I worked the 2023 CQ WPX contest this weekend as single operator QRP. I used the EFHW vertical beam on 15m and 10m with some activity on 40m and 20m using the S9V31 vertical. I started with the beam pointed just East of North on 15m. Propagation conditions were interesting as we had just come off a strong geomagnetic storm. 20M was very noisy and it seems that most activity was centered around 15m and 10m which fell in line quite nicely with my antenna plans. I worked QRP on this contest ion 2019 and 2020 and closed about 50 QSO’s with scored just under 5,000. This weekend I worked 106 stations across 26 countries and 86 unique prefixes for a claimed score of 15,824. Here are some charts regarding the contest performance:
Most all of the contacts were made on 15m and 10m. I would point the antenna East of North early in the day and then switch to more Southerly and then more Westerly directions during the course of the day. Changes take less than 5 minutes to implement. I think that the antenna is a winner. There are just a few improvements I’d like to make:
Replace the hysical links with traps to simplify band changes.
Pre-deploy additional mast stakes to simplify moving the reflector element.
See if I can replace the adjustable matchbox with a fixed one for operation only on 15m and 10m bands.
Predicated gain is about 4dBi which is considerably better than a plain vertical and provides good low level radiation. I tested directionality by switching between the S9V31 vertical on stations facing away from the beam. I should note that trying to make contacts with just the vertical was difficult. This antenna might end up being an interesting choice for field day this year as domestic contacts were not difficult to close.
I did not have time to get the traps built for the 2-band EFHW vertical beam antenna before the start of the 2023 CQ WPX contest. I instead made this a linked antenna with a slightly longer 10m element. Both 10m and 15m show directionality howver the EFHW matchbox could not achieve a perfect match on 10m. It was close enough to use the antenna tuner to bring it to a match without difficulty. This is a good antenna for use when some level of gain and front to back rejection is needed. It is simple to setup for portable operation and only needs a 6.5 foot radius and no radials for operation.
Improving this antenna will require the use of the traps to prevent having to take the whole thing down to change bands. I am also exploring how to best match this preferably with a dedicated 2-band matchbox that does not require adjustments. Changing direction can be facilitated by adding a couple of additional mounting stakes at the desired bearings. It is fairly easy and quick to move the reflector element to a new position without taking the whole thing down.
I used this antenna this weekend on the CQ WPX contest with very good results running QRP. More on that on an upcoming post.
With band conditions improving on 10m & 15m I am thinking on how to improve antenna gain in a portable antenna for those bands. The Moxon for 15m works great but is tricky to setup on the Spiderpole. Full or shortened Yagi’s have the same issue. Inverted-V Wire beams can get messy to setup as they need two support poles and tie off on the ends plus they are hard to rotate.
I am now looking at the vertical beam as a compromise between gain and portability. A 1/4 wave vertical beam works well for a single band but does require radials. This makes it difficult to relocate a reflector or director to re-aim. I have been looking now at the EFHW antenna. In its basic form this is a 1/2 wavelength of wire on a specific band that is end fed through a matchbox for tuning. Band changes require a new wire length for a specific band but can be accomplished using links. This antenna has shown to be a proven performer by itself. What I am looking at now is to replace the links with a trap so that the entire antenna does not have to be brought down for a band change. There may be a way to replace the variable match with a fixed one as I am looking to match high impedance on only 10m and 15m. A counterpoise of about 1m is needed along with a 1:1 choke at the feedpoint.
This forms my driven vertical element.
Now to form a vertical beam I use the same trap for 10m and cut matching parasitic wires. I have the separation between the elements at .13 wavelength at 15m but fix that for both 15m and 10m. This promises about 4dbi gain in the forward direction. Changing direction is super simple in that the parasitic element only needs to be relocated with no radials to contend with. Here is some modeling of this antenna on 15m:
Here is the predicted performance on 10m:
This antenna shows some nice low angle gain which will be handy for DX. I recently tested the 15m mono and version and certainly noticed the directionality. I’ll start working on a trap for this and hopefully try out this weekend.
There were many personal factors that kept me from running competitively on the ARRL DX SSB contest this last weekend. I had intended to run this with either the 15m Moxon or the EFHW vertical beam but I just did not have the time to deploy either. I did not have an opportunity to operate the contest until nearly noon on Sunday.
Weather here was nice so I opted to take out the IC-705 with the JPC-12 antenna and setup for QRP “field day” style. Working 10m & 15m I managed 10 DX QSO’s in about an hour and a half. The contacts I did complete were done without difficulty. Furthest contacts were to Canary Islands and Argentina. 10m appeared to be the better band during this time.
I submitted my log as QRP non-assisted. All in all, I was glad to get outside with the radio and enjoy making some QRP DX.
Adventures in Amateur Radio 