Strictly, Shannon was a mathematician who approached information theory from a non engineering perspective. And the famous Shannon curve giving the absolute theoretical limit of performance for a c
It is not that specific model, but I do have a small man-pack type Racal auto ATU that has a not totally dissimilar output stage 2C10 is 68pF 2C13 is 180pF But in mine 2C11 does not exist. The main i
And because it's chirpy CW and we've all moved on from that by now. Been there, done that Andy G4JNT On 13 July 2016 at 19:30, Chris <[email protected]> wrote: Probably because it's so easy
Most of your messages are ending up in my Spam box, in spite of me declaring each one as "Not Spam" It appears the GMail server checking (or whatever part of the Inet is doing it) is claiming your me
There is currently work going on in the WSJT development suite with a new class of error correcting code, Q-ary Repeat Accumulate , or QRA codes. These appear to give several dB of improvement when
I've just been trying to use my new Smart Meter to measure the mains power consumption of on of my 137kHz transmitters, the QRP 180 Watt linear Tx. I took the display unit out to the shed where th
Ideas wellcome ! :-) I like the W1YD design http://www.w1vd.com/137-500-500WTX.pdf Don't need the keyer and would use an ICL7667 as dual mosfet driver For the mosfets what I have here is a coupl
I've fired up my dual mode WSPR beacon on 137kHz, transmitting on both WSPR-2 and WSPR -15 in alternate, pseudo-randomly defined slots. To avoid confusion in the database, the WSPR-2 beacon sends the
Best so far is DL-SWL at 842km in JO52HP who has been reporting since I started the transmission. Few new reporters since darkness fell I hadn't intended leaving it on overnight, but will probably
Correct. I have a PIC that reads timing data from a GPS and at the right timing uses a set of pre-stored WSPR symbols to calculate the frequencies for the tones and sends the resulting data to an A
No 41dB is NOT a real S/N figure and is due solely to your artificially restricting the noise bandwidth gon gin ! If you use a receiver bandwidth any narrower than the full SSB bandwidth then the
Hi all, I started to write the second part of this tutorial but when finished i was not happy with the result. The first thing one can say is that you will need a very frequency stable receiver. The
WSPR, as in all the WSJT modes captures the signal synchronously; an entire block at soundcard sample rate, so isn't affected by IRQs and the like. In effect, all decoding is done off line, in teh
Has anyone tried locking an external USB soundcard to GPS? Chips such as the PCM290x family use their own 12MHz crystal, and it's relatively straightforward to provide 12MHz locked to some master re
There was a problem delivering your email to: [email protected] WHAT HAPPENED? The domain name of the email address is not valid. WHAT CAN YOU DO? WHO ARE WE? RATE THIS EMAIL 908 Main Street #310, Lo
Won't the sound card's input filter, the anti-alias filter, extend this pulse, however short it is, into something the sampling rate will always see? So there is no need to deliberately lenghen it.
