The remote base is currently working 100 per cent as designed and one could be very happy with it for a long time. However three concerns have surfaced in the first full week of operation. These concerns could just be kept in the back of one’s mind and not acted upon or a timetable could be set up for upgrades. After all this is the main station now. Here is the list of concerns starting with one that has already been blogged about.
The 20 meter antenna is weak. It is an inverted vee with the apex at 39 feet. It’s model shows a gain of 4dBi over average ground at 15 degrees take off angle. It’s signal gets beaten out by almost any other station in a head to head contest to work a DX station. First item on the wish list is a better antenna—higher, more gain at 15 degrees. A hex beam might be a good solution. (Cost, $500)
Next concern is one that was discovered last night when trying to work Iran, EP2A, on 40 meters CW. It is a rare country and there was a huge pileup last night for the current dxpedition. The receiver on the Kenwood TS-480 was hopelessly swamped by the strong signals of the pileup overpowering the puny front end with it’s poor dynamic range. It was a little spooky in the sense that the receiver was tuned to 7.019 MHz but there was no static, no background noise, no EP2A signal. It was as if a large attenuation had been inserted in the coax. It was very very quiet. Disabling AGC made no difference. Front end overload completely shut down the receiver. That was caused by the strong pileup signals. Rob Sherwood’s receiver test web page (sherweng.com) shows the TS-480 has a dynamic range of 72 dB at 2kHz. For comparison an Elecraft K3 has a dynamic range of 101 dB, roughly 1000 times better (30dB). The Kenwood is ok for JT65 because even when there are pileups the signals are never extremely strong. For serious DX chasing with incredibly strong pileups the TS-480 just doesn’t cut it. Second item on the wish list is a replacement transceiver. An Elecraft K3 might be a good solution. (Cost, $800 for a K3-zero [already have a K3 ]).
Third concern on the wish list is more battery reserve. Once the sun quits powering the solar panel the station can run on it’s batteries for approximately two hours before discharging to 50 per cent. Then the station needs to be shut down for the night to avoid shortening the life of the batteries. Calculations for battery reserve had been only a guesstimate. It’s clear more is needed. The panels on the other hand seem to be very adequate because the batteries are typically recharged by mid morning each day. Third item on the wish list is to double the battery capacity. Two more Walmart group 29 marine batteries should be a good solution. (Cost, $200)
Total estimated cost, $1500. Next wish: wish there was an extra $1500 hanging around.
May 12, 2016 Update to each item – Batteries are doing ok if the system isn’t allowed to run all the time. There is plenty of operating time available as is. (I went ahead and added a third deep cycle marine battery in June.)
As for receiver overload it doesn’t happen with the JT modes, just DXpeditions on CW. Those are infrequent. Never the less the remote software for the IC-7300 is on order and should allow using the IC-7300 at the site if that becomes more necessary. ( When I tested it the remote software worked ok for CW and SSB but was a total failure for digital. The remote congested the data channel and the digital signals we choppy.)
And finally the 20 meter antenna upgrade has been given some more thought. See the separate new post with the full story. (I put the phased verticals on hold when I got the second remote base working for 20 meters.)