G0MJI's blog

Radcom, G4JNT and Wspr above HF

Am I the only person who found the article in June 2013 Radcom by Andy Talbot strange. If I didn't know better it might have come over that some people have an agenda against free experimentation.

The article made certain assumptions about the (implied) misunderstanding (we are wearing the wrong trousers apparently) of operators on bands above HF. What if the operators already knew and understood the issues raised, but wished to experiment regardless?

When I obtained my license it was with the understanding that we would use it for experimental purposes.

We are experimenting!

4m Real Time Online Wspr Window For Free

Spurred on by VK2UB's page (cheers Gordon!) I finally got round to initializing my own here: http://www.qsl.net/g0mji/Grab%20Page.html
A great idea which could be incorporated into the Wspr program/site as an option?

If it isn't updating I am either off air, or it crashed.

If there is nothing to see, well that's 4m Wspr for you.


4m Wspr: Things I Didn't Know

I have put together some things I have noticed about using Wspr on 4m here:


Now that 4m is on the map it would be good to spot and be spotted by new stations.



4m Map


Frequency accuracy 6m 4m - some observations over the years

I have used several Yaesu radios over several years on these bands. None of them, possibly due to the way frequencies are synthesised in the radios themselves, have been accurate enough at 6m or 4m to place a Wspr signal accurately in the Wspr window. The higher the frequency the greater the error. I believe this to be common in many radios, not just Yaesu. The issue can be compounded by transverters.

My old faithful Yaesu FT847 for instance must have its dial frequency set 150hz low to put it within a couple of hz of where it needs to be on 4m. Given a window of 200 hz only this can mean transmitting outside of the window if the radio were centred and no adjustment made. Happily I have been aware of this from the start and as the radio is very stable can be certain it is on frequency. It does mean frequency hopping is out though unless I stay on HF were the problem is far less noticable.

I have noticed many stations on 6m who appear to be outside of the window. I have verified my radio with two separate station who have access to GPS disciplined receivers.

Perhaps many do not realise inaccuracy of transmission by a hundred hertz or more may be the reason you are not being spotted. Obviously make sure your clock is accurate first . If you still aren't spotted perhaps, as I was once, you are out of the window! Go to 0% tx and observe for a while then adjust the radio until your window agrees with average spots of others more or less.

Useful tip: given to me by Jim, look at your average report in the 'activity' menu and compare it with your set frequency in the Wspr window. This can suggest whether you are high or low. Obviously this relies on a transmission spotted within the window, and also on the accuracy of those spotting. It is a useful guide. It is worth spending some time doing this on several bands to build up a picture of your radio's accuracy. The FT847 is only a few hz out on 160m for instance.

4m Wspr Update.

Posted also on The Four Metre Website:

Yesterday was a good day for 4m Wspr: Stations in Essex, Northamptonshire, Merseyside, Greater Manchester and Cumbria were spotted, or spotting, on the band. The four metre Wspr database runneth over!

I will be on air every evening whilst the radio works, usually between 5-9pm for anyone who wants to try. Generally pointing South-East towards the continent (anyone out there?) horizontally polarised. I can switch to vertical given notice.

If you want to try and you have no one to listen drop me a message and I'll happily try and spot you.

Thanks to everyone who had a go, it was fun.


Please can we have a 4M filter on the map?

Most bands on the Wspr map have a filter in the drop down menu. 4m is absent even though it is possible to filter results for 4m in the old database. A very few of us in the UK are trying out 4m Wspr. There are allocations in this band being made available across Europe so there might be others out there who don't realise we are trying (some would say very trying!) :) It would be much easier to get people to try if they could see the activity as per the other bands.

Thank you for reading.


Interesting 4m 'Noise'

I've noticed this 'sweep' on the waterfall most days during daylight hours on 4m (in the absence of Wspr signals). When I ran on a vertical omni it wasn't present, when I switched to a horizontal dipole it was faint in any direction, on the turnstile it is quite prominent. I'd have thought it a local sproggie if it were not for the fact it disappears at night - see attached image if it works.


4m Wspr resistance

While I have had some support in the attempt to get Wspr going on 4m I have to say there seems to be some antipathy towards the mode on there. Here's one on The Four Metre forum:

''I'm not surprised at all that there is an absence of spots in the database.
In the first instance very few operators will know that you are 4M-active.

More importantly though, why would a cw/ssb operator want to sacrifice their operating time by listening to 70.0286MHz? They will be tuning up and down the band looking out for Sp-E openings - or more likely just watching the DX Cluster for openings.

Or is it an automatic monitoring system when you're not in the shack and we'll just have to park the beam in your direction.

WSPR isn't suitable for VHF anyway, is it? Well - that's what Joe Taylor told me when I spoke to him in person about it. ''

Not exactly encouraging and I felt quite guilty for being the source of this apparent indignance. I did point out that the operators on 6M seem to be doing just fine with VHF Wspr. I thought it was all about experimentation, not sacrificing operating time, well it is for me...

4m wspr

Having run for 3 weeks or so with 5-50 watts into a vertical half-wave antenna I have switched to horizontal antennas. There was some criticism of my use of vertical polarisation on the Four Metre website. I don't believe this to be a significant issue as there do not seem to be any stations working 4m Wspr anyway. I did want omni-directional coverage and a vertical is the easy method. However the turnstile is complete and up around 25 feet. I am running 10 watts and have had some signal reports from human listeners on 70.0286-USB so the signal is getting out. However, as with the vertical there does not seem to be anyone active on 4m Wspr and it's not possible to be spotted unless there's a wspr receiver on frequency. Check the old database.

I'm off work this week so I'll keep it going on 70.0286 USB during daylight hours.

I did receive some communications via email from continental stations suggesting they'd like to spot, even though they are not allowed (as yet) to transmit on 4m. Here's hoping...

2 False reports on 4m

2010-05-27 18:32 DF4PV 70.030079 +12 -3 JN49ax +47 50.119 G0MJI IO83ni 840 522
2010-05-25 18:14 IZ1ERR/1 70.030070 -11 -4 JN35uh +37 5.012 G0MJI IO83ni 1176 731

These are incorrect. Perhaps I switched between bands without terminating the Wspr program. What a shame it would have been nice. Bri G0MJI

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