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.