AmateurRadio.com

Well, I have ordered one (yes I know I could have made one although not in my present state) so I hope this can be erected in the next few weeks, although I shall need help to do this as I am no good on ladders in my current poor state of health. It would be good if I could get a long wire erected at the same time for LF/MF use, although this could wait. At this time I am going for a single big-wheel rather than a stack.

I have decided against buying a 70cm big wheel at the same time as this would require a new length of low loss cable too. I also checked my existing low loss cable and this seems in good condition, so it will be reused. I may make my combined 2m/70cm antenna into a portable antenna when I have found out why the VSWR is poor.

See https://sites.google.com/site/g3xbmqrp3/antennas/bigwheel .

Bob, G3WKW, has passed on this information from Joe Taylor K1JT:

“Date: Fri, 07 Aug 2015 16:28:19 -0400

Several people have asked for an update on development of the “Fast modes” in WSJT and WSJT-X.  So here’s a brief summary.

First, a review of some relevant terms and motivations.  It’s convenient to think of the various WSJT protocols (“modes”) in two groups:

*Slow modes* — JT4, JT9, JT65, and WSPR.  These modes are designed for communication with extremely weak signals — often too weak to be heard. Target propagation modes include EME and long-distance troposcatter on HF-and-up bands, and QRP Dxing on the LF, MF, and HF  bands.  Relevant signal amplitudes are approximately constant over a minute and more, aside from so-called “libration fading” for EME. Transmit/receive sequences are 1 minute for JT4, JT9, and JT65, and 2 minutes for WSPR.

*Fast modes* — JTMS, FSK441, ISCAT, and JT6M — and now also *FSK315* (implemented in WSJT) and *JT9E* through *JT9H* (implemented in WSJT-X. These modes are made for communication with rapidly varying signals:for example, meteor scatter, ionospheric scatter, airplane scatter, and scatter off the International Space Station.  The decoders are designed take advantage of short enhancements of signal strength.  T/R sequences are 30 seconds (or sometimes even shorter).

Bill, ND0B, has implemented a trial version of FSK315 in WSJT.  Think of this mode as FSK441 slowed down to 315 baud; the bandwidth is therefore narrow enough to make the mode legal in the “CW and data” portion of the 10 meter band.  Bill and a few others have been experimenting with FSK315 and also ISCAT-A on 10 meters, under dead-band conditions, using meteors and ionospheric scatter propagation.

I have implemented experimental submodes of the JT9 protocol in the program branch WSJT-X v1.6.1.  As with JT4 and JT65, letters following the “JT9” designator indicate increased spacings between the FSK tones. Traditional JT9 (now also called JT9A) has tone spacing 1.736 Hz, so the signals used at HF and below have total bandwidth 9*1.736 = 15.6 Hz.  The widest of the new submodes, JT9H, has tone spacing 200 Hz and therefore bandwidth 9*200 = 1800 Hz.

When used with the standard 1-minute periods, the wide JT9 submodes should be useful for the same purposes as the wide JT4 submodes: microwave EME, for example, where libration fading can cause Doppler spreading of 100 Hz or more.  Used in this way, all JT9 submodes are “slow” modes; they use 1-minute T/R periods and keying rate 1.736 baud, and they send the full 85-symbol message protocol in 85/1.736 = 48.96s.

Optionally, the wide JT9 submodes can now also use “fast” keying rates equal to their tone spacing.  “Fast JT9H”, for example, uses keying rate 200 baud, so the full message protocol is transmitted in 85/200 = 0.425s.  The message is sent repeatedly for the full Tx period, in the same way as done for the other fast modes.

The fast JT9 submodes should be very effective for meteors and ionoscatter propagation, especially on the 6 meter band.  Sensitivity should be similar to ISCAT, or perhaps slightly better.  Because JT9 includes strong forward error correction, decoding results are like those for all the slow modes: you should see messages exactly as they were transmitted, or nothing at all.

Tests of the fast JT9 submodes are currently under way, with excellent results.

   — 73, Joe, K1JT”

Time and again I have been struck by just how unsporadic Es is. OK, good days are random but there seems to be a pattern that more northerly and Scandinavian stations on 10m and 6m are better later in the day and later in the season. I actually wonder if these more northerly reports really are Es at all. There is every chance I am totally wrong, but I have noticed this over several summers and I question that Es is truly “sporadic”. I’d be interested to hear the views of others on this.

One thing is certain: we still have a great deal to learn about E-layer DX propagation. Es is certainly a fact on many summertime EU QSOs on the higher HF bands and 6m, but I am sure the multi-hop explanation for some very long distance QSOs is not right.

Like many of my projects, this transceiver is “on hold” due to my stroke. I am still too unwell to do much in the way of designing and building. One day, not too far away, I hope to complete this project. If anyone else wants to do this, please use my schematic as a starting point. With a small PCB it would make a nice club project.

It will make an ideal simple rig for nattering across town, especially as 10m loses its fizz and starts to act more like a vhf band again. Such conditions may be with us for years. I fancy putting this in a box like the old Heathkit Lunchboxes with a proper LS amp and LS.

See https://sites.google.com/site/g3xbmqrp3/hf/tenbox .

I wonder when the next round of price drops will come on Japanese gear? The big Japanese players such as Yaesu, Icom and Kenwood have had an easy ride of late and been able to dictate prices. Now the competition is waking up, I expect they will be facing tougher times.

The latest exchange rates (UK pound to Japanese Yen) is £1 is worth about 193 Yen. Not many years ago it was less than 130 Yen to the pound. In real terms, Japanese goods should be much less expensive. At the moment both the UK dealers and Japanese are doing very well thank you from a customer base prepared to pay high prices. Expect big falls between now and the year end. This will be partly due exchange rates becoming much better (for those in the UK) and partly due to the increasing threat from the non-Japanese suppliers. Don’t you find it amazing how low cost some Chinese hand portables are compared with similar products from Japan? Rip-off come to mind – charge high prices for Japanese goods as long as the suckers pay.

No, the age of UK amateur radio consumers being taken for a ride is ending. The next time you discuss prices with UK dealers remind them of competition and exchange rates! At the moment their margins must be very high. Japanese goods are priced too high in the UK – fact. A few years ago I was more sympathetic, but not any more. UK consumers should pay a fair price with the dealers getting a fair margin, but please don’t take us all for mugs. I shall buy when the prices are fair and not before.

If I have this wrong, I shall be interested to hear the dealers viewpoint. Exchange rates have got vastly better and I do not see this reflected in end user prices here in the UK.  Someone is making very handsome profits.

Consumers – vote with your wallets and do not buy overpriced radios.  I have said before, the FT817 is classic example: all development costs were recovered years ago, so the price should be considerably lower than it is. Dealers have dropped the price somewhat, but it is nowhere near what it should be for a very mature design.

Thanks to Phil G4HFU (see earlier post) I have been reacquainted with the old PW adverts that got me dreaming over 50 years ago. I wonder if other blog readers can point me in the direction of old UK magazines and adverts? I was first interested in radio and SWLing in the early 1960s.

Back then, the world was a very different place. The Beatles were still in the future.  We lived under the constant fear of all out nuclear war (I was terrified in the 1962 Cuba crisis) and most amateur DX was by CW or AM. Although RTTY was around, most digital modes were not. Magazines like Practical Wireless, Radio Constructor and Short Wave Magazine were filled with goodies I drooled over, but could not afford. Even now I do not like parting with money for amateur gear unless there is a good chance of getting very many years of good service from it.

I think the RSGB must be getting short of articles for RadCom.

Last month they reviewed a linear that cannot be legally used in the UK because of its high power. There were a couple of critical letters about this in the August RadCom. Why did the RSGB print this review at all? We, in the UK, have a power level of 400W pep on most bands and we should encourage UK amateurs to keep to this. I have rarely used more than 5-10W pep and even 100W sounds like incredibly high power! No, let us have more articles in the spirit of amateur radio. Not everyone is interested in big, overpriced radios, linears, towers and huge HF beams. Just a few watts is enough to span the globe.

Anyone can work the world with 1000W and an HF beam on a tower. You can also video conference world wide for free with Skype!

QRP is a real challenge. High power rigs, big HF beam and linears are more about egos. Personally they do little for me.