User manual RAMSEY VLF1

[. . . ] VLF1 Tune in on all that low frequency action your rig has been missing!Get down below 400KHz with an effective and easy-tobuild design. · · · · · · · · · Converts 400KHz shortwave up to 4MHz. E - Z hookup with built in "feed thru" antenna connections - no need to disconnect when not in use!Complete and informative instructions guide you to a kit that works the first time, every time. [. . . ] This will also help us to get acquainted with the updown, left-right orientation of the circuit board. VLF1 · 8 VLF1 PARTS LAYOUT DIAGRAM VLF1 · 9 ASSEMBLY INSTRUCTIONS Once you've begun to install some of the longer leaded parts, save a couple of clipped off leads to use as jumpers in construction of your VLF1 kit. Don't be afraid to completely solder all three ground connections as these will also limit the "stress" on the input and antenna connections. Be sure to use enough heat to properly "flow" the connection. Orient the switch so that the end of the switch extends over the edge of the PC board. Recheck your connections for a shiny, smooth solder fillet connecting the component to the PC trace. The next few parts will make up the low-pass filter at the antenna input of the VLF1. One of the smaller blue green or light tan parts that looks like a resistor). Install C2 . 015uF capacitor (little brown chicklet marked 153), next to L1. The ferrite core is almost an ideal material for wire stripping and if you tug on the wire and it scrapes against the core, the insulation will come off. The wire must be delicately threaded through the holes in the core. VLF1 · 10 12. Now, take 2 of these pieces and twist the ends together about a half an inch. Slip one end of the wire through one hole of the ferrite core, and the other end through the other hole. Next, take one of the wires and wind it up through the opposite hole and then down through the first hole as shown in the picture. Snug the coils as much as you can without having to use anything but gentle force on the wires. Your transformer should now look like this: VLF1 · 11 16. The twisted part is the center tap of the secondary and the other two ends make up the end points of the secondary. This provides amplification for the mixed signal fed to the output jack. Now take a break from this part of the board and mosey over to the left side and you can install the heart of the VLF1, the integrated circuits. The 7404 is part of the crystal oscillator that generates the 4MHZ Clock. Take a previously saved piece of clipped off lead and bend it into the form of a staple that will fit in the holes marked "JMP2". Place it into the holes as though it's a resistor or capacitor and solder it in place. Install U1, the CD74HC4053E analog multiplexer/demultiplexer, next to U2. [. . . ] However, customer satisfaction is our goal, so in the event that you do have a problem, take note of the following. DEFECTIVE PARTS: It's always easy to blame a part for a problem in your kit, Before you conclude that a part may be bad, thoroughly check your work. Today's semiconductors and passive components have reached incredibly high reliability levels, and its sad to say that our human construction skills have not!All our kit parts carry the Ramsey Electronics Warranty that they are free from defects for a full ninety (90) days from the date of purchase. [. . . ]