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Understanding Propagation
Contact Me: W7ACP

Welcome to South Western IDAHO

  • South Western Idaho has a very wide range of terrain, vegetation, wildlife and climate.  Here in Caldwell, we are at the Western end of the Treasure Valley, formed initially when the Yellowstone 'hot spot' was located here.  As the Yellowstone caldera has moved (well, the effect of the caldera moved on the surface - most likely the hot spot stood still and the Earth's crust moved over it.), the mountains created by tectonic action in the collision of the North American Plate with the Juan DeFuca Plate were 'melted' by the hot spot.  The modern day result is a valley running from the Oregon-Idaho border toward the Southeast to just North of the Idaho-Nevada border then turns Northeast toward the present day location of the Yellowstone hot spot in Montana.  This valley is surrounded on all sides by the Rocky Mountains or its cut-off remains in the ancient Owyhee Range.  The valley floor is around 2,400 feet above sea level (at my location) while the surrounding mountains and ridges run to about 6,000 ft to the South and 8-9,000 ft to the north.  This has created a very unique weather pattern for the valley, where storms coming toward us from the West typically, dry out as they leave the Owyhee's (to our South), and start precipitation again when they hit the Rocky's to our North, leaving us with an average of 11 inches of rain and 8 inches of snow annually while Idaho City, just a few miles away in the foothills of the Rocky's receives an average of 27 inches of rain, and McCall, several miles to our North and well within the Rocky Mountains receives over 25 inches of rain and a whopping 138 inches of snow annually.  All of that describes how the Treasure Valley and the Magic Valley are an agricultural paradise.  Lots of water (from all that mountain snow), long growing seasons, and when the fates allow, nearly 5 months of continuous 'perfect' weather. All we need to be a 'destination' would be to have an ocean beach ... but alas, what we have is called a 'High Chaparral' where grass, sage brush and the invasive Russian Thistle (tumble weed) thrive.  Where the land is not in active farming we have endless tracts of 'BLM' (Bureau of Land Management) controlled land that is generally accessible to the public while also available for ranching and in some places it is home to herds of wild horses.  My wife and I love to take trips out into the desert (excuse me 'High Chaparral') to see the sights, smell the smells, and meet the wild or nearly wild life of the area.
  • Some photos we have taken from around the area click here.

Station Equipment

HF Radio & RF Path

  • Alinco DM-430T Switching 12v 30A Power supply.
  • Yaesu FTDX10 HF/50MHz 100W Hybrid SDR Transceiver
  • Morgan Systems M-400X Broadcast Band Filter 3.5-5.4Mhz 200W 50 ohms ( Updated 12/03/2021.
    The various wave traps and other AM BCB filters did not appear to work in part because I was looking in the wrong place.  FT8 being a 'weak signal' protocol was not dramatically affected (or so I thought), and when I was looking for other signals (mostly SSB) I wasn't finding them.  A big part of the reason was that I had a lot of additional RFI from local sources that had not been attenuated and these sources signatures appeared to be IMD (repeating equal frequency spacing).  After dealing with those, using the Palomar RFI KIt (below), the Morgan M-400X was exactly what was required to clean up the remainder.  The difference was a very dramatic doubling of the number of FT8 decodes per period, and noise levels of S6 on 40M, S5 on 30M, S4-5 on 20M, S0.5 on 17M, S0.5 on 15M, S0.5 on 12M, S1 on 10M and S0.5 on 6M.  The increased ability to scan the band and observe RTTY and SSB was very dramatic.  There are still discrete RFI signals of both single frequency and 'fuzzy' throughout the entire spectrum, some come from one (and only one) of my two Windows monitors (Scepter 20"), and as yet undiscovered sources.  The monitor's power cable has 3 turns through a 1/2" Ferrite (Fair-Right V0) which does reduce much, but not all of the noise from that source.  I think what I'm seeing is a signal generated within the monitor, and given the low cost of the monitor plus the low degree of interference I'm going to call that a win.
  • Palomar Engineers Coax Noise Filter CMNF-500-50GB <= 38dB rejection of common mode current 1-60Mhz.
  • Palomar Yaesu FTDX10 Transceiver RFI Kit 8 RFI/Noise Reduction Filters 3 ea. ring and 5 ea. 1/2" snap on beads.
  • NOTE: When placing the 1/2" snap on beads; take two or three turns of wires through the center then gently close the bead while watching the receiver, as the magnetic field couples you will notice the effect in reduced noise.  If you have the wire length (and diameter) to take more turns its easy to adjust and test.  When satisfied snap the bead shut.  As a practical matter, try snapping a bead shut and getting it open again without any wire to see how it's done, once in place it may be difficult to determine.  In my case, the Scepter monitor power supplies were creating a lot of noise, and five turns in each power lead quieted the noise down to about 5.5dB (+24.5dB on the FTDX10's waterfall).
  • NOTE: DC Power leads that came with the radio are quite long (about 6').  I installed the RFI Torroids with 14 turns through the center, all in the same direction.  All of the ferrite chokes are installed as close to the radio as is practical.  I installed one of the 1/2 ID beads on the USB cable (from the computer for CAT control and audio), I even put a choke on the CW key line!
  • MFJ 993B IntelliTuner Automatic Antenna Tuner.
    NOTE: I really like this tuner!  The FTDX10 has an internal tuner that can do quite wide match, but this tuner can do so much  more it makes it worth the additional expense.  It has made my intentionally non-resonant 95.375 foot antenna wire (connected through the Palomar 'Bullet' 9:1 UNUN) functional on 80M through 10M and it provides a 1:1 match to the radio most of the time.  What it's doing is coupling the transmitters power into the transmission line, UNUN and antenna.  Very little reflected power toward the radio.  All that power is either radiated as RF or as heat in the antenna system.  So far it appears to be radiating RF far more than heat, as I increased my 'footprint' as seen on PSK reporter significantly. 
  • MFJ 1708B-SDRS SDR Receiver TR Switch
    NOTE: This switch makes it possible to run the RSP1a as a spectrum analyzer looking at the output of the radio.  It also allows the SDR to be used to observe a wide spectrum of frequencies while operating the transmitter.
  • MFJ 1701 6 port Antenna Switch common through NI4L HF Choke Line Isolator (CM choke) to reduce RFI.
  • SDR Play RSP1a (Software: SDR Uno) connected through the TR switch to allow receive operation even when transmitting from the FTDx10.
    This device uses a sense antenna and amplifiers to invert local noise signals and add them back into the receiver antenna input during receive.  It has a built in TR switch that apparently MFJ is not very confident in, but my transceiver doesn't have a distinct TR output that is easily accessible, so I'm relying on the built in.  Turns out that on my unit the T/R Delay must be set to 0 (full CCW) versus the 10 (full CW) the manual specifies to allow the TR relay to drop out at all.  Many YouTube videos describe the operation of this unit, and a few even discuss the sense antenna, but rarely do they delve deeply into how it works.  I intend to write up my experience as an article on this web site, but for now, my experience is that if you have an end fed half wave antenna as your main antenna, you are going to want a similar antenna as a sense antenna.  If you want to use this device to reduce AM Broadcast Band interference, it is essentially useless, and if you want to use it to mitigate left over local noise it might be possible, but it's going to be difficult to setup and may need to be changed as often as you change bands.  At the moment I'm thinking of removing it, but I put it in front of the SDR, so I'm might leave it in the circuit for a bit to investigate using it with the SDR to create a useful "PANADAPER".  


Narrowband Antennas

    • Wolf River Coils SOTA (Modified) tunable vertical with ground plane 40M through 20M.
    • TRAM 1480 VHF/UHF 6db colinear 5/8 wave, mounted atop 8' of black steel 'fence top rail'.  Connected directly to BTECH UV-25X2.
    • MFJ-1979 17 ft collapsible (tunable) antenna - uses vary from SDR input to active antenna for comms.  Recently re-installed for use as sense antenna for the anticipated addition of an MFJ-1026 Deluxe Noise Cancel / Enhancer / Antenna
    • HamStick antennas; 75, 40, 20, 15, 10 meter.

Uncategorized Antenna Equipment

Retired Antennas

    • Retired: Alpha Antenna JPole Jr. 34' End fed 'sloper' feed end at 30' AGL (Above Ground Level) sloping to 10' AGL fed at the North end with the wire sloping to the South, so East/West should be strongest signals, you would think, but read on! 

VHF/UHF Radio & RF Path

Computer & Data Path

  • Mac Mini - My office workhorse; produces the secure (LetsEncrypt) Internet presence for this web site, (Apache HTTP Server) publishes several MySQL databases, handles all storage, video, html editing, email, etc.

  • Retired: Acer Notebook - configured primarily for Application Generation with AppGini for MySQL databases.
  • Retired: Toshiba Satellite Notebook - configured primarily for Radio Control with DxLabs, WSJT, and other radio control software.

Test Equipment

  • Fluke 77 DVM (circa 1970, my old friend!)
  • NANO VNA Network Vector Analyzer
  • Looking for an inexpensive 100 Mhz dual trace storage oscilloscope. Thinking about YEAPOOK ADS1014D among others.
  • NOTE: The RSP1a SDR makes a fine spectrum analyzer to sample transmitted signal.  My current antenna is selected by a switch box, then routed through the MFJ 1708B SDR TR Switch to the RSP1a and the Yeasu FT10Dx transceiver.  When in transmit there is just enough RF energy still present to provide the RSP1a with a very usable sample.  Good way to check for modulation and spurious emission (my first harmonic is less than 30 db down - GOOD!)  Tuning my audio card volume and WSJT-X's power control shows that for FT8 mode I can run the selected audio card at full volume, and the program power level at 100% without distortion and that I do not have to apply any wave shaping to produce a clean transmit signal.
    • 20210730 I captured this screen shot from the Spectrum Analyzer app running on the RSP1a.  Conditions: WSJT-x FT8 Tune mode with transmit frequency set to 1000 Hz, Power 100%, into Palomar 55 antenna, sampled by RSP1a inline via MFJ 1708B.  First harmonic is -33db 4th harmonic is -50.5db.  The signal is averaged over 20 sweeps.

Yeapook ADS1014D Oscilloscope


  • Skimmer (not until it works with my SDR or another inexpensive one).  Skimmer is expensive - but it could be worth it since there are few reverse beacons near me.  But not until I have a proven antenna system ...
  • DXLabs - Best radio control, DX, Contesting software, but it needs a native CW decoder!
  • WSJT - The best way to 'do' FT-8 etc.
  • JTAlert - Adds serious functionality to WSJTx for things like 'worked before' and 'Calling You'.
  • NOTE: As of July 2021 I have configured WSJTx and JTAlert to cooperate and control FT8, logging (both local and LoTW) and spotting.  Working on how to automatically and timely update LotW and QRZ logs.
  • PSKReporter
  • CWGet  - Works off the sound card, so it can work with DXLabs Winwarbler. 
  • CHIRP - Allows programming HT's to the same channel (frequency) etc. even if they are different model numbers from different manufacturers. But its a bit 'clunky' - I may have a look at creating the same functionality using some other tools and database(s).

Project List

Antenna Analysis
VNA analysis of my antennas - or - Learning how to use VNA Windows software.
4NEC2 modeling and analysis of antennas and antenna design ideas.

Antenna Install and Test
  • Using a 30' flag pole to 'fly' a wire antenna and stay under the radar (maybe).
    As well as how well it works, and how much sensitivity it has to installation direction.

    NOTE: This project is mostly complete.  The Palomar 'Bullet' and 95.375 ft #14 THHN wire antenna is designated antenna 'P95'.
  • Using two 17M 'Hamstick' antennas to form a vertical dipole, model and test. 
    • If this works as I think it will, these should make an ok DX antenna.
    • Based on results, construct a self supporting, vertical half wave 40M antenna, then add additional vertical half wave antennas to the structure to create a multi-band 40M-10M antenna with low radiation angle.
    • Cut for FT8 operation, these are the half wave antenna lengths:
      • 40M 66.00'
      • 30M 46.12'
      • 20M 33.22'
      • 17M 25.83'
      • 15M 22.18'
      • 12M 18.75'
      • 10M 16.65'
    • 4Nec2 Analysis HamStick
    • 4Nec2 Analysis VDipole
Comparison to Wolf SOTA vertical and other antennas.

Transact (or something) the DXLabs and WSJTx MS Access log databases on JWIN into MySQL tables on JMAC so I can archive, and manipulate, display etc. outside of the applications.  See if AppGini can ingest 'em?  Otherwise use Open Office Db to enumerate and export?

One Click Reports I want to write:
  • List today's QSO's by time.
  • List today's QSO's by band and distance.
  • List states & countries QSO'd today.
  • List outstanding QSL's.
  • List QSL's by date/time.

Shack Grounding
  • Ground rod installed & connected - working on eliminating noise and KCID AM before I write it all up.  The ground rod is connected to a 'loom' which is usually found inside an AC distribution panel, but in this case is screwed directly to the wall behind the desk.  There are 9 positions, one ground wire/equipment per.  Currently using 1 for the ground rod, and 4 for equipment grounds.
  • I have found a bit of a difference in potential between the 3rd wire ground and the ground rod.  I've made up a jumper and plug that allows me to easily bond the two grounds for testing and evaluation.  So far I have found no significant effect one way or the other.
  • Pending:
    • Lightning Ground
    • Signal Ground
    • EMI Ground and Shielding (I've got a great large (1490Khz/1KW) KCID AM ground wave transmitter 500 yards to my East).  Working with Palomar Engineering to get the RF (both mine and KCID's) on the coax shield stopped before it gets to the radio using filters and chokes.

Radio Continuity of Operation

  • New battery for UPS
    • Power OP strip from UPS (JMac & display, JWin & displays, ext drives, HF, VHF & UHF radios, HT charger.
  • New automotive/deep cycle battery for transmitter(s)
    • Solar charger.
      • Recharge all radio and UPS batteries.
    • Switch radio over from commercial to battery.  Temporary immediate phone, CW only.
    • Generator
      • Switch house (RV) and entire shack to generator (change 50A and 30A source from commercial to genset), consider FrostKing heat tapes etc. Temporary all modes.

Reduce QRM on 160, 80, 11, 10 meter bands due to KCID and general noise.

DMR Digital Mode Radio

ICOM ID-51 Docs

Delta Loop Antenna(s)

Completed Projects