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Messages - swxx

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Tactical Corner / Doomsday Clock: Worse than Cold War Era, now 23:57:30
« on: August 29, 2017, 11:11:24 AM »
Even worse than the cold war:

Bulletin of the Atomic Scientists

You know what, there really IS NOT an ideal QRP rig out there at all!

The PFR-3b and HB-1B do come close to it. The PFR3 advantage is the built in tuner, that's nice having it in the box and the 34mA RX draw. The HB1B already on RX draws more than twice that at 80-90mA, though still much better than many others, even the QCX draws 150mA! Advantage is the general coverage receive and variable bandwidth. I just don't like the look of the HB1B for some reason and it LOOKS like a radio that would attract attention at airports where you are entering without a license and require import bureaucracy even for transit. The PFR3 I don't think looks like a radio but like a bit of test gear or a toy of some sort. "Portable Field Radio" doesn't sound dangerous. So I'm biased to that I think. An IDEAL survival radio would be:

* 50mA or less power consumption at least optional to switch off stuff except RX and have it as low as 30mA.
* Variable bandwidth or filter, so that at least one can listen to AM/SSB
* General coverage RX
* TX on 4 bands: 80/40/30/20 or for tropics a version with 40/30/20/17-15
* TX working even outside those band edges, useful in emergency
* Built in auto-alarm on 4 second dashes, or on callsign being received (if having microprocessor such as QCX) though can do without this feature
* Loudspeaker! Not just ear phones. Even if a small loudspeaker that can be optionally plugged in if it draws more current.

Basically the PFR-3b if it were improved to be able to listen wide to SSB and 2) to have an optional loudspeaker switched in, with no other modifications, would be acceptable, if with an extra band (80m, OR 15-17m), and not blocked from TX just outside the bands, would be IDEAL even without general coverage RX though that would be icing on the cake.

Or the HB1B if it were having lower power consumption on receive, 2) optional loudspeaker switched in, 3) built in BLT as in PFR-3, and not blocked from TX outside of band edges, and without those labels that give away that it is a transceiver, would then also achieve this ideal.

EVERY TiME over the past few years I look at all the QRP rigs, I see that there is NO ideal one that I'd really want. I think PFR-3b may be coming closest to it if only Hendricks could be persuaded to create the PFR-4b with above improvements but still managing the low current on receive.

Indeed there is no one magic band at HF. At night even 3.5MHz may be too high and then too low at midday. Gils suggestion for 2m or 6m SSB is thus very good! Not by accident do many militaries use 6m and some wont give it up for amateurs, The SWS site Radio Ray showed above is very useful. I also like VOACAP program by G4ILO for easy quick glance,

Net Activity / Global Radio Relay Network
« on: August 28, 2017, 02:20:38 PM »
If we look at a few logical points: in the event of a Major World Event the break down of communications which have never been so centralised in all history, dependent upon a few important nodes on the internet and satellites, and the fact that these will almost certainly collapse in the event of a major disaster such as a nuclear war, or a major environmental or other catastrophe, then we know that the most likely communications to survive long-term is low-power and predominantly CW communications.

However, with low power and modest antennas (forget 7 element yagis up 30m post TEOTWAWKI) the reality is that even on CW communications will only be reliable, especially for the many coming years of this solar cycle minimum, only for one or two hop E or F layer propagation. Before anyone says ahh but I often work DX using 5W on HF, yes indeed, but not to other QRP and with both sides being QRP also in antenna terms. In this case, during solar minimum, and on frequencies below 10, 12, 15 and 17m (which are not so often open), it is not at all easy and certainly not reliable to have communications beyond a couple of F layer hops or 3,000km or 3,000 miles.

So, let us consider, post TEOTWAWKI, with all broadcast stations on HF either off air or just broadcasting unreliable information or propaganda, how would one get information from OTHER parts of the world, from citizens, using QRP? There are several problems that will make that a very sporadic, difficult and hit and miss affair: days and weeks of endless trying! If you have to listen for 3 weeks to find some news from Australia while you are in Europe, and if you have to transmit for a total of 10 hours to get one single message through to a distant location (calling, calling, repeating, failing, re-arranging etc) then let us calculate: 10 hours of TX at 500mA = 5Ah. 3 weeks of RX at 100mA = at least 33A assuming 16 hours a day desperate listening around. If you had 100W and a 7ele Yagi up 30m, you could likely have done all this with a saving in power! BUT we do NOT have that luxury and we have to prepare accordingly.

For many of us, it is not just important to find out what is happening 10km, 100km, 1000km away, important as that naturally would be, but also, to find out whether there are other parts of the world that are in better shape, loved ones in remote parts of the world may they still be alive (not about getting through to them specifically, that would likely be impossible without normal communications infrastructure working, but just to know whether all of America was wiped off the face of the earth or not, is Australia still an island afloat, is Africa a place to head for from Europe or should it be Scandinavia, etc). So how do we do long distance communications reliably and effectively with QRP power and QRP antennas? VIA RELAYS.

If we have a network of stations running QRP who are one or at most two hops apart, who have pre-arranged schedules, nets, frequencies, and above all procedures and skill in sending, receiving and relaying written messages, then we are able to do this, if we do not, we really are not able to do this.

It is a generally much overlooked reality that on CW "Chinese Whispers" is doomed to failure. Passing a message even with one relay between almost all radio amateurs ends with the message being incomplete or changed. ONLY those who have previous professional experience in formal messaging, and even they are often having no experience of relaying messages, and particularly those radio amateurs who have sufficient experience in "traffic nets" are able to do so. It is very common for "good CW Operators" to think that if SHTF they will be able to relay messages: the reality, proven time and again, is that when they hear <CT> they don't grab a pen and write down, and even if they do, they do not know how to efficiently get fills for missing letters and words, how to check whether the message they have is actually accurate or not, how to avoid confusion in poor Signal-to-Noise Ratio, QSB, QRM, etc. All this is really only learned by on air training in the art.

It would be very good for Radio Preppers to form some new, or join, some existing CW traffic nets, and to start building a relay bridge that can potentially span the globe.

Let us consider some human realities: in a SHTF most of us are not going to be altruistic, willing to use up our batteries passing messages for others! Most if not all of us are going to want INCOMING information, and less willing to give OUTGOING information (which is required for incoming information elsewhere) and almost no one is going to be willing to RELAY information between two OTHER stations. Most will be listening, few willing to send. So HOW do we overcome that? Quite simple! BENEFIT.

If you act as a relay and take part in such a network, you benefit by getting information that you will only get, if you participate and in return, you too are able to send and receive information. By just listening, sure, you will pick some up, but there will be many gaps, incomplete messages, and you won't be entitled to just come on air and ask for this and that repeats and information if you are not yourself an active participant helping the others.

What I'm talking of here though is not an ordinary traffic net, but a relay network. Not everyone is necessarily on the same frequency at the same time. But each sked is to a single hop destination in different directions. A system to route messages is required. A format for the messages to avoid confusion and to ensure reliability. A procedure to ensure accuracy of count, and to find out which word is missing without an entire repeat. I am not going to, here right now, give all that information, you can find it at sites such as Communicators Without Borders and Radio Relay International.

What I am advocating here is that we can start thinking of some training frequencies and skeds to practice and to build up ROUTES along which messages and thus information can be relayed. A difficult task for example: from Europe to Australia. From Australia to South America. Using QRP and simple wire antennas, via relays. Even with 7ele yagi and 1kW, the path from Australia to much of South America is currently very difficult.

So perhaps we can discuss some ideas on how we could practice these things, outside of North America and Australia where such networks exist, what do we do in Europe (so many amateurs but no such traffic nets I believe) and Asia, Africa, Latin America. Among us we may already be enough to stat building such bridges. For long distance reliable single or double hop, we are mainly looking at 40, 30 and 20m. Any ideas on how we can proceed? Are there existing networks we can join, train in and extend? Or do we need new ones that can interface with existing ones?

Research in Europe and Australia has long established that at those mid latitudes the 60m band area (5MHz) is the most reliable short NVIS propagation. It is for this reason that emergency services etc in Australia and elsewhere use this part of HF more than any other, and also the reason why amateur radio was not generally granted much space at 60m as a result of the WARC conference. It is very heavily contested. So in reality, it is not 80m nor 40m, but 60m that is most useful all round. But that does not stop those other bands from being useful for NVIS. But if we are looking for BEST then I think it's 60m.

Thanks feedback, incorporated in original post. WHAT ABOUT TJ5A? Now added to original post. TJ5A is SSB and CW, adjustable 300mW to 20W, large internal speaker, general coverage RX 2-30MHz, and 8 TX bands 80/60/40/30/20/17/15/12m. The only downside I see is weight 1.5kg. 200mA current draw on RX is not great (6 times the PFR3b and MTRs but still better than full size rigs including FT817ND)

Technical Corner / Re: General Coverage Survival Receiver
« on: August 28, 2017, 02:55:18 AM »
RadioRay by the looks of it you'd be able to supply a lot of gas! That could be tradeable for other things, the excess that isn't used  :D

New To Radio / Re: How much power do you need?
« on: August 27, 2017, 12:41:55 PM »
What i mean by that is CW can be copied by most at 10dB below noise, and some of us can copy at 13dB below noise after many years of training,

New To Radio / Re: How much power do you need?
« on: August 27, 2017, 11:01:46 AM »
Well I agree of course! Yes the 7ele Yagi was doing the heavy lifting to hear my 100 Mega Micro Watts :-) but believe me if you live out in a remote part of the world on the other side to Europe where you don't often hear strong CW signals, hearing 599 from Europe on a quiet band was NICE :-) and I'm not the type of person who needs nor chases 599 signals, I enjoy picking CW from -13dB SNR! The fact he was 599 with 10kW, means with 100W he would have been 569 to 579 with that 7-ele Yagi, and that's likely how strong I was over there. I got "5NN" but don't believe that, this was a contest stations, most contesters know only 5NN and can't send anything else. Of course the 10kW would be illegal, he was honest enough to give an honest answer, and we all know most amateur radio contests these days are all about cheating.

It is of course the fact that the antenna is the first thing you need to optimise, and while power is another way, rather inefficient as you get higher and higher as each time doubling your power gives only 3dB gain (or half an S meter point in theory, though manufacturers cheat by making it 3 or 4 dB sometimes so that signals look stronger on their radios -- everything now is about cheating). But we are about making batteries or alternative power sources last longer, and about getting away with as little power and consumption as we can. I DO get that. I was just saying, I liked hearing a real 599 from the other side of the world, it reminded me of the days of the powerful coastal stations.

New To Radio / Re: How much power do you need?
« on: August 27, 2017, 08:49:43 AM »
And over SSB there is already a gain of up to 20dB.

I know you meant CW here ;)

Indeed I did mean OVER SSB, CW already has a gain of up to 20dB. :-)

New To Radio / Re: SSB BFO setup
« on: August 27, 2017, 08:46:24 AM »
Hi, as your questions seems to have been missed, and I may be able to help with the second question: CW "normal" and "reverse". A CW is just a "carrier wave" it is just like an AM transmission without any modulation. If you listen to CW on an AM radio, you won't hear any tone. If you listen on an SSB radio, there is a carrier being injected "beat frequency oscillator" that mixes with the CW to produce a pitch. If that BFO is offset by 500Hz you will hear a 500Hz pitch CW. But that could be on EITHER side of the CW frequency. If it is 500Hz up or 500Hz below, you will hear 500Hz tone. So, CW "normal" is one (above or below) and CW "reverse" is the opposite side of the CW signal. This helps when there is adjacent interfering signal(s) because by using either "N" or "R" you may get rid of that noise. But of course Google is also your friend here and you may find better answers:

Hope that helps!

New To Radio / Re: Do I need an SWR meter for a backpack rig?
« on: August 27, 2017, 08:40:39 AM »
Thanks, very educational, good solutions!

Updated original post with QCX power consumption values.

VHF and Above / Re: Extend Range With 2m VHF SSB Radio.
« on: August 26, 2017, 09:13:25 AM »

I would get the MTR4b...

Yes but what's your reasons? I know for you 20/30/40/80 is essential. If you take 80 out of the equation though would you still get the MTR-3 or -5 and if so, why above the others? For me 80m is normally not important as usually I'm near the equator. For me long term durability, and the other factors above mentioned are what's making my choice difficult. The QCX work out actually cheaper and seem to have more features, provided they are durable, than all the others, and you end up with multiple separate small rigs which has advantages over all eggs in one basket?

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