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Full Version: Uniden Bearcat 980SSB - MOSFET Failure and Fake RD16HHF1
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I'll share my story with you so you don't make the same mistake that I did Smile

Out of the blue one day the TX on my rig just stopped - without any reason (so I thought).
With my limited knowledge of electronics and help from YouTube (thanx birdman3931ny) it was found that the Final MOSFET (RD16HHF1) had blown.
As I always do, I sourced some replacements from eBay - they were pretty cheap so I bought a bunch of them.

When they finally arrived I soldered in the new MOSFET in place and turned on the rig - the fuse immediately and aggressively popped.
Thinking it must have been a bad MOSFET in the bunch I replaced it again and upped the fuse rating by 1 amp - this time, not only did the fuse pop but so did the MOSFET Driver (Q206 - A1725 Transistor).

I ordered a bunch from Digikey and, while waiting the delivery, I stumbled upon some hints that the RD16HHF1 MOSFETs I got off eBay may have been fake.
Further research confirmed that I had been supplied a bunch of fake RD16HHF1.

You will notice the difference here between the real deal and the fakes. Tell-tale signs include the missing indented markings and the fact that the lettering on the fake RD16HHF1 was easily rubbed off.


Again, I hit eBay looking for the real deal. I found a supplier that had a picture of the real deal so I checked out another bunch of them.
After I completed the purchase I had this nagging suspicion so I asked the seller for a guarantee that they were original as described (yeh... I know... should have asked the question before checking out). His answer was that he did not know how to tell the difference between the real and fake and agreed to refund me.

I then bought some original RD16HHF1 from a UK supplier (albeit a bit more expensive but at least I had a guarantee).
When the MOSFETS and Transistors arrived I promptly replaced just the A1725 (Q206) Transistor and checked the drive voltage to the MOSFET gate.
Thanx to YouTube (again) it was brought to my attention that the drive voltage to the MOSFET was way too high (6 volts).
I turned down the drive voltage to 4.9 volts and soldered in a "real" MOSFET replacement. Problem solved and a big lesson learnt when purchasing electronic components from China.
You're asking yourself why I battle to get MOSFET and Transistor replacements? Well, not easy when you live in New Zealand and no one supplies them locally.