Propagation Updater

You go on the BBRC site and check the propagation updater to see what bands are looking OK. It says 15 and 20 are good during the day and the night. You check out 20 Mtrs at 10.30 pm and it is completely shut down!!!!! This seems to happen every time I try it. Is it always this wrong??

73s Charles g0ska

Panoramic Camera

This one has to fall under the 'why didn't I think of that?' heading. 

Take a series of cheap mobile phone camera modules, put them inside a ball which you can print using a 3D printer (I want one!) add an accelerometer, ATTiny and some other electronics to trigger the cameras at the zenith of the balls flight, post process the resulting images and hey presto, you have a panoramic picture. Oh you need someone to throw the ball in the air as well of course!If this doesn't quite make sense, this video by the 'thing's' creator Jonas Pfeil should explain all. Now remind me again 'why didn't I think of that?' 

I know you're out there!

I thought I would try asking my QSL Manager by email whether there were any cards waiting for me, and he very kindly replied saying there were seven sitting in my bin, so I sent him an envelope. He had kept the cards since 2006!

Three of the cards were I consider very treasured and sentimental, and will go in with the rest of my collection. By the way, at the rate I am going it will probably take me about a thousand years to get DXCC! Of the other four, two were for RTTY contacts, one with Uganda, and the other with an Indonesian station. I then was supposed to have had a multi band contact using CW and SSB with a station in Djibouti, and a plain old SSB contact with Java, again Indonesia!

The cards covered contacts made in the period between 2006 and 2008, and I dont recall for example making them using BBRC club equipment, so somebody out there was thinking my call was available for them to use. I am deliberately putting this on public record so that whoever you are....I know you are out there; I do listen; and if you are still there with my callsign, I will take action.

Rant over. :-)

Heard at the RSGB Convention

70 cms will definitely be out of bounds for amateur use, because like in Stratford, they will most likely be using it for radio linkage of the timing mechanisms needed to provide accurate timing for the Rowing and Kayak events at Dorney. The transmit outputs there will need to be high enough to overcome any potential interference from other transmissions on shore or those carried on the escort boats, and that says to me these could be potentially very strong signals round this way. And by the way, dont think about jamming because they now have measures in place to triangulate on jammer or illegal signals down to within a 5 metre square.

Droitwich latest

Not sure how many of you out there still listen to LW (198 kHz) these days, but I still find it helpful not only on an occasional basis for Test Match Special, but on a routine basis. I note the BBC on 6th October announced that they would not be putting more resources into LW, as part of their strategy for cutting back on overheads, to try and make the books balance. More recently they interviewed (I think it was on the Today programme) a Senior Engineer who said they only have a limited number of the very specialised final output stage glass valve bottles remaining, and it was implied that when these are used, they will then use that as the reasoning for station closure. The other part of this same interview was with an Engineer of the Danish broadcast service, who said they regarded LW there as still important because of the number of gaps in coverage over there which LW filled in. He was clearly not a fan of DAB! Apparently when the station needed replacement they went to Harris (one of a number of suitable makers) who have provided them with an acceptable transistorised LW transmitter which works very well thank you.

Just thought I would pass it on. Where theres a will theres a way.

A printer saga?

Well maybe, and maybe not. Lets tell you what happened and I will let you decide.

In December 2010, I was seduced by Kodaks current advertising campaign claiming lowest printer costs. It wasn’t my intention to purchase a printer, but when just before Christmas I went into that well known PC Computer Store on the Bath Road in Slough, and saw this pile of Kodak ESP5210 printers being sold at a special half price deal, I relented and took one home.

It installed well, copied scanned and printed out all as per the tin. Great. Over the coming few months I then started to have a series of issues with BT who are the ISP here. The maximum they were capable of delivering here was just under 3 MB, and that was on a good day. It wasnt helped that in different parts of the house we achieved differing results, and it was noticeable that the front of the house was achieving slower download speeds than at the rear of the house.

We had been previously with Virgin Media here, but as they seemed incapable of delivering more than dial up speeds, we switched to BT, because at least that gave an improvement in our download performance here, and we have been with BT for the last 3 years. I was always concerned about BT however because none of the cabling when it was first laid down on this estate was laid in ducts, and worse, the price of copper at that time (1972) was such that they decided they would install coax to house with aluminium inners. The result over the years has been repeated call backs to reconnect corroded cabling. The tendency of the clay soil here to retain water even though we are on the side of a hill, even caused water to erupt out of the pavement near us during times of heavy rainfall, and that hasn’t helped!

So when Virgin announced they were now delivering up to 100 MB to our street I was very tempted to switch, particularly as we were already cabled up for them. We had signed a contract with BT which wasn’t going to expire until 31^st October this year and to exit the contract would have meant buying our way out, which earlier in the year would have been expensive. However, matters forced our hand here, and we experienced in late July and early August a series of service outages/failures/dropouts.

I made a series of calls to BTs broadband faults centre in (I think) Bangalore, and on the first two occasions I was happy enough with the outcomes. Then at the beginning of August I made the first of a series of three calls them with further complaints about the broadband delivery here, and on each occasion they said they had made an “adjustment” which would fix it. In each case the fix lasted 24 hours, and when the fix on the third day hadn’t worked, exasperation kicked in, and the call to Virgin got BT booted into touch and installation with VM was made on the 16^th August. The interesting thing was that although we had to buy our way out of the contract, BT were prepared to offer a replacement telephone contract with 3 months rental free, which we took up because whilst Virgin could offer the broadband they had run out of line capacity and we therefore have had to keep the phone with BT.

Download speeds were noticeably improved and typically in most parts of the house went from typical dial up speeds (what BT ended up delivering) to around the 20 to 25 MB level, (we had ordered up to 30 MB speed here).

We still however had the issue of download speeds being noticaeably slowere at the front of the house. A call to Virgin came up with a number of suggestions, including to try using a free 2.4GHz spectrum analyzer, called inSSIDer2.0 available from www.metgeek.net.

So I downloaded this and was able to see which of the 13 available channels were in use here. As I carried the laptop around the house, it was noticeable that stronger signals were being received co and adjacent channel from the neighbour over the road, who had one of those broadband Belkin routers occupying a large spread of spectrum. Nevertheless I was able to identify that channel 13 was not in use locally and once I switched the router frequency here, downloads and general operation of all the laptops almost instantaneously improved.

Wait for it. The printer however not only stopped working; it couldn’t connect with the system here. I racked my brain cell. I called Kodak and chatted with them on their LiveChat facility. They promised to escalate the issue but could not resolve it.

I took another look at inSSIDer2.0, and noticed that it displayed a channel 14, and that channel 14 wasn’t available as an option to QSY to here. I took a look on Wikipedia (yes, reader!). Reading up about Wifi and the spectrum allocations I saw that within the 2.4 GHz allocations, channels 1 to 14 were available in Japan, channels 1 to 13 were available in Europe, and in the USA the allocation was 1 to 11.

I went back to the printer and looked in the network config and saw that the machine was setup for USA, presumably in firmware, and it was certainly not possible to change this within the machine setup procedure.

Bingo! Dilemma! The problem with the printer had been isolated without outside assistance. However the dealership concerned have a reputation for not giving refunds easily. I fished out the receipt, and visited them, and after explaining all this (which I wasn’t sure they understood) used the magic words “the equipment sold was not of merchantable quality”, and it wasnt long before I got a refund.

I ended up going to another dealer (Big T) using a discount coupon to get a fiver off, and got a Kodak ESP 5250 (the next model up) this last weekend, which installed first time, functioned beautifully, found the network (because it was a European model), and has performed so far flawlessly.

So for me the moral of the story is be careful when you think you see a bargain, because once again what you see is what you get, and you can get problems down the line when you least expect them.

How much capacity in that dune?

Varicaps have been around for ever it seems so I suppose it was only a matter of time until someone came up with a alternative. Peregrine Semiconductor has released (full production in Q3) a switched capacitor chip with built in SPI interface.
Sadly they don't allow access to their datasheets of mere mortals like me so some of the following is from different sources.

Called the DuNE the range of digitally tunable capacitors (DTCs) have either I2C and SPI digital interfaces and are on a 2x2mm QFN package. They feature  a series configuration C = 0.7-4.6 pF (6.6:1 tuning ratio) in discrete 126 fF steps, Shunt configuration C = 1.2-5.1 pF (4.6:1 tuning ratio) in discrete 131 fF steps and  High RF power handling : (>+38 dBm @ 50 Ω, 30 Vpk RF) and linearity. Switching speed is 5uS - though I don't know if that figure includes settling time.
With a frequency operation range of 300MHz to 3GHz it could be of use to us amateurs when it becomes available in quantities though Peregrine have its possible applications as Tunable Filters Networks, Tunable Antennas, RFID, Tunable Matching Networks, Phase Shifters and Wireless Communications.
Covering most of the bases there then.

Well its better than data sheets I guess

Stuck looking for that data sheet?

Can't find the dynamic parameters?

What's VMax anyway?

You need the help of Captain Zilog

In what seems to me to be a slightly bizarre marketing vehicle Zilog have launched a online comic.

In the current episode Captain Zilog  comes to the rescue of the car plant when it's infested with robot worms.

I won't spoil the ending here, you'll just have to go and read it yourself

I still think it's a bit strange but it has at least worked sufficiently for me to now know that Zilog didn't die with the Z80. Captain to the rescue indeed.

Hameg Scopes

I have been offered a small quantity of working Hameg scopes for postage cost only (Probably about £15 each). Model 203-6. Good general purpose 20MHz dual-beam models, modern-looking and compact. Manuals and cheap probes are readily available on the net. Contact me via Charles G0SKA if interested. 73 Jeremy.

Nice water feature... No that's my aerial

This idea is not new (see Ionic Liquid Antenna) but I haven't found any designs using a current probe rather than direct coupling into the water stream (Comments welcome).




The option shown later in the video using a land based aerial and pipe looks like a more viable idea to me, otherwise is seems like a strong wind could cause havoc to the SWR.

National Museum of Computing

The excellent National Museum of Computing has released this video showing some of its work and exhibits.




Those who went on the visit to Bletchley Park with the club a while back already know the details but for anyone considering a visit I would highly recommend it as it encompasses not only the above but many other interesting exhibits relating to the work carried out here during the war.

Sadly when I was there earlier in the year the national amateur radio center is one exhibit that wasn't yet open.

One day.... soon?

Eye Eye

I was reminded of the 1986 Star Trek film The Voyage Home where Scottie gets bemused that the computer doesn't respond when he talks into the mouse (4:09 in the video below) the other day when I tried yet again to use voice search on my Android phone.

Science fiction hasn't quite arrived as my search for Hotel in Datchet came back looking for Hotel in Test Kit but it is frustratingly close and it seems that it might be at a level where we hobbyists can start having a 'play'. National Instruments have a interesting article 'EyeMario' in which they have published the source code for a interface between a human eye and an old Nintendo games system.

While it uses a NI single board computer the dev kit of which seems to retail at £779 and some custom hardware to filter the input from the electrodes placed around the face, it's not beyond the bounds of belief for a interested party.

The article also provides a interesting insight into the companies Lab View product as used to design the system. Of course, having to have electrodes connected to your face before you can use a piece of equipment let alone the new definition for eye stain that players in the demo look like they are going to suffer puts this in the almost there category but we are getting close.

Now off to find that test kit.

Long live analogue

OK so everything is going digital these days isn't it. Well not quite, you may be surprised to know that a new solid state self steering aerial currently under development by the Queen's University Belfast's Institute of Electronics is shunning the digital domain and processing in analogue using 'specially adapted phase locked loop circuits'.
The ESA project is developing a 1.6GHz demonstrator but with a view to a final device operating at 20 to 30Ghz. The team lead engineer Dr. Neil Buchanan says :

"We believe that self-tracking antennas offer the prospect of much simpler and more cost effective alternatives to other current approaches. That, we believe, makes them ideally suited to a variety of end uses."
"For example, satellite broadband aircraft antennas are extremely complex. They need to be linked into the plane's on board navigation system in order to find the satellite. In trains and road vehicles, they consume a lot of power and they require mechanical parts for tracking purposes."
"We believe that across these applications the solution we are currently working on could reduce power consumption by a factor of 10, weight by a factor of five and cost by a factor of four."


More power to has (analog) elbow.

BBC to be turned into a private organisation

OK, that's a deliberately controversial and factually incorrect headline but is does seem that Auntie may be thinking of privatising it’s commercial arm. Amazingly,  BBC Worldwide is currently generating 10% of Britain's creative exports. With sales of £1,074m and a profit of £145m a sale of 50% of the could bring as much as £1billion into the Beeb's coffers. Not bad for a few TV Shows

For anyone complaining about the cost of putting aerials on masts....

How do you fancy having a go yourself? I get shivers just watching this guy, especially when he is getting towards the top and climbing using what appears to be coach bolts.

Incidentally this video originates at The Online Engineer which provides great and informative reading for anyone interested in broadcast engineering. You won't find it there anymore though as it was removed by web site owner Russ Brown to protect his friend who supplied the footage. If appears that a war of words blew up over the legality of the methods used by the workers in the video. Such is the power of the Internet though that cat was out of the bag. Not wishing to violate any one's privacy, I should point out that the above video is linked from  Live Link and it is them who continue to host it.

Ian