My Version of Wes Hayward W7ZOI / Terry White K7TAU  Spectrum Analyzer

Last Update  12/17/99

After one year of putting it off building the  Hayward/White  Spectrum Analyzer featured in QST Aug and Sep 1998 I have finally have some output on the O-scope.

You can buy the kit of boards and parts for about
190 bucks from Kanga US.                                   Click To Kanga US Web Page for info

US  now has an add-on optional  Tracking Generator
for about 40 bucks without mixing xtal (S.A. dependent).

******press thumb nail PIXs below  for fullsize PIX. ******

This is the front view of my almost completed unit. I used a 3/4 inch angle aluminum for a frame and have attached the modules to the frame with various methods. the frame is about 11" X 11" X 10". The small scope I use for this sits on top.

My SA is using the kit boards and parts but I have scrouged enclosures, cables, power supply and attenuator to save on cost of project. typical ham actions. the power supply is at the bottom and to the rear. All the kit boards except for the Sweep board are housed in small RF tight milled aluminum exclosures scronged from a dumpster. The sweep board is is a separate PC board HB enclosure that has sections for the attentuator, xtal calibrator, tracking Generator interface and all front panel controls.

This is a closer look that the front sweep/attn sections and the lineup of RF enclosures at the rear. The enclosures already had F-type connectors so I used them and the cables to match. BTW all unused F-connector milled and threaded shafts are plugged with as much aluminum foil as possible to eliminate signal leakage. All DC voltages are entered into these enclosures via feed-through caps. The power supply is an old linear +/- 15v unit for another junk source. The attenuator is a high quality 0 - 59 dB unit with 1 dB steps and SMA connectors. The RF input and the Tracking Generator output interfaces use BNC connectors.

This view is from above and back of the unit. the front panel is a double sided PC board. these front sections will be sealed after complete checkout of the various modules.

This is the bench view before the frame was built.

This is the inter-frame of the 70 mHz Low pass filter. this frame is enclosed in one of the deeper milled boxes.

This is the 110 BandPass filter frame. This early version was modified to have shields placed between the three sections. I am getting  the image at about  -65 dB down from the desired side. This section maybe reworked at a later date.

This is the 10 mHz xtal calibrator board. HB, ugly construction. Power switch on front panel let you turn it on or off. Source select swtich let's you pick cal. output vs. external RF source.

This is the output from the 10 mHz xtal calibrator in the S.A. The Sweep is set to max (70 mHz).

This is the output from a MightyMite 3.686 mHz QRP transmitter a two transistor rig @ 50 mW via a 20 dB external attn. This rig is using a three pole PI LP filter. The unusual baseline at the left of the display is caused by me overdriving the S.A.

I will be following this up with output PIXs from various tests on gear that I have.

BTW the O-scope  is about as basic as you can get.

Sam Billingsley   AE4GX   Atlanta, GA   North Georgia QRP Club

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