Can i use 27mhz rf power bjt in a vhf power amplifier ?

Thread Starter

Maz2858

Joined Jan 27, 2021
27
Hi, i have 2 27mhz rf power transistors and i want to know if i can use them in a vhf amplfifier
The transistors are c2314 + c2078
The maximum frequency in the datasheets are ~150mhz so can i use them at ~90mhz for power amplification
Thx
 

Papabravo

Joined Feb 24, 2006
21,159
Hi, i have 2 27mhz rf power transistors and i want to know if i can use them in a vhf amplfifier
The transistors are c2314 + c2078
The maximum frequency in the datasheets are ~150mhz so can i use them at ~90mhz for power amplification
Thx
Sure - knock yourself out. BTW the small m in "mhz" actually means millihertz, but we knew what you meant. The correct usage is the capital "M" for MegaHertz.
I know - picky point, but there it is.
 

sparky 1

Joined Nov 3, 2018
756
2SC2314 is technically a VHF transistor. Ft vs Ic curve might peak at 25 to 45 Mhz. I am not sure, just as an example.
The frequency transition might be 5 times like ft 300 MHz the signal to noise however might be unusable. I have a few circuits
made years ago ( turned out not so good) did'nt have complete RF datasheet and VNA were expensive, today hams have mini vna they might
have tested a cb transistor on 10M 6M 2M. Possibly you may want an MRF transistor for your vhf project.
 
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Thread Starter

Maz2858

Joined Jan 27, 2021
27
That is my point. Transistors are not made for a specific frequency, as far as I know. Can you link to the datasheet?

Bob
Just look on internet for the datasheet, theres written something like "application : 27mhz amplifier" or something like that
 

sparky 1

Joined Nov 3, 2018
756
The Sanyo datasheet above p.3 Collector efficiency test , adjusting the 100pF you would expect typical output 1.8W with power input of 35mW at 27 MHz this holds true for higher frequencies interpreting graphs on p.3 the fT - Ic 180mA 10V 290 MHz
One example of a second stage might use RD12MVS1 so you can see full datasheet PA level
https://pdf1.alldatasheet.com/datasheet-pdf/view/426417/MITSUBISHI/RD12MVS1.html
 
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