Saturday, April 29, 2006
Got the Appalachian Trail dipole put together. I used an MFJ 33' fiberglass pole to hang it up on. That put the feedpoint roughly 30' off the ground. I had the legs in a rough "inverted vee" configuration. The end insulators were about 6 feet off the ground.
The first attempt was resonant with an SWR of 1.3:1 at 6.8 MHz.
I shortened it up another 1.5 ft and got really reasonable results.
Here is the SWR curve. The Y-Axis is SWR with 1.0 at the bottom and 0.2 unit intervals.
Since my three main operating frequencies on 40m are 7.060 and 7.250 and 7.2685 MHz that should work just peachy.
I called CQ both CW and SSB but nobody came back. Answered a CW from W7WE but he didn't hear me. Finally asked for a signal report from a group that had just broken up. Jim, K6SEK came back and gave me a 56 or a 57.
Jim is exotic DX. Aptos, CA. All of 20 miles away. Hi hi!
I'll have lessons learned from tuning and using the Appalachian Dipole later this evening...
The first attempt was resonant with an SWR of 1.3:1 at 6.8 MHz.
I shortened it up another 1.5 ft and got really reasonable results.
Here is the SWR curve. The Y-Axis is SWR with 1.0 at the bottom and 0.2 unit intervals.
Since my three main operating frequencies on 40m are 7.060 and 7.250 and 7.2685 MHz that should work just peachy.
I called CQ both CW and SSB but nobody came back. Answered a CW from W7WE but he didn't hear me. Finally asked for a signal report from a group that had just broken up. Jim, K6SEK came back and gave me a 56 or a 57.
Jim is exotic DX. Aptos, CA. All of 20 miles away. Hi hi!
I'll have lessons learned from tuning and using the Appalachian Dipole later this evening...
- Top segment: Weight supported
- Top segment: Ring Guage
- MFJ Pole: Coax supported vs free
- MFJ Pole: "Coming down!"
- Yaesu FT-817 "SWR meter":
The top segment of the MFJ pole is about as thick as the tip of a fishing rod. It really won't support weight. It also flexes... A lot. I wound up not using the top segment. Instead I kept it inside of the second highest one for additional strength. I have absolutely no warm fuzzies that it would support one end of a dipole. The sideways loading would seriously flex it.
The ring at the top of the highest segment is not large enough to pass insulated #14 gauge wire. Or a standard 6 to 8 inche cable tie. I wound up using a length of scrap 26 gauge "stealth wire" to attach the feed point.
Having the coax dangle free also caused the top of the pole to flex. I solved that during the second trial by masking taping the coax to the pole. It helped considerably.
Chuckle. Let's just say that they like to come down on their own. Mine did. Twice. I need to be really anal retentive about pulling them out, then twisting them to make good solid contact. I might even consider some duct tape to keep them from "getting going."
Three segments until power limiting, 1.8-1.9:1 still gives zero segments.
