Welcome to HamAlyzer®
by Sam Kennedy, KT4QW
Last Update 04/08/03

Hams!!    The HamAlyzer adds a whole new dimension to Ham Radio operation. With the increasing popularity of high quality audio on the ham bands, this is an operating tool you can't afford to be without! You can now see and understand why audio sounds the way it does.


HamAlyzer is a user friendly implementation of FFT Audio Spectrum Analysis software for Windows... optimized for Amateur Radio use.

   HamAlyzer Screen Actual Size

   HamAlyzer is an audio spectrum analyzer program based on the FFT (Fast Fourier Transforms). The HamAlyzer is a special adaptation of the Spec-tacle audio spectrum analyzer package which has been around for some time. It has been tailored to meet the operating needs of Amateur Radio operators. It's basically the same math "engine" that the very expensive audio spectrum analyzers use. It can be used to observe the spectral content of the audio transmitted and/or received by various amateur radio (and other) modes... You can now see why an incoming signal sounds the way it does! See how signals have been set up by ear with various equalizers on the ham market... not always a pretty picture!

    The HamAlyzer Features...
  Views 0 to 4.0 kHz. Switches to other views.
  Uses only small portion of computer screen.
  Allows real-time, averaging or peak traces.
  Plots amplitude in dB vertically.
  Plots frequency horizontally (linear).
  Mouse Click shows exact freq. & levels.
  Saves trace in JPEG file with a single click.
  Record as Wavefile...analyze later.
  Easy to E-mail trace image or save to file.
  More than one image onscreen at one time.
  Image monogram... your callsign.
  Positioned on computer screen as desired.
  Saves last settings for next session.
  Compatible with popular sound cards.
  Easy to interface with transceiver.
  Many options selectable.


Built-in Options

   The Options Menu appears when selected on the Main Menu. To the extent that the options available are not self explanatory you will understand when you use the free trial download program. It's a full strength program with a 10 day life. Note that the graphics included on this page may appear slightly different than those of later versions of HamAlyzer.

   My preferences are as indicated, except that I like the peak setting displayed in Red and the average displayed in Blue. The peak display is normally the final product of the process and for me, red shows up better on the screen and in the printed copy.

   Note that the "Capture to" Clip can be useful in pasting the resulting captured image into other documents... including email.

   "Screen Type" is controlled on the main screen. Each type has a slight difference in display technique. This choice is just a natter of individual choice.

   For detail information on features and options, read the "ReadMe" file included in the download software package.


Some Operating Notes...

A "captured" trace of a ssb station

     Not that It's a difficult concept, it's just difficult to explain with words. Just download the free trial copy and you will fully understand. See the "Captured" trace below and it will give you an Idea what you can expect. This trace was made during a QSO and as you would probably expect by looking at it, was a high quality ssb signal. Note that you can see the receiver passband. Of course any QRM shows up in it's proper relationship. You will find that you want to run the HamAlyzer constantly as part of your regular operating environment.

      This station's spectral content runs from 100 Hz to 3,000 Hz with little variation. In my opinion this is about the maximum useful bandwidth in regular amateur communication. Needless to say, this station sounded very good.

     Note that the receiver passband shows up at the high end. Also note the low level, high frequency "bump" of noise beyond the transmitted signal...



Digital Recorder...A Bonus!

     Not part of HamAlyzer, but once the transceiver's audio-out is connected to the computer sound card, you can use the Windows Sound Record feature without any other installation or expense..

Up to 60 seconds of high fidelity sound can be recorded. This recording may be played back or may be saved as a .WAV file. If you connect the soundcard audio-out to the transceiver's modulation input, you can play back while on the air.

     It is beyond the scope of these notes to explain the connections between various transceivers and sound cards in detail, however the basic connections are included below work fine. When recording your own signal off the air, (assuming that your transceiver has a monitor feature that will allow this) precautions must be taken to prevent rf from getting into the audio record stream.

     Also keep in mind that once a wavefile is recorded, all you have to do is drag the file (or many files at once) from an explorer window and drop it onto the plot window of hamalyzer, and you'll get a long term spectrum of the wavefile (peak too, if it's selected). Alternatively, click the file button and select a file. So you can record events as they happen, and then analyze them afterwards at your convenience.




A Basic Interconnection Cable

   Somehow you must get the receiver's audio into the computer's sound card. Since the microphone jack is always present on the computer sound card input, this seems to be the most dependable point of connection. Remember though, the receiver is producing a much higher level of audio out than is required by a microphone input. Thus the cable below simply incorporates a simple "volume control" in the interconnect patch cord. A 10k Ohm potentiometer is used, however it will work using a wide range of resistive values. While this method can produce an impedance mismatch, the sound card doesn't seem to care. The standard used on most, if not all, computer sound cards in MONO operation uses the LEFT channel which is connected to the TIP of the phono connector. It is always possible that the MONO audio may appear on the RING connection. Check this out if you do not get audio through the cable.

One of Several Possible Basic Connection Methods

   The connector pin-out shown is for the modern Icom transceiver. Many other types of connectors are used in other transceivers. You will have to research your operating situation. Note that if an 1/8" stero plug is used on the receiver end, the HamAlyzer is useful for monitoring from handheld transceiver and ordinary battery operated AM/FM radios. Yes the HamAlyzer is a useful tool for the Short Wave Listner as well.

   Use a well shielded cable for building this assembly. Minimize the amount of conductor that is unshielded in conjunction with installing the potentiometer. If this cable is used for monitoring while you are transmitting, it provides a golden opportunity for rf to get into the audio. Not a desirable condition.

     This same connecting cable allows you to use the Windows recording function as explained in the above section. But remember, when recording your own signal off the air, (assuming your transceiver has a monitor feature that will allow this) precautions must be taken to prevent rf from getting into the audio record stream.

     Start with the potetiometer positioned fully ccw, and advance it cw until you achieve a suitable monitoring level for the HamAlyzer.



SWL's Choice

   The connecting cable shown below is useful for connecting small radios including HTs, scanners, FM/AMs. This connecting method is a favorite for Short Wave Listners and for general Ham use with portable and Hand Held radios. Of course it's very good for checking CD players and other sources of music.


Connect to Small Radio's Earphone Jack

   Yes, the HamAlyzer is a very useful tool for the Short Wave Listner as well.


CAUTION
 There is always a risk of damage to one or both equipments when connecting them together. The cables and methods operate effectively with my equipment. However, I assume no responsibility for use of the interconnection assemblies and methods described above.

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... Happy DXing !