----- Repeat Message -----

Coupling a longwire antenna to a G3 or other uldx receiver.

This is the Mark III version in text-format :-)
The dots are to be ignored; they only serve for spacing
so that everything lines up! This was composed in Arial 12 point.
Ideally, monospacing would be better, but that would only
work if a monospacing typeface were everybodys default.

L1 and C1 are in series, followed by C2 in parallel to L2,
the "cold" end of which junction is earthed.
L3 is placed parallel and close to the internal ferrite of
the receiver.

...........................................................C2
...............................................I------------II------------I
...........................L1.......C1......I.........................I
Longwire >>>---()()()()()()----II-------I.........................I--------------Earth
...............................................I------()()()()()()()-----I
...........................................................L2..........................<----
"variable gap"
................................................. ()()()()()()()()()()
...........................................................L3
L1 trap inductor (eg short ferrite antenna from old AM radio)
C1 trap variable capacitor to tune out unwanted signal (ditto)
L2 ferrite antenna from old AM radio
C2 tuning capacitor from same
L3 internal ferrite in G3

Variable gap : move apart or closer for optimal L2C2 tuning of wanted signal
and best rejection by L1C1 of unwanted signal. There will be some interaction
between the three variables C1, C2 and gap. Fun to fiddle with! For greater
safety, using the G3 on battery power would avoid any indirect earth loop via
the wallwart - and probably be quieter. You wouldnt hear much
when static builds up anyway!

My next project will be a crystal set! My most formative experience was my
very first crystal set. It didnt work. Eventually I realised I should not have
connected all the posts on the breadboard together :-)))))))

Still learning,

Michael UK