Tag Archives: WSPR

Completed Linked EFHW

I completed the linked EFHW later yesterday afternoon and tuned the 15m, 17m & 20m bands. I removed about 6″ of wire to tune 15m, 2″ to tune 17m and about 3″ to tune 20m. The antenna is deployed vertically on a SOTAbeams Travel pole up 30 feet. I am using a TV mast tripod as a base. In the field I would lash the mast to a fence post or other similar support.

I tested the antenna on my base rig at 100W and made three easy SSB contacts. Two of these were EU DX contacts. I  left it tuned for 20m and ran WSPR for the last 12 hours. Here is the map:

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This works out to 112 unique heard spots with 66 unique heard by spots when running 1/2W. Looks like the antenna is a winner for Field Day! Only thing I will likely try today is adding a 1:1 choke as I am seeing the SWR swing a bit on SSB transmit.

Some Thoughts On WSPR Data for Antenna Comparisons

I have been keen on using WSPR data to compare the performance of antenna systems. I haven’t worked out a detailed metric but I thought I’d share some thoughts on how the data can be broken down. When looking at 24 hours of WSPR data on a specific band I am seeing the the number of unique stations received is a clear indicator of the antenna’s overall performance and pattern. If this is enough to make the WSPR Challenge board for that period then another clear indicator. As an example, the homebrew Buddipole on 20m (even with resonance being outside the band high) came in at #22 on the WSPR Challenge site with 143 unique stations. I have been hard pressed to make the WSPR Challenge board with the end fed horizontal or the magnetic loop antenna (indoors). So the higher then number the better.

The number of stations hearing me on WSPR is a different story. The ratio of stations heard to stations hearing me is rarely equal. This really depends on the efficiency of the antenna, something that is not evaluated on receive. If I transmit at 1/2W I can expect fewer stations received than if I transmit at say 1W. This will not be a linear increase. What I am seeing is that some antennas have a high count of “heard by” stations for a given power than others. This gives a relative indication of the antenna efficiency. There may be a way to correlate this with a given antenna by testing at different power levels.

 

20m EFHW is Back On The Air!

Lawn maintenance time again and I still haven’t permanently deployed my radials. Took the 40m 1/4 wave down today and picked up the radials.This is a tedious process but not too time consuming. I had the most difficulty in getting the travel mast to retract as it sticks sometimes. Went ahead and setup  and re-tuned the EFHW for 20m as it doesn’t need radials to get hung up in the lawn mower. I am running WSPR as NO5V/1 now to compare against earlier data. I made several USB contacts this afternoon with it. Band conditions were terrible as geomagnetic storms are still raging. The QSB was awful but I did manage to secure a solid 59 into Vancouver.

Next Iteration of the Vertical Antenna – End Fed with Radial Field

I reconfigured the 40m 1/4 wave vertical as and end fed vertical by removing the 1:1 choke balun and installing the 9:1 matchbox as before. One big difference was that I connected the radial field to the ground lug of the matchbox. I have run 24 hours WSPR on 20m with the following results:

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Not bad at all with 132 unique spots thus far (on a fairly bad day of propagation indices). Will try this on other bands soon.

Running 40m 1/4 Wave vertical on 20m

Overall I am very impressed with the 40m performance of the 1/4 wave vertical. For grins I am running 20m WSPR by running through the antenna tuner. The tuner found a match and after only 8 hours had enough unique receives to make the WSPR challenge yesterday. The count is now up to 123 and I expect to be on the board again with a very decent showing. I will continue testing on 17m then over to 80m and 160m. Not expecting much on the low bands but am interested in the results. I am not going to run on 15m because it is resonant on that band as a third harmonic to the 40m primary.  I’ll leave 12m and 10m on the DXxtreme as that antenna has proven itself well on those bands (when they are open).

Update on the 40m 1/4 Wave Vertical

Ran WSPR last night on 40m with the 1/4 wave antenna. Here is the Map as of this morning:

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Started running some JT-65 this morning and while difficult to run pile ups, I am getting QSO’s with JA by calling CQ. On my third one since starting this morning:

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Overall I am very pleased with the performance of this antenna. I’ll be doing some tests on 15m as well although the band has been quiet.

Vertical End Fed Antenna on 40m

The vertical end fed antenna using the 9:1 matchbox and 30 feet of wire has looks like a winner on 40m WSPR. It did not make the WSPR challenge board but has shown a respectable 120 unique contacts and a nice spread of DX stations.The mast has held up nicely with a bit of electrical tape at the joints. Here is the 24-hour WSPR map:

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Busy Week on 20m WSPR

I have been running experiments on various antennas this week on 20m WSPR. NO5V is my current base antenna, the Ultimax DXtreme 53 footer up about 20 feet and horizontal. NO5V/1 is the EFHW tuned for 20m and NO5V/2 is the same wire as the EFHW but run as a non-resonant end fed with a 9:1 matchbox and about 30 feet of coax as counterpoise. I am also able to compare this data with that from N5CEY who is running a 1/4 wave vertical at his QTH about 20 miles from here. I will be looking at formally crunching the data but what is apparent is that the current base antenna is not as sensitive on receive as the vertical antennas. This is based on the WSPR Challenge results and A vs. B listening tests. The verticals are nearly equal in receive capability with the EFHW marginally the best. Both of my verticals compare well with N5CEY’s 1/4 wave vertical but he still seems to have a slightly more sensitive system as he gets better signal reports on WSPR from more DX stations.I plan to setup my own 1/4 wave vertical this week to evaluate before I turn my attention to the S9V31.

I did a quick test on 40m in the NO5V/2 configuration and was getting good 40m results as well.

Testing End Fed on WSPR

I am now testing a variation of the end fed antenna on 20m WSPR. I am using the same length of wire as the EFHW but am now using the 9:1 matchbox. I have 50 ft of coax running to the shack where I am using an autotuner to match. I have an air choke of 6 turns of coax not at the feedpoint but at the shack entrance. This configuration uses the feedline coax as counterpoise.

So far results are very similar to the EFHW but I will wait for two days to collect the final data. Meanwhile, I am going to require the EFHW matchbox to try and get a better match to try again.

Two Days of EFHW 20m WSPR Data

I got the travel mast back up and this time added some electrical tape to help keep it from collapsing. It has been fairly breezy here this week with gusts up to 15 to 20 mph which plays hob with keeping the mast deployed. I am running the 20m EFHW with on WSPR as NO5V/1 with 500mW. I have run this configuration for two full days and made the WSPR challenge list on both days. I am comparing this data with N5CEY which is a nearby station running WSPR recieve only with a 1/4 wave vertical. Here are the results:

2/27/17 – #46 with 116 unique stations recieved vs. N5CEY at #42 with 121 unique stations

2/28/17 – #46 with 122 unique stations recieved vs. N5CEY at #40 with 130 unique stations

I should note that the mast partially collapsed about 4-6 hours before 00:00 UTC on the last day and I lost about 6 feet of mast height. There did not seem to be much of a difference in performance with WSPR. When mapped N5CEY is clearing getting more DX spots. This is interesting because a 1/2 antenna should do better at lower angles than a 1/4 antenna. I suspect that I have some losses with the EFHW matchbox in terms of lossy wiring which I am going to address today and then retry