Full-color, full-resolution graphics from the pages of QRP Homebrewer

QHB #10 -- April 2003

 

The NJQRP "Sniffer" Field Strength Meter, by J. Everhart, N2CX and G. Heron, N2APB

Here’s one idea of a layout for the board. The white circles represent pads.  As indicated in the text, this just happens to be my layout … yours could be entirely different, more ergonomic, and better performing for you.  Be ingenious and come up with your own version!  And how about an enclosure?!

Manhattan-style base board, 3” x 6” with “island pads” cut with NJQRP Islander Pad Cutter. (Standard “PC dots” could also be glued on for pads.)

Partially assembled Sniffer

Simulation plots showing selectivity of front end

Table of frequencies covered in tuning range.

Figure 3: Winding toroids for L1 and L2

Figure 4: Close-up view of mounting C1 and J1

Figure 5: Mounting the L1 and L2 toroids

Figure 6: Mounting components

Figure 7: Mounting the IC socket

Figure 8: Mounting the trim pot

Figure 9: Mounting the meter on standoffs

Figure 10: Closeup of the Sniffer’s Manhattan-style construction

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