Thursday, May 15, 2008

FB QRP Homebrew From India

I always liked the descriptions of the ingenious homebrew stations used by Indian radio amateurs. This morning I came across VU2LID's site and found this:

A typical Indian QRP station will use a modified AM broadcast (BC) receiver, for the receiving part. The transmitter will usually have a final RF power amplifier using BD139 (or some power MOSFET like IRF530), driven by a Variable Frequency Oscillator (VFO) and chain of buffer/driver amplifiers (2-3 stage). Most of the stations use Amplitude Modulation (AM). Commonly available medium power Hi-Fi audio amplifier modiles using integrated circuits (like the TBA810), driving a modulation transformer forms the AM modulator part.


The above drawing was done by OM Bhasi, VU2UCY (SK)

2 comments:

  1. I love hand drawn circuit diagrams.

    reminds me of the computer equivalent Ralph.

    Thanks so much for doing a blog, love the podcast of course too.

    ReplyDelete
  2. Good to see one of the most popular ckt in VU... one of my first transmitters...

    73,
    Gopan
    VU3HPF 2E0XUU.

    ReplyDelete