Tuesday, November 24, 2009

Three band MEPT, 3.5999MHz QRSS QRG update

Two subjects in one posting...

3.5999MHz:

Here are simple ones, I have not seen before:
  1. 3.6 = 14.000 - 10.400 = 14.000 - 2 * 5.200
  2. 3.6 = 14.400 / 4 = (2 * 5.200 + 4) / 4
  3. 3.6 = 7.200 / 2 = (5.200 + 2)/2
#3 may be tricky in terms of filtering.


Three band MEPT:

#1 of the above combinations has added value, since the 14.000 oscillator could be modulated, providing a 20m MEPT at the same time. At the same time, cf. an earlier post, 14.000 can be down converted to 7.0599MHz by means of a 15m QRP crystal.
Summarizing:
  • 80m: 3.5999 = 14.000 - (2 * 5.200)
  • 40m: 7.0599 = 21.060 - 14.000
  • 20m: 14.000
The crystals for 5.2 and 14.0 are easily available, e.g. Conrad, Reichelt, DigiKey...
As for the QRP crystal, know your sources: Box73, ESS, QRP clubs, etc.