7.040 MHz Quartz Crystal HC49U CASING
40 Meter Amateur Radio band WSPR Tx 
 
IQD Branded
 
7,000-7,040 kHz    200 Hz    Telegraphy. 7,030 kHz - QRP Centre of Activity     
7,040-7,047    500 Hz    Narrow band modes
 
7.040000 MHz  30pF 
CW / DATA Portion of 40m Band -
 
Ideal for WSPR Transmissions on the 40m band (7.038600 dial setting for Rx) as seen by the images - showing my homebrew QRP WSPR Tx - source audio from iPhone App - RF balanced fed via ATU into outside wire dipole.  Great fun and interesting when experimenting to see how many bands I can sucessfully operate on using this circuit.
This crystal slots directly into the relatively simple homebrew transmitter circuit described in the book 'QRP Scrapbook' available from RSGB bookshop - a book full of interesting QRP circuits and projects, this crystal would be an ideal modification!