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Understanding Propagation

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
  • DLW Associates FL1718 Passband Filter 1.8 - 54 Mhz, Stopband 40db 0-1.7Mhz. 
  • MFJ 1708B-SDRS SDR Receiver TR Switch
  • 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.
  • Antennas On The Switch

    • 'P55' - Palomar Engineers Bullet Antenna 55' 9:1 UNUN 500 Watts PEP (200 Watts FT8).  50' of RG-8XII (Davis) to the 9:1 UNUN hoisted to the top of the 30' aluminum flag pole (un-grounded), with the 55' wire sloping Southward to 7' AGL.  
      • NOTE: This antenna replaced the Alpha JPole jr in the same configuration because the Alpha cannot handle 100W FT8.
      • NOTE: Reconfigured to run the 9:1 UNUN at 2' AGL, wire up the pole to 30' AGL then to the South sloping to 7' AGL.  NO DETECTABLE CHANGE IN ON-AIR PERFORMANCE.
      • NOTE: 'Brick Wall' broadcast filter does attenuate KCID by 40dB, but the common mode signal on the coax is still there.  Replaced it with Palomar Engineers CMNF-500-50GB Isolation filter.  KCID still detectable, but it is reduced significantly.  Broadband White Noise is still an issue, and apparent difficulty detecting remote stations using the spectrum analyzer function of FTDx10 remains.  Sub-Note: FT8 signals VERY detectable.  I'm talking about everything else - RTTY, SSB, SSTV, CW.  Is anybody out there?  DxLabs Spot says so, I'm having all sorts of trouble independently confirming it ... ARGH!
      • NOTE: Connected 17' counterpoise at 0' AGL.  NO DETECTABLE CHANGE IN ON-AIR PERFORMANCE.
      • NOTE: The 55' wire is good.  I think I can 'fly' 84' may be better. Look for a write up soon.
    • 'WOLF' - Wolf River Coil SOTA Special (SOTA is Summits On The Air) Packable Vertical Antenna with Buddipole  extensions (2 ea. 11" and one 32" - 54" total) and longer (84")whip antenna similar to this
    • 'STICK' - A truck mirror mount re-purposed to originally support a collapsible vertical for the RSP1a SDR.

    ZEP Antenna Configurations

    The Palomar 55 9:1 UNUN connects the 50 ohm coax to a psudo-random length of antenna wire.  I say psudo-random because there are specific requirements for the length that this wire should not, and can not be.  That would be any lenght that is resonant on any band the antenna will be used on.  Picking a practical wire length is non-trivial to operate on 80-40-30-20-17-15-12-10 Meters.  In my case where I am severely constrained, I believe I can get away with about a 60' horizontal run combined with the 30' height of the tall flag pole.  An 84' foot wire probably is the longest I can expect to use at this location.  136', 140.5', 117.5' and anything over 295' are options, but too long (maybe).

Config 1

      In the first configuation, I put the UNUN at the top of the pole and ran the wire out terminating with a 10' nylon rope to keep the end of the antenna out of reach of passers by.  

      Config 2

      I discovered through reading various antenna manufactures descriptions of working antenna installations, that the UNUN doesn't have to be especially far above ground, and that the antenna wire doesn't have to be especially straight in any plane.

      So for this configuration I mounted the UNUN at about 5' AGL, ran the antenna wire (55') to the top of the pole, 30' AGL and then down to 7'.  This shortened my horizontal run 20'.

      Config 3

      In this configration I added a 17' counterpoise to the UNUN, mounted it at 2' AGL, and ran the 55' antenna wire up and out as before.  Horizontal run about 17'.

      During testing of this configuration, I tried an AM Broadcast "Brick Wall" filter to reduce the effects of KCID on my receiver.  The filter did EXACTLY what it advertised.  Input signals at AM Broadcast frequencies were attenuated 40dB.  It was here that I recognized the QRM was coming from common mode current on the outside of the coax braid (which was grounded - and that makes zero difference to RF on a 50' run).  The Brick Wall was returned, and a Palomar Engineers CMFN-500-50GB filter was installed to decouple RF on the braid and drain static on the braid.  This made a substantial reduction in KCID interference at lower HF frequencies, but there is still more than I want, particularly as the frequency goes up.  By 10M it's 'nasty'. 

      Config 4

      Since I have about 60' horizontal I wanted to increase antenna wire length, to increase 'intercepted RF' - eg: increase sensitivity, so shortly I will install an 84' #14 THHN wire.  The UNUN will be at 2' AGL and the horizontal run will be 64'.

      1.  ZEP refers to Zepplin - the German air ships.  Their antennas were trailed long wires run through similar impedance matching networks. 
      2.  In my QSO 'Notes' field I list sent and received signal strength and then add the antenna and configuration information if you are interested in a particular QSO please let me know and I'll respond to you by email.

    Stand Alone Antennas

    • TRAM 1480 VHF/UHF 6db colinear 5/8 wave, mounted atop 8' of black steel 'fence top rail'.  Connected directly to BTECH UV-25X2.

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.


  • 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.
  • 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.

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.
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:
  • 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.

Completed Projects