KX3 - more pictures

Some nice shots of the new Elecraft KX3 QRP transceiver at http://www.worldwidedx.com/elecraft-kx3/134267-elecraft-kx3-hands-preview.html.  This rig has still to start shipping nearly 12 months after first announced although the first units should be on their way to happy customers within weeks now. There were some late changes following extensive field testing and some supplier issues.

QRM on VLF?

DK7FC, PA3CPM and DF6NM have all been TXing today around 8.970kHz with reception reports coming in from many of the western European grabbers. DF6NM is running some 20dB less ERP than Stefan yet is appearing on UK grabbers quite well just HF of DK7FC. PA3CPM is a much weaker signal although he has been copied by Paul Nicholson in Todmorden UK. Activity is likely to continue over the weekend. Here is a screen grab from Eddie G3ZJO's VLF grabber today showing 2 of the active stations quite clearly. Notice the timescale on Eddie's grabber: between markers it is 4 hours in his DFCW6000 window, so don't expect snappy QSOs on VLF.

Dropbox Windows Registry issue - NOT fixed!

Having struggled to get Dropbox files sharing working on my main WinXP PC I today did a full uninstall and loaded a new version 1.1.45.exe from http://dl-web.dropbox.com/u/17/Dropbox%201.1.45.exe and I was back in business for the first time in 3 months. Within 10 minutes though, the same "unable to access vital Windows registry data" message reappeared! What the heck is going on???

iPod Touch external audio - success!

Thanks to some input from Robin G7VKQ I have now managed to get an external mic to work with my iPod Touch 4g. He referred me to http://www.blackcatsystems.com/ipad/iPad_iPhone_iPod_Touch_Microphone_Wiring.html which shows that a resistor to ground is needed to make the device recognise the external mic is in place. In the end I found a couple of ways to make the connection work (shown below).

When used with the Spectrum View app from Oxford Wave Research I was able to connect my lightbeam receiver to my iPod Touch 4g and record QRSS3 and CW transmissions. This is 10wpm CW being received at home between rooms by scatter in broad daylight.

iPod Touch 4g repair video

Ever wondered how one would go about repairing an iPod Touch 4g if one went wrong? I chanced upon this video describing how to disassemble it. This Apple device is quite remarkable as it does so much in such a small space and having seen just how it is constructed inside I am even more impressed. However, even having seen this excellent video I think it is beyond my skills to repair it if it went wrong.

iPod Touch, SpectrumView and external mic input

A few days ago I mentioned SpectrumView as being a very useful package for the iPhone and iPod Touch 4g for audio measurements and spectrum analysis. Well, I've now got a 4 pin jack plug and wired it up (according to the best published data I can find) as an external mic input. To my great disappointment nothing happened and the internal mic was still being selected. I am wondering if something has to be asserted to select the external mic input? Anyone know please? What did I do wrong? The ring nearest the jack body is the mic input and the next ring down is supposed to be the ground. I checked the plug was correctly wired. Help!

New personal DX record on 160m JT65

SP3CUG has just spotted my 5W QRP 160m JT65 signal from my tiny loft antenna at a distance of 1063km. This beats my best DX so far (a report at 1007km from SM on WSPR) on 160m using the small indoor antenna. I cannot see him TXing which is a pity as he may be able to work me.

VLF E-field probe design from DK7FC

DK7FC's VLF E-field probe antenna

Stefan DK7FC is well known for his experiments at VLF. Here is his circuit for the E-field probe he designed which is in use at many VLF grabbers around Europe. It is highly recommended.

Further 481THz G4HJW reception "over the horizon"

G4HJW received on 481THz over an 8.63km non line-of-sight path

Bernie G4HJW was 20dB S/N in 0.67Hz bandwidth earlier this evening at my local test site 8.63km NLOS from his QTH "over the horizon". Bernie was using his Phlatlight beacon with 1.082kHz tone. The sky was clear and starlit, so this was clear air scattering not cloudbounce.  About 15 minutes after I first copied him it seemed to get more hazy and I was struggling to find his signal at all.  Best results appear to be with a clear sky and aiming at the horizon. 

On 3 attempts copying G4HJW's optical signal it has been (1) 30dB S/N, (2) no copy and (3) today 20dB S/N in 0.67Hz bandwidth over an 8.63km NLOS path. I am still using the BPW34 detector in 100mm optics.

160m JT65 QSO with loft vertical

JT65 QSO with 2E0ZRQ this evening on 160m

Managed to work 2E0ZRQ who was running 20W to a longwire with my 5W to the tiny loft vertical antenna this evening on JT65-HF. This is my first QSO with this mode on topband at a distance of 148km.