Project Ideas

 

2025

Its interesting to note, that while I often have the next big idea, it changes before I get started. I have gone from wanting to build a big HF station, to 6m / 50 MHz DX/EME, now to 23 cm / 1296 MHz EME as the next "thing" I get into.

In the case of 23 cm EME this time, this time I have equipment ordered, enough to a point of receiving other stations. Worry about the power amp / talking back later.

This is a list of different options to consider.


1296 MHz EME

Moon Bounce on the 23 cm band (1296 MHz) with Q65 weak signal mode.

23 cm may be the easiest band to get operational on with-out existing equipment above 6m / 50 MHz.

Or for example someone with a 2m / 144 MHz setup for weak signal work (radios / amps / antennas / parts / experience), might make 2m EME much cheaper path to try first, likely all you need is a good LNA at the antenna, a few hundred watts into a horizontal Yagi at moonset/rise. The bigger stations will be-able to complete a contact. 

I have nothing above 50 MHz, going to 23 cm first seems like easier path! 23 cm EME also appears to be the next most popular (fastest growing) to 2m band. Smaller antennas, more gain,  lower power levels when done right.


Basic Targets / Reference Points

  • Hear your own echoes (minimum equal stations needed for QSO)
  • 250W TX Power
  • Dish dia of 10λ (2.4m at 23cm), gain is approx 28 dBi
  • 2 dB feeder/divider/connector/phase cables loss total
  • Min 20 dBi gain, pref 24 to 25 dBi

24.7 dBi can be obtained with a pair of 56 Element Yagi's:

  • Estimated gain is 24.7 dBi
  • Linear polarization loss of 3 dB, puts us back to 21.7 dBi (just over the 20 dBi target)
    • Adding two more with efficient divider and phase cables adds 2 dB back
    • But this gets expensive (4 Yagis that are 15 ft long) to get sub 23.7 dBi
    • We're running into diminishing returns very fast
    • Switching to a dish and gaining 3dB out of the gate with circular pol, a 1m dish will likely outperform a pair of 56 element Yagis, and is a lot cheaper from RF Ham Design.
    • Seems to be - try it with a Yagi, it'll work, but you want more, dish is inevitable.
  • 40 ft of LMR-600, power divider, phase cables, connector losses total around 1.5. dB


Parts


AA (Antennas Amplifiers (Serbia), DXE DX Engineering (US), Q5 Signal (US). 


Docs


Limitations

  • Min antenna height of 30 ft
    • Limits mast placement to outside shack window
    • Allows most of 30 ft cable to be used for height vs horizontal waste
  • Minimum 250W output
  • 500W and H stack will perform near same/better than 2.4m dish with 250W?
    • Still take a 3 dB hit with linear polarization?
  • Upgrading from LMR-600 to LDF7-50 or larger will make the next biggest gain
    • Connectors are very expensive !
  • Careful calculation of system losses (I might be wrong!), even at 3 dB I should be close to hearing my own echoes


Misc


Shopping List

  • N right angle M/F
  • Entrance Panel(s)
    •  
  • Grounding wire gauge ?  (bonding grounding points pet NEC code)
  • Parts for Apex Mount
    •  
    •  
  • Az Rotator with good precision
  • Parts for El positioner
    •  
    •   
  • a



2026


50 MHz DX / EME


Was going to do this in Summer 2025..

Upgrade from 3 Element LFA to 6 over 6 stack.


Propagation

  • Meteor Scatter, 1000 miles, year round, MSK144
  • Sporadic E, 2500 miles or more with multi hop/TEP, spring/fall, FT8/CW/SSB
  • F2, 5000+ miles / global, solar cycle peaks with SFI around 200+, FT8/CW/SSB/AM
  • EME, Anywhere when the moon is up, Q65-30A?


Tower

ROHN 25G

Estimate Rohn will be around ~$2500

ROHN 25G 10 ft Height - x3 $546 https://www.dxengineering.com/parts/roh-25g

Tower Section Top - x1 $300 https://www.dxengineering.com/parts/roh-25ag2

Carlson Hinged Base HBP25G-HD - x1 $430 https://www.dxengineering.com/parts/ces-hbp25g-hd

https://absak.com/shop/rohn-towers/ - local Rohn supplier


Rotator

Yaesu G-1000DXA Heavy Duty Rotator - 22 Square Feet

https://www.hamradio.com/detail.cfm?pid=H0-002759


Antennas

EAntenna 50LFA6M, Yagi, 6 meters, 6m, 6 Elements, 20.75 ft. Boom Length, Loop Fed Array

https://www.dxengineering.com/parts/ean-r2010114

Start with two, go-to four for EME.


Pre-Amp


Power Amp


Coax / Phase Lines


Controllers



Pre 2025

With a move out of the city (Seattle area) back to Fairbanks Alaska planned by mid 2021 2022 that got my think wheels turning on what sort of amateur radio station I'd like to build up given that we'll be semi-rural with a little bit of space to play with, and maybe some spare dollars to put into a pursuit for once in my life.. Go big or go home.

Some thoughts and notes..

Being that far north (64 degrees / 200 miles south of the Arctic circle): 

  • HF propagation is more challenging.
  • The climate - winters are cold, snow and ice, below freezing near six months of the year.
  • Remoteness - getting stuff shipped takes longer and costs more.

This will necessitate high(er) performance antennas that are robust, reliable, and able to be serviced with out any one else's help. Once it's all said and done I don't want to have replace or fix much for a good 10 to 15 years.


Amplifiers

Mercury IIIS


Antennas

Good performance on HF between 40m (7MHz) and 10m (28MHz) means Yagis, including the WARC bands except 30m (10MHz).

With 40m in mind a height of at least 60ft (~1/2 wave length) is needed for reasonable gain to develop at lower angles.

OptiBeam caught my eye.

  • No moving parts or traps.
  • Computer optimized designs.
  • Well rated on eHam for mechanical design, easy assembly, performance, customer support.
  • Been around a long time. Made in Germany.

After looking over the different models, the bands they cover, and (important to me) what they look like my picks are:

OB2-40M (40m loaded Moxon), eHam reviews 5/5.

OB9-5 covers 5 bands from 20 through 10m, eHam reviews 5/5.

That leaves 6m, a G0KSC designed LFA Yagi, five or more elements, undecided.


Towers

I need to be-able to service, make adjustments, and/or change things by my self so no tower climbing or hiring someone to climb, and no cranes. This means I need a crank up tower (telescoping sections), and likely a tilting option to lay the tower over when its in the town position.

CrankupTiltoverTowers on Groups.io looks like a source of good information.

So far my current thoughts for a tower is Tashjian Towers which offers these free standing crank up towers with optional tilt over bases for these models:

  • LM-354 - 54 foot, 18 sqft wind loading.
  • LM-354HD - 54 foot, 45 sqft wind loading.
  • LM-470 - 70 foot, 24 sqft wind loading. This comes standard with motorized crank-up.

The OB5-9 has just under 8 sqft wind loading, the OB-2-40M has just under 6 sqft wind loading at 80 mph for a total of 14 sqft, add on a ~15ft mast in the top, and a 6m yagi that's maybe near the limit of the LM-354. So either LM-354HD or LM-470.

http://www.heightstowers.com/


Rotators / Positioners

Large heavy antennas need an equally suited rotator, so far these are on the list:


Low Bands

Since 40m and the upper HF bands will be well covered that leaves the lower HF bands (30, 60, 80, 160m) to experiment with. Depending on space, tree placement, etc, order of preference:

NVIS:

  1. 160m 1 wavelength horizontal loop for 80 and 160m*.
  2. Doublet*.
  3. Some combination of OCFDs and/or trapped dipoles.
*Open wire fed directly to high quality 1:1 current balun into remote tuner via short coax jumper.

DX:

  1. 80m (space permitting) 4-square array!
  2. 80m two element phased array (OVF), horizontal dipoles at 70ft + or verticals.
  3. 80m half square.
  4. 80m 1/4 wave vertical.
  5. 160m, loaded vertical or inverted L.


RX:

  1. K9AY loop (already have it).
  2. Experiment with beverage, flags etc.


Software

https://icom.va2fsq.com/ - Win4IcomSuite.

http://www.n3fjp.com/ - Logging.


Misc Links

WB5THT Tashjian tower install.

AB7E OB2-40 and OB16-3 install.

CrankupTiltoverTowers@groups.io | US TOWER TIP OVER.

CrankupTiltoverTowers@groups.io | HD rotators for CuTo towers with HD antenna.

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