One approach to an RTTY contest is to send a checksum with the exchange. Even a single character checksum will be reassuring to a recipient of the exchange, especially if the checksum is computed ove
Send "AGN?" of course :-). You can even automate the "AGN?", but with poor propagation, the back and forth could end up sounding like Packet Radio :-). Sending the serial number twice is a form error
"AFSK" and "FSK" can mean different things to different people. FM AFSK has a very different meaning for example, where the "AFSK" is modulating an FM carrier. This was the original meaning of "AFSK.
The K3 paddle mode requires a non-standard Morse prosign (di-di-dah-dah) to cause immediate termination of a transmission. What an abomination! 73 Chen, W7AY _________________________________________
If we fall for that oldest trick in the world, the politicians at ARRL have won. For me, there are multiple separate issues here. One of them is the change in RTTY occupancy on 80m. Another one is to
RF preamps improve noise floor but reduces the large signal capability of a receiver (a.k.a. overloading). On the lower bands, 30m and lower, the sky noise is usually way over the noise floor of any
If you are willing to manually ride the RF/IF gain controls, "AGC off" is best. As David G3YYD has pointed out, you need the "gains" of the Mark and Space tones to be perfectly equal. Under poor SNR
Just like with filter bandwidths and AGC, there is also a cold, hard, objective way to set the RF gain. Please allow me to explain. This is long. If you just want a monkey-see-monkey-do directions, j
When I posted the following, I did not supply the justification why you want to adjust the noise floor for a largest acceptable SNR loss. After all, you could even adjust the receiver gain so that th
(Hi Bill.) Long ago, I had pondered how to objectively test built-in PSK31 and RTTY decoders in the Icoms. Later, Elecraft also decided to add built-in decoders. The key to testing RTTY demodulators
Not everyone has the time nor the inclination to create an interface just for you. But you can create an interface for your program (since you know the internals) to mimic a protocol that one of thes
The reason I have often heard for preference of low tones is that the op actually listens to, and tunes a superhet radio using a knob. As one gets older, the higher tones are too shrill; in mild case
I am not sure what you mean by a "high powered" sound card. Sound card works with millivolts to hundreds of millivolts, and very high input impedances. Very little power involved. If you mean the dyn
At one time, I started writing a review of various sound cards, but I switched to writing demodulators right into an SDR, so I never bothered to finish the white paper. With an SDR, you don't need a
The one person who might know would be Raj VE6RAJ. However, Raj too disappeared from the RTTY contest scene after getting married. 73 Chen, W7AY _______________________________________________ RTTY m
With an FT-1000MP (or Mk V), why not feed the output from the two receivers (A and B) into separate sound cards, or to left and right channels of a sound card? You can then be decoding and printing b
Technically, DominoEX is probably my all-time favorite mode. It has multiple speed selections, good error vs SNR, and the speed it can tune to a station is the best I have seen. The latter is made p
fldigi is a cross platform program. There should be a Windows version. It may not have some of the specialized stuff (like being able to see very weak signals in the waterfall, a tuning aid that sho
Please allow me to play the pedant for a moment, then follow with less off-topic comments below. What we have on HF *is* an all analog world. This is why we need modems that allow us to take discret
The SignaLink is more than just a sound card -- it is one of the few interfaces that has a built-in VOX-based PTT, something that is missing in interfaces many times even more expensive. For folks w