ISS Flash Project

Guido PE1NNZ has sent me this interesting link about a recent experiment with the International Space Station using optical frequencies. See http://www.cqdx.ru/ham/ham_radio/iss-flash-project/ .

Back home again and the 472kHz transverter

Icefield Parkway, Alberta

After nearly a couple of astounding weeks in British Columbia and Alberta, Canada my wife and I are now back home. The scenery and wildlife were just amazing, especially the bears like the one below seen just a few metres away from us.  Although I only managed about an hour of shallow sleep on the plane back from Calgary last night I decided it was better to fight the jet-lag and get on with some chores rather than crash out and wake at 2am tomorrow.

One of the 8 black bears we encountered - this one VERY closely

Once the lawns have been trimmed and the hedge cut, I've decided to crack on with the design of a new transverter for 472-479kHz as the next project. Already there is activity from Germany and there are a number of NDB beacons to allow the receiver part to be checked. Jan 1st 2013 (the likely date of release in the UK) will arrive far too soon.

I am trying to decide on the choice of IF as I want to use an unmodified FT817. 28MHz will allow 472-479kHz to appear "in-band", but at 28MHz the start-up drift as the LO settles will still be some tens of Hertz. This hasn't proved problematic with WSPR, so guess this is my choice. At least the dial will directly read the "right" frequency e.g. 28.477kHz will correspond to 477kHz.

In view of the picture above, I am not sure what power the transverter will use bear-foot (sorry, weak joke).

Knife Edge Refraction at VHF

Currently I am sitting in a log cabin (with a log fire) surrounded by snow capped mountain peaks wondering how 2m propagation would be from here. Sharp mountains often allow good propagation into screened valleys by refraction over the peaks sometimes with strong signals. Unfortunately I have no ham gear (apart from Echolink) to try it. Instead I am just enjoying the views. 10cm snow forecast tomorrow here, HI.

Canadian Rockies

For the last few days I've been in the Canadian Rockies. The scenery is truly the very best I've seen (inland) anywhere on Earth. The 300km drive today from Banff to Jasper had snow capped mountains and azure blue lakes and rivers all the way. Only seen 1 HF antenna so far and that was from the Rocky Mountaineer train from Vancouver to Banff.

Germany gets 472-479kHz

Surprisingly, news on the wires today that German amateurs have been granted early access to the new MF allocation. I wonder if OFCOM will release it early too?

"LF Today" RSGB book on special offer

This excellent introduction to LF/MF amateur radio is available from the RSGB bookshop at just £7.99 and I can recommend it. It helped me a lot when I started and still gets referred to regularly.

CW on 136kHz

Mike G3XDV reported normal speed CW activity on 136kHz with QSOs with G3KEV and DK7FC's normal speed CW beacon. Although harder work with QRP, 136kHz is an ideal band for CW contacts. A lot of people are saddened that digital weak signal modes have rather put CW on the shelf.

VE7 Repeaters

Now 23 hours without sleep having arrived in Vancouver after a long flight from the UK. Currently in the hotel room trying to work some BC locals via Echolink connected repeaters. What I really need is SLEEP though!

First country gets 472kHz allocation

Monaco is reported (by 3A2LF) to have allocated the 472-479kHz band to radio amateurs from May 18th as a secondary allocation with a maximum power of 1W EIRP. Others are likely to follow in the following 12 months, we hope.

FT817 replacement - 2 years away

The following (extract from a) post from Bryan KE6ZGP appeared on the FT817 Yahoo group in the last few days.

"Tom interviewed the Yaesu rep about their new FT-DX3000 and the FT-1D, when all was said and done he started taking questions, I went ahead and asked about a possible replacement for the FT-817. The rep then stated - due to some parts (like the LCD screen) either being no longer available or extremely hard to find, they will likely replace the FT-817 in a couple years. He wasn't sure when exactly, R&D hasn't started on anything, but the earliest we can expect to hear any solid talk is two years from now."

Now I assume this data is good and the rep from Yaesu is properly informed. If so, then any replacement to the FT817 is at least 2 years away. This gives Elecraft a clear field for a couple of years with their new KX3. The only other QRP radio on the horizon is the Ten Tec Argonaut VI which is due out towards the end of the autumn this year.

Hendricks QRP Kits

The BitX SSB transceiver on the QRP Kits website

http://www.qrpkits.com/ have some really nice kits on their pages these days. If you are new to QRP then they offer a very nice way to join in the fun. One example is the very neat version of the famous BitX 20m SSB transceiver designed in India originally. They also have plenty of CW kits and accessory kits like ATUs, attenuators and simple pieces of test gear. I've never actually built any of these kits but they look well designed with clear building instructions.

The future of HF amateur radio

There is no doubt that HF amateur radio is changing. Fewer people ragchew these days (do you agree?) and there is considerably less activity outside of contests, mirroring a change already seen on the VHF bands. More people are using digital modes instead of phone and there is much more use of software tools to detect DX, decode and encode CW, PSK31, etc. The hobby is changing: some of the new ways of operating are very good, but along the way we are in danger of losing something of the appeal of the hobby perhaps?

Now, there is also another factor: it is very likely we will have seen the end of active sunspot cycles once the present low peak of cycle 24 declines. Many of us who experienced the peaks of 1957 through to 1980 are very unlikely to experience similar ones in our remaining lifetimes. Propagation on HF may never be as good as the second half of the 20th century for another 100 years. There are also theories that HF propagation is not as good as it was, even assuming similar solar activity, as if the ionosphere is actually changing its behaviour.

Then there is the challenge of spectrum pollution. This is already a menace for many of the lower HF bands but even bands like 10m and 6m are affected.

So, the challenge now is to look to the future, positively, and see how the future of HF will be redefined. I have no idea what the next 10 years will bring, but I suspect the use of our HF bands will be quite different by the 2020s.

Photo editing - try Gimp

Gimp screenshot example from the Gimp website

For several years I had been using an old version of Photoshop Elements to carry out basic editing of photos to add to this blog and my websites. When I "restored" my PC recently I made a decision NOT to reinstall it or MS Office, instead planning to use freely available alternatives.  For the photo editing I opted for a freeware package called Gimp, which many will know ... but I didn't. As far as I can tell so far it does everything I could before and quite a lot more all for nothing. See http://www.gimp.org/ for more information and various downloads.

My thanks

Thank you so much for everyone's support yesterday when I was feeling quite down: nine replies on the blog and as many again directly by email is true support in the best spirit of amateur radio. The message is "don't let the idiot's beat you down", which will be my motto.

Ours is a GREAT hobby and I guess we have to accept there will be a few bad apples in the orchard.  Anyway, firmly back in gear here with a list of projects far too long to do any time soon. Several interruptions likely in the next few weeks but I'll be getting my teeth into some good ones very soon.

Very simple Spectrum Analysers

On the GQRP Yahoo group recently there was some further mention of very simple spectrum analysers with some links to very impressive, yet simple circuits. I was recently offered an old HP analyser but it was very large, very old and quite expensive: I did not want something that might soon go wrong and take up a lot of space, but I still need something simple to allow basic spectrum measurements. Nothing too accurate is needed, just an indication of harmonic levels and the like.

In essence, a spectrum analyser boils down to a receiver with a swept oscillator with its output connected to a display such as an oscilloscope. In its most simple form it could be just a crystal set in which the tuned circuit is replaced by a varicap tuned circuit with the rectified output going to a display.  The voltage applied to the varicap is a sawtooth waveform (for example derived from a 555 timer IC) which also drives the x axis of the scope: this makes the tuned circuit sweep a band of frequencies over a second or so with the receiver's rectified output connecting to the Y axis of a scope. The resulting scope trace is then a picture of the band being scanned.

Shortwave scan on the VK2ZAY mint tin spectrum analyser

An example of a simple spectrum analyser in a small mint tin is at Alan VK2ZAY's site http://www.vk2zay.net/article/256. Although Alan was doing this design for fun, the resulting circuit based around a VHF super-regen receiver in the IF is quite remarkable.  It is a seriously useful piece of test equipment. This is the YouTube video of Alan describing the circuit:

An earlier simple design is available at http://www.qsl.net/n9zia/spec/Homebrew_Spectrum_Analyzer.pdf which uses the sweep voltage to control the local oscillator of an existing receiver.

More complex designs have wide dynamic range, more linear displays and narrow IF filters to improve the resolution. "You get what you pay for", but simplicity is still capable of providing something very useful.

A very sad day

Do you get days when everything goes wrong? Today was one of these for me.

A few weeks ago I suggested, after a long 5 day outage, that the RSGB LF-reflector migrated to a Yahoo Group. In my experience Yahoo groups are great: messages, files and photo storage and a great way to share and archive information with others of like mind. In over 15 years I have rarely had problems with any of the groups to which I belong.

After a few weeks, the group leader G3WKL decided to make the move to a Yahoo group having "taken the temperature" of the original group members. Then the "fun" began: a few people objected and started a flame war and I was centre stage of the hate, in particular from one particularly nasty and forthright individual. I could name him but will not stoop so low.

My intentions were good: I wanted to let people know that all they did with the original Blacksheep mailing list could still be done, but so much more too. Things like archiving of messages, 100GB of both file and photo storage etc.

The resulting avalanche of nasty and ill-informed posts, many of which were directed at me, has frankly sickened me. My faith in the hobby has been shattered by the bad feeling and unkindness of a few ill-informed individuals.

Amateur radio is usually a friendly and helpful community but in the last few days I have seen an altogether different and darker side of it, one which shames the community.

To be honest, I have never been nearer to throwing in the towel and taking up another hobby. This is indeed a very sad day.

472kHz designs

GW3UEP's website has some useful new designs for 25 and 100W transmitters for the new 472-479kHz band which is expected to become available Jan 1st 2013. These designs use very standard and easily available parts and are very simple to duplicate. They would be an ideal starting point for anyone wanting to get going on the new band in 7 months time.The designs are based on earlier ones for 500kHz.

Part of GW3UEP's simple TX for 472kHz

My May Objectives - achieved

This month I had two objectives:

   (a) make my 10m halo into a dual band 10m/6m version.
   (b) complete my 481THz optical speech transceiver.

Although a few days late, both objectives have been achieved with decent contacts on 10/6m and a 10.5km 2-way QSO on 481THz AM.

Several things will interrupt any objectives in the next month or so, but my next objectives are:

   (a) Improve the sensitivity of my optical transceiver RX.
   (b) Build a new transverter for the 472-479kHz band due to be released Jan 1st 2013 in the UK (we expect).

The first will allow me to use the dual-optics 481THz transceiver over longer paths. I hope to make some contacts over 20km in the next few months.

The second one (472kHz transverter) only needs to be completed before Christmas, but I'd like to get this moving soon. If possible I'd like to run the PA at around 20W - my earlier 500kHz transverter was just 5W - and to improve the RX sensitivity and selectivity. This new band will be a most interesting allocation and I expect quite a few stations to give it a try.

Joining the "over 10km" optical club

This morning I got a note from Stuart G8CYW which surprised me:

"Roger,

It has occurred to me that you have joined a "select" group, who have made an optical contact over 10km here in the UK with modulated LEDs. I had a quick count up of the people I know about and I do not think there are 10 yet. (probably more I do not know about though) .....so no small achievement."

So apparently very few of the people experimenting with 481THz red LED optical communications have broken the 10km barrier for 2-way QSOs. This surprised me. At the same time I am even more encouraged to continue this fascinating area of amateur radio as there is so much more I can do. The beauty of this is that test equipment needs are basic, skills needs well within my capabilities, and the results when success comes are extremely satisfying.

Multi-hop transatlantic Es on 10m

What I think is multi-hop Es propagation on 10m this evening allowed me a QRP contest exchange with NR4M in Virginia USA on CW at a late 2222z.  Big contests show up these openings so it is worth some late evening WSPRing too when there are no contests running.

Despite the usually poor summertime conditions, Es can open up the band in surprising directions.

New LF Yahoo Group

After some debate, the old RSGB LF-reflector is now migrating to a new Yahoo group at http://uk.groups.yahoo.com/group/rsgb_lf_group/ . If you have an interest in the VLF/LF/MF amateur bands such as 8.97kHz, 136kHz, 472kHz and 500kHz then you may want to join. It is sure to become one of the most useful resources on the web for up-to-date information as well as a valuable archive of schematics, photos and ideas.

My first 481THz 2-way QSO

The 481THz kit at the G3XBM/P end of the path

This evening, thanks to Bernie G4HJW, I managed my first 2-way optical QSO over a path of around 10.5km.  For the AM baseband QSO, Bernie used his Finningley transceiver with 100mm optics and I used my simple AM TX  with my modified KA7OEI receiver with unbiased BPW34 connected directly to the FET gate.  For some reason, the RX in my dual tube transceiver (the one on the larger tripod) was about 3-4dB less sensitive than the separate RX, so in the end I used this to copy Bernie at a solid 58-9 with scintillation.

481THz transceiver ready for QSOs

The electronics of the 481THz AM transceiver

My first complete optical speech transceiver has been finished and is ready for a line-of-sight test over a few kms. The pictures show the assembly of both the electronics and the optics. All the TX and RX electronics are built "dead bug" style on a piece of copper laminate and housed in a small metal box. There are holes for the BPW34 detector diode and the high brightness LED that line up with the focal point of each 100mm optics tube.

The optics showing the 2-tube construction with sighting scope

A quick "in strong daylight" test down the road over 0.3km was successful one way: my wife could see my TX beam strongly and I could detect my CW beacon OK, so I am hopeful that a proper 2-way amateur QSO with this kit should now be possible. Sensitivity at night is very considerably better.

G4HJW is set up to do a 2-way test, so this is now likely to be attempted in the next few days. if successful I will then try to make a better, more permanent, version.

144MHz across the Atlantic?

A new beacon, GB3WGI in Ulster, has been approved by OFCOM. When turned on it will radiate at least 100W ERP (possibly much more) in the direction of the USA. It will be monitored in the USA and Canada for possible 144MHz openings across the Atlantic.

For many years people have speculated about the possibility of working across the Atlantic on 144MHz. On very rare occasions, this might be achieved by various propagation modes including multi-hop Es, auroral E, tropo or MS, or more probably a combination of these. There have been tantalising hints that this path has been open before now, but no objectively verifiable proof. With new weak signal modes it surely will happen sometime soon.

481THz optical transceiver progress

My AM baseband optical transceiver build is nearly finished (mechanics and electronics both almost complete), although I have to optimise the sensitivity as it is several dB less sensitive than my stand-alone optical receiver.  I am not quite sure why. All being well I should be ready for a real QSO with fellow local optical enthusiast G4HJW next week.

RSGB member for 50 years

When we got back from seeing our grandchildren in Kent today there was a small package from the RSGB on the doormat. I'd not ordered anything, so was a little puzzled what it might be.

Inside was a very nice letter and a personalised callsign RSGB lapel badge as a thank you for being a continuous RSGB member for 50 years this month. Apparently it was April 1962 when I first joined. It was very gratifying to get this: thank you RSGB!

Things have changed a great deal in the hobby since then, but there is as much, if not more, to enjoy today than back then. Whether I get to reach 60 years of membership remains to be seen but I certainly intend to do all I can to enjoy radio electronics for as long as I possibly can.

The RSGB has had a difficult recent history but it deserves our support so that it can work for UK radio amateurs in the years ahead.

Finningley Optical Transceiver (G4HJW)

Bernie G4HJW is well known for his innovative microwave designs as well as many other good projects in recent years. This year he has produced another winner for the Finningley Round Table in mid July:  a baseband optical transceiver kit designed with SMA components. For details see http://www.earf.co.uk/nanotrx.htm . I am not sure if Bernie is planning to make kits available more generally. Bernie has tested this design over a 65km line-of-sight path recently.

Dayton and new QRP transceivers

Not being in the USA, I don't get to visit the big Dayton Hamvention held each May, but I do look out for announcements from the big suppliers about newly released products, especially QRP radios. Elecraft were displaying the new KX3 and Ten-Tec announced a new Argonaut VI due to be released later this year. This is a little larger than the FT817 and has HF only coverage (less 12m) but looks ideal for a high spec, inexpensive QRP radio up to 10W. For more on the Ten-Tec Argonaut VI (was the Ten-Tec 539) see this link.

But, yet again Yaesu has NOT released, as far as I am aware, a successor to the FT817.

One of the best places to look for news of Dayton is http://qrper.com/ which has reports and photos of new products.

Sonicencoders.msi - where can I get it?

My 7 year old Dell Inspiron 630m WinXP laptop has been restored to "as factory settings" to properly clean it out of files detritus that had accumulated over the period despite numerous defrags, ccleaner clean-ups and deletion of unwanted files. I've loaded Windows service packs, McAfee etc and all seems to be well ....apart from one small annoying issue: I keep getting a pop up box  telling me I need a file called sonicencoders.msi to install some software which I think is to do with some Sonic software for DVD burning. This never goes away and it tells me the file is on a D/ drive which I don't have access to. This is a partition allowing full and partial restores on a Dell machine.

Searching the internet it appears this is a very common issue yet no-one seems to be able to tell me where to find this file which I appear to need to even delete the files that are causing the problem. Ccleaner doesn't allow me to delete it, neither does the usual Windows add/remove programs.

When I first had the PC, from my son about 5 years ago, I seem to vaguely recall having the same issue and I managed to fix it but I haven't a clue what I did back then.

Anyone know how to get this file or how to stop the annoying pop-up message? I am not a PC expert at all by the way, so keep it very simple. Ideally someone please email me the file and put me out of my misery.

136kHz grabbers and a DC receiver for the band

A list of all the known LF grabbers (on-line to the internet LF receivers) in the world is available at http://icas.to/argo/grabbers-list.htm . A receiver to use with a 136kHz grabber is available as a kit or ready built from http://icas.to/e/ . This is a simple, but effective, direct conversion design which is already in use at several grabbers around the world.

Germany- Venezuela on 136kHz

DK7FC has been helping YV7MAE set up a grabber for 136kHz and over the last month they have been improving the system day by day. Last night Stefan's DFCW signal was copied quite well for the first time over a distance of 7818km. This is the first time a European station has been copied in South America I believe on this band. The grabber can be seen at http://dl.dropbox.com/u/74746618/LF/YV7MAE_LF_Grabber.html .

Universal QRP Projects Box?

This is really a follow-on from the previous post. As a "mechanically challenged" QRPer I really do hate the stage of putting a completed project into a tidy box. Some people love drilling holes but many do not, so I wonder if there is a market for a "universal" QRP projects box with pre-drilled holes at the front and back? Perhaps a variation of the GQRP Limerick project box could be made available for wider project use?

Most QRP transceivers need a power connector, a coax socket and a key on the back. They need a VFO(or VXO) control knob, a gain control and a socket for phones. Maybe another control and a couple of front panel switches.

So, I wonder why no-one (as far as I know) produces a pre-drilled box that could be used for a range of projects. Surely there is a market for this. A set of water transfer control legends could also be supplied with the box (remember the Radio Constructor sets?).

Just my thoughts having spent an afternoon engineering a 481THz transceiver mechanics and drilling an aluminium box.

How I hate drilling boxes

This afternoon I have been "engineering" my dual lens optical transceiver mechanics. This consists of 2 34cm long 110mm drain pipes (with 100mm lenses at one end) fixed together on a tripod mount with a sighting scope attached to one tube and an end piece at the focal points which will support the aluminum box housing the detector, the TX LED and the electronics. I had to work out how to support the two tubes in close alignment and how to fix these and the electronics to the tripod mount. This has involved a fair bit of mechanical engineering, which is the part of the hobby I absolutely detest. By this evening I think everything is ready and fixed together OK. The electronics box has all the holes drilled for switches and sockets. Now all that remains is to build tidy versions of my sensitive detector and AM transmitter.

When everything is finished - the end is in sight now - I will ask Bernie G4HJW for a sked over a fairly short (2-3km) line-of-sight path to check alignment and that everything is OK. Assuming this goes well then it will be time to try a 481THz QSO over a reasonably DX path.

Light beam RX improvements

This afternoon I played around with my light beam RX trying to squeeze a few more dB of sensitivity from it. Well I think I have managed it by further optimisation of the electronics and by optimising the focal length. Now, in the dark, a barely lit LED in the ceiling of my lab is detectable on the bench without optics. With the 100mm lens I can detect a 1kHz subcarrier on the 481THz optical signal when there is no sign at all of the LED being illuminated. Some tests using an LED as a detector were less successful, so my plan is to make a dual optics AM transceiver with 2 drainpipes and 2 100mm lenses. With this I should be able to work the local nanowave stations over line-of-sight paths.

JT6m 6m QSO

This evening was a slightly historic occasion: my first ever QSO using JT6m mode on 50.230MHz. I have used JT65HF on HF but this was the first time with JT6m. Now you may be expecting me to say I worked some exotic DX by MS but this first contact was with M1BXF who was only about 20km away! Listening (more accurately looking) on 50.230MHz has resulted in seeing European DX on 6m under flat band conditions using JT6m. It can be quite entertaining to just leave the RX and PC running to see what DX turns up. You'd be surprised.

QRP Auto-ATUs

For some years now I have owned an Elecraft T1 auto-ATU which works very well with the FT817, especially with the FT817 interface cable which automatically retunes the ATU when changing bands on the rig if the settings have previously been used. Just recently I started to have problems with this ATU when sometimes it simply refused to work. I contacted Elecraft for help and they replied to my email overnight, which was pretty good customer service. In the end it looks like the problem is just battery contact pressure: I managed to snap the plastic that ensures good pressure on the battery contacts and, by chance this evening, I found that pressing the battery hard brought the unit back to life. I may replace the 9v battery contacts with a snap connector. 

On the subject of QRP auto-ATUs, has anyone experience of the LDG Z-817? This is a bit bigger than the diminutive T1 but in some ways is a better arrangement for home use. This has to be retuned every time bands are changed but the method of interfacing to the FT817 control (to change mode and power during tuning and then switching back automatically when done) is good. The memories also store previous tunes so retuning when changing bands takes just a second or two I believe. I also like the way the Z-817 sits on top of the FT817. The T1 is fine for portable use but I never quite know where to put it when used on the desk at home!

Now, of course, if the FT817 replacement ever happens (Dayton in a few weeks maybe?) we will expect to see an ATU inside the rig, as for the Elecraft KX3.

Radio Nederland and shortwave broadcasts

One of my favorite shortwave broadcast stations back in the 1960s was Radio Netherlands . I still have my QSL card from them somewhere. When testing my shortwave crystal set today I noticed a strong transmission of the Dutch language service today in the 31m band. Little did I realise (until tonight) that this is the very last day ever of transmissions in their worldwide Dutch language service.

The HF broadcast scene is quite a lot different from when I last seriously listened some years ago: there are far fewer English language services to be heard. I guess these days people who want to find out about different countries listen to broadcasts on the internet.

Also, the CW maritime services, which could be perfectly copied sometimes on a crystal set as a result of cross-modulation (the CW sounded like a raspy hiss keyed) are long gone. One of my interests some years ago was seeing how many HF marine coast radio stations I could positively ID on a simple crystal set: the answer was quite a few around western Europe.

In fact SWLing on HF is rather a dying scene I think, although devotees will no doubt disagree.

Crystal set sensitivity experiments

This afternoon I had a little play with a simple crystal set to see what sort of minimum discernible signal (MDS) was possible. My previous experiments with single germanium detectors had yielded an MDS of around -55 to -57dBm in the 5-30MHz range with a high impedance crystal earpiece.

Today I tried the same test with both germanium diodes and a hot carrier diode (HP2835) with and without some bias applied to the diode(s). Best results were with the HP2835 and with about 0.11V forward bias applied. Only a few uA are needed so battery drain is next to nothing. MDS was around -62dBm for a well modulated AM signal. For the tuned circuit I used a T50-6 toroid with around 20 turns with an antenna link winding adjusted for best sensitivity/selectivity and a 365pF variable capacitor .

Incidentally, forward bias for the diode could be obtained by rectifying other signals available on the antenna such as MW/LW broadcasters using a separate tuned circuit, rectifier and reservoir capacitor. I must give this a try sometime. Several hundreds of mV DC should be possible.

Then I tried switching the diode with a second signal generator at a power of between 1-10mW to see what sort of sensitivity could be obtained on a CW signal. MDS improved by around 25dB to around -86dBm i.e. I could just hear down to around 10uV. This would be a just usable level as a basic HF SSB/CW receiver.

I also tried the same tests with a pair of high sensitivity ST-3 headphones that Michael AA1TJ kindly managed to find for me. These are much lower impedance than the crystal earpiece so I experimented with antenna match and the match of the diode to the tuned circuit, expecting a better performance at the best settings. Disappointingly, the results were several dB worse than with the crystal earpiece.

Now, the results with the crystal earpiece are very close to those (without bias) that I obtained some years ago, so I don't think my hearing (at 63 years old) has changed much for the worse. So, Michael must have incredibly sensitive ears as there is no way I was able to hear down to the levels he could with his passive receivers.

At the moment I am playing with the AM crystal set with -62dBm sensitivity listening to shortwave broadcasters. Fun.

Six continents on 10m WSPR

This afternoon I exchanged WSPR reports with RI1ANF in the South Shetland Is in Antarctica on 10m. This now means I've had reports this year from every continent on the 10m band using 5W or less with the wire halo antenna.

PA1B's power attenuator calculator (see link below)

As this is all getting rather too easy (!) maybe I need to follow Bert PA1B's advice and build a switchable attenuator so I can repeat the challenge with much lower powers. See his power attenuator design page for details of how to make suitable RF attenuators to reduce QRP rig output powers to milliwatts.

50MHz, 432MHz and 481THz this evening

Well, this was an interesting evening. Just after teatime I noticed 50MHz was open with some strong Es signals from Europe. A few stations were worked on QRP SSB using the newly erected halo antenna (S52NR, S53OQ and OE5FIN). Heard, but not worked, on 50MHz were CT8/K0RUI in HM68 (Azores Is) and 4X4DK in KM72. Both DX stations were good solid signals on the halo.

Stations worked on 432MHz this evening (5W/4el)

Later I went out portable with my FT817 (5W) and my small "coat hanger" 4 element yagi for the RSGB 432MHz activity contest and worked 14 stations in just over an hour before closing as it was dark and I could not see the logbook very well. Best DX 155km although I did hear, but not work, F8BRK in IN99.

Finally, for the very first time, I have detected GB3CAM on 481THz (red light beacon) at a distance of 32km from the Nine Mile Hill site where I was active in the UHF contest. Signal was weak with lots of scintillation, no doubt caused by the rain that started up just as I began listening with my 100mm optical receiver (KA7OEI/K3PGP hybrid). If I can find another 6dB sensitivity I think the signal will be solid in low haze/clear conditions over this LOS path. GB3CAM is a very low power light source, so copying it is a big challenge.