09-29-2003, 06:26 PM
I am looking for Info on a V-J 90PL 2M linear if anyone can help me. I can find no information anywhere on the Inernet. I aquired one that works but no paper work nor a sure instructions on the input and the output of the amp. Any info would be appreciated.
thanks for reading my post.
Look inside the amplifier for the numbers imprinted on the RF transistors. This will tell you alot about the capabilities of the unit. Specifications for many RF transistors can be found on the RF Parts web site. RF Parts has the specifications of many Japanese (2SC) and Motorola (MRF) transistors:
The definitive information source on solid state RF amplifiers are the Motorola application notes and books written by the late Helge Granberg, K7ES.
Some of the Motorola Application Notes (look specifically for Application Note AN 791) can be found on the Communication Concepts web site (look for 144 MHz designs)
You VHF amplifier should be similiar to the CCI Model 335A or 875A.
Helge's book written with Norman Dye is the original source for solid-state RF amplifier design and construction: Radio Frequency Transistors - Principles and Practical Applications, 2nd edition, 290 pages ($ 44.95).
John Matthews, G3WZT, article Guidelines for the Design of Semiconductor VHF Power Amplifiers in Sept. 1988 Radio Communication - is another excellent source. Check your local library or Amazon for copies.
Helge's Application Notes (Adobe Acrobat) usually included a PC board layout and template.
MANY solid state amplifiers use these same PC board layouts (AN-791 and AN-762 were very popular), others make subtle changes to avoid royalty issues or to allow for specific parts substitution.