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Propagation and Mobile Phone issues


#1

Hi Guys

Spent the morning on the eastern fringe of the Brecon Beacons walking GW/SW-020, SW-016 & SW-026. On first hill couldn’t get a self spot for 2-fm or 7-ssb due phone probs so went straight for 7-cw and got picked up by RBN OK. However, on SW-016 & SW-026 only managed to get my 2-fm self spots out but was unable to get 7-ssb self spots to go and my 7-cw sig was not being picked up by RBN. Also had probs getting onto Sotawatch on the phone. Don’t believe the self spot issues are DB related just phone issues, but a little surprised that RBN didn’t pick up my cw sigs - must be really poor propagation today.

Thanks to those who worked me and sorry to those who couldn’t hear me for what ever reason. At least managed to qualify all 3 summits on CW from first and 2-fm from last 2 summits.

Activation blog to follow in due course.

73 Glyn G(W)4CFS/P


#2

Hi Glyn,

For me HF propagation was up and down all day (worst in the morning). As for phone coverage, I deliberately have a smartphone with dual-SIMs so that If I can’t get to one network, I have a chance to get to another (both use PAYG SIMs). Might be worth considering for your next Smartphone (strangely, it’s often the cheaper phones that come with 2 SIM sockets, not the big name ones - go figure).

73 Ed.


#3

They’re often the models aimed at markets like Kenya, where almost everyone has a mobile phone, and folk often need to have access to more than one network because coverage is patchy…


#4

It’s not only Kenya where network access is “variable” - Australia has a similar problem - running an Optus and a Telstra SIM there gives coverge almost everywhere that coverage at all exists (which isn’t everywhere). Here in Germany, where Deutsche Telekom doesn’t cover Vodafone seems to, and vice-versa. I’m still suprised that Apple and Samsung don’t have dual-Sim versions of their phones, but I guess if the majority are sold through the newtork provider in the US, they will lock the phone to their service in any case.

Ed.


#5

Hello Glyn,

First of all congrats on managing to activate all 3 summits despite the phone issues, we’ve all had tough activations and that fourth contact is always the best :wink:

I wonder if you were trying to spot yourself using your mobile internet connection? I like to use @MM0FMF great SMS spot service, just send a text using your regular mobile connection and it appears on the website. This helps a lot because quite often on summits the mobile internet connection may be a bit patchy but the mobile coverage will remain.

If you’re already using SMS to spot yourself and still having issues, you may want to try changing your phone settings to use a 2G connection instead of 3G/4G. This often results in a stronger signal for me, I’m sure someone more technical than me can explain why, but it seems to add an extra 2/3 bars to my signal.

I use an iPhone 6 which is great in urban areas but when you get out into the sticks it goes to cr*p, certainly not a ‘DX phone’, whatever that is!

Cheers,
James M0JCQ


#6

To ask an obvious question, did you try switching the phone on an off?? My phone will often lose signal, so I turn it off and back on and suddenly I have 3/4G!! Most odd, but it does seem to do the job.

The other way is to put it in Airplane mode and then back into normal mode, this has worked for me in the past.

As James says, the best bet is to use the SMS service, far more reliable.

73

Matt G8XYJ


#7

Hi James

I also use the Andy’s SMS service which is brilliant. I think my phone automatically switches between 2G and 3G/4G ( Samsung S5) need to investigate. In most cases I don’t have a prob just yesterday - as I said I think I was jinxed.

Glyn


#8

I think most phones do this, but I have times when I still barely have a 4G/3G signal but not enough to send a spot. When I manually switch it down to 2G, the signal goes up and I can send the spot with no trouble. Something to try in the field next time :smile:

As Matt @G8XYJ says try turning it on/off or flipping into flight safe mode, this has also worked for me.

You have CW/RBN to fall back on to get spotted, as an SSB op I’ve used the WAB net on 40m to work enough stations.

I’ve also messed up my SMS spots (and not realised until after that they never appeared for chasers) and had to activate the hard way * shock horror *.

Either way, I totally agree that Andy’s SMS service is fantastic and I’ve used it a lot while out in EA1/EA2/EA8 to spot myself the cheap way :wink:

Cheers,
James M0JCQ


#9

Thanks for the nice words about the SMS spotter They’re most welcome at a time when the DB isn’t working and my inbox is just a little full!

I hope to get to EA8 before Christmas and if the DB isn’t working I might stay there! Assuming my back continues to improve I hope to bag some summits. If my back is not fixed then I shall drink myself silly :slight_smile:


#10

The local Ron Miel has superb restorative properties. Also excellent used over Canarian bananas - fried and then flambe. Watch out for your whiskers!


#11

I think the accepted wisdom is that the SMS service runs, or can run, on the 2G connections around 800-900 MHz, whereas the higher data volumes required by 3G and 4G services are all run and require higher bandwidth on the higher frequencies, which have higher losses and shorter range. I understand that the lower frequency band will also support small efficient websites like spotlite, so it’s worth trying that when 3G/4G coverage is spotty.

Andrew
VK1DA


#12

Originally the SMS data was carried in the control channel and not a data channel for 2g phones. The control channel has more resilient error control as it is the link between the handset and network. This means that SMS (on 2g) stands a much greater chance of making the trip than any other comms to the phone.

3g and LTE/4g phones have very much higher bit rates which is why they can do multi mega bps comms. But that speed comes at the expense of power used and bit error rate. Or if you want to go very fast you need to use more power and you need a very good signal to noise ratio between phone and tower. As the signal to noise drops then so does the speed.

I haven’t looked into the specs as I used to do with 2g, but the basic signalling between the phone and tower takes place at a low rate with a strong degree of protection against errors. This is so the network can tell your phone to receive a call or message. When a voice call occurs your phone ramps up the data rate. For internet access, 3g/LTE phones try to establish the highest data rate and the signal to noise ration has to be very good for high rates.

It’s because the phones try to establish high bit rate links that internet access “in the wild” can be difficult but as SMS is carried at slower rates it will work. Of course if you can get a data connection working you’d be silly not to use it.

On top of all of the modulation rate info there is frequency selection. Frequency bands exist at 800MHz (newish) 900MHZ (very old), 1800MHZ(old) 1900MHZ(old), 2100MHZ(quite old) 2600MHZ(new). The higher frequency bands have more BW so you get more channels and more data. The low frequency bands over better distance and work much better in buildings.

So you have to consider absolute coverage of the network, the frequency band the network has where you are, whether your network forces you to use the higher frequencies first, the actual mode your phone is in 2g.3g,4g etc. and it all gets awfully complex very quickly. So in my case I pull out my phone on a summit and look at the signal strength meter and try to load the spots page. If it doesn’t do that quickly then I’ll use SMS if I need to self spot. I can’t be bothered flipping phone options to see if I can make the data link better. If it works out of the pocket, good. Otherwise I’ll stick with SMS.


#13

Thanks @MM0FMF and @VK1DA for the explanation. Very detailed and informative!

Ditto :smile:


#14

And your battery power does too, surprisingly. LTE gets its speed down to OFDMA modulation which requires the handset PA to work at optimal efficiency.

4G isn’t as impressive as everyone thinks, it fell short its expected target in terms of technology. 5G looks to be more promising OR rather it is will do what 4G was SUPPOSED to do.

Jonathan