The true sample rates of the soundcard were then measured by other means, they were: 8002.87 samples / second for the DAC (used to transmit) 7938.09 samples / second for the ADC (used to receive) One
The spectra (and and block diagram of the modulator) can be found at : http://www.qsl.net/on7yd/PSK_TEST/psk_test.htm when I went to that page, I got a reply "page not found" Seems to be OK by now (t
Hello Laurie & group, I have thought about synchronising the Tx and Rx using some form of universal time signal but 1) this might be thought as cheating and 2) the path variations, phase changes etc
Hi Marcus & group, 1. WOLF is using cosine-shaped zero-crossings with a risetime of only 5 ms, which causes a few extra sidebands on each side of the spectrum. I'd prefer to extend the cosine-envelop
In an attempt to compare the different PSK-like modes I built a kind of 'universal modulator' that could generate a PSK signal, BPSK signal and all variations of these. Such a modulator must be able
Hello John, In fact Valerio's signal looks rather clean for BPSK, so I guess that he did a similar thing as Jim and 'cleaned up' the output spectrum by AM envelopping the signal. Real BPSK (hard phas
Hi John, What do you want to do ? If you just want to 'toggle' 1 or 2 lines in order to key a TX or so you can easily write the code yourself, but if you need real RS232 communication I would suggest
Hello group, I received 2 very interesting pictures from Alan, G3NYK, and Markus, DF6NM. They show a summary of the CFH recordings in the period September - Decemebr 2000. I did put them on the web,
Hi Mike, Have a look at : http://www.wireless.org.uk/dk5pt-f.htm It shows a very small loading coil (using a pot core) made by DK5PT. 73, Rik ON7YD Just to clarify, the problem I am trying to fix is
If you load it with ferrite you will certainly increase its inductance and also its efficacy as a receiving antenna but the radiation efficiency on tx will decrease accordingly (the difference betwe
Hello Dick, The power FET's that are used in LF-Pa's are less vulnerable than most bipolar power transistors. These FET's are designed for switched power supplies and can withstand quite a lot of mis
To be honest I don't understand most of the 'newcomers' problem. Regarding the receiver : 136kHz is CW only (apart from a rare PSK / BPSK signal), so the ability to copy CW is the first need. I assum
Hello all, I just uploaded a series of recordings of the Greek station SXV. I received this recordings from Alan (G3NYK), they date from the period February - May of this year. Once more a nice colle
... Several suggestions were made as to how to encourage newcomers onto 136kHz. It was felt that once active, stations were reasonably well looked after by other band users. ... Suggestions were: * R
Thanks to Dick PA0SE for doing further tests. Replacing the antenna with a increased capacitance from a vacuum variable has lower losses than the "antenna circuit" but it is a reasonable approximatio
Hello group, I am not sure that propagation on 137kHz is much correlated to 1.8 or 3.5MHz. On those bands (160m and 80m) DX propagation is mainly via reflection at the F2 layer and the signals are at
At 12:00 13/05/01 +0200, PA0SE wrote: So my conclusion is that the difference in current must be due to radiation from the coil. The late Klaas Spaargaren, PA0KSB, once told me that in an article on
Just received following mail : From: "Davidson, John" <[email protected]> ... I want to make a home bru crossed field antenna to play with & try it for the AM BCB with a crystal radio.
At 09:58 11/05/01 -0700, you wrote: Hi Guys, I moved my loading coil yesterday and the ground loss dropped from 103 ohms to 91 ohms. That is 12 ohms removed at a stroke! ... Whether my signal will be
