excellent HF propagation in Cycle 23

With little more than a G5RV antenna up about 8 meters in the barn, Icom IC-725 at 100 Watts, an MFJ-945 antenna tuner to match impedance and a firm connection to a deep well for ground, I have been getting > 10,000 km contacts this summer. One notable contact was Rarotonga in the Cook Islands on the 15 meter band (21 MHz). He noted how fortunate they were to have 24-hour power vs. many of the other islands which had it only during day, provided the fuel wasn’t running low due to delayed shipments. With less than 0.01% of United States power coming from solar, the cost is presently too high despite the immense cost of shipping the diesel fuel. As in much of the widespread Pacific Islands, air conditioning is not as common as it is in the United States, but naturally appliances that run 24/7 like refrigerators and freezers are nearly as common. He felt it was a comfortable life on Rarotonga, and that if I really wanted an isolated contact I should look for VP6TC from Pitcairn Island, over 3000 km to the east of Rarotonga and about 9000 km from me.

HF conditions with high SSN > 120

The remarkable thing is that 20 meters (14 MHz) band has just become so crowded. I feel that 15 meters (21 MHz) band is now like 20 m activity used to be, that I need to go to 15 m just to get some breathing room with a simple dipole and 100 Watts. Thanks to the broad frequency band of 10 meters (28.0-29.7 MHz), that band is uncrowded for me–although the G5RV is a poor performer on that band.

I feel I greatly benefit from an excellent ground and rural location yielding very low noise levels. I can hear the spark coil systems of pre-electronic ignition cars and tractors from over 100 meters distance on the higher frequency HF bands.

CB radio with high SSN > 120

On the “freeband” of illegal operations, I hear CB operators clogging frequencies especially from 27.45-27.60 MHz, with spillage up into the 28.0-28.3 MHz band. The CB operators seem to avoid going into the voice band. A healthy high rate CQ call on CW seems to discourage the pirates in the 28.0-28.3 MHz range.

There are also remote broadcast links; WJFP on 26.47 MHz FM from Fort Pierce, Florida booms in with huge signal strength.

As far as legal CB radio use, it has become difficult to talk 5 km on AM from base station to base station during most days. Only SSB is usable and one turns the RF gain all the way down to make it tolerable.

GMRS 462 MHz transition from CB 27 MHz

We have turned to GMRS (462 MHz citizen’s band) in place of an extensive SSB system for family and friends. There is a lot of UHF crystal controlled equipment coming up on eBay for the price of crystals, 25+ Watt radios in great working condition. We use analog tone CTCSS to make it simpler with old non-Motorola equipment. However with fluctuations in temperature and great UHF antennas up high, we have had occasional tropospheric ducting from over 400 km away on GMRS! I made sure to train family/friends on keeping the monitor (CSQ RX) switch “off” when not in a conversation, which eliminated 98% of the issue.

GMRS Base to mobile Range: 50 km with 25 Watt radios and 15 meter high omni base antenna.

GMRS Mobile to mobile range: 10-20 km with 25 Watt radios and collinear high gain omni mobile antennas. This is in wide open farm areas with gentle elevation (the 20 km range situation was benefiting from a 10-20 meter terrain elevation advantage).

GMRS Base to FRS portable range: 15 km with cheapo but well-performing FRS portable and 15 meter high omni base antenna. That was done with some effort (walking around to find the best spot outdoors with the FRS in flat open area).

Path modeling

On 15 meters, NEC2 shows the radiation elevation peak of the G5RV to be all over the place w.r.t. azimuth. I.e. the contact would be completely implausible for certain azimuths if the model holds. I have an unusual feed arrangement that I haven’t modeled, as well as some wiring in the barn that could be broadening and/or lowering the radiation angle. One could essentially figure out what the radiation angle must have been using an assumption for virtual height and a 2-hop path.

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