Welcome to the Jarvis 2024 DXpedition | N5J

K8R is now on the air testing SuperFox, antennas and equipment ahead of the real thing in August.

This is our last chance to get everything right. A RIB DXpedition is different than a traditional one where you can fix and move things around on the fly. With us, once equipment is on the island, it is very hard change things or fix what is not working. Our plan is to get every station and antenna working here, and put it all back on the RIB boat as is, hoisted it up onto Magnet, ready to be launched at Jarvis.

The K8R test set-up is on a narrow beach on the north side of Tutuila Island, which is the main island of American Samoa. The beach is a private beach (Gurr Private Beach at Maloata) where the owner was gracious enough to allow us to set up and operate. This is an ideal location for a small DXpedition from a remote but still easily reached place. Take off to the north is over water. But for us, the beach is too small, as eventually we plan to have seven stations and 8 antennas.

We have now four stations operational. Three of these stations are remote controlled and one is local. Because the beach is small, our antennas are close to each other, but so far our filters seem to be working.

We have been slow to get up to speed due to the almost constant heavy rains of the past five days. Finally today (Thursday), we had a partially dry day and were able to get some work done. We will be on the  air as much as we can and all signal reports will be much appreciated. TKS and 73, George, AA7JV

We have completed our testing of the low band Jarvis Special antenna. Operating as FW7JV, a total of 800 QSO-s were made. Unfortunately, we had to go QRT early as we need to move onto American Samoa and there is a narrow WX window to catch. Many thanks to all who called and those who sent singal reports and analysis of our signals. They were extremely helpful as we were making daily changes to the antenna. (You can get only so far with antenna modelling.) A 45 foot tall 160 meter antenna is difficult under any circumstances. Normally, we stand our antennas in salt-water which gives them an almost perfect ground. When you have a very good ground, you get away with a lot of shortcomings (like low radiation resistance, verr low feed-point impedance, etc.). Unfortunately on Jarvis, because of the powerful surf in the lagoon, we wont be able to stand the antennas in the water. Instead, we will locate them at on the beach at the high-tide line and run wires to aluminum ground posts in the water. This was the configuration we've tested at FW7JV, and after four days of experimenting, we got satisfactory performance on 160, 80 and 40 meters.

We got permission to set up on Nukuhione tomorrow morning. We hope to be on the air tomorrow afternoon (June 25, 0200 UTC), and then move to 160 meters around 0600.

Nukuhione is a small, uninhabited cay on the NE side of the atoll that surrounds Wallis Island. It has a long sandbar that looks ideal for antennas.

Starting on June 25 we will be testing new antennas from Wallis Island (FW), operating as FW7JV. This will be a realistic test using RIB-s and antennas mounted on a sand-bar in a situation very similar to what we will have on Jarvis Island during the upcoming N5J Jarvis operation. (I will be going ashore this afternoon to see the village chief with a bottle of scotch, trying to get permission to set up on small cay nearby. Fingers crossed.)

The most important test will be of the new 160 - 10 meter vertical. This is a 45' tall -- I should say, 45' short -- vertical without top loading wires. The low height is mandated by the US FWS, written into our Special Use Permit. Further, our permit specifically states that any time our antennas cause harm to birds, the FWS representative on site will shut us down. Therefore we are making sure that the antennas are as bird-friendly as possible. From experience on Ducie and Cook Islands (VP6A and E51D) we know that vertical masts of some diameter are easily seen by birds and avoided, even at night. Horizontal or sloping wires, however, especially when high, even with streamers can be hit by birds. Another danger posed by high wires is that birds want land on them and wire can easily twist around their legs, trapping them. Therefore the new antenna does not have any top loading wires. Instead, we have a large 34 micro Henry inductor at the base of the antenna that brings this short antenna closer to resonance, with a feed point impedance that is within the tuning range of the base mounted antenna coupler. This is a serious compromise because losses in the inductor can be substantial. Hence the detailed testing we have been doing since T32JV in May and now on Wallis.

For details see the ANTENNAS tab. 

160 m Operation from Wallis:

FW7JV will be on 160 meters CW starting at local SS around 0600 UTC and again at 0900 for NA SR, as well as at local SR at 1700. We need actual signal reports to get an idea of how the new antenna is working. Wallis is about 1400 miles further SW from NA than Jarvis. If you can work us from here you can be pretty sure that you can get into the N5J log in August. (Note that while Jarvis is only #75 on TB, FW is #28 according to Clublog.)