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30m - what can it do?


#21

Hi John,

Yes, it’s intersting to watch. Just starting to see a ton of decodes including Italy and Germany. Shame I cant press the Enable Tx button!!


#22

Band seems to be waking up after a quiet start. Can see Central Europeans working ZL,VK and JA but no DX decoded here… Yet?


#23

Hi Compton,
Don’t forget WSPR - which is a great way to see which bands are open to and from various parts of the worls and the majority of these stations are automatic and hence don’t depend on whether people are in bed or not - of course getting contacts when you can see a path is open DOES depend on Ops being there!

Since the WSPRnet has got problems with its Google mapping I now use this Aussie site to monitor WSPR: http://wspr.vk7jj.com/

73 Ed.


#24

VK1DA’s activation was getting louder and ZL1BYZ was a great signal. But my mast collapsed! When erected again, Andrew had QSYd to 20m and no sign of John.

Maybe another chance this hour?


#25

Seeing tons, Africa and EU, Russia, JA etc on FT8, No M1EYP though.


#26

Tom,
Didn’t hear you or your chasers, assuming you made contacts. Your signal reports from the RBN receiver were huge. Mine was barely above the noise in VK4, no wonder it was a marginal contact with VK4TJ.
VK5CZ called me about 4 times, I responded each time but I am guessing he was calling without hearing my cqs.
Conditions were pretty odd. Earlier at home I heard a LZ1 calling CQ on about 10118 so I hoped we would make contact. But no EU callsigns heard (on summit).
73 Andrew VK1DA/VK2UH


#27

K index is 3. Things in my experience on HF start to get strange and shut down from 3 up.
Still tons of decodes on 30m FT8 happeniing. Lots of J’s


#28

Kp has dropped to 1
image

Solar wind speed is down to 322
image

Looks like pre-auroral enhancement on the way.

73 Ed.


#29

Sunday 17th February 2019 - The Cloud G/SP-015

I was up with the 0500z alarm, but wasn’t really getting things done very quickly after that. By the time I’d got out of the house, drive to Bosley, walked up the hill and set up on the ledge beneath the cliffs (essential for shelter for the 10m mast & GP on such a blustery morning), it was gone 0730z. An hour later than my intended alert time, but still about right to hit any propagation that might be on offer.

The new GP aerial, radio-wise, works well. It receives well, and gets out well. But practically, it doesn’t work well. I’d chosen to use some very lightweight wire - this is superb for dipoles, but not really robust enough for groundplanes, especially great big ones like this. I was concerned about the strain on this wire, particularly the radials, so I used a mast guying kit to try to get around that issue. That seemed to work on the GW/NW-043 activation a couple of days earlier, but I suffered several breakages this morning.

The good thing is that I have now worked out everything I need to do - and materials I need to use - to rebuild the antenna, which I hope to do this week.

It was unfortunate that the first breakage occurred just as the signal from Andrew VK1DA on VK2/ST-053 was really starting to come up. I listened to him working John ZL1BYZ, who was a big signal with me. By the time I was QRV again, Andrew had QSYd to 20m, and I never found John again.

The activation wasn’t a complete failure though. I made a total of 56 QSOs as follows:

30m FT8: 10
30m CW: 43
2m FM: 3 (including S2S with Bill G4WSB/P on Stiperstones G/WB-003)

The last QSO before taking down and packing away my crumbling antenna, was T45FM, a special event station for Punta Maya Lighthouse, Cuba. So there was a little bit of DX at least.

Now to put the lessons learned into practice and rebuild the 30m GP so that it is more fit-for-purpose!


#30

HI Tom
30m can do many things, but is does not provide much in the way of NVIS propagation; I listened for you this morning on 30m; both CW and FT8 but could not get a whisper of a signal from you!
With the F2 critical frequency reusing to go much above 3 or 4 MHz most days at present, it is very frustrating hearing all the stations calling you, and not be able to get in myself at all.
I need more 80M activity in the mornings, please!
73
Ken


#31

I’ve just refreshed my 80m antenna Ken, so that is definitely coming.


#32

Thanks Tom, will listen out for you and anyone else active using what little NVIS propagation we have at present.
73


#33

That is good news for me!


#34

Do you mean to say you use the antenna to support the mast and no other guys normally? That explains all the antenna failures you’ve written about.


#35

I have long time been a fan of the 30m band, so I welcome your idea of visiting this powerful band more often. I remember making QSOs with places in Spain about 400 Km away of me and most of Europe at the same time, but it’s got a bit longer lately, probably because of the winter season, being perfect for contacts ranging 800 up to 2500 Km during the day and allowing great DX at the good times around sunset and sunrise.
I recently chased you on 30m CW and this has always been my money band, much better than 40m, where I often receive signals from central Europe with more difficulties here in this periferic European country.
I remember HB, OE, DL not being copiable on my balcony antenna when they were on 40 and 20m but being an easy contact on 30m.
I encourage everyone to always give 30m a try.
73,

Guru


#36

It definitely explains some of them. It definitely doesn’t explain all of them.

I’ve only had a number of antenna failures because I’ve done a lot of activations. I think the rate of failure is quite low.

It is only the HF GP antennas where the radials have been doubling as the guys. Strain relief at the centrepiece / feedpoint has been factored in to the design of these, and I’ve not had that many problems with my GPs. I’ve done several hundred activations with my 20m GP. I can’t be bothered to plough through the reports to count the fails, but it’s in single figures.

The 30m GP is big - requiring a 10m instead of 7m mast - and a bit more thought going into the design and deployment of the antenna.

Ironically, it is looking like the idea of using mast guying in addition to / independent of the radials on the 30m GP was a mistake. The 10m poles need less encouragement than the 7m poles to collapse due to the weight, and the independent guying cause some extra downforce it could have done well without.

I’m not saying that I should have just tried to keep the 30m antenna / 10m mast upright using the 3 radials alone; as I say, in my experience you are OK with this with GPs up to 20m, but 30m is too big - mainly because of the mast size. However, on reflection, it might have been better than the extra guying system which caused at least as many problems as it solved.

I’ve been rethinking and redesigning the antenna, and the ways of deploying it on a hilltop, this afternoon.


#37

You might consider the idea of a loading coil part way up the vertical (not at the base), just enough to shorten it to fit the smaller mast.


#38

595 activations for me, not all using the dipole.

The spade terminal on the end of the dipole has come off. Both pieces, once each.
The RG174 dipole feeder has broken the shield once on 2 separate lengths of cable.

These are failures due to wind flexing the elements and coax supporting it’s own weight. Not all 595 activations used the dipole, but I’m picking 500 as a nice number. 4/500 = 0.008% or 1 failure every 125 activations. I had one the other weekend. I’m hoping the next fail will be in Spring 2021.

This excludes FMF running about like a bull-in-a-china-shop failures and tripping over the wires and damaging them.

Oh most definitely it does. Typically we’re using PVC hookup cable with tinned copper conductors. Repeated wind based flexing will work harden the copper to the point it can easily fracture. Making it take any strain beyond supporting it’s own weight will hasten the process. My own PVC hookup wire dipole elements have always failed at the dipole centre end where the cable supports the weight of cable plus the wind loading.

My 2yrs working for a defence contractor taught me more about connector and cable failures than I thought possible. We’re not going into battle… we’re doing something more important! If I’ve sweated my way up a hill that antenna is damn well going to work :slight_smile:


#39

And several of my antenna fails have been due to dogs off leads behaving in a similar fashion.

Others have included over-tensing a nylon guyline, causing the pole to collapse and an acryllic insulator to fracture (two days ago being the latest example) or me not spotting a kink in the radiating element which later caused the wire to snap (this morning).

I’ve had cheap eBay SO239 to BNC adaptors fail on me.

So

…is nonsense. As I say, it definitely explains some of my antenna fails, definitely nowhere near all of them. Not that I’ve really had that many out of 2500 activations. But these things happen… :wink:

There are pros and cons, and a balance to be struck. I agree with the basic premise that any additional strain at all will shorten the life. So will mast collapses, so my approach today was flawed and worsened the situation, not improve it.

Experience (of which I also have a bit) has taught me that radial guying systems are generally OK for GPs up to 20m. The number of fails they cause out of several hundred uses needs to be set in context against the extra weight, speed in setting up / take down, and most importantly, issues arising from independent guying systems. By the time I’ve had a problem with these antennas, they’ve been due a refurb (replace feeder, radials, driven element etc) anyway.

When that mast necessarily changes up to a 10m one, then an independent guying system is crucial. Instead of its absence meaning that you might have to rebuild the antenna after a couple of hundred activations, it could mean you need to rebuild it every couple of activations!

However - not the way I guyed it on Friday and this morning. That was flawed and it would definitely have been better without it. I’ve processed this experience and have come up with a solution.

That’s a fine attitude to have. My approach is slightly different. Mine is more like “If it doesn’t work, I’ll use one that does”. I’ve always got a back-up option. Mind you, it is worth noting that on this antenna that is still in testing/development phase, I still made 53 activator QSOs on it today… :wink:


#40

Good to hear you having a go at a 30m gp. Don’t give up, you might end up with one that would be suitable for certain summits in certain wx?