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Yet another puzzling E-Bay Auction


The transistor shown in that auction has had one screw over tightened and most likely is very warped and will not make a good contact to the heat sink without a good lapping in.
 
Hummm I think you are right Mack.....
Maybe I should go with these...
10pieces,SD1446 / SD-1446 Transistor A14 | eBay

At least they look like they have been over tightened equally and might sit flat on the heatsink?
Do you think they get like that from the Manufacturer refurbishing process?
They must have to screw them down for the guy`s with the little finger`s to get in there to rebuild the transistor.
I think I will write and ask if lapping the bottom is part of the refurbishing process.

73
Jeff
 
If you've ever popped the ceramic cover off of an mrf455, you could see that it's possible to "refurbish" them. I just wonder why the transistor was bolted in place, but never connected since there is no solder on the leads or ... maybe the leads were replaced in the refurb process. Just a thought.
 
AudioShockwav said:
Hummm I think you are right Mack.....
Maybe I should go with these...
10pieces,SD1446 / SD-1446 Transistor A14 | eBay

At least they look like they have been over tightened equally and might sit flat on the heatsink?
Do you think they get like that from the Manufacturer refurbishing process?
They must have to screw them down for the guy`s with the little finger`s to get in there to rebuild the transistor.
I think I will write and ask if lapping the bottom is part of the refurbishing process.

73
Jeff
Click to expand...

$398 :eek: Must be made of Gold instead of copper...
 
That looks like it's for a quantity of 10.. $39.80 per sd1446 still sounds a tad high to me though..

They do have a bit of gold in them.. the tabs are gold plated, as are most of the internal bonds and traces.
 
AudioShockwav said:
Hummm I think you are right Mack.....
Maybe I should go with these...
10pieces,SD1446 / SD-1446 Transistor A14 | eBay

At least they look like they have been over tightened equally and might sit flat on the heatsink?
Do you think they get like that from the Manufacturer refurbishing process?
They must have to screw them down for the guy`s with the little finger`s to get in there to rebuild the transistor.
I think I will write and ask if lapping the bottom is part of the refurbishing process.

73
Jeff
Click to expand...

I think it's more a case of quality control and they're pulls from some not fly by night amp manufacturer.lol

hahah yeah I bet they lap for free.
 
eagle1911 said:
That looks like it's for a quantity of 10.. $39.80 per sd1446 still sounds a tad high to me though..

They do have a bit of gold in them.. the tabs are gold plated, as are most of the internal bonds and traces.
Click to expand...

The tabs are not even gold plate, they're brass.
 
The core metal may be brass, but according to a very good reference text I have here from Motorola (Radio Frequency Transistors: Principles and Practical Applications by H. Granberg and N. Dye), which is the only reference I have since I don't have the necessary stuff to test gold, ceramic stripline-opposed-emitter packages such as these and most other RF power transistors have gold-plated tabs. This is supported by the fact that they don't oxidize or corrode like they would if they were brass on the surface. The electrical contacts aren't made entirely of gold though, for obvious reasons. I don't know with absolute certainty if the configuration described by Motorola is an industry standard, but it's very likely that it is since everything else about that type of package is standardized.
 
Last edited:
eagle1911 said:
The core metal may be brass, but according to a very good reference text I have here from Motorola (Radio Frequency Transistors: Principles and Practical Applications by H. Granberg and N. Dye), which is the only reference I have since I don't have the necessary stuff to test gold, ceramic stripline-opposed-emitter packages such as these and most other RF power transistors have gold-plated tabs. This is supported by the fact that they don't oxidize or corrode like they would if they were brass on the surface. The electrical contacts aren't made entirely of gold though, for obvious reasons. I don't know with absolute certainty if the configuration described by Motorola is an industry standard, but it's very likely that it is since everything else about that type of package is standardized.
Click to expand...

Looks a little tarnished to me, what say you?

pills.jpg
 
True.. my post was addressing a post by jessiejamesdallas who was in turn responding to a link posted by Audioshockwav for SD1446 transistors, which are made by ST. I was off-topic from the original transistor in question.

That transistor looks used to me from the marks around the mounting holes.. that tarnishing could be wear from use in a test jig or other prototype device. Of course they could also be brass.. I've never used anything from RFG, so they might have done something different.
 
Hummmm I wonder why all of there auctions are listed as "private" ?
Used ?
Do you guy`s think they are selling used Transistor`s as "Manufacturer refurbished"
Has anyone wondered how one might go about "refurbishing" a solid state device?
I know the the Chinese have tiny little fingers....maybe they have tiny little soldering Irons?
WoW
And I threw away all of those 2879`s that I burnt up back in the early 80`s and All I had to do was re-build them....or should I say Refurbish?
Hey, any of you guys got any blown up transistor laying around that I can have....my 401-K needs to be padded a bit.
things that make you go hummmmmmmmmm.

73
Jeff

( starting to smell a little fishie )
 
:LOL: :LOL: :LOL: :LOL: :LOL:
Ok guys, I started this thread, as a bit of humor.
It is a Chinese company that is selling cleaned up used transistor`s as "Manufacturer refurbished"
There is no company, manufacturer-approved By Motorola to "rebuild" there transistors, nor is Motorola rebuilding there own transistors.
The MRF 455 is being built by MayCom, that is the only place you can get a REAL MRF 455 unless you find some that have been stored away in a parts bin at a radio shop for 20 years.
You can not rebuild a Transistor.
It works or it don`t.
This is a perfect example of how company's in China will rip off unsuspecting consumers.
If you go look at the Auction site in the link the auction is private.....there is a reason for that.
Also go look at some of the feedback for auctions they have had in the past.
Caveat emptor
Have a great day.

73
Jeff
 

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