avoid damage.
– Operational conditions. LiFePO4 might not work as well under cold temperature conditions, and while the other chemistries typically don’t work that well either, at least they don’t get damaged and aren’t like the Tesla in needing to maintain a “climate control” system for the batteries. How well such packs handle vibrations is not certain as well.
– Safety. This is probably a major point that needs regulatory approval. Countries are likely to have their own crash safety standards, as well as reliability requirements, and whether any Li-chemistry battery “built randomly” can handle it is a question. I know from a small experience in space-qualified Ni-MH battery packs that pack construction can be the make-or-break for safety especially where vibrations are concerned. Also, as many of the strings operate at DC voltages greater than SELV, many jurisdictions will not allow unqualified people to service, install or maintain such systems.
– Lifetime. To eke out the maximum lifetime from the cells requires more than just hooking them up. A proper battery management system is still most preferred, and as currents/voltages get higher, making them reliable and safe becomes more challenging. The cell count will also contribute to the complexity. Temperature management for the pack to prevent it from overheating is also a potential concern.
– Insurance. Will a company offering such packs, or retrofitting them, be able to be so sure of the safety of their solution that they could afford to guarantee them? The cost of a set of batteries is likely comparable to the majority of the cost of a petrol combustion car today, so if you’re trying to sell them to consumers on the premise they are good for ~8yrs+, you need to “stick around” and develop a reputation, and back it up with “something”.
– Compatibility. Existing EVs are likely to have their own proprietary interfaces, programming, charge-control algorithms, etc. To get the data required to understand and reverse engineer the process is effort, and to produce modifications to improve compatibility is costly, especially if there are several variations of firmware or hardware involved.
Don’t get me wrong – I’m not claiming it can’t be done. In fact, it might even be beneficial to many who just want a little more from their car. But one has to remember, an EV is still mechanical, and still requires service. By the time you’ve worn down a battery and are thinking of selling them second hand, there’s a good chance that other mechanical parts in the motor also need refurbishment or replacement. For example, Tesla owners are finding their drive-trains are giving in at around the 100,000 mile mark, whereas some petrol cars can run three times as far, so refurbishment might not make sense depending on the economics of maintaining the remainder of the car.
I suspect a majority of car vendors offering electric vehicles see this as a new opportunity to “vendor-lock-in” the end users by limiting access to information, spare parts, service information and services to only their own approved service people. That doesn’t help this situation in any way, so we are at the mercy of their decisions sadly.
– Gough
Thank you for your excellent answer and explanations.
You are exactly right.
All I can do is to build Li-Po Li-Ion battery packs for personal use.
At the same time I have contacted a number of battery pack building services, welding 24V, 36V, 48V battery packs for e-bikes, so I expect to get professional support in developing Li-Ion battery packs for UPS, wheelchair, e-bike and a small electric car (RV).
BTW
Chemistry o0f my Moli 26700A cells looks to be standard 4.2V Li-Ion
basing on technical specification sheet (no more manufactured)
http://www.molicel.com/ca/pdf/IMR26700.pdf
more about Moli Cells
http://www.molicel.com/hq/about/aboutus1.html
I use standard Li-Ion 4.2V charger , inserting oversized cylindrical Molis into a single bank (one of two) and it takes 5-6 hours to get them fully charged ( voltage rises from 0.02V to 4.2V – no warming) – since I have got them fully discharged (0.02V) I try to give them second life.
In 2016 I recharged 90 Pb gel 3.5Ah 6V batteries discharged to 0.05V (or never used since the date they left factory in China many years ago).
I am sure, I should avoid prismatic Li-Po cells to avoid pillow effect (known from tablets) since a single pillow can damage multi-layer Li-Po package.
Hope to get used oversized Headway 10Ah single cells
next week for tests.
BTW
Just purchased 3G 7 inch tablet coming with GPS, testing GPS since no sats with demo Android apk GPS Test app from Play Shop by Google.Need to install another GPS test app since this one supports AGPS so I get a list of sats for my geolocation by Internet 3G link but no signal level for such sats to calculate GPS Fix.
Life is not easy with all this hardware and software nowadays.
IMR generally means high rate Lithium-Ion, so care is advised. Such low voltages suggest that they have been overdischarged – generally a floor value of about 2.5V is recommended, below this metallic lithium plating may compromise the future reliability of the cell causing catastrophic internal shorting. However, it could be that the cell has a protection PCB and the low voltage indicates the cut-off is working, in which case continued use is okay.
I use GPS Status & Toolbox (https://play.google.com/store/apps/details?id=com.eclipsim.gpsstatus2&hl=en) myself, and it’s worked well for me on all devices. It has AGPS clear/download and shows per-satellite signal strengths and sky positions. It also shows other sensor details for supported sensors. If you still have trouble, maybe you have a defective GPS module, a bad antenna/poor connection or some interference/jamming where you are (or insufficient signal).
– Gough
i am an MD interested in dect special wireless headset development. see radflowspace.com
Need your talent. thanks
Thank you Lui,
I have installed your GPS Status & Toolbox (previously installed GPS Status) and no GPS signal at all. It looks like my new 8GB quad 7 inch 3G double sim, GPS enabled tablet requires a visit to service.
Ok, AGPS downloads topology of sats for my geolocation calculated by mobile operator but no GPS signal at all ( after 1-2 hours).
What’s more, G-sensor doesn’t look to work properly in GPS Status & Toolbox either since centre target levelling with this app is not the correct levelling for my table, desk …
So life is not easy with GPS tablets.
In theory I can manually remove back cover to see if GPS antenna is connected but i’m afraid to get my warranty cover unvalidated, in case of next problems.
I just bought it new with an intention to verify geolocation accuracy, GPS fix sent and recorded by GPS tracker (to SD card) vs. GPS data captured by logger app installed on tablet).
G’day Gough,
You have conducted some reviews of TV broadcasts specifically looking at some newer Hi-Def formats. Some of these Clayton’s Hi-Def formats seem to involve different video and audio modulation techniques, or perhaps I should say encoding. Many TVs older than just 3 years cannot decode either the video, audio or both on the like of Nine’s HD channel.
As a function of your reviews have you compiled a list of all used or likely to be used contemporary formats?
Regards
Salve Dr. Gough, sono italiano mi scuso se mi rivolgo a lei nella mia lingua, possiedo un signal generator Newtronics model 200 SPL.
purtroppo mancano i transistor Q16 e Q17, le chiedo se mi può aiutare comunicandomi il tipo.
Ringrazio e saluto cordialmente.
Angelo Lombardi
Hi Lui,
After reading your post on fixing a USB, I was wondering if you have any best handy hints to try and fix my now snapped USB 3.0 with months of work on it that I wrote for students that I teach. Stupidly, I thought I had backed it up more recently than I did.
Any help, if you have the time, would be very much appreciated.
Kind regards
Joe
Hi sir there.
I would like to know if the Spectrum Lab program can work well in the Icom IC-R75 to use it only as a Spectrum Scope by connecting the rs232 / USB adapter and using Windows 7, I would like to use it only to monitor signals, to see and searching for adjacent radio signals and in ham bands. That is all.
Thank you very much for your reply.
73 Jorge
Spectrum Lab (by DL4YHF) is a program that performs fast-fourier transform (FFT) of audio data to present a spectrum waterfall or graph. This requires, at its least, an audio input from the radio – for example, you can hook up the record output of the IC-R75 to the line input of your sound card. This will produce a real-time spectrum of the passband of the receiver, which will depend on the filter options installed and selected on your IC-R75. Spectrum Lab also has some rig control abilities under TRX control under options – you will need to set the correct radio address under CI-V to be able to control the IC-R75’s frequency using the boxes at the top. I haven’t experimented with wider scanning using Spectrum Lab now that SDR radios are fairly commonplace – maybe you could investigate building some macros to accomplish this.
However, a more rudimentary, but very fuzzy way to build a power spectrum using the CI-V interface alone is to use something like Ham Radio Deluxe (the old v5) which has a Spectrogram feature which basically scanned the frequencies automatically while plotting the S-meter values. This is very crude and not at all able to distinguish an SSB/AM transmission from a CW trace, but does not require an audio input.
– Gough
Hi Lui,
no new traffic from you in the last months.
I would appreciate your research paper on used laptop batteries and controllers, BMS, balancers and what can be done with stand-alone used laptop battery
My sugfgestion is power bank.
Thank you and wish you all the best,
success and prosperity in private and business life
darius
Hi Darius,
There may well be some more posts soon. I have been in the process of a major upheaval due to a number of things, and as a result, I’ve basically had to “rebuild” everything from the ground-up. As a result, I’ve had no time to put anything up even though I have some data I’m still waiting to analyze.
Besides that, there are other things in my life that I must attend to as a priority – the blog is more of a thing for “when time permits”.
Thanks for your concern!
– Gough
Hello Dr. Gough,
I Recently found your youtube video where you were able to adapt your Kaypro 10 keyboard for use on a modern PC. I’m trying to do the exact same thing. Your video was very helpful but I was not able to see the underside of your breadboard and need to know how to wire the phone cable so I can then connect it to my USB to TTL adapter (I’m using this one https://www.amazon.com/gp/product/B075N82CDL/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1 ).
If you could provide just a few hints or links that might be helpful I would be greatly indebted.
Kind Regards,
Jess
It’s been a long time since I did that project – basically I posted this short note with the video thinking that it was obvious to replicate:
http://goughlui.com/2012/12/03/tech-flashback-kaypro-keyboard-its-still-alive/
Only three connections are necessary – a 5V positive, a ground and a receive data line. One trap to look out for is the order of the phone wiring – some wires are made “roll over”, indicating that the order of the wires reverse, while others are straight through. Get this wrong and you could fry something! Because I was told I needed to reverse the lines in my roll-over cable, I decided to make the break-out here: http://goughlui.com/2012/12/01/tech-flashback-reviving-the-kaypro-4/
That didn’t work, as the phone cable seemed too thin, and the resistance was too high. Not wanting to call it a day, adapting it to a modern PC was more of a test to see if the keyboard was still viable. As a result, I lopped off one end of the cable and used the colour coding inside with the remaining jack to ensure connections are in the right order.
If you take the time to examine the keyboard internals (http://goughlui.com/2012/12/01/tech-flashback-reviving-the-kaypro-4/), you will see the wiring from the jack to the PCB. Unfortunately, the photos don’t show the pin-header connection to the board, but there are four wires – Red, Green, White, Black (similar to USB). If you trace the connections from Red and Black, you might find that they go to the capacitor next to it (a polarized capacitor) with the Red to the +ve and the Black to the -ve. If that is the case – congratulations, you’ve identified which pair is the power pair. If not, whichever pair is connecting to the capacitor +ve and -ve is the power supply. By checking continuity and the wiring of your plug, you can figure which colour wires that corresponds to.
As for the remaining two wires – as you really only need the keyboard’s transmit data line, you can try each one alternately to the TTL serial adapter’s RXD line and check in a terminal if anything shows up. Whichever one works is the “right” one, and as the PC is not transmitting out of the RXD line, there’s no chance of damaging the keyboard that way.
I didn’t document this almost six years ago, as I felt it was a bit obvious and it was very much just a “weekend project” – but in hindsight, maybe I should have.
– Gough
Dr. Gough,
Thank you for taking the time to respond to my question. Prior to messaging you I had taken my keyboard apart to clean it and examine the leads going to the connector. I initially had done exactly what you outlined in your fourth paragraph. I have power going to the keyboard from the USB adapter I linked to you, and the caps lock light works as does the piezo beeper with all the key presses. However, when I try to determine which of the two remaining KB leads will send a signal to the RXD on the USB adapter, I get no indication that a signal is being sent. Did I get the wrong adapter? or would this indicate that the keyboard is not fully functional?
I greatly appreciate your insight,
Jess
I hope you have a TTL 5v adapter – but beware that some cheapies may have counterfeit chips which cause problems.
To check if your adapter is working – just connect the TXD and RXD lines together to form a “loopback”. Open up Hyperterminal, select a fixed baud rate of 300bps with no flow control and see if what you type into the window is echoed back. If it is, your adapter is functioning correctly.
Then try connecting one of the remaining wires from the keyboard to the RXD line on your adapter. Press a key and see if it appears in Hyperterminal. If it doesn’t, swap to the other line and repeat. If both do not seem to work … it’s probably time to crack out an oscilloscope to see if there is even a signal being emitted. If not, maybe the IC on your keyboard has issues, or the key contacts might have oxidised and it’s not actually detecting keypresses. This might be temporarily healed by disassembly and cleaning with contact cleaner, or repeatedly pressing the key harshly.
Best of luck.
– Gough
Hi there,
This is I hope a pretty simple bit of information I require, will be building a Hex 3653 but I wonder do resistors have a correct way round ?, should I be exactly matching your pics on your print out for resistor position ?.
By the way your guide Hex3653 looks just great.
Gerry.C
Resistors are non-polarized components and can be put in either way around with no harm.
– Gough
Thanks mate for the info as i was about to purchase Deta downlights from Bunnings but now after your extensive review I am now not going to purchase them and get a more reliable brand…much appreciated
Hello, Gough,
Thank you for your excellent work on the modem protocols. Can you check or be able to communicate your thoughts on this issue: which protocol is best used on vocoder communication channels, such as Skype, Viber, Telegrams. Will V.22 or V.32 work? What speed can I get?
Best regards
Sergej Kalinin
I don’t want to recover data from my Syquest cartridges, I want to know how to destroy the cartridges before tossing them. I have at least a dozen cartridges. I have 2 EZ Flyer Syquest 230MB drives. I have the Power Computer these were used on, but I don’t know if it still works. It has not been used in many years.
If you want to destroy the data on the cartridges, there are always several ways which range in difficulty and paranoia level:
– Easy: Physically run a strong magnet over the surface (e.g. some neodymium magnets obtained from hard drives) which will cause damage to the encoded data and pre-encoded servo marks that allow the drive to position the heads. The cartridges then cannot be reused or reformatted due to the loss of this low-level formatting. However, you might find that some patches aren’t necessarily erased if you do it by hand.
– Slightly more difficult: Use a degaussing wand that is used by professional media recyclers or to clear residual magnetic fields from TV. This should produce an alternating magnetic field which may be more effective at erasing the medium, but with the same disadvantages as above.
– Lazy: Unscrew/smash the cartridges open with a hammer, scratch/grind the material into dust. On the upside, no specialist equipment is required. However, destruction can be incomplete.
– Less lazy: Get a working machine and drive, format the cartridge using a full overwrite format. Effectiveness will depend on the utility – a full format should at least zero out the user area, but remnant data may remain as some utilities save unformatting data, others only verify the surface but do not overwrite it (for the reason that a user might goof and need a way back). Remnant data may also remain in the skirts/guard bands of the tracks due to random positioning error – while not recoverable by the drive, it may be recoverable under expert analysis (although highly unlikely).
– Paranoid: Get a working machine and drive and erase the disk using a utility that follows the DoD 3-pass/7-pass or Gutmann 35-pass overwrite procedure. Much less likely to have data leakage although the paranoia level of the Gutmann is less justified on more modern devices due to the outdated RLL/MFM encodings which it targets. Other people prefer just to overwrite the whole surface numerous times. If you attach it to a machine running Linux with a SCSI interface, it’s as simple as a dd command to do a full random/zero overwrite. However, due to the drive’s own internal defect management, clearing data from bad/reallocated sectors is not guaranteed. There are SCSI low-level format commands, but whether this actually does clear these reallocated sectors is not certain.
Of course, the super-paranoid should use a combination of methods to ensure secure media destruction at all levels – logical, physical. That being said, I would probably hang onto those drives – they could be worth something to someone, especially those who might need to recover some data from their own cartridges.
– Gough
Spelling correction… it’s “compliment” (praise) not “complement” (goes well with). 🙂
Thanks for that – fixed!
– Gough
Hi Luo, was just reading one of your earlier posts re: Salvage: Audio Telex Communications ATC 5400 & Australian Monitor ATC5101-3 PA Speaker’.
Recently purchased our new house and noticed we have the same cream grill in our ceiling, but damaged 🙁
I understand these would be harrowing find but was wondering if you could steer me in the right direction for a replacement grill only (no speaker).
Also enjoy reading your posts.
Many thanks.
Cheers
Peter
Unfortunately, I can’t help you there as I only managed to come across the speakers after they were being torn out of a commercial installation and thrown unceremoniously into a skip after having been in place for 20+ years. As for whether anyone actually stocks such a thing, I would not have a clue as I suspect it may be an older design. Perhaps you can find a different grille of a similar size or perhaps maybe a system specialist that installs fire protection panels may be able to source them?
– Gough
I saw the circuit board on google search and i have three of them. i would like to know the pin out for that board. i’m sure it was a hi voltage inverter but i’m not sure how to hook it up. the number on the bottom is 1220986-2 it has 4 pins.
I found it after searching your site. it is power converter module to the Texas instrument calculator you tried to fix…I have three of those modules in new condition i would donate to the cause if you still need them!
I still work with fax systems, I really enjoyed reading your fax page and learned more. Many thanks for taking the time to post information.
Glenn
Hi All,
In relation to this post :https://goughlui.com/2016/06/10/review-teardown-deta-det190-7w-warm-white-dimmable-led-downlight/
I live in the UK and recently purchased these downlights – but here in the UK they have been branded as ‘Arlec’ however once you open the box the actual units are branded ‘Deta’ with the SKU code DET190GB
I am struggling to find a suitable Dimmer module – I must have tried at least 12 different ones – Arlec suggested at least 6 of them but none of therm worked so they refunded me the cost of the downlights! – however the one mentioned in this post that resolves the loud buzzing issue I cannot source here in the UK, only in Australia apparently. –
I even asked DETA UK about sourcing this product DETA branded 150W “Universal” (trailing-edge) dimmer, model 6031″ but thry say they cannot source it either !!
Any suggestion for an alternative greatly appreciated.
Thanks
There should not be any special requirement except for the dimmer needs to be a trailing-edge type. There are many LED-compatible trailing-edge dimmers on the market – there’s nothing that leads me to suspect the “cheap” DETA version we have here performs any better or worse than any other type of trailing-edge dimmer.
If the units continue to buzz loudly even with a trailing edge dimmer, just double-check that the markings to see that it is a dimmable version. Sometimes you get superficially similar versions of products with different drivers internally. Otherwise, it could also be because of your local power quality – e.g. if your nominally-sine wave mains electricity has a lot of noise/distortion from power-line signalling, that could manifest itself as buzzing or flickering. Finally, it could just be poor manufacturing of any internal coils, inductors and transformers with loose windings …
– Gough
Thanks for your response Gough.
The LED units are labelled as dimmable, with built-in drivers, and my current dimmer modules are branded as Varilight VPro Trailing Edge which apparently are ‘market-leading’. I’ve tried different modes within the dimmer modules to no avail. I suspect there is a design fault considering Arlec were very prompt in refunding me the units but I had already installed them throughout the ground floor. 4 gangs – each with up to around 9 units per gang. I will persevere! Kind Regards, Raj
hi
my one is caromodual slimline. i change the washer from bunnings. still the moment i open the water inlet i can see water comong in the bowel. i dont know how to fix it
You need to make sure the outlet seat is clean and flat, and that the washer has been fitted properly so that it is even all around the circumference of the plunger so that it seals properly in the closed position. Make sure the plunger assembly is correctly and fully seated.
Otherwise, you might have to investigate further and call a plumber … or replace the cistern if it is damaged.
– Gough
Hello Gough,
Hope you are well 🙂
I always want the Sony AN-LP1 active antenna but never get a chance. I get mix reviews on this Antenna just wanted to ask you, how does it compare to Degen DE31MS? I just bought Degen antenna. I live in Sydney south west area and I have tried some stations like CGTN radio station on 11760khz compare to whip antenna I don’t find any different.
Do you think the Sony AN-LP1 would be alots better than the Degen DE31MS?
Appreciated your help.
Thanks
Sunny
I have a little problem with my new Orico 9558u3-v2, non raid. I saw that you have already disassembled the Raid model, so I wanted to ask if there is anything to consider, do I only have to loosen the star screws at the back? Is it necessary to loosen all of them or just the ones on the outside? I don’t want to destroy it and if it’s easy to get to the LED, thank you.
Happy Birthday to You,
Happy Birthday to You,
https://www.youtube.com/results?search_query=happy+birthday+to+you+marilyn+monroe
since comments disabled at your main webpage
https://goughlui.com/
darius
Hello! It’s good to see a fellow geek who’s good at blogging. LOL
I used to work on developing the first soft modems at Motorola back in the late 1990s to early 2000s. I remember testing against all the other modems, and when we were developing 56K, learning the sounds of the other modem manufacturer’s bong tones (DIL). I was the one to actually implement the V.92 standard on our existing V.90 soft modem. I loved the technology, and really feel bad that all that work has gone to waste because now we have broadband. Such is technology.
Good luck and happy geeking!
Jim in Reading, MA, USA
Trying to see if I can post a comment. I tried to post a comment/question about the strap on your Sofirn SC21 flashlight review (thank you for that), but the comment did not post.
The comment did post. All comments are personally moderated for spam purposes.
– Gough
I am looking for some help to try to figure out some faxing issues. I am a old telecom tech in Pennsylvania. We have been moving the telephone systems off of Verizon to in house trunking . In all my years I have never had such faxing issues. The new trunking is SIP. We have had some issues with faxing. It is intermittent. Personally I have called the fax, heard it ring answer and listened to it negotiate, then the fax fails. Is there a way to read the signal to see where it is failing? I can verify the call gets to the fax but once it answers I am in the dark. I hear the negotiation but I don’t know why it fails, because sometimes it works . This happens on inbound and outbound.
Unfortunately, there’s a potential myriad of reasons Fax over VoIP can fail – sometimes that’s down to (internet) network conditions, the equipment (specifically the ATA, firmware), the service provider’s gateway (some have T.38 issues) and fax machines (sometimes it’s a signal gain issue, other times they do quirky things with their negotiations).
There is no easy way to know exactly why it fails especially if you’re dealing with a physical fax machine. If you have a PBX with a software fax (e.g. hylafax), you can always check the logs and it may even be more reliable. You may experience issues where certain machines use proprietary mode (e.g. same-brand to same-brand, for example, Matsushita/Panasonic have their own “whiteline skip” features) or they attempt to use “high speed” or “colour” super-G3 faxing (as those use V.34-based modems which cannot be carried over T.38 and are not supported). Sometimes, some ATAs (and some firmware versions) may occasionally not detect fax tones reliably, or the gateway at your voice service provider may start a call as voice and then “switch” to T.38 once it detects the fax tone and your ATA may fail at this switch point (one way audio, or loss of all audio is usually a symptom). Sometimes this can be down to how this switch is done (e.g. REINVITE). Other times, it could be firewall issues with the network.
If you change everything to non-T.38 and eliminate jitter buffers and echo cancellation, you could end up with a “dumb” audio channel to basically pipe the fax over (G.711a/u passthrough), but the reliability of this solution is very suspect as it depends on the gateway and packet loss characteristics. You can often violate timing specifications and have data corruption as a result. But if you have T.38 working, this is supposed to fix all of this by having the local ATA and far gateway decode and regenerate the fax signals, piping the data between over the internet in a “redundant” and more robust fashion. The downside is when T.38 has issues, you have some hard-to-trace problems as a result.
I’d say it’s probably a good time to retire the fax – most organisations here have already done so willingly, others have migrated to online fax services. Fax over VoIP can be hard to make reliable.
Your best bet may well to be to use a packet sniffer to listen in to the data conversation between the ATA and your VSP (or PBX) to see what differs on successful calls or failing calls. Debug this like you might debug an IP-communications issue.
– Gough
You are a great man 🙂 I found you when I dismantled the power bank