vhf ampand transmiter schematic


Posted on Feb 6, 2014

Another version of the 1W VHF amplifier for the FM transceiver, well, in fact, it`s still the same version since I didn`t managed to get 1W. YET! Today I made some tests with a 2n2553 and a 2n2866. it melted solder in one of the base resistors (never I had seen such a thing, normaly resistors burn), a 27 Ohm one, made with 3 different resistor. but the power was: 1. 6mW thats mili!


vhf ampand transmiter schematic
Click here to download the full size of the above Circuit.

So I still have to learn a little more on VHF amplification. 2 more 2n3553 went belly up. it`s always the emiter junction that breaks :) Anyhow, Pedro - CT5JZX, today sent me a schematic he found for me to have a look and get some ideas! Funny, it`s basically the same schematic I use on the transmitting part, that`s normal, most parts of my schematic came from Miguel - PY2OHH site. VHF oscilator buffer (BFR91 with 100k to base): I have two, one for the PLL and the other for the output amp part. Both connect to the same place via DC decoupling caps.




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