Thursday, 6 June 2019

Small, passive HF Loop made down under

A while ago a radio listener from Australia contacted me with photos of his passive HF loop whose creation my blog had helped inspire. I thought I'd posted photos on my original page Inductive vs Transformer coupling but I'm forgetful and scatty and had forgotten. It's a far more attractive loop than my own and shows you what a professional finish can be gotten from homebuilt antennas.



I really like this concertined plumbing pipe for small loops. It looks well professional and much better than the thinsulate grey plastic pipe lagging I've tried before. I shall have a scratch around the plumbing suppliers to check it out.

Friday, 31 May 2019

Saudia OPS LDOC Jeddah 8968 khz

Thanks to Mike at HF Aero Blog I have just heard my first HF ops frequency for years, apart from Stockholm. Caught Saudia OPS in Jeddah talking in English to SVA806 as it started its descent for Dhaka. So this was 31.May.2019 at 1722UTC.

I miss the written frequency guides of the 1980s and 1990s and also the Airwaves frequency guides from Photoavia Press, and to be honest I have been a bit lost without them. Internet stuff is mostly decades out of date and I haven't found any blogs that are useful for HF frequencies. Sure I know the North Atlantic, South Atlantic, MID, SEA, INO, PAC ATC frequencies. And several military SSB ones for German, French, Portuguese, Spanish and USAF. But my main interest is civilian stuff, and then mostly the OPS/LDOC side of it.

There's a Russian LDOC freq active on 11193 khz I think. Anyone know of anymore???

It can't just be Saudia and Aeroflot who use HF!

I will try and blog EVERYTHING of interest here.


Saturday, 6 April 2019

Smith-Waite Centennial Tarot

I have often read comments about the Smith-Waite Centennial Tarot (Pamela Colman Smith Commemorative Set) from people who say they do not like the "artificial ageing" done to the cards to give them an old and antique feel.

Well, I recently bought an Original Rider Waite tarot deck (more about that in another post) and decided to do some comparing of the Smith-Waite Centennial to some original scans of the deck it was based on (an original Pam-A Rider Waite deck from a private collector). The scans are available here and what I did was print them onto high quality paper and put my Smith-Waite Tarot-in-a Tin deck next to them for a direct comparison.

The left-hand image is the scan and the Centennial card is to the right of it.


As you can see, the cards have not been artificially aged at all. In fact the Pam-A deck, which is now over 100 years old!, naturally shows signs of ageing and the Centennial has done what I think is a superb job of restoring them to what they would have looked like originally.

The only shame is what US Games did to the card backs that are awful. Why I wonder didn't they put the original crackled backs on them? Or even a Roses & Lillies pattern? It seems a missed opportunity indeed to have gone to such extraordinary lengths to obtain such a top quality restoration of the original Pam-A deck, and then to add these newly-designed and non-descript backs.

I hope that soon a deck will come out that corrects this, and we tarot lovers will finally have the perfect Rider Waite deck!

Friday, 1 February 2019

Homemade HF magnetic loop for SWL / Receiving Inductive vs Transformer Coupling

fig 1

fig2

fig 3

fig 4
fig 5
I can't believe my last post was almost a year ago! Anyway, I wanted to share a new design skill I have learnt for coupling my small magnetic loops antennas. As those of you who have read my previous posts might know, I have been using these homemade passive tuned loops for years now, as they are consistently the best type of aerial for urban dwellers like myself who can not or don't want to put up elaborate outdoor aerials or ground rods for earthing them. They are easy to make, can be built for less than $10, and are much more enjoyable and satisfying to use than any commercial aerial I've tried.

Up until now, the main 35-40cm receiving loops have been coupled to the radios inductively. This means I have made a second loop from a piece of coaxial cable or insulated wire about 1/5 the diameter, which is then connected to a coaxial feed cable, very close to the main loop but not physically connected to it (this is inductive coupling) and away you go. (see fig 1)

Recently I have decided I want to try to amplify the loop a little, and I have bought a 9-12v low niose amplifier (ready-made), and small variable resistor (to adjust the gain). But in looking at commercial loops like those from PK Loops in Australia, and AOR, I have noticed they do not have these somewhat unsightly secondary loops in their design, and I have wanted to trhy a different coupling method to smarten things up a bit.

I'm not heavily into technical jargon as it overwhelms me and puts me off starting new projects when the instructions full of it. Usually what these articles are saying is very easy and straightforward, but the complicated language lowers my confidence and makes me think it is too technically demanding.
But as I have got older my confidence is improving and if you look around carefully you will come across one or two articles that are easier to understand and ebncourage you to have a bash. Hence my reason for blogging about loop aerials for so long.

Anyway, to cut a long story short, I have ditched the ugly second loop and gone over to transformer coupling. It is way easier and give the finished loop a cleaner, more professional look.

All you need to do is buy a small ferrite ring (toroid). A T130-2 is 1.3inches in diameter and perfect for the job. I bought two from Bowood Electronics for just over £5 incl postage. Personally I would have thought that for receiving only it wouldn't make too much difference what toroid you used, just so long as you can get half a dozen or so turns or wire and your main loop through the centre.

A word about toroid sizes: a T130-2 is 1.3 inches diameter, a T30-2 is 0.3 inches diameter. The first number relates to the diameter in inches. I can't remember the second one, but again for SWL I don't think it matter enormously. You just need a ring of ferrite.

I searched high and low for information about this as I wanted to know how many turns I needed, what type of wire, how the turns should be wound etc etc In the end I got the gist of it, and learned through reading and trial and error that for max efficiency it works best when the turns are evenly spread around the whole circumference of the toroid. I tried two or three and could tell that compared to the inductively coupled loop certain frequencies wouldn't peak up properly. I increased up to 15 and it was worse! Finally, through a long process of trial and error, I found that for my small 1 foot loops I needed 7 turns of wire (I used the blue wire from standard twin-core 5 amp electrical cable).

One end of the wire goes to the coax braid, the other end to the centre core, and then just plug the other end of the coax feed into the radio.

This new form of coupling seems to produce results just as good as the inductively-coupled loops. Better to my ears in fact as there seems to be less noise. Now, if I were to test the SWR, I could'nt guarantee the transfomer coupled loops were any better. They may even be worse. But I'm a SWL not a radio ham, Im not obsessed with measurable figures and standing wave ratios,'and my loops are for receive only, and I have listened to extremely weak sideband signals on the same loop, swapping from one coupling method to the other, and honestly, I couldn't tell any difference.

I MUST STRESS THESE LOOPS ARE FOR RECEIVE ONLY. DO NOT TRANSMIT EVEN QRP SIGNALS ON THEM. THEY ARE NOT DESIGNED FOR THIS. YOU WOULD NEED AN APPROPRIATE CAPACITOR (for QRP work, more widely spaced vanes at least), THE TOROID VALUE MIGHT BE OF MORE IMPORTANCE, AND THE MATERIALS USED MIGHT NEED TO BE TOUGHER TO COPE WITH THE RF POWER YOU WERE TRANSMITTING.

Anyway, that's enough for this afternoon. Let me know if you have any comments, questions, suggestions etc I love hearing from anyone interested. If you have never made any stuff yourself, take my word for it: IT IS TERRIFIC FUN. You'll save hundred of pounds, the finished product can be made to look pretty decent with only easily obtained bits and pieces, and using it will give you a buzz no commercial product ever will.☺

I realise I have not put any construction details for the loop so I am attaching a png from Mike at Merseyradar. co.uk who kindly did a diagram for me.

The main receiving loop is 35cm diameter and has two windings with a switch to select whether you choose one or both of them. It is tuned with a small variable capacitor that I bought on eBay and the two gangs of the capacitor have been joined together to give what I think is 760 PF capacitance but it maybe 1000pf as I'm afraid I bought it years ago and don't have the purchase details anymore.

If you were to use only a single loop winding and omit the switch then you would get a tuning range of approximately 5 to 30 mHz. But with solar activity so low over recent years I really needed it to tune down to the shanwick Night-Time frequencies in the nighttime frequencies in the 2, 3 and 4 MHz band. Oh and I also like listening to the maritime calling frequency of 2182 kilohertz, so 2 MHz seems an appropriate place to stop for my requirements. 

I also want to update you about the plans to amplify the loop as these have unfortunately been a huge waste of time! Hours of work and waiting for components to arrive from China just resulted in a whole lot of noise being pumped into the system and the whole loop became completely unusable. I am slowly coming to the conclusion that if you are turning to a loop because an outdoor antenna will be too noisy than the last thing you want is amplification. 

It may be different for a professionally constructed loop like those from aor or PK in Australia, but I strongly suspect after years of having tinkered around with aerials for shortwave listening that any performance improvement as a result of amplification would be marginal at best. So my advice would be to forget about any expensive commercial product and have a bash at building one of your own. It's so much more rewarding in every way. 

And if you do have any stories to share about your experiences with loop designs please feel free to comment. 


Sunday, 25 February 2018

HF Aero Logs February 2018 incl 8894 khz Algiers

30JAN18 1009Z 5708khz French Navy HR clg "Armour"
05FEB18 0825Z 5687khz German Air Force GAF083 dep.0809 selcal AJFL alt freq K, M
05FEB18 1035Z 11217khz GAF083
06FEB18 0731Z 6535khz TAM8084 Sao Paulo - LHR wkg HF Oceanic FL330
12FEB18 1836Z 8903khz Air France 804 wkg Niamey FL400
13FEB18 0940Z 5690khz Irish Coastguard SA wkg C252 ops want you to call us on 125.025 VHF
16FEB18 1830Z 8861khz TUI5052 Sal-Brussels wkg Canarias nxt call 133.0 and selcal chk
16FEB18 1834Z 8861khz JMK417 clg Johannesburg Oceanic no reply
17FEB18 0745Z 8894khz 7T-VJB wkg Algiers req selcal chk after landing from Montreal
17FEB18 0835Z 8894khz 7T-VND Twin Oter wkg Algiers on 335radial 150nm from VOR "IMN"
19FEB18 1639Z 11300khz Emirates 702 wkg Mogadishu FL390
19FEB18 1847Z 8861khz Cabo Verde 691 from Boston wkg Sal Oceanic ctc now Sal 128.3
23FEB18 0720Z 8894khz ZS-DIH wkg Algiers (Let 410 of Red Cross)
23FEB18 0722Z 8894khz Royal Air Maroc 290 to Casablanca FL340
23FEB18 0723Z 8894khz THY538 Ougadougou to Istanbul wkg Algiers climb FL350
25FEB18 0735Z 8894khz ZS-DIH Red \cross Let410 wkg Algiers req Hassi Mesaoud weather

Saturday, 9 December 2017

Learning theTarot de Marseille (Keywords)

A few weeks ago I published some keywords for the Tarot de Marseille that I had been working with. But I have come up with another version that works much better for me, and I wanted to post them on my blog. Nick's Numerology website has been a huge help in learning the numbers and I thoroughly recommend it.

If, like me, you have come from a RWS tarot background, the challenge is additionally hard when it comes to learning the TdM as we have already learned a lot of meanings and associations between cards and pictures. And all of this need to be re-learnt. That is a huge challenge. Even after months with the Tarot de Marseille, you only have to mention "6 of Swords" and I see people in a boat, or "6 of Cups" and I see the funny little pixie visiting the girl. In fact, some numerology + suit meanings I am learning for the TdM tie-in quite closely with Pamela Colman Smith's charming drawings. But I think if you really want to learn the Tarot de Marseille and allow your creativity in to the learning process as well, then you need to do your best to try and put to one side any knowledge accrued with the RWS cards.

I have asked myself, as there are so many numerological systems and if there is no recognised meaning of the numbers in numerology even within one system, then there can't be anything to learn. And I would think about switching back to the more formulaic meanings of the RWS. But that would be a shame and a mistake which I only realised after readings Nick's ebook in which he says the very numerological meaning of the word "NUMEROLOGY" means it is open to interpretation. In other words, that there is no "right" or "wrong" meaning of a number, and that our very creativity and intuition is part of the process. We just need to discover a system that makes sense to us and our world view and our spiritual understanding, and then apply it.

I myself have always been sceptical of people interpreting "fives" as conflict and challenge and instability. For me, it has always been a number of expansion & learning. It is one of the reasons the RWS tarot felt wrong to me eventually. But if you have a particular liking for and affinity with qabalistic numerology, you probably won't agree. This inexactness of the art is at once fascinating to me and a cause of much frustration, as my more rational mind doesn't like it one bit!

Anyway, I hope that you can expand these jpegs to read enough details and I hope you find them a useful springboard for your own study of the Tarot de Marseille.