Well, its been a while since I’ve been able to play radio, however, a few changes have been made. For starters, I upgraded my Linux netbook to Ubuntu 12.04 (touch pad was freezing on me in previous version). Unfortunately, the upgrade had disastrous results for my radio platform. For the time being, I have reinstalled Windows 7 on the netbook and in the future I will likely dual-boot.
Temporary antenna installation
The other notable changes have been with my FJ Cruiser installation. When I installed the FT-857D, I used two cables with PL-259 connectors on one end (radio side) and Larsen NMO mounts (on the antenna side). Initially, I had only intended to use one of the NMO mounts at a time for VHF/UHF work – I was going to try each location to see how well they worked versus the other. As it turns out, I never really used the location (shown in the photo to the right) since it would require installation and removal of the antenna(s) every time I went to park underground.
NMO rain cover
I ended up capping the mount with a plastic rain cover that I picked up at a radio shop in Durham for $3. The lower antenna section that I made a bracket for has a 1/4-wave whip for 2m permanently mounted to it (with the option of swapping it out for a 5/8-whip).
NMO to SO-239 adapter
This past week, I finally decided that I would re-think my HF installation and that I would use the NMO-to-SO-239 adapter I picked up at the same time as the rain covers. The idea was that I would use the adapter to connect my HF antennas via the permanently installed antenna mount. To prevent feedline losses, I decided that I would shorten the cable on the NMO mount.
Common mode choke (aka. ugly balun)
As I had never actually installed a PL-259 connector before, I was a bit hesitant. I decided the best thing would be to do a practice connector on my current mode choke (ugly balun) to get a feel for the process.
The wire was many feet too long, so I placed the choke in the furthest mounting location from the NMO mount and marked the cable for cutting. The installation of the PL-259 was very straightforward and went fairly well (in my estimation). There was no continuity between the shield and the core (good thing!) and everything checked out in terms of visual inspection.
Eager to replicate my success with installing a PL-259 on some RG-8X, I turned my attention to the smaller RG-58/U. This one was definitely more difficult as there was much less braided shielding to work with, however, the connector was soon installed and tested fine.
ATAS-120A HF antenna
With the cable cut down to the appropriate size, I was excited to test the setup with my ATAS-120A HF antenna. I conected the NMO-to-SO-239 connector and a 3′ patch cable with the antenna on the other end. I fired up the radio and hit the tune button and … nothing! Knowing that the antenna used DC injected on the coax to extend and retract, I immediately suspected that there was a break (ie. open) in the signal path. After a bit of investigating, I turned out that the NMO-to-SO-239 adapter was the culprit.
Inside the adapter, there is a ring that connected the outer body to the threaded portion of the SO-239. The ring was not making electrical contact with the outer body and thus, the open circuit. Using this adapter would have been very bad (and frustrating) had this defect not be found.
With the adapter repaired, all was well with the modified installation.
I also bit the bullet and mounted the detachable face-plate of the FT-857D to the dash of the FJ using the plexi-glass bracket I hastily cut and bent while testing potential mounting locations. In the future, I will likely end up changing the bracket out for something which offers a more sturdy mount (the face-plate tends to bounce a tad at the moment). For now, the installation is good enough considering I had been simply leaving the face-plate in a cup-holder as an interim solution.
… more to come!