Tag Archives: WSPR Challenge

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.

 

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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).

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:

2017-03-15_9-20-24

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

20m EFHW Vertical Revisited

Back in December, I setup the 20m EFHW antenna up as a 20m vertical and was able to make enough unique receive contacts to make the WSPR Challenge board.I have not since reproduced this performance. Today I started from scratch in a way. I first checked the matchbox I had built previously and confirmed the capacitor setting for 20m. This was dead on as before with a 3.9k Ohm resistor. Next up I replaced the 20 gauge wire with 16 gauge. This required about 30.5 feet to start out with . I setup the travel mast and the wire and then pruned it to resonance on the 20m capacitor position. I wired it up and immediately started seeing good performance on SSB compared to the end fed wire horizontal. There was a marked improvement in received signal strength. Running about an hour on WSPR showed 50 unique receive spots. Running JT65 is showing my signal making good rounds to Europe, South America and Japan.

I am going to play with this setup awhile and then turn it over to WSPR overnight and see how it does.

UPDATE: Should note that I made an SSB contact in South Carolina today and received a S9+10dB for the first time using this antenna. Right around dusk the travel mast collapsed and it was to dark to fix…sigh

Testing proceeds on the 30 foot Vertical

I setup the travel mast as before with 30 ft of #16 wire strung up vertically. This time I connected it to a 4:1 balun and added 12, 16 ft radials layed out on the grass. Where there is little space I just wrapped and folded the radials to fit the available space. It is located about 20 feet from the house. This is a temporary rig to evaluate its performance versus the end feed version. Right now I am running 1W WSPR on the 20m band. Here is the 24 hour performance:

2017-01-19_9-21-46

This worked out to 108 unique spots…not enough to make the challenge board but still respectable. Will complete these next 24 houyrs at 00:00 UTC and then switch to 40m for two days. I’ll then do the same with the end fed match box.

Testing End Fed Verticals

I installed a piece of 2″x2″ angle aluminum in the ground outside the shack to support my vertical travel mast. This works very nicely with the tie down straps.

photo-dec-30-5-23-26-pm

I tested the EFHW on 20m yesterday on WSPR and found that it was hearing and being heard quite well on 1W. I shifted this to the end fed matchbox that I have had for some time. This requires the tuner but allows for multi-band operation. I used the same wire as the EFHW of around 30 feet. I modified the coax arrangement so that the air chock is at the window panel instead of the feedpoint. This gives the remaining feed line as part of the counterpoise. This seems to work well. I am getting reports comparable to the EFHW on 20m with this antenna. I was able to have a good ragchew with a station in AZ on 100W SSB using this antenna. I am keeping this up through 00UTC today and see if I score in the WSPR Challenge.