Month: December 2014
Welcome back, readers! It’s been almost half a year since I last penned some radio notes for you to go over, and it’s been a busy year! We’re almost on the doorstep of the winter holidays, and I’m looking forward to a wonderful Christmas season this year. At KK4TSJ, we’re settled it at our new station and getting comfortable with HF and VHF operation.
I wrapped up the first version of the KK4TSJ HF/VHF base station on July 4th, 2014. I’ve got a Yaesu FT-897D with an integrated LDG AT-897Plus as the primary transceiver and a Tigertronics Signalink USB audio coupled sound card modem to integrate with Flrig/Fldig/Flmsg and other ham software. I’m still relatively inexperienced with digital radio modes, but I have had some success decoding CW and PSK31 on the 40 meter, 30 meter, and 20 meter bands so far. One day I’ll learn to copy CW by ear, but atleast I have a tool to fulfill that use case for me in the meantime.
The radio is solid, and it’s taken some work to get the station in a station that I’m getting more than static, and it has definitely been worth every hour of effort. Much more can be done, but I’m beginning to understand that maintaining a radio shack is like maintaining a vehicle and requires constant attention and maintenance and attention to detail. It is remarkable that I now have the capability of communicating with people worldwide thousands of miles away, and I never cease to be amazed by that fact!
I won the FT-897D on an eBay auction from a gentleman from California, and it came with many frequencies with calls from the San Francisco, Palo Alto, and Stanford areas. I saved a copy of the original channel programming with the memory clone mode in Chirp and began to program my Georgia frequencies. I have since found that the CAT (computer aided transceiver) support in hamlib (what Flrig et all make heavy use of) is lacking in a few areas, but it’s perfectly workable. The CAT SWR meter read out is very coarse, but there does appear to be some unpublished specifications of the Yaesu SWR meter reading message that aren’t fully implemented in hamlib that could be added. I haven’t had the spare time to code in support or understand hamlib well enough to add it, but I hope to change that circumstance over the coming holidays.
Well, the interior of the shack is only half the equation! Every ham worth his bacon knows that your radio doesn’t work without an antenna. From GoVerticalUSA, I picked up some four foot military surplus green aluminum mast sections from, a ground stake and plate, some vent mount mast clamps, guy rings, rope, and lots of coaxial feed line. This part was definitely the most difficult, and I had to erect the mast with only 10 of the 12 sections to be able to mount it stably with the HF antenna hanging off the side. The Wireman has some better ladder line standoffs, but I didn’t have the time to get an order out before I wanted to raise the mast, so I made some standoffs from 1/2″ schedule 40 PVC sections with u-bolts from the local hardware store to get it going quickly. I didn’t have a decent ferrite bead for the feed line, either, so I just coiled up a quick ugly balun.
I’m noticing that the compromise for the ugly balun narrows my bandwidth on the 70 centimeter band quite a bit to the point that the band edges trigger the transceiver’s high SWR power fold-back circuitry. I doubt that would happen with a basic 0.5″ diameter mix 43 ferrite bead in the same place. The lack of decent ladder line standoffs (or an HF antenna hung from a tree instead) tends to pull on the mast in the direction of the ladder line.
The VHF/UHF antenna on the top is a Comet GP-3, and it’s a 5/8 wave 2 meter antenna on top of a 1/4 wave 2 meter antenna. It works on UHF, but not very well, but I can get the MATPARC and W4QO UHF repeaters near me just fine. As for VHF, it is superb and I’ve been able to work simplex with Archie, KK4EQB, on 2 meters from Smyrna, GA to College Park, GA and able to hear each other almost like we’re on the same repeater. I am easily able to get into my closet local repeaters on the lowest power setting at almost full quieting. Ones further out need more power, but I’ve got a radius of almost 50 miles that I can easily operate.
The HF antenna is a G5RV/ZS6BKW multiband doublet fed with a 1:1 current balun on a no-brand toroid. After putting it up, I think the toroid is rated for power transformers and likely performs poorly, but it’s coming down next time I work on the setup. It gets me out and gets me heard, but it’s not what I’m going to use for a long term HF setup. I look at it as a stepping stone to get me on the air somehow, and I definitely learned a lot of lessons that are only learned from experience. My next HF setup will be a significant improvement over the present one!
Interior Feed Panel
On the interior of the house, I cut into the drywall with a keyhole saw and pulled out some minor amount of insulation to make space for cables and fittings. I picked up a 3 gang mud ring and a blank electrical face plate from the local hardware store. I drilled some holes out of the blank for bulkhead connectors and ground strap and routed some short RG-8x patch cables inside to the external bulkhead connectors. I know that some bulkhead connectors are long enough to go through the entire wall, but that’s not what I wanted to do.
On the exterior of the house, I mounted a DIY fabricated aluminum grounding plate on the exterior fascia of my basement wall. It’s 1/8″ thick aluminum plating that I cut down with a metal cutting blade on the table saw. Lacking an angle grinder, I smoothed the cutting edge down as much as I could with coarse grit sandpaper and block as well as some metal files on hand. I drilled out the holes with the drill press and a step drill bit. If you intend to drill into metal plating in this manner, support it with a wood block to prevent the bit from bending and creasing the plate.
As for performance, all of this has been completely worth the effort! I have a much better VHF installation, and I’ve got HF capabilities. I’m not satisfied with the HF quality, but it’s functional and is much like my prior VHF setup was before this one. However, I cannot complain too much! I have been able to hit the West coast, up and down the East coast, and Europe. I’ve received Africa, Asian, South America, and it’s incredibly interesting to practice receiving HF on single sideband as well as AM. The setup does seem to pick up some local HF stations, but seems better at DX and skip in a North-South pattern. The next setup will have an East-West pattern from the start of the plan! NC4FB has a much better write up on this particular antenna than my efforts will do, and you can find that at http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/ to see an analysis of the theory, dimensions, construction, and SWR plots of various bands through this antenna.
Well, this post has taken almost 6 months in the writing just the same as the station took almost 6 months in the making. It’s been fun and I’ve got more projects in the pipeline, so stay tuned for more updates!
YIS ES 73 DE KK4TSJ