2010 AWA Bruce Kelley QSO Party

The last two weekends I participated in the AWA Bruce Kelley QSO. Except for curious visitors, transmitters must be limited to 1929 (or earlier) designs and not crystal controlled.

This year I used my Hull Hartley at 10 watts input and a Drake 2B receiver. The change from last year was having a 80 mtr vertical available rather than a simple end fed wire. Unfortunately SE MN was under a blizzard warning for most of the first weekend of the party and I was busy elsewhere for most of the second weekend. Self excited oscillators like the Hull Hartley are prone to frequency wobble whenever the antenna load changes. My vertical swaying in the blizzard wind was too much for it. Rather than wobble all over the band I again used my 105' end fed inverted "L".

Even with only 3 watts out to a low (10' -15' off the ground) antenna I made 11 contacts and worked both east and west coasts. I had a good time.

Maybe next year I'll have an amplifier for my Hartley so that I can use the vertical (with the sway) and run closer to 6-7 watts out.

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.
   

More C-Pole Vertical Array

After building/using my two C-Pole array I'm starting to rethink my plan.

KF2YN's C-Pole vertical array design calls for dedicated C-Poles (each pruned to have a 25 ohm input impedance) and phasing lines that both transform the antenna impedance to 100 ohms and set the phase delay between the two antennas. On the surface this looks doable but I've a lot of concern about getting the phasing lines right. W8WWV's measurements showed about a 4% delta as he measured the electrical length of a 17.1' long piece of coax. Also, I don't want to dedicate two C-Poles to an antenna that I won't be using much.

A local friend of mine wants to build a self supporting C-Pole antenna like mine. I can feed two verticals with arbitrary (but equal) lengths of coax and a simple Tee connector at the antenna tuner to make up for the 25 ohm combined feed impedance...no need to worry about electrical lengths. In addition, self supporting antennas can be positioned anywhere to point my signal where I want it to go that day. I can even boost the gain a little (up to 4.8 dB) by separating the antennas 5/8 wavelength.

It's still August, I should have another couple of months of outside weather here in Minnesota.

A Two C-Pole Steerable Array

Yesterday I finally got my two C-Pole phased array up and on the air. In fact, after tuning it a little I easily made two QRP contacts, one with N2UGB in NY and the other with CT4RL/1 in Portugal.

My journey from idea to an antenna was based on Chapter 13.3, "A Steerable C-Pole Array" in Brian Cake's book, "Antenna Designer's Notebook". Here Brian presented a design based on phased array theory and modeling. Brian was not aware of anyone that had actually built one.

The C-Poles themselves are made from Radio Shack 18 gauge stranded hookup wire. 1/2" PVC pipe is used for the top and bottom 40" spreaders. For easy supporting, the two C-Poles are in the same plane and aligned with the rope joining the two antennas. The upper inside corners of the antennas are connected by a 33.5' length of rope. This insures correct spacing. Support ropes are tied to the two top outside corners. Instead of a relay I used a coax T connector. L3 was added/removed as needed to change the radiation pattern.

Without L3 the array is endfire and, according to Brian's modeling, good for 1.18dBi gain. By adding L3 into the short/L2 side both sides become 3/4 wavelength long and the array has 3.5 dBi gain broadside.

I learned a little along the way about...

• Baluns and phasing lines...The phasing lengths include the phase delay introduced by the required choke baluns. I had planned to use air core baluns consisting of RG-8X wound around 4" plastic coffee "cans". What I found was that each balun takes about 1/4 wavelength (electrically) of coax. By the time I added the baluns to L1 and L2 in the accompanying diagram I couldn't separate the antenna by a physical half wave. I was forced to use more expensive ferrite toroid baluns that require less coax.
• Adding/removing L3...The switch/relay proposed by Brian in his design introduced its own challenges. The relay/switch is part of the phasing network. I found that my DPDT toggle switch with the needed connectors introduced more phase delay to the point that I was again in trouble with the physical separation of the two antennas. I eventually used a T connector instead.
• Supports...Finding trees with the right separation, orientation, height and limb placement can be a problem...especially for a temporary installation in the park.
• Measuring the electrical length of coax...My MFJ Antenna Analyzer gave a broad X=0 reading. My grip dip meter gave a sharp dip but not on the same frequency as the MFJ (The ARRL Antenna Book recommends against using a dip meter). Eventually I averaged the two MFJ endpoint/X=0 readings to get a center/single frequency and then calculated the coax electrical length based on that frequency.
• Gain...1 to 3.5 dBi of gain is hard to notice when asking for signal strength comparisons under real band conditions.
  

This antenna array may be a good alternative for someone with properly located supports but my typical picnic table operating style doesn't always allow that. This was as interesting exercise but I'll probably keep using my single C-Pole when I'm at the park.

QRP operating at Myre-Big Lake State Park

This last weekend Beth and I took our camper trailer to Myre-Big Lake State Park near Albert Lea, MN. I had along my K1 and Crappie Pole 20 mtr C-Pole vertical.

As expected the C-Pole antenna worked well. Over the weekend I had 11 contacts including WA3SLN (PA), K4SPO (KY), K3WWP (PA), AF4O (TN), WB2PEF (NY), VA3RKM (ONT), WB6OJB (CA),WB4KLI (KY), WD9F (IL), W2IQK (NY) and W9LD (WA). I also started a QSO with AB7KT (NV) but that QSO was as victim of QSB/QRM/QRN.

Charles, K1ETU, from Oneonta, NY, spotted me and stopped by for an enjoyable "eyeball QSO". Bill, a camper from Louisville, KY, also stopped by bringing his two sons. Bill has been interested in ham radio since a teenager but had never gotten a license. Now he's thinking of locating a Louisville Radio Club and working on getting his ticket.

The crappie pole frame for my C-Pole really stands out in a campground. It looks like some sort of tall skinny game target or goal. Lots of campers noticed it as they walked or drove by, some asked about it. My favorite comment: "I've never seen a camping accessory like that before".

More W0VLZ Operating

Strong signals are few and far between here at the Shady Creek Resort but I'm still been able to make contacts using my K1 running five watts into my Crappie Pole C-Pole antenna.

My surprise contact yesterday was EA6UN on the Balearic Islands off the coast of Spain in the western Mediterranean Sea. That's over 4600 miles on my five watts. I found Jurek calling CQ on 14.050 MHz with no responses. He came right back to me and gave a 579 report. Today's QSOs have all been to the west...WB6HGJ (CA), W7LPV (AZ) and N6IV (CA).

W0VLZ Operating

I have almost a week to kick back at a lake resort here in north central Minnesota. As usual I have my K1 along. In the past I would have made use of a tree as an antenna support for my end fed 67' wire antenna. This time I'm using my Crappie Pole C-Pole antenna.

Conditions have been marginal at best with strong signals few and far between and QSB the order of the day. Daily operating has been rewarded by a few contacts....VE3FIT (Toronto, ON), N3EIN (Coatesville, PA) and
W9FHA (Evansville, IN). Another contact, with K9WWT in Merrillville, IN, was a victim of QSB. My signal went from 589 to unreadable in the length of George's initial transmission.