This changes with each contest but here is what I have as of 7-Aug 2023 in preparation for the Sept ARRL VHF contest. During these lovely 105 degree F July and August weekends I’ve been hard at work making some modifications. I’m in the process of moving the 2m directional so that it is at least 23 inches away from the 6m Moxon. I’m also adding sleeves for the mast pipe clamps for easier storage, and antenna reassignment (Satellite and hopeful for EME some day!).
In the photo below, 2M and 6M are properly space. Before I moved them the 6m receive had about 3 to 4 additional S units of noise when I transmit on 2m (S3 background noise would become S7). I originally assumed they were too close but I marched forward since they are perpendicular (mostly) to and almost a 3rd harmonic from 50.2 MHz to 144 MHz. When I moved it down the strong noise almost completely went away on 6M while 2M is transmitting. 2M was not effected by 6M transmitting.
As for the sleeves, after moving antennas around a couple times I realized I needed to find a way to improve assembly/disassembly time without altering safety. I found that 1 1/4 inch electrical steel conduit is a great fit over 1 in PVC, so I purchased a 10 ft piece of conduit and a metal cutting blade for the sawzall and some 1/4″ x 2″ stainless steel bolts. Also the 6m Moxon is normally in the attic serving as my 6m base antenna, and when in storage the 2m yagi has to be removed to fit into the shed. Again, hopeful one day to use it for 2M EME with Q65 mode.
Chokes
Once I added the DC to AC inverter to charge the laptop, noise became a real issue. When the inverter was on it filled the 6M band scope with bands of noise like I see anytime a switching power supply for a Raspberry Pi is plugged in. So I had to buy some clamp on Ferrites or “Ferrite beads”. I found a chart at DX Engineering that displayed the proper Ferrite mix to use for different frequency ranges and from there determined I need Type 61 since I’m operating 6M to 23 cm. I found that Digi-Key had plenty in stock, in a variety of sizes, and made it simple. I ordered various sizes from 4.29mm to 18.34mm but here is the type I ordered: https://www.digikey.com/short/8wqdrwjz I snapped four of these 13mm hinged Ferrites onto the 6m coax as it enters the IC7610 and most of the noise from the inverter went away! I did the same for the LiFePo4 battery and the DC Inverter to be safe.
There is also a LOT of noise from the USB GPS receiver that I use to set my computer clock and I could not find the proper place to filter this noise. More trial and error may be needed.. but as soon as the driver loads for the GPS receiver the S meter goes toward the red! I’m sure it is an I2C over USB serial data as I’ve witnessed the same exact noise on my satellite AZ/EL Arduino project. The RF noise from these is getting in somewhere. For now I just tether my phone and sync the laptop clock that way. I suspect I could spent another day figuring out where this noise is getting in but I have a work-around.
Aluminum Inventory
| Band/Polarization | Make/Model/Desc |
| 6M Horizontal Stressed Moxon | Par Electronics SM-50 http://www.parelectronics.com/stress-moxon.php |
| 2M Horizontal Yagi | M2 Antennas 2M7X https://www.m2inc.com/2m7x/ |
| 2M Horizontal Stressed Moxon | M2 Antennas OM-144 http://www.parelectronics.com/moxon-OM-144.php |
| 1.25M Horizontal Yagi | M2 Antennas 222-10EZ https://www.m2inc.com/FG22210EZ Funny enough, I wanted the 7EZ to have a wider beamwidth since I rotate the car not the antennas however shipping for the 7EZ was $100 (factory direct was the only option) and shipping for the 10EZ was $9.. making the 10EZ less expensive.. now I just need a transverter… |
| 70 cm Horizontal Yagi | M2 Antennas 440-11X https://www.m2inc.com/440-11X/ |
| 23 cm Horizontal Yagi | Comet CYA-1216E https://cometantenna.com/amateur-radio/base-antennas/single-band-2/ |
| 2M/70cm/23cm Vertical | Comet Base Vertical GP-95 https://cometantenna.com/amateur-radio/base-antennas/tri-band-3/ |
| 2M/1.25M/70cm compact Vert | For daily driving around and entering parking garages.. I have the NMO mount COMPACtenna 2M/220/440 Tri-Band. https://compactenna.com/#2M220440 |
Most recent pic
23cm and 70cm on the driver side.
2M on the passenger side. 2M and 6M are now over 23 inch apart and all are mounted using a sleeve with one 1/4 inch x 2 inch bolt and nylon lock-nut.
All antennas also have a paracord holding their nose up and to dampen stress from hard bumps on the road.