[SOLVED] Rf/Microwave transistors

[ali ghafoor]

where can i find datasheets for rf transistors..i have been searching GOOGLE for a long time but found nothing..part number is 68142...any website to get information about rf/microwave amplifiers; more specifically power amplifiers??

 

[Bob60]

Everywhere. What do you prefers BJT, FETS. Generally interesting are Siemens-Infenion, MaCom, Hittite, UMC ( viva la France ), Renesas-NEC, Excelice, Mitsubishi, HP, Phillips, Motorola, Alpha Industries-Skyworks, Hope RF, Rich Tech and so on and reincarnations of those companies as well.

 

[Ow@i$]

searching only for "68142" will not going to give you anything there better be a complete name of the transistor like may be for example "mf 68142" or any other thing

 

[Bob60]

Probably may be NEC family transistor NE68139 sot 143 Si BJT.

 

[ali ghafoor]

actually i have an RF power amplifier kit with me..and i need datasheets for its components(power transistors)..but i am unable to find any...transistor part numbers are :
-> QBH-749B (manufactured by SPECWAVE)
-> 68157H
-> 681842
i don't know about manufacturers of last two transistors...i need help.

 

[ge]

Any chance of posting a pic? "QBH" makes me think of a company in Philadelphia that Spectrum Microwave bought. Ow@i$ is probably correct in that it will be difficult to identify the manufacturer without a complete part number.

 

[albbg]

68142 could be an old RCA transistor, as you can see at the following link (I don't know if also datasheet are available, you can ask to concordecomponents):

http://www.concordcomponents.com/part_search.aspx

I didn't find anything about 68157H, but possibly is the same brand (RCA)

 

[ali ghafoor]

i am still standing nowhere. "68142 could be an old RCA transistor, as you can see at the following link (I don't know if also datasheet are available, you can ask to concordecomponents):" this is not a transistor you told about..@albbg

 

[Bob60]

These historical RCA transistors you can change with BC148, BC158, for instance.
For notice// Diffusion from planar technology never stops. That process with low temperature is quite slow but after 20years transistor, will be different like before. Time machine is no way to stop.

 

[ali ghafoor]

These historical RCA transistors you can change with BC148, BC158, for instance.
For notice// Diffusion from planar technology never stops. That process with low temperature is quite slow but after 20years transistor, will be different like before. Time machine is no way to stop.

dear Bob60, these transistors u told about (bc148) are small signal...but i want large signal power transistor(because these transistors have been used in power amplifier)..which can be used as an equivalent for above mentioned transistors..if you know any..please do tell me..

 

[Bob60]

dear Bob60, these transistors u told about (bc148) are small signal...but i want large signal power transistor(because these transistors have been used in power amplifier)..which can be used as an equivalent for above mentioned transistors..if you know any..please do tell me..

OK no problem. Pls detailed what do you mean power amplifier. Is it audio PA. And is it swapping unit. As for AF here are a lot of IC especially D class with hight efficient and discrete transistor at these case sound like anachronism.