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Where To Get Sets and Parts For discussions about swapmeets, rallies, NVCF and BVWS, car boot sales, antique and charity shops, dealers, newspaper adverts, the local tip and just about any other source of equipment (other than eBay). |
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16th Mar 2014, 6:17 am | #1 |
Heptode
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
Posts: 827
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Cheap Chinese multimeter and radio kits
From suppliers on AliExpress (http://www.aliexpress.com),
I have bought these kits: "Mf47 meter kit electronic kit diy kit spare parts" at £7.56 including postage. This is an analogue multimeter kit with a 50uA (20 kilohm/V) movement, with a nicely finished case and took a couple of hours to build. It has some shortcomings with regards to electrical safety against today's standards, but compares well with similar kits Tandy sold around 1980 for £20 and meets the stated specification. Worth the asking price for the fun in building it, with a useable meter at the end of it into the bargain! "S66E" transistor radio kit: 4 for £11.60 (free postage) 6 silicon transistors, MW only. The circuit will be familiar to anyone used to the germanium versions from the 1960s that sold for a similar price back then! Again took a couple of hours to build one. It works, but the speaker is horribly small. Again, worth many times the asking price just for the fun of building it. The instructions are only in Chinese, which just added to the entertainment. |
16th Mar 2014, 10:24 am | #2 |
Octode
Join Date: Sep 2005
Location: Welshpool, Powys, Wales
Posts: 1,327
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Re: Cheap Chinese multimeter and radio kits
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16th Mar 2014, 11:12 am | #3 |
Retired Dormant Member
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
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Re: Cheap Chinese multimeter and radio kits
Does one have to provide a PSU, or is it a 'live chassis' design, I wonder?
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16th Mar 2014, 11:50 am | #4 | |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,567
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Re: Cheap Chinese multimeter and radio kits
Quote:
It's battery operated.....
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16th Mar 2014, 5:44 pm | #5 |
Octode
Join Date: Mar 2011
Location: Sheffield, South Yorkshire, UK.
Posts: 1,453
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Re: Cheap Chinese multimeter and radio kits
Interesting stuff. Thanks for flagging it up.
- Joe |
18th Mar 2014, 2:16 pm | #6 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,934
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Re: Cheap Chinese multimeter and radio kits
yes, thanks for flagging it up; it's a bizarre bazaar. The meter kit is available as a ready built meter for an extra 90p if you want it. Weird!
B |
5th Feb 2016, 10:38 pm | #7 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
Posts: 2,085
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Re: Cheap Chinese multimeter and radio kits
The five radios depicted are just some representative samples of what is available out there.
The grey radio 'D08' and the Paensonic are both TRF's The grey radio uses the TA7642 clone of the old Ferranti ZN414 driving a 3 transistor amplifier. The superhet kits can come in 6 or 7 transistor forms, the difference being an extra stage of IF amplification. Audio is as good as can be expected from a 2" speaker in a plastic case. Construction of these kits depends on getting the right colour IF transformer in the right place. The blue radio is one of the six transistor sets. The switch on the volume control broke very soon after completion of the radio and I had gone to the bother of aligning it properly. I gouged a hole through the case & fitted a sub-minature SPST switch. The red radio has an output transformer as well as the phase-splitter transformer in the driver stage. I have no clear idea which is which. I managed to work out the colours of the IFT's thanks to Google, but said resource was no help when it came to the two audio transformers. This is one radio I have to sort. The Paensonic... I would urge you to avoid it, although it is a simple TRF and does not need alignment it has design / production flaws. Tuning the FM side is like balancing on a knife-edge just to add to the fun. The AM section is a smeary mess, the tuning being the exact opposite of the FM side. The audio stage of this seems to have plenty of power from the IC amplifier The grey TRF (D08) shows how the good TA7642 can be. The grey set was bought from Aliexpress. The postage was about 3X the price of the radio. This is the one dad and son could do together - if there was more life on MW to make it more useful. These little kits are a very good way to keep out of the pub. They are cheap as chips. |
5th Feb 2016, 11:00 pm | #8 |
Octode
Join Date: Oct 2003
Location: Newbury, Berkshire, UK.
Posts: 1,770
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Re: Cheap Chinese multimeter and radio kits
Vaguely tempted by having a go at building one of these, but as you say, the major problem is finding anything to listen to on MW now. Back "in the day" we went round with such devices clasped to our ears listening to radio 1 on 247 metres.
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6th Feb 2016, 3:39 am | #9 |
Heptode
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
Posts: 827
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Re: Cheap Chinese multimeter and radio kits
These kits and their ilk are now more widely available (on eBay, for example) in many more variants, including radios with FM and analogue tuning and ones with FM only and digital tuning with surface-mount construction. There are also many for digital alarm clocks, including the ones with large digits, transparent case and backup battery, which are really rather good.
The point still is that you can get a couple of hours' entertainment building one for the price of two pints or a pack of cigarettes. If it works, that's a bonus. And if you can find a use for it, that's better still! If your budget runs to £15, then there are "DSO138 kit" (genuine or otherwise, see http://www.jyetech.com/Products/LcdScope/e138.php to tell the difference. I found it after I bought a fake, but it does work.) which is a very useful, though not particularly good, oscilloscope. And there are better and dearer ones if you are prepared to write the cost off if they don't work... Cheers, Martin. |
6th Feb 2016, 7:32 am | #10 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
Posts: 2,085
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Re: Cheap Chinese multimeter and radio kits
The red 7 transistor set I had some problems with. It is the HX108-2.
All the stages are now drawing about the right amount of current as measured across the test points. There is still no audio out of the speaker. While I could identify the right IF transformers by the Chinese writing naming the colour I need help with the two little audio transformers. I may have put them in wrong, but I have no clue which is the driver transformer & which is the o.p. I have been looking at images of the HX108, but the colours change. I am wondering if I can tell which is which by taking the resistance through the windings. Until I know for sure this one is definitely on hold. That green radio is another 6 transistor set: 9018-2, referred to as the 'birdie six'. Electronically I believe it is the same. There is one around that has a transistor wired as a diode for detection, I can't remember the number. I have seen the AM/FM kits other than that Paensonic. I just hope that those do not require the builder to eliminate manufacturing mistakes as well. |
6th Feb 2016, 10:16 am | #11 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
Posts: 2,085
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Re: Cheap Chinese multimeter and radio kits
The HX108-2 employs a 9018 transistor wired as a diode for detection purposes.
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6th Feb 2016, 3:10 pm | #12 |
Hexode
Join Date: Oct 2003
Location: Near Glasgow, UK.
Posts: 309
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Re: Cheap Chinese multimeter and radio kits
I have the oscilloscope. Based on the info on the site it's genuine. Mine is the older one where you have to attach the smd stuff yourself. Updated firmware is available for it now. The company did not make this available at first because of the issue with fakes. Got it from Banggood. Also bought a component tester as it measured esr. I have compared against an older probably better one and it seemed quite good. I also have a MW and a FM radio to build. FM radio has a sm chip to solder. Alright if you're used to it but I'm not. This radio has a frequency display, clock and timer. Frequency range is from 72MHz-108MHz. Am about halfway through it's construction. It amazes me how cheap most of this stuff is especially if you consider it is mostly sent here from China.
Regards, Ken. |
8th Feb 2016, 5:50 pm | #13 |
Nonode
Join Date: Aug 2010
Location: Resolven, Wales; and Bristol, England
Posts: 2,608
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Re: Cheap Chinese multimeter and radio kits
The FM radio works, and sounds quite good. Alignment is trivial (adjust the tuning capacitor trimmer, move one coil a bit further apart), the digital frequency display shows the correct local frequency for R4 and shows the same frequency as my RF signal generator when tested. The speaker is minute but it has remarkably good sound for speech radio. It doesn't do justice to Bach though.
And it was fun to put together, especially as it cost less than the current price of a bottle of discounted rioja.
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8th Feb 2016, 11:02 pm | #14 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
Posts: 2,085
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Re: Cheap Chinese multimeter and radio kits
Mole42uk: Which kit did you get & from where?
I was thinking: Do most of these kit radios only use AA cells. I recall seeing one somewhere that looked like it had a 'C' cell. Usually the item descriptions are a joke, as if they dumped the original Chinese into Google translate & pasted that into the listing. Good for a laugh, but not as a information source. |
9th Feb 2016, 11:19 am | #15 |
Heptode
Join Date: May 2008
Location: Selby, North Yorkshire, UK.
Posts: 951
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Re: Cheap Chinese multimeter and radio kits
I have also built the Paensonic radio, and it works very well on FM (it's used to give our canary something to listen to!), it needs some careful adjustment of the width of the coil to bring the middle of the band to the middle of the scale though
Mine came from Banggood for about £4 I think
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9th Feb 2016, 5:50 pm | #16 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
Posts: 2,085
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Re: Cheap Chinese multimeter and radio kits
Nobody has offered any ideas on improving the AM side. I assume it is therefore beyond hope.
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11th Feb 2016, 1:49 pm | #17 |
Nonode
Join Date: Aug 2010
Location: Resolven, Wales; and Bristol, England
Posts: 2,608
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Re: Cheap Chinese multimeter and radio kits
It was the one from Banggood - their description is "DIY FM Radio Kit Electronic Learning Suite SKU300276" priced at £5.49 and the UK Customs weren't interested.
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11th Feb 2016, 3:18 pm | #18 |
Heptode
Join Date: Apr 2003
Location: Ayr, Ayrshire, UK.
Posts: 631
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Re: Cheap Chinese multimeter and radio kits
I got one of the HX108-2 radio kits from Banggood.
The one they're currently supplying is different to that pictured on their web-site. http://www.banggood.com/Seven-AM-Rad...-p-946167.html It now uses 7mm sq. IFT's and works surprisingly well. I choose this one over the other AM radios on offer because it's a superhet circuit and uses three IF transformers and a proper push-pull output stage. Andy Last edited by radioman; 11th Feb 2016 at 3:20 pm. Reason: Extra info. |
11th Feb 2016, 3:47 pm | #19 |
Heptode
Join Date: May 2008
Location: Selby, North Yorkshire, UK.
Posts: 951
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Re: Cheap Chinese multimeter and radio kits
Oddly, Banggood have no free shipping on any of the AM/FM radio kits at the moment, all the P&Ps are over £12!
Im sure these were all free shipping not long back. I was going to get a couple for my son and his mates to build
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11th Feb 2016, 4:07 pm | #20 |
Heptode
Join Date: Apr 2003
Location: Ayr, Ayrshire, UK.
Posts: 631
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Re: Cheap Chinese multimeter and radio kits
I never spotted that !
When I got mine last October the shipping was free. Andy |