70MHz 4m Sporadic E and lesser events

For several years I have looked at 4m in the Es season. An ideal tool for examining propagation is none other than WSPR. What other mode would give me instant proper reports today during some antenna improvements I was making. I am using a simple 1/2 wave dipole home made and mounted in my loft. Go on ask the question, I bet it has gone through all our minds, “what is a 1/2 wave at 4m”? 2m you fool.

Today conditions were pretty flat and some of the regular TX stations were not around it seems, luckily M0NKA had left his WSPR capture running so when I raised the dipole as high as I could and re orientated it slightly I saw a 3 to 5dB increase is signal.

Additionally I had Spots from other usual spasmodically possible stations and one new Spot G6HSM at 172Km all with a genuine 5Watts except for G0MJI who needed 10W to get a Spot today but then he is 8Km further 😀


It is a pity there are not more stations willing to give 4m WSPR a try, it may be the lack of stations but it has always appeared to me that 4m is not influenced as much by Aircraft Scatter as 6m or 2m.
I have never used DX Clusters etc. ‘cheat lists’ to get my contacts and idea of conditions, shame there are not more active beacons on 4m. WSPR does the job of indicating the propagation from my QTH, for me. I hate the modern lack of SSB activity on the VHF bands until there is an opening then all the bellowers, some with affected procedure come up en mass and its dog eat dog and no one wants to work a fellow G station. When the band closes, off they go until someone blows the whistle again.

How many stations I wonder have been intimidated into not daring to use WSPR on 6m and up due to not wishing to be seen in “the wrong trousers”. Its such a pity that those who don’t understand are the most vocal, making statements about how much Doppler there will be on a 6Hz wide signal which must cause trouble. Fact is Aircraft Scatter does not generally have an adverse effect on WSPR. Aircraft Scatter can be made use of in a technical controlled manner using WSPR or Opera and there will always be fortuitous coincidental Scatter which produces results for minimally equipped stations.

Those who do not understand, need to understand that they must stop thinking in terms of AirScout for WSPR Aircraft Scatter. I have nothing against AirScout for the purpose it is intended, which is not WSPR, the very mention shows that the penny has not dropped for them, yet they set themselves up as expert commentators. One has to smile.


2 thoughts on “70MHz 4m Sporadic E and lesser events

  1. Hi Eddie, perhaps the lack of 4M ssb is due to the lack of rigs with ssb. Until 4M was released in Europe it was a non-band for rig makers so UK users had to transvert. 4M is a GREAT band, propagation can be very good, antennae are easy to make and you can still hear the odd bit of AM once in a blue moon….

    We used to have a local natter-net on 4 AM, hi power AM mobile was found to be excellent for EMC testing of car and house alarms, a quick “WAALLOWWW” could make some streets come alive…

    Thanks for relaying diagrams for Watson power supplies some time back. I had bought a second hand W-25AM to power an IC706Mk2. Seemed to work ok. But then noticed 50Hz sidebands on some but not all signals from the acc socket. No great hum on audio though. Scope probe on 13.8 V revealed a 50 Hz spike of around a volt. Thanks to the diagram it could only have been one part, took out the 14 case screws and changed C15 reservoir cap for the “op amp supply”. The cap had become what we used to call a fat cap- dome ended and with a nice high esr!

    So back working without 50Hz sidebands….

    Alan G8LCO


    1. Hi Alan, really I was referring to the whole VHF spectrum re SSB and including CW. In any opening there are masses of operators emerge then go back into hibernation.

      Yes I like 4m I used to do very well on a H.Brew 1W out transverter its not like that these days. I cant remember how many ele my North pointing beam at the old QTH was, I built it in the loft in situ it was the whole length of the house, reflector at one wall and I stopped adding dirs. when I hit the other wall.

      Pleased to be of service with the PSU info, the internet is a great place, if I can pass anything on relating to Radio or Motorhomes I do.


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