Spectrum Analyzer v1.0

This is version 1 of a spectrum analyzer I built based on Wes Haywards W7ZOI and Terry White's KZTAU architecture. I have made design changes mainly because some of the parts are way to pricey for me to purchase. Further refinements and features are are added as the problems or need presents itself. Most of the simulations and initial calculations are done on EMRFD Ladpac tools.

Calibration oscillator is connected to the SA

Architecture

I chose a 2nd IF of 25Mhz there are disadvantages in using this frequency.1. The chosen log amplifier AD8037 has better linearity at 10Mhz
2. Narrow band 10.7Mhz IF filter are readily available.


Other things that are highly recommended when building an SA.
1. Signal Generator with frequency range that can cover the BPF filters
2. Highly sensitive RF Power meter.
3. Lots of BNC connectors
4. A copy of EMRFD


People that helped me a lot.
1. Wes Hayward- http://w7zoi.net
2. Todd Gale -http://http://www.qrp.pops.net

Here are a few more pictures.

I am using a 100Mhz clock IC for my 2nd LO. To remove the harmonics a low pass is used. The latest version is using a 9th order filter.

5th Order low pass filter.

The 2nd LO is being tested for proper output levels.

Some useful links for parts and tools
1. Rigol Oscilloscope used for the build and testing - Rigol DS1052E 50MHz Digital Oscope with 2 Channels, USB Storage Access, 1 GSa/sec sampling
2. Hammond Aluminum Boxes - Hammond 1590B Aluminum Diecast Case
3. Coaxial Cables - CableWholesale 6-Feet RG58 AU Stranded BNC Cable, Braided (10X1-01106)