And I thought the dinosaurs died out 650 million years ago :-) Andy G4JNT (Never used a valve in my life. Dislike morse but forced to use it occasionally on microwave bands, and find its a good a cod
Good - I'm glad to know the telecomms opeators have thought about the vulnerabilities inherent with putting all their eggs into the GPS timing basket. I had been told - clearly from a not too informe
Having now completed and mostly tested two VE2ZAZ GPS Controlled oscvillators, I can say I'm rather more than quite impressed with what can be achieved. Both GPSDOs were built using good quality sing
The whole over-air interface for the mobile phone system has to be locked - the frame structure in GSM is critical to microseconds, and has to be synchronised between all base stations. I believe 3G
The article has a very good point to make about GPS jamming though. I think its probably the first time I've seen it talked about in the open-press. Our telecomms infrastructure now is so critically
That's because no one sends anything in !!!!!!!!!!!!!! As I said in a previous posting a few months ago to one of the many groups (microwaves, probably) - its positive feedback. People see reduced te
Was pondering this while out walking the other day, and couldn't come to a satisfactory conclusion either way... A small magnetic loop mounted vertically has a defined radiation resistance that is a
Two pijnts... 1) Satellites Having just joined Amsat (because I felt I 'ought' to) I'm less than impressed with a) Oscar News which has had no technical content in the two issues so far received, and
Radcom redraw all diagrams anyway - and now with wiggly resistors. Theyt tend to leave the text alone unless there are glaring errors or bad English, so it looks as if you could be onto a winner. Giv
Which big bang ? A few superpowers may have tested the occasional EMP weapon with 'interesting' findings, but no one ever deployed one - they all realised the potential for damaging thier own infrast
Tnx for the replies on this. In the original post I'd forgotton that Chu-Harrington described a sphere just sufficient to enclose the antenna, so a pair od crossed loops would fit into the same size
EXcuse meThe only country that doesn't oficially use the Metric system is the USA, along with two tiny ones whose names don't come to mind. And look what not using it cost the Nasa space programme! I
Not speculation, I've had several discussions with him on the subject, and my idea of Radcom going unstable had him quite amused. But it is a feedback situation, and as in all control systems, the wr
Excellent. And if more people used computer generated morse for transmitting, the decoding software would be more reliable still. We don't want any of this hand sent, badly formatted stuff :-) Andy G
Your dual tone proposal is an excellent idea but suffers from one major drawback for LF. Being a dual tone sysytem, it requires a linear transmitter. If you could adapt the scheme to a single tone on
Looking at the list of BBC Publications ( http://www.bbc.co.uk/rd/pubs/whp/index101-120.shtml ) the author of this paper, R.H.M. Poole, has also written one on electrically short antennas; and on a f
Yes that's correct. The Txxx is a size designation, -2 is iron powder mix 2, suited for MF to low HF. For SMPSU / LF transformers Siemens N80 material is a substitute for 3C85 / 3C90.(hope I've remem
Having just had to make an active antenna for HF (for gainful employment-type work, not Am. radio purposes. The commercially made one we've ordered is on five weeks delivery and it was needed before
