80 Mtr Vertical Performance

I wondered if my 80 mtr top loaded vertical is a good antenna for the Bruce Kelley Memorial 1929 CW QSO Party. Part of the loading is the top 6' of two of the guys. Any sway at all causes a guy to sag a little shifting the load my Hartley sees. This causes my signal to FM/wobble...distracting to say to least and aggravating if the band is crowded. I needed to know if the gain offered by the vertical over my endfed wire was enough to outweigh the the wobble it introduced.

The reverse beacon network at http://www.reversebeacon.net/ allowed me to get a good idea of real antenna performance. All I had to do is call CQ and any reverse beacon stations hearing me automatically posts my call, frequency and signal strength to the web. By switching between my low endfed wire and my vertical I could get a good A vs B comparison. By doing this over a period of time I could see how changing nighttime propagation impacts this comparison. Monday night I did exactly this and then sorted though the data to see how the two antennas compare from about 8PM (2:00 UTC) through the next morning.

What I found was that for the east coast (PA) the vertical offered 8-10 dB gain throughout the night. While not always a spectacular performer it is almost always better than my endfed wire...but signal reports all mention the wobble/FMing introduced by antenna sway. Based on this I'll stick with my endfed wire for the early evening hours and then switch after about 10PM when the band activity dies down a little.

For next year's Bruce Kelley QSO Party it would be nice to have this problem solved by building a '29 style amplifier to use with my Hartley. Fortunately my 1934 transmitter already has an amplifier stage in between the oscillator and the antenna. My vertical will work fine with this transmitter during the AWA Linc Cundall Memorial CW Contest in January.

More 80 Meter Vertical

Yesterday I did the final pruning on my 80/40 meter vertical.

This antenna is a big improvement over my 105' endfed wire. Last night on 80 CW running only about 10 watts I worked KK1K (VT), VE7SL (BC) and VE3AWA (ONT). All gave me good signal reports and had no trouble with the QSOs. In addition VE7SL reported I went from s6-s7 to unreadable when switching back to the endfed wire. VE3AWA reported that I went from s9 plus to s8 when switching to the endfed wire.

I also checked my antenna performance used the Reverse Beacon Network at http://www.reversebeacon.net .This is a network of receivers/computers connected to the internet. They auto log the frequency and signal level of any CQs heard. By calling CQ using both the vertical and the endfed wire I got a good idea on how the two antennas compare. The network consistently logged me when I used the vertical and never heard me when I used the endfed wire. At the locations on the Reverse Beacon Network, the vertical was the clear winner. But there were no reverse beacon stations in MN, WI or IA. My endfed wire might have done better if evaluated using nearby reverse beacon stations locations.

I was asked about my radial system. I have eight 30' insulated wire radials stapled in the grass. 30' seems short, I expected to need 67' (1/4 wave on 80) long radials. I measured the resonant frequency of the radial system as I would an 8 element fan dipole with two 4 element halves. 30' seemed to be right. Velocity factor must have a big impact on the length of ground mounted radials.

This new vertical should definitely help my AWA QSO Party scores.

More 80 Meter Vertical

Beth has commented that I need to get a "Frequent Buyer" card for my local big box hardware store. Since starting on this project I've been making trip after trip to buy yet one more bunch of screws, a particular clamp, a spool of wire, a ..... the list goes on. For a project that started with a $7 set of fiberglass poles this one certainly is a great example of "the devil's in the details".

I'm finally to the point of pruning it to frequency. Along the way I've fashioned a hinged base out of a large gate hinge and two conduit hangers, I've added 40 meter capability and I've made the bottom 23' a four wire vertical cage. Top loading is provided by two 6' elements forming the top ends of two of the guys, a coil wound out of 14 gauge insulated wire on a piece of 4" thin wall PVC sewer pile and a vertical 6' element. 40 meter coverage is provided by a 9' stub (connected directly to the top of the 23' vertical cage below the coil) that makes up the top of the third guy. Additional support is provided by tying the mast to my deck railing at approximately the 9' level.

Normally this will be a winter installation. I plan to paint the mast white.

Actual on the air reports will need to wait until I finish tuning it to 3560KHz.

80 meter vertical

As I look forward to cooler weather I've starting to think about 80 meters. With the winter months 80 becomes quieter and a better band for "DX". 80 is also to best band for my 1929 transmitters. I'd like to put up a better 80 meter antenna. Right now my endfed wire is only 10'-15' off the ground. If works OK for Minnesota but not much else beyond that. The radiation angle is too high. My backyard was too recently a corn field. Nothing back there is tall enough to support a higher dipole or end fed wire.

I'm going to start with a 30' to 35' 80 meter center loaded vertical and maybe even top load it a little. For a mast I'm going to try some of the fiberglass camouflage netting support poles / antenna masts seen on ebay these days. AI4WM has a good article on the web describing these poles . I found some with the fiberglass reinforcing ring on ebay fairly cheap. A trip to my local big box hardware store resulted in several "attachments pictured:

1. 1.5" Conduit Hanger - This allows me to attach coils, pulleys, etc to a mast or they can be used to attach to mast to something else (like a fence or a post).
   



2. 1.25" PVC Cross - This fits nicely over the top/male end of the mast.
   
   
   



3. 2" x 1.5" PVC Reducer - This I found in the electrical department. With a little drilling to add a few wire loops I should be able to use this to attach guys
   



4. 1.25" PVC Plug - This goes in the top (when mounted) arm of the PVC cross. It will give me a place to add a 6' whip above the top fiberglass mast.