There is a website called aliexpress.com which many of you may already know about. It has a tremendous selection of Chinese (and even other countries products). When you think Chinese, you may think "ugh, cheap junk." However, this may or may not be true.
Let's look at a few examples of some Chinese products and how they measure up.
First, because it is the last thing I received lately, let's start with my 100 volt 50 a voltmeter / ammeter. This little guy is digital and it sucks.
A $3 volt ammeter from China
Here is why it sucks. I purchased this meter to be a panel mount meter on my 140 watt homebrew amplifier. Naturally, I purchased a matching 50 amp shunt. So first, I ordered the amp in red / blue, but I received red / yellow. Then I discovered that the voltage and current will read current up to 10a without the shunt, but with the shunt, the amp reading is way off. For example, at 15 plus amps of current, the meter reads 0.65 amps. I then tested the voltage reading on a lab power supply and discovered that the actual voltage was, for example, 9.0 vdc, yet the meter read 7.2 volts.
Some meters from China feature adjustment potentiometers to calibrate voltage and current. This one doesn't, so what you receive is what you get. This is probably the biggest mistake when ordering from China: check out competitive products to see if there is any significant feature and quality difference.
So, this meter is essentially a sad sack that will probably be used with some QRP transmitter project just to provide a reference. I may be able to modify the circuit by added an external resistor where needed, but that will require some experimentation. One can use a potentiometer externally to find out a specific ohm value that can be used to modify the display.
How's about some other Chinese goods. Well, I cannot argue with the prices of semi-conductors. I have purchased many different transistors and they have all been fine. Connectors? generally no problem. Knobs? Not so great. I ordered a bunch of panel knobs that have a white line in the switch. The knob from Dan's is first-rate.
A high quality knob received from Dan's Small Parts
A Chinese Knob
If you notice, the Chinese knob looks like the paint job was done in a 2nd grade classroom by visiting 1st graders.
Some things have really been unexpectedly good. For example, 12vdc relays, a set of step drill bits up to 32 mm, some really nice metal cut letters and numbers for a front panel, a rear brake disc and caliper for my grandson's go-kart that I am building (not specifically a ham radio project unless I put a vhf/uhf mobile in his go-kart), a Nextion 2.4" display which was a tremendous value, magnets and springs for a homebrew iambic paddle project, and a Dremel type drill kit.
The Dremel tool is particularly handy since it is invaluable when working with small mechanical aspects of your latest project. Then there are these:
Alligator clips that I wouldn't recommend to ANYONE
What could be bad about alligator clips at a price so low that you can't believe it? Well, I happen to think that alligator clips are pretty dang important. They should work perfect EVERY time. These clips are cheap, and they are better off being tossed then used for 3 reasons. 1) The use of silicone plastic or some similar type of plastic makes these darn things almost impossible to use. They just keep slipping in your fingers. 2) they are not soldered...they are crimped and are crimped so poorly that they are ready to fall apart at any time. 3) the teeth won't grab small wires and leads.
What is the point of all this? Buyer beware. The product might only cost $1.08 or $0.85 or whatever, but if they stink, then you will have waited for 30 days for the things to arrive only to discover that they are not fit for your shack. On the other hand, some products are really excellent, so it appears that even in the same product catagory, you can have 2 manufacturers that produce the same product where one is just fine, and the other is pathetic.
So how do you tell? There is no sure-fire way to know if that thingy that you are ordering from overseas is going to work just fine for you. However, with Aliexpress, you can click on "orders," and then the company that has the most units sold will be at the top of the list. Then you can look at their stuff and decide if it looks okay. Some of it is also common sense, and when it comes to critical components; they should only be purchased from a reliable source.
Collins KWM-2 PTO
Above is a KWM-2 PTO from one of my Collins rigs. Rebuilding this PTO is a scary and difficult job, and replacing all of the silver mica caps is not easy. There is NO WAY you do this job with parts from a unknown manufacturer or vendor.
The bottom line is that if the product is simple and cheap and you cannot not find it in your country for a fair price, then buying from China might be a solution. Keep in mind that you will wait 3 weeks or 5 weeks or longer to receive your order depending on the product. The good part is that if they send you something that is DOA, then they will refund your money...and SHIPPING is quite often FREE. So build those projects and try to get your parts locally, but when in need, consider ordering from overseas.
73, Mark 4x1ks
1 comment:
Hi there I am so thrilled I found your website, I really found you by mistake, while I was browsing on Yahoo for something else Customs broker China
Post a Comment