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Old August 24th 07, 11:17 AM posted to rec.radio.amateur.homebrew
Highland Ham Highland Ham is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 250
Default My vacuum tube homebrew transmitter

With commercially manufactured equipment now mandated here for foundation
licence applicants my greatest fear is that we will lose our greatest
priviledge of being able to design and build our own transmitting equipment.
My first SSB transmitter was, of course, all valve. It started at 483Khz
with a phasing system followed by two half lattice crystal filter sections.
Output started as a 6146 and then grew to 4x811A's in parallel. One of the
real problems was getting the VFO really stable and the best I came up with
used the worm drive capacitor out of one of those TU6 tuning boxes with the
tuned circuits connected remotely via coax lines to the oscillator stage
which was on the main chassis.
All a long time ago but I still believe that such experiments were a good
way to learn and am also of the opinion that the newcomers who simply
purchase a commercial rig are missing out on a lot of the basic fun that we
had when a piece of junk disposals equipment could be transformed into
something useful.

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Firstly , Foundation Licensees in the UK are permitted to use
self-constructed transmitting equipment from an 'approved kit' ,
whatever that 'approved' means.

The younger generation(s) are no longer interested in our hobby for all
the well known reasons, Internet- Mobile Phones - Sat TV - iPod etc.
Their first priority is 'socialising' and a 'nerd' sitting in a shack
soldering and using test equipment is NOT socialising.
Moreover ,homebrew equipment is NOT necessarily cheaper than
off-the-shelf stuff (with the exception of very basic equipment and
peripherals).

Being involved in assisting people to get a Ham licence , most if not
all recruits are retired or are about to retire.
We now live in 2007 and beyond ............that's the reality .

However ,being an old fogy myself .....I still do enjoy home-brewing.


Frank GM0CSZ / KN6WH north of Scotland