K9IQY

Brad Dye

ex KN9IQY, KN4BK, KM5NK, WB4JCF, ZP5TQ, WA4VXU, WA9RVL, /TI2, /9Y4, /6Y5, /KP4, HH2FJ

Licensed amateur radio operator since 1957
Licensed FCC first-class-commercial radio operator/engineer since 1964

P.O. Box 266
Fairfield, IL 62837 USA
618-599-7869

Latitude: 38.3540702°
Longitude: -88.3579018°
Grid Square: EM58ti

WSPR on Softrock Ensemble RXTX Project Update

September 23, 2015

The FCC requires that the mean power of any spurious emission from a station transmitter transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. So to operate on 30 meters (10.1 MHz), and keep it legal, I built this Low Pass Filter to attenuate the second harmonic at 20.2 MHz.

If anyone has the equipment to check the frequency response of this filter, and would volunteer to do so, please let me know . These hand-wound toroids may be a little off.

DE K9IQY

My latest project is a general coverage radio receiver, tuning from audio frequencies to 30 MHz in one Hertz steps — locked to the GPS constellation. The “dial” is a beautiful color monitor on a laptop showing 190 KHz window of the band as a spectrum analyzer. I have been involved with many kinds of radio receivers for over fifty years — amateur, military, and commercial. This one is a dream come true. When I was a young ham, I dreamed of the day when I might have a receiver that would read out to one kilocycle (before we used the term Hertz). Now I have assembled one that reads out to one Hertz and is accurate to ±70 µHertz — and thanks to GPS — it will maintain this accuracy as long as the GPS satellites keep working. It was nice of the US government to spend many billions of dollars just to keep my radio on frequency. (HI)*

* "HI" means "ha ha" or laughter in ham radio lingo.

Check out my project here .

Current equipment in use:

• Softrock Ensemble TXRX
• Icom IC-7600 HF/50 transceiver
• Icom IC-R8500 general-coverage receiver with the high stability oscillator installed.
• RFSpace SDR-IQ Software Defined Receiver (SDR) modified as described above and on my project page here.
• Palstar BT1500A balanced antenna tuner
• Icom IC-208H 146/440 FM transceiver
• Ameritron AL-80B KW HF linear amplifier (a single 3-500Z tube)
• Astron RS-50M 50-amp analog power supply
• ANTENNA-1
  DX Engineering 30-Meter Vertical Antenna model DXE-30VE-1 and the DXE-RADP-3 Stainless Steel Radial Plate with 60 #10 AWG copper radials and one 5/8” X 8 ft. copper-clad ground rod at the base. (See photo below.) Also have an Alpha Delta model ATT3G50U Transi-Trap™ Surge Protector and a Polomar Engineers model BA-8 1:1 current BALUN installed at the base feed point. The transmission line is 130 ft. of Times Microwave LMR-400-DB^® watertight coax cable buried 1 to 2 inches below the ground. The trench is becoming invisible as the grass grows over it. The 60 ground radials are stapled to the surface of my lawn using “landscaping staples” that look like “U” shaped bent pieces of coat hangers about 4 to 5 inches long, but are available — ready to use — at the home supply stores. This antenna is used primarily for WSPR low-power communication on 10.138.700 MHz.
• ANTENNA-2
  Full-wave, horizontal 160-meter loop antenna made of one continuous length (618 feet) of #12 copper clad, steel wire. The antenna portion is 558 feet long and the lead-in uses the remaining 60 feet of wire to make 30 feet of ladder line using ceramic insulators. This antenna covers nearly one acre of land and is supported by two Rohn towers, two Heavy Duty Fiberglass Telescopic Poles, and two trees for an average height above ground of 40 feet. This antenna can be tuned on all bands — 160 through 10 meters — with a Palstar model BT1500A fully balanced antenna tuner. I like the design of this tuner very much because it uses twin-rotary coils — one on each side of the ladder-line output, and the BALUN is on the input side of the tuner — where it should be — *IMHO*.
• ANTENNA-3
  A Radio Shack® Outdoor Scanner — a Ham Discone Vertical Antenna, 25–1,300 MHz about 30 feet above ground. Don’t laugh at the Radio shack brand — this antenna transmits effectively at 50, 144, 220, 440, 900, and 1296 MHz. The major problem with this antenna is that whoever designed it knew a lot about antennas but not much about the reaction of dissimilar metals. The reaction of brass screws crimped into stainless steel tubing causes the ground plane radials to snap off easily — like pieces of dried spaghetti. I have spent many hours repairing this piece of junk — even buying another one to get parts. At least I have learned how to solder stainless steel in the process.

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