THE DIPPER
 
This fine project was found on Talino's site, IZ7ATH
and works very very well up to about 35Mhz. It starts to fall off over 40 Mhz and dies by about 50 Mhz. Winding the coils was a lot of fun. Since building it, QST Magazine, May 2003  pp 54 also has a similar project worth looking at. You can jump to Talino's site with this link ...IZ7ATH

The circuit diagram :   RCA 40673  sub: BF960
dipper circuit


The top view:
Dipper
Note BNC output at top
for coil attachment.

NO FREQUENCY DIAL!!!
It is assumed that you have a frequency counter to read directly off the BNC on the front panel (beside the mode switches) for a very accurate indication.
I never liked the crude dials on most homebrew dippers.















Dipper and matching coils
dpper and coils
The coils were made with
26g enamel  wire, on simple
1/2 inch cpvc tubing.

The BNC connectors on the coils were epoxied in place.

Packing Tape was wound on the completed coils to keep the wire  wrappings stable.

Labels made with a
Brother P touch
















PCB:
    H=58mm L=80mm

PCB  The pcb was done with the
  felt marker / ferric chloride
  technique, using letterset
  style donuts for the copper pads.

  Holes then drilled with the Dremel.







Board Layout:

Board  Parts placement diagram.










Coil Info:

coils

These values are a starting point.
Wrap turns and and test as you go...
Gamma MHZ Length
mm
Diameter mm Turns
num.
Inductance microH.
3-4,5 30 21 75 60
4-5,5 25 21 62,5 48
5-7,5 19 17 47,5 24
7,5-11 10 17 25 10
10,5-16 11 11 27,5 5,5
15-22 6 11 15 2,5
20-31 6 9 15 1,80


Thank you Talino !