6 Meter Transverter
How to cut solder pads using a
drill press.
Here is the 6 meter to 10 meter transverter that I
have been working on ever since Dayton Hamvention of 1998 where I
bought a 11 mhz crystal to start it with. I was looking for a 22 mhz
xtal, but couldn't find one. I just built a frequency doubler for the
11 mhz and it seems to work just fine. You can see the mixers (Silver
boxes, SLB-1's) , there is one each for the receive and xmit stages;
two T/R relays and lotsa little toroids everywhere! The little 1/8"
jack is for the T/R function and that ground-during-transmit signal
comes from my President HR-2600 10 meter all mode. I've tried this
outfit in FM/AM/CW and SSB and have had good signal reports.
Is it ugly? You bet it is! Does it work? Of
course!
Top View showing entire circuit.
Here is the power amp circuit MMPS UH10 preamp
transistors to a 2N3725 predriver to a 2N4427 amplifer transistor.
Produces about 2.8 watts rms (34 vp-p at 50 ohms)
How
to cut the solder pads using a drill press
Inexpensive Drill Press
set-up
Note the "Vee" notch cut into
the drill bit using a small grinding wheel and a triangluar file. The
leading edge of the 1/4" drill bit is sharpened to a point while the
trailing edge is beveled back so that it doesn't touch the circuit
board during cutting of the solder pads. When using the pad cutter,
make sure that you have a firm grip on the circuit board! Otherwise
it will try to move and really mess up the board. Practice on a piece
of scrap pcb first.
Ta da! Successfully cut solder
pad. Now just use some sandpaper to clean up the edges and it will
work just fine. Make sure that the copper is cut completely away from
the pad.
Hints:
1. Use a cheap drill bit. Some
of the better ones are hard to grind and sharpen.
2. Run your drill press at a
higher RPM setting. That keeps the bit from wanting to "walk" across
the pcb, rendering massive destruction to your little
board!
3. Hold on very tight to the
pcb.
4. Bring the bit slowly onto
the board, don't use a lot of pressure.
5. Just cut enough to remove
the copper.
6. Need bigger pads? Use a
bigger drill bit; 1/4" bit makes 3/16" dia pads; 3/8 works nice for
about .25" pad. Bigger bits than these require a firm hand on the
pcb!
73 de NS8O