Universal Serial Bus (USB) is one of the few interfaces on computers that is certainly a big success story. You plug in your Camera, Memory stick etc, and in most cases it loads up the drivers and in a few seconds you are away, who can remember the hours spent messing around configuring RS232? However, on smaller devices, Tablets and Mobile devices, the USB socket and plug are scaled down in size (micro or mini USB), my Chuwi Vi8 is no exception with only "One" micro USB socket and one mini HDMI:
The One and only micro USB socket is not only used for data, but also for charging the device. A lot of excess daily wear and tear, plugging in and out, switching between USB devices. Of course the idea of cutting down to one socket is to help keep costs down in production, but how long can the socket possibly last before something gives?
The best way is to expand by using a cheap USB Hub, and there are quite a few different types available for a couple of Pounds. These also allow conversion back to standard USB for other devices, and a seperate power feed via another micro USB socket which can be used to charge the device while the hub is connected in theory anyway, read on:
Although this solves the problem of USB connection. There is another problem with this arrangement, the weight of the hub and devices hanging on the end of the Tablet, putting unwanted stress on the USB micro socket on the side of the Tablet, there has got to be a be a better way of fixing this and tidying it all up.
I was lucky, I had a case that came with a USB Keyboard, could I work out some sort of method of attaching the hub to the case? I had an idea!
A visit to a discount stationary shop while I was in town, I came across a packet of medium sized binder clips. The sort you use for holding files of paper together and hanging up on a hook for reference. The clips came in a pack of twelve for 69p making the fix less than 6 pence!
The clip provides an excellent amount of force suitable for the job of trapping the hub to the rear of the case. There is no movement and it is quite secure:
Once happy that it is square and fixed to the rear of the case, the two leverage arms, hooks or whatever you wish to call them can be detached from the main body of binder clip and discarded.
This provides the solution, and as you can see all the weight and stress is removed off the main cable and the micro USB socket on the tablet. With the sockets happy and tidy on the back of the case ready for use:
All seemed ok? I could then use the hub with various USB devices, but when I came to charge the tablet via the micro USB charging socket on the hub, this was found not to work? I came to the conclusion it was not wired into the hub or faulty in someway, I contacted the ebay dealer for a replacement he offered me $1, so I had to use the ebay tools to force his little Chinese hand to give me my full refund.
Shortly after, I found what looked to be a better USB hub from another "reliable" ebay dealer. This type has a switch to change between charge, or data, plus an extra USB Port:
This was a tighter fit under the binder clip due to the hub casing being slightly thicker, but all is now well, I can now charge the tablet without removing the micro USB from the side of the tablet, plus I have three USB sockets at hand, one which is taken up with the USB keyboard in the case:
Problem sorted and all put to good daily use using keypad and mouse, all fed by the USB hub attached to the rear of the case:
It is a known fact that China has been cutting through import red tape for many years now. We have all purchased Baofeng's, cheap electronic components, tablets, computer hardware and many other items that we all have bought directly from China to benefit our radio hobby.
Ticking the CN22 as a gift, or marking down the value of items, is in effect deceiving the import rules. It appears that this activity has not gone unnoticed by the UK VAT man, and some traders are complaining about this practice too, saying that they cannot fairly compete. Could the door be about to close!
The Master of the QRP Video, Peter Parker - VK3YE has launched a new ebook for the Kindle titled Minimum QRP.
The book is available for purchase direct from Amazon for a few Pounds, Dollars, or whatever currency your country uses. Just search "Minimum QRP"
The book is written and put over in the simple Peter Parker methodical way, but if you still don't understand the book, don't worry, you can always refer back to his amazing back catalogue of VK3YE video material on his channel. If you like the VK3YE Youtube output buy the book, you will not be disappointed, there is something in it for everyone from the novice to the converted.
If you don't own a Kindle like myself, this doesn't stop
you reading and purchasing. There is a Kindle App available for Android and iPad. Or if you just want to use Windows on your PC to read, there is a
Kindle program to download for free from Amazon. App
information and download link here for UK users. Once you buy the ebook the file is then downloaded into your Kindle folder.
Each month brings three Amateur journals, two arriving via the post. I get used to the time of the month when they arrive. QST is always the later one, but since it changed some years ago to bulk shipping for it's distribution (Shipped to the UK then redistributed by another company over here) it has never arrived any later than the 23rd of the month..
Of course I receive the automatic email telling me I can read the electronic version of QST, somehow though this method never has the same appeal as the real paper version.
September was nearly at the end, the leaves were falling off the trees Autumn was well in process, but still no QST. I knew it was lost, can we even trust the postman these days to deliver our mail? I contacted the circulation department at the ARRL, I soon received a quick response to my email. I was asked to hold fire until the 1st of October and contact them again, which was only a few days more to wait, a bit more patience never hurt anyone. The 1st came, still no QST, so I was back on the keyboard again, I was informed one would be sent out straight away from the USA. Today it arrrived 7 days later..
After many years of being an overseas ARRL member this is the first time I have never received QST. It is good one can send an email and get sorted very "quickly" well done ARRL!
You can wait in for some parcels for days, your promised they will be there but they never quite arrive when you expect. I predicted the Wouxun would arrive from Martin Lynch & Sons on Wednesday, I told the XYL to be around as I would be out working, she had just got back in time from the hairdresser. Arrival, there it was 11:10am delivered by UPS.
There is a lot of technical info out on there about this radio, the best, if you want a fair and unbiased review, get down to Hans PD0AC who has tested many Chinese radios with the proper test gear to a professional standard.
What do I have to say about it so far:
Like all new toys one is always eager to have a play. The radio came complete with external charger, wrist strap, belt clip, dual band antenna etc. A quick read of the well detailed manual might put your head in a spin, plenty of stuff to note. But like most of these Chinese radios once you understand the menu system it is easy to get to grips with. I slided the 2600mAh battery on the back of the main chassis case, it snapped and locked into place with a firm click. This made the radio feel quite weighty and rugged, I only have small hands and they only just made it around the body while holding it firm.
Switching on, we were in business, a clear bright display made a change from the simple plain two line LCD HT's I have.
A quick test to check the internal firmware version, is achieved by holding down the 3 key while turning on the radio. Mine showed Version V1.05, which I understand is the latest which is shipped with the radio during production. *Note there is no user way of upgrading the firmware from an external PC..
2m and 70cm are always very quiet around here, but I was lucky my friend Gary M0TTO was just signing with someone on the 2m band over at Lichfield QTH. I pushed the PTT and gave him a shout, he came straight back to me, he reported the audio sounded really nice and crisp! I said what was the signal strength like? He said end stop! But of course it would be, he only lives about 6 streets away, I turned the power down to Low, still end stop. The received audio sounded good, and plenty of volume still left in the wick should I have required a bit more. In the middle of the QSO it suddenly stopped TX, I was still pressing the PTT, I released the PTT and then pressed it again, it started Transmitting again, but shortly after the same thing happened. I was a bit curious at first, but I remember these radios have a Time Out Timer "TOT" Menu 06 this was only set at 60 secs, I increased the time out period and it stopped the annoyance.
Conclusion: I have always rated Wouxun as being the better of the quality end of production from China, I feel this radio brings them into a new era and still keeps them at the top! Certainly they have had problems in production like any other, but I am sure the Japanese big three feel the threat. So far I am pleased with what I have bought at the price of £69 inc UK delivery makes it an excellent buy. I still have to program it up for repeaters etc with the free software. Which can be downloaded from Wouxun or you can use the free Chirp multi radio programming software, which also supports this radio in a basic format at the moment.
Somehow, I managed a month without any real Amateur radio activity, the MDT kit remains unbuilt!
August is always a month when we have to entertain our youngest daughter, keeping her active during the school holiday proves harder each year as she gets older, especially when it doesn't seem we have had any real Summer to help us along.
The best day out was a trip up to Blackpool, we do this journey every year, taking the train from Stafford, and heading North, changing at Crewe, and on to Preston.
We like it up here spending the day walking the Golden Mile, the people are always friendly and the food great! There are lots of interesting little shops not just on the sea front, but also in the back streets which we like to peruse at our leisure. I know there is Amateur Radio activity up here from the front sometime close to the water, but I didn't see any sign of anyone.
Now getting back into the Amateur routine along with a few other chores as the Autumn approaches, and of course the MDT kit has to be built during the next few weeks. I have no planned visits to any rally in the next few months, so I decided to make a little purchase from Martin Lynch & Sons . The Wouxun KG-UV8D Handheld, 2.5K step version has been dropped in price making it a very attractive purchase for £69 including FREE shipping to UK. This beats any best ebay price I have seen, and makes it easier should it have to be returned under warranty. I ordered one at the weekend, I expect it will arrive about Wednesday, as today is a Bank holiday here in the UK when most take a rest, or extend their weekend break, as it is the last Bank holiday now before Christmas.
I look forward to making a few tests with the Wouxun, comparing it with one or two other handhelds I have, taking it out on location.
Short form reviewing the MDT kit from Ozqrp a few weeks ago, and then watching the VK3YE Video, gave me the urge to purchase a MDT40 kit. Of course miles are no barrier to this hobby any longer, a quick click and it was in the shopping basket. I coughed up the green ones or Pound notes and sent it over via Paypal.
Less than 10 days later a card dropped through my letterbox. Please pay up? "Unfortunately we can't deliver your item because there is a fee to pay". Meaning it was subject to UK Import Duty of £7.63, plus a £8 Post office charge on top! I really don't mind the Tax, but the Post Office charge of £8, I find this a big no no! A fee for them to handle it and take my money. The Post Office deliver parcels and letters everyday from around the world, and never ask for anymore, until we get into stuff with duty added by customs and then they add this extra sting on top of the bill.
This made the total of the purchase including duty a little over £61. The tax might have taken the icing off the cake, but the kit still represents excellent value for money. Please don't be put off, Ozqrp has done an excellent job of design, and putting this kit together as you will see below:
Post office then satisfied, I walked away with a receipt and the MDT goody box..
The components came well packaged in a sealed box, with all components wrapped in bubble wrap inside.
VK2DOB the owner of Ozqrp has done an excellent job collating all the components together for the MDT, all which have been separated off into little bags and clearly marked. The case comes with pre drilled, clear labelled, front and rear separate panels for the unit, including the hardware and the knobs. Even a Microphone plug has been included in the kit, so you won't have to spend time hunting around or having to go out to purchase one.
A well designed doubled sided PCB, which already has the only SMD component (the varicap diode) soldered to the board . This will save everyone time from fiddling around, especially those like myself with ailing eyesight.
Last night I printed out the manual and bound it up into a simple folder. I recommend everyone print out "all" the 42 pages, and read it from cover to cover a couple of times before starting. Although what may be quite a simple and straight forward process to me, there is still quite a bit for the novice to take in.
The next time I write on this blog I guess certain parts of the kit will be completed? For now, I leave you with two more excellent VK3YE MDT videos, including extra modifications of the unit.
Just when everyone is taking Summer siestas and there seems very little news around to talk about. Along comes a new Direct Conversion 40m Transceiver kit from Australia.
The MDT DSB kit is manufactured by Ozqrp, capable of 2W PEP, it has a full swinging VFO 7.090MHz - 7.130MHz or 7.050MHz - 7.110MHz. A complete kit of components including PCB, and case for $80 (Aus) less than £40 UK plus carriage. Which worked out at $12.50 (£6) posted to the UK, when I did a quick trial purchase test and popped it into the shopping trolley on the Ozqrp website.
May brought Radcom the RSGB's monthly magazine for its members. It normally takes me about a month to hunt out the bits what I want to read, then it gets filed in the pile with the rest. A quick flick through is always the norm, this months (June issue), I was perusing through at great speed over my evening tea, I hit the bi monthly QRP page written by the Rev George Dobbs (G3RJV). What is this, my name and callsign suddenly grabbed me! George was reviewing my Blog and items I had pulled to the front from the Chinese and others.
History lesson: The first time I came to know of a George Dobbs, was back in the mid 1970s when I was a schoolboy at around the age of 12. I built his project Making A Transistor Radio published in a Ladybird book. A three transistor germanium circuit that was slowly put together in stages from a crystal set, to a fully working regen radio. Built without a soldering iron, perhaps he didn't want us to burn our fingers? Components clamped down under screws and screwcups on a piece of wood. The radio worked first time and was the first electronic project I ever built. At the time I didn't know much about George Dobbs, only 20 years or so in the late 1990s, I would return back to the book and discover that this was the G3RJV George Dobbs associated with the G-QRP club he formed in 1974. Since then, George has gone on to write many QRP related books, monthly insert Carrying on the Practical Way in Practical Wireless, and of course QRP in Radcom and a few others.
So it was an honour to find he had devoted his entire QRP page over to my blog. My wife has got fed up with me by now picking up and down Radcom every five minutes and reading the page over and over again. She said of course your going to blog it, you bet sure I am!
George starts his review of my blog explaining the name "The Font of all Knowledge" and how linguistic scholars that make up half of the RSGB would lay me open to scorn for using the name Font, but how Oxforddictionaries.com claim households are split over the word scone. Of course being a man of the cloth he would know from the amount consumed at the tea parties he has resided over at the Vicarage over the years of his service. The real secret is I take no applause for the name, this I give over to my linguistic friend, scholar, and blogger Roger G3XBM, who is the one whom is responsible for thinking it all up. Before I started my blog I was passing him over information "and still do" about useful links that could prove valuable to be included in his blog. Roger refered to me as the Font of All Knowledge, so I decided to use this when I created my blog late last year.
I now hope that puts peoples minds at rest where the name came from.
Once George has made every one happy, and comfortable, with the name and the importance of its place within the hobby. He then continues forward taking a look at the items I have reviewed, the pixie kit which G3XBM also picked up on and built one.
The Oscilloscope Kit, I recently noted and passed the information over to G3XBM:
I have been very happy with what I have seen G3RJV write, and I am glad the blog continues to score many daily hits from Amateurs around the world. Of course its up to me to find things new, this will continue, when I see something good, and of value, along with other aspects of the hobby I am involved in.
Thank you G3RJV for bringing this to the forefront of Radcom, and thanks to G3XBM for creating the name "The Font of all Knowledge" Swoon! (I only went to a Comprehensive school that got burnt to the ground twice in 4 years while I was being educated there.)
Amateur Radio has taken a back seat over the last few weeks with various family problems.
However yesterday, I had a bit of spare time and I was all revved up for testing a Baofeng with its battery eliminator. This is the part that takes the place of the HT battery pack and slides on the back of the radio instead of, providing regulated power from the car battery cigar lighter socket, in essence you make yourself a cheap and cheerful mobile rig.
I needed to just test it all out and check that it worked before fitting, and the MP-304 power supply which I had recently bought was still sitting on the dining room table in its box, handy for a few Volts so I thought?
on the MP-304, there was no deflection of the meter, (meter switch was in the correct Volts position)? I got
the DMM out, and measured the output, plenty of Volts, but still no
indication on the Power supply analogue meter?
Should I return it? No chance, with all the hassle of someone having to wait in for the courier to collect, it had got to be worth a look. Anyway, I used to test power supplies by the hundreds, when I worked in the industry, so I did have a good chance maybe?
required! Took off the top of the case and I was inside, no going back now. First I measured at the rear of the meter terminals with
the DMM, no Volts, nothing on the rear of meter switch that changes between Amps or Volts either. This then leads us back to the
plug that plugs into CN2 on the control PCB. Just as I was about to measure at this
point, I could see the Blue wire (I have marked it with a small red arrow above) was raised, with its termination tag in the plug sticking out, I unplugged the whole skt from CN2, and the Blue
terminal had not been pushed home in the plug in the factory, a smart push and
it clicked in place. Plugged it back into the PCB socket and switched on, and the meter then sprung
It does make me wonder
if the Chinese really test this stuff in the factory? Time and time again I have come across problems with Chinese equipment like this, which should really be sorted in the factory before shipping, I don't believe QA exists? The problem here is, the dealer gets a bad name, and really it isn't his fault, he buys in a pallet load, one or two get put out for demonstration, and then the rest are stored ready to be shipped out in the original sealed boxes they come in.
After fixing this, it did however give me the chance to have a good look inside and see what it was made of :
Build quality really wasn't too bad, a nice hefty transformer feeding a quality bridge rectifier, control board (which I have already mentioned), that sets up the limits and then drives the outputs. A good quality heatink blown at by a fan, which is triggered by a stat when the temp gets to a certain level.
Cased back up, I was then back to the point where I had started at a couple of hours earlier, testing the Baofeng:
A couple of months ago my friend and Blogger G3XBM was into buying Pixie kits from China, he thought he had bought a bargain for the £7.00 he paid for the kit? Shortly afterwards I found the kits at around a couple of Pounds lower than Roger had bought his for. But this was short lived, a week or so later Roger blogged that Andy Cutland had found them for £3.19 pence, this undercut my price yet again by nearly £1.50!!
Well the story continues!! I have now found the Pixie kits cheaper yet again!!! The complete kit as above (inc PCB components and Xtal), all for a penny pinching £2.89p ($4.30 US), and the more you buy the cheaper it gets! Oh yes I forgot the price "Includes" shipping!!
You could buy several kits without busting the bank, and put them on different Bands with Xtal and small mod of low pass filter changes.
Is this now the cheapest Transceiver kit in the world, or can anyone find them cheaper still??
The normal good old British early Spring wet weather, had stopped any Sunday outside activity, even the cat was having non of it, she was well tucked up after her lunch. Nothing interested me on the television, a boring afternoon ahead or maybe a sleep in the chair?
I remembered there were 2 years worth of Practical Wireless magazines and a few Sprats scattered over the house. 14 were together, 2 were stuck in a drawer by the bed, and the rest were eventually found mixed up with several other piles of junk, which had been dumped together when the XYL had been on one of her recent mad cleaning rounds.
Someone had got me the binders for a present last year, again they took a bit of searching for? But I eventually found them, and set to work. After an hour or so, all were now together sorted and bound, ready for the bookshelf a real professional job!
I like to keep my magazines bound together, making quick reference easy when I want to go back to an article. Todays effort will help with a bulk of projects on the list which you will hear about in the future .
Yesterday evening I received an email from Martin Lynch & Sons that they had despatched a package to me. I was a bit puzzled at first, as earlier in the week I had received my early birthday present I had ordered a day or so before, so I couldn't work out what the package would be, perhaps they had made a mistake?
Then I remembered, I had entered the ML&S guess the Caption competition on their Facebook page. A quick surf over there and I found I had won a Kenwood hand towel, which arrived promptly in this mornings post:
I certainly won't be using it on my face, it will be put on the wall in the soon to be refurbished shack.
If you want to keep up with the top deals and offers at ML&S, join in by liking their Facebook page, it is well worth keeping your eye on!
A refurbishment of the shack is long overdue, and some advanced birthday money prompted me to take up one of ML&S recent deals. I had been looking at various Linear power supplies to feed the new layout, and the MP-304mkII would fit the requirement of servicing the array of rigs I have to feed.
Ordering was quick which I did over over the phone, as normal with Martin Lynch & Sons, the faultless delivery was on time! Infact so quick! I had forgotten to tell the XYL, so she was surprised by the delivery.
The MP304 is sold as a 30A supply, that does 15A continuous, and 20A for 15minutes @13.8V. Supplied with a mains voltage of 230V 50Hz.
There are various output connections on the front, including a handy Cigar lighter socket that can supply 10A.
The supply is variable by an adjustable pot on the front panel, which is biased in the middle of its range to set the supply at the nominal 13.8V. The output is adjustable between 1.5V & 15V DC. With a sliding scale of V/I) (Don't expect 15A Max at 5V as this works out at about 7A)
The large easy to read analogue Meter is switchable either to Volts or Amps.
Supply regulation is better than 1% and a noise figure <10mV is quoted.
We will see how this performs when I will load it up and do a few measurements in the next day or so.
A short form manual is supplied, a circuit diagram would of been useful for servicing in the future. (I have not seen one on the web?)
First looks are good, and not bad for the money of £99!
So far it is the only Amateur Radio video I have made. I find I can write about this stuff, quicker and better than I can make video's. However I have not ruled out future output if I find something decent to record and I have the time to edit the footage.
For now I will leave it to the likes of VK3YE and K7AGE etc, both who output some great "updated" interesting Video's over a wide area of various Ham Radio subjects.
Quite correct Helen! But not the type you were thinking about, that live with the Elves down the bottom of the garden?
I got involved in this one with G3XBM recently, when he had ordered a kit from a different dealer at a
slightly higher price, I was determined to get the price
down by using various search method tricks I have come to learn over the years.
The kit(s) arrived from China, within 10 days of ordering. The PCB quality for the kit is excellent! Included is all the components, One Crystal (7.023MHz), and even the schematic and component list were supplied from this ebay dealer. All for a penny pinching £4.70p at the time I ordered! * Note the price has increased slightly to £5.20p ($8 US) as I write this. This does ask the question though, is this the worlds cheapest transceiver kit including delivery?
I intend to do a couple of mods to my Pixie as I build it, I will replace the 47K preset with a 47K Variable Pot so I can have a couple of KHz Frequency swing or pull to hand when I mount it inside a case. I will also switch in a couple more Crystals 7.030 & 7.040MHz so I can have a bigger spread of the 7MHz CW Band to work with..
The Pixie transceiver has a lot of history too its name, and various mods and developments have been done over the years. If you want the full facts, grab a copy of The_Sprat_Pixie_File from the G-QRP Club Website.
Think about becoming a member of the G-QRP club while you are there, as this club is well worthy of joining! Without them the Chinese would not be producing these kits today!
For those who are after full circuit details etc for the Chinese version of this kit try this link here.
I have previously explained how to go about building the M328 in Part (1)
Now this is where it all gets very interesting!
When I watched the VK3YE video (A number of times may I add), I had always wondered about the 35pF offset and why Peter couldn't eliminate it? I had read the manual written by Karl-Heinz Kubbeler, upside down and inside out around the area of calibration (Section 3.2). I had felt maybe Peter had missed a step, or maybe two? But it would only be when I finally built the project I would be able to put my theory into action! After all I couldn't just pop over to Melbourne and explain, it is not a couple miles down the road from the UK is it, and doubtful some nut with a theory would be welcome asking for a phone number anyway??
Before you start calibration you will need to make yourself a three pronged shorting link, and a get hold of a 100nF (0.1uF) Capacitor. The value can be greater, but not less than 100nF, which will be required for the final part of the Cal procedure:
You then insert the link into all three terminals (1,2,3) on the bottom terminal block, make sure the connection is tight. Press the On button this will put the unit into Self Test Mode:
When it gets to "T4 Isolate Probe" which I assume means Test 4? Remove the Link smartly! Do NOT touch any parts of the unit as it resumes its test and calibration cycle:
Let it move on, until it gets to the last screen which at this point you will require the 100nF Capacitor and Insert it between Terminals 1 & 3:
Leave the capacitor connected, you will see the value pulsate on the bottom line of the display as it is calibrating
(Mine read 91nF). It will keep pulsating the value until the test concludes (it can take about 2 mins?). When the test finishes it will exit the calibration mode as indicated on the display, reverting to
testing the Capacitor and indicating the value being tested as below:
(Sorry about the breadcrumbs on the bench, this is how one works when into resolving problems)
The unit then times out after about 30 secs and switches off.
Now if you have gone about this procedure correctly, when you next turn on the unit it will no longer display the 35pF offset as shown at the start of this blog, the display will show the following after the initial Volts check and sign on etc:
You are now ready to start testing your components. Which we will come to in Part 3.
Shortly after I proved my theory about the elimination of the 35pF offset, I contacted VK3YE via email. Peter came straight back with a BIG thank you, after he too had tried my method out, and it had worked on his unit first time! The only problem he had found, he couldn't then test small value capacitors? Eg: 47 pF measured fine (48pF) but 22pF was not recognised? Hmmm!
I spent my teatime reading the manual again, and found it!:
Part of the introduction in the German manual states:
10: One capacitor can be detected and measured. It is shown with symbol and
value can be from 35pF (8MHz clock, 70pF @1MHz clock) to 40mF with a
resolution of up to
1 pF (@8MHz clock].
So nothing below 35pF will work. Or will it?
Peter mentioned in the last part of his email:
Still you can get around this by making a small jig with (say) 100pF for
use with small capacitors and just deduct 100pF.
Interlude time now, in between writing up the Calibration procedure for the M328.. We will push this little one in to keep you all happy.
I have a few various projects to build over the next couple of years, some that will require a regulated supply to feed various DC Volts (low noise is a must!). I had been running through my mind various ideas using regulators on some stripboard to mate up the supply rails, I had a few emails between my friend G0FTD on the subject, he said take a look at these "5" seperate LM317 boards already made up on a PCB, complete with heatsinks for just over £5 ($8 US), which works out at just over £1 each! I couldn't even buy the heatsink for a £1 over here, never mind the LM317 and the PCB. I ordered five they arrived within 10 days from HK, a couple of the LM317's were not bolted up tight to the heatsinks, but a quick tighten with a screwdriver and all was ok, what a bargain!
Time to test one.
Most of what I will be requiring is between 3.3V and 5V with a 12V dryfit battery on the input end.
To prove I just rigged up a quick lash up with 15V feeding one module from my bench supply:
I was able to able to obtain a precision swing of between 1.25V & 13.5V as the the output is made variable with a multiturn pot attached to the PCB, ideal for what I am looking for.
Conclusion: Another good purchase from China that is useful, money and time saving in project building!
Not only have I come across various types of regulator modules (some switching types so be careful!), but also LM386 Audio Amp modules, Timer modules and even a 3 Axis Magnetometer PCB built and ready to go!