Posts Tagged ‘WSPR’
6m – past the best?
July 7th, 2014 | 
Author: I am beginning to think that 6m is now past its best both for Es opportunities and, of course, for F2 propagation. Almost zero Es on 6m in the last few days, mainly locals and a little GDX. I may give it a few more days before QSYing back down to 10m where both Es and F2 DX are more plentiful.
10m conditions should be good for N-S F2. Sunspot count is 256 (high) and 20-30MHz propagation is forecast to be “normal”.
If anything, solar activity has staged a bit of a comeback lately, but this may be just a blip.
UPDATE 1545z: As if to persuade me to stay on 6m, CN8LI (2113km) was spotted at 1450z.
UPDATE 1810z: No more Es here since CN8LI at 1450z. One blog reader tells me that I should try JT65 as there is more activity. JT9-1 worked well for me on MF with international 2-way QSOs with very low mW ERP. I think JT65 is more commonly used on 6m?
QRP Labs Ultimate 3
Some months ago I was planning an afternoon at our local Fab Lab, partly to help raise their profile and partly to introduce some club members to the easy to use laser cutting services they have. We designed an profiled a case for the QRP Labs Ultimate 3 WSPR transmitter.
It occurred to me that I haven’t really shared the experience having been enjoying myself at the 24 du Mans race, celebrating my parents 50th wedding anniversary and having a birthday. None the less, its time for a catch up.
The U3 is a fairly simple build, in its basic form takes about and hour and a half to build and test. Start adding the various extras like a switchable band pass filter (for 5 bands!) and a gps unit and the time to build, well builds up. The kit isn’t complex and doesn’t use smd’s (although I’ve never understood the fear of them – whilst my eyes are still ok) and there’s only 4 coils to wind for the basic version.
The biggest issue was how to box it up. After trying various configurations we settled on a very simple front and back panel design, Others, like the desktop version or ones with castellated fixings either looked a bit cheesy or were hard to put together and prone to breaking. A simple 2d CAD sketch is loaded onto the machine, plonk in the materials and you’re away. It couldn’t be simpler. Anyway here’s the semi finished product. I need to do something about the spacers as they look awful but its nearly there.
6m – WSPR spots from 4X1RF (3519km) yet again
My 6m 1W ERP WSPR signals are yet again being spotted in Israel.
I think this is now 5 days this season he has spotted me at this incredible distance. In all I must have had around 20 spots if not more from him? The considered wisdom is this is Es, but I do sometimes wonder what the propagation mechanism is. The lack of stations at intermediate distances may be because few are active on WSPR, but it “feels” like a single long hop, not unlike F2. My station and antenna are basic.
People who know better than me tell me it is not F2. Whatever, I am very pleased to have my QRP station being spotted so often in Israel.
Today, starting at 0704z, he has spotted me 6 times already by 0846z.
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| 6m spots by 4X1RF (1W ERP here) to 0830z today |
Most Es spots seem to be from Scandinavia currently, just 1 from Italy.
UPDATE 0942z: Just Scandinavian Es for the last hour here.
UPDATE 1530z: Another spot from Israel of my QRP 6m signal at 1314z. That makes it 7 just today!
Sporadic E
2014 Es is gettig ander way. I will be keeping an eye on 6m and 10m bands. Now is the time for WSPR. This requires a computer. I’ve managed to get the WSPR software running on the shack computer using Windows remote desctop which allow me to see whole screen on the laptop. This is more useful than I expexted. Olga discovered the shack computer keyboard is broken. It prints one letter from the next column. The funny thing is I sought it was my brain broken not the computer.
I had hoped to be using one of Hans Summers Ultimate kits I purchased several weeks ago. But I think it is beyond my ability to buibd this. Shame there isn’t a bild and tested version.
10m, then 6m, WSPR
Overnight, I remained on 10m but the only spots were by Es were from Norway, France, Spain and Germany plus G4KPX( local). No Es “super DX” here sadly!
At around 0904z I moved back up to 6m WSPR. with 1W ERP. G0OQK (98km) was spotted 3 times (so far) with moderate drift or Doppler , G4IKZ (18km) was spotting me at good strength and OH7AI (2000km) spotting me by Es at 0928z at -21dB S/N for the best DX so far today.
Sunspot count is 72 and 20-30MHz propagation “normal” so I’d expect F2 DX N-S today on 10m.
Alpine storms and Es
I cannot remember the supposed link between Es and thunderstorms (something to do with sprites going upwards from thunder clouds?) but with plenty of thunderstorms in the Alps, I wonder how Es will be tomorrow? Maybe conditions to southern Europe will be good on 6m Es?
Although I probably could safely reconnect antennas this evening now the storms have passed, I think it will be better to wait until the morning.
Knowing my luck, the 6m band will open transatlantic tonight and I shall miss it all! That would not be the end of the world.
Using the Ultimate3
Until now it has been attached it to a dummy load with the FUNCube Dongle Pro+ SDR in close proximity as a receiver for experimental purposes.
One unresolved issue was it being consistently off frequency. The DDS modules used are prone to temperature fluctuations and component variances so the Ultimate 3 has the option of using a GPS module to provide both an accurate time source and an accurate 1PPS input which can be used to self calibrate. Except in my case it had proved to be unreliable.
I am using one of the inexpensive GY-GPS6MV2 modules containing the U-Blox chipset I posted about previously with the additional tap off to provide the 1PPS TTL signal.
Initially the GPS module was connected in close proximity to the Ultimate3 but struggled to maintain lock probably due to interference from the DDS module. Even when lock was achieved the calibration never seemed to work. I posted a question on the yahoo support group and from the answers I verified the calibration setting were correct so the only likely culprit was the quality of the 1PPS signal.
The serial NMEA sentences and the 1PPS signal from the GPS are likely to be required in other planned projects, such as an 'shack clock' and a GPS disciplined frequency standard. So I decided to put the GPS module into a waterproof housing that can fitted on the shack roof in clear view of the sky and away from any potential interference. A multi-cored cable supplies power and the TTL RX/1PPS signals being fed back to the bench.
Sourcing an inexpensive weatherproof enclosure (£2) and waterproof cable gland were straightforward enough. I mounted the GPS module on a piece of strip board and replaced the on board LED with one mounted in the enclosure so I easily determine if the GPS had achieved lock, since it only flashes when it has. The LED is sealed with epoxy resin. It should be noted that the outputs of the U-BLOX chip are only rated at 10mA so bear it mind when selecting an LED and calculating the current limiting resistor. The connecting cable is some surplus unscreened alarm cable fitted with a couple of ferrite clamps.
The GPS now has no trouble achieving lock and quickly sets the Ultimate3 clock. Researching the 1PPS problem I hadn't come up with anything definite, as the signal looked okay on the oscilloscope. But I decided to fit a 10K resistor pull up resistor between the 1PPS output and the 3.3V supply on the GPS module. If this actually made the difference I have no idea but the Ulimate3 now successfully calibrates the DDS using the GPS.
At the moment I have configured the beacon to run WSPR and I have been spotted by other operators. Initially I wasn't getting much RF out of the device and it turned out to be a combination of poor connection caused by me not removing the enamel properly on a toroid winding and an iffy antenna connector. Both have been corrected and now get a measurable deflection on the SWR/Power meter. With the additional of a second power amplifier FET it is around 200-250mW.
I purchased the Ultimate3 with a low pass filter for the 40M band and while I have had some European spots the results have been a little disappointing. 40M has turned out to be almost unusable at my QTH due to QRN/M so not sure if that is having an effect, also the antenna I have isn't naturally resonant on 40M so is going through a tuner which will certainly be introducing some losses, without the tuner the FETs get very warm!
With this in mind I have purchased some additional LPFs for the 30M and 20M bands and the LPF relay switching board for the Ultimate 3 so can try/run multiple bands.
