A few years ago I made an active broadband loop antenna for HF for 'official' purposes. This consisted of a 300mm diameter loop of 3mm copper wire into a common base amplifier made from a 2N5109 tran
I'd left the receiver running to catch IK5ZPV but hadn't optimised the gain setting and it got clobbered by Laurie's signal 20 Hz away. There was something on the right freqeuncy, but a +70dB signal
time" (GPS time even better the software/hardware). Surely, if the 1us jitter is a function of clock timing synchronisation then by averaging over many 1s periods, as the Brooks Shera design does, e
I was transmitting 0.2 then 0.1Hz shift DFCW centred around 135921.5 for the last two nights until approx 0100z. If your much weaker signal was as much as 15dB weaker........ (I'd be very very surpri
I was transmitting 0.1 Hz wide DFCW from 1950z to 0110z, Lo/Hi freqs 135921.45 / .55. ERP about 14dB lower than the 'big' UK stations. Have a dig into the noise see if you can see anything. Andy G4JN
I also noticed bad interference from a fluorescent tube - wondered why the waterfall background got lighter just after I'd started watching it in real time once. Here, the light is located 3m under t
4 hours is not at all an unreasonable period for a valid QSO, especially when we are using a bandwidth of 2 minutes ^ -1 I once took 45 minutes to complete a QSO on 10GHz using CW repeated continuous
Yes - that's why I'm engineering it so the PTT line operates the chip reset pin and only brings the PSU up via its soft-start on transmit. 'JNT Good reason, it is just that the EMC engineer in me has
A pair of car batteries used on a /P expedition could easily discharge to 20V. The modern high power DMOS devices (for 1.3, 2.3 and 3.4 GHz) that this PSU is aimed at powering like a constant 28V Vcc
Does anyone know the permability and spec of 3c85 material? I cannot find this info in any of my tech info books. The T200 series seem very low like u10 powdered iron whereas the 3c5 ferrite type are
I'm not criticising the S/W, just saying that in life generally there is a strong tendency to make things excessively simple for everyone to understand, to the detriment of those who really do want t
What we call "Dumbing Down" in the UK (and the US ?). It happens a lot with science programmes on television, and a lot more with science education in schools and universites :-( :-(( Andy G4JNT If y
One method for determining S/N ration in an environment where signals and noise are constantly changing - used a lot in Radar and Other techniques - is an algorithm called Constant False Alarm Rate.
A couple of weeks ago there was discussion on this reflector about using LORAN as a source of LF propagation information. I forwarded these on to Perter, G3PLX, who looked at LOARN for this purpose s
Where is the array pnpat[] used ? It is declared at the end of the listing you sent, but not referenced anywhere else. Not being a C programmer, it will take a bit ot time to translate the code ;-| A
I modelled this, generating ET2 Coherent waveforms with gradual phase transitions and stored as .WAV files, then played back into the Coherent decoder. With a Raised Cosine phase transition slope and
I would like add Wolf coding to my PIC based BPSK generator. Stuart, can you reveal the exact coding details, I can't find them in any of the documentation on the Web. Just a comment that the mesage
I doubt if 1s pulses could be extracted from those. The reason they are so cheap is that all the electronics is on one custom chip driving the LCD, with no extra connections accessible. Exactly the s
Another solution is to run G3PLX's PSK31 SB software. There is a setup routine in the software that allows the Soundcard sampling rate to be calibrated. The procedure is given in the Help file, acces
According to the latest theories, time may be slowing down. By acccepting that the speed of light has been continuously reducing from the point at which the universe was formed, they've worked out th
