Yes, I have been bitten by the forged chip syndrome.
I bought what I thought were two seven band audio spectrum chips but, for the life of me, could not get them to work properly. They were marked very clearly as seven banders but did not respond properly to the seven band coding libraries. After much recoding and retesting, they started to give rational results. Turns out that they were five band chips not seven.
I wanted a five band analyser and had planned to use code to merge a couple of the bands but the five band chips saved me the trouble and so the forgeries actually worked in my favour.
A search on the 'net turned up others that had found the same forgeries. What I find incongruous is that I could not find five band chips from the usual sources.
I'm yet to find a Chinese 8x8 RGB LED matrix that works properly (given up on finding one).
I think that part of the trouble is that many sellers are only dropshipper agents. They have little knowledge of electronics and are just agents for larger suppliers. They don't have the knowledge or resources to test what they sell and are totally reliant on the manufacturers. Many are operating on margins as low as 2% and can't afford to upset their suppliers. The manufacturers are divorced from the end buyer and don't care what grief comes back from faulty products and so they can adopt poor practices with impunity.
From: main@UltralightDX.groups.io <main@UltralightDX.groups.io> on behalf of Andy ZL3AG via groups.io <zl3ag@...>
Sent: Thursday, 9 April 2020 10:23 AM
To: main@UltralightDX.groups.io <main@UltralightDX.groups.io>
Subject: Re: [UltralightDX] AM radio that use a chip for the receive circuitry
I can't find my notes right now to give you speficis, but be aware that many of the chips shipping from china are old versions, and many of the breakout boards and modules don't bring all of the chip leads out so you can't always make use of all the features of the installed chip.
So to avoid disappointment, you need to look at close up photos of the items to try to figure out which one would be best for the job.
On 9/04/20 12:43 pm, Phillips wrote:
> Hi All,
> I would like to try my hand at using a MCU such as an Arduino to control a Si4735.
> Si4735's are available on eBay Australia 5 for $US7.14 ($AU11.55), but they are SSOP packages.
> My old eyes and shaky hands can't handle SMD's even with magnifying lenses.
> Does anyone know if/where I can get Si4735's in a through hole package or on a breakout board?
> Stay safe folks,