CW timings for amateur radio satellite beacons
Friends,
I am looking for exact dit time, dah time, intra-letter timings, inter-letter timings and inter-word timings for CW beacons from amateur radio satellites. For example, AO-999, dit time 52 milliseconds, dah time 156 milliseconds... and so on.
Is there a comprehensive list that gives precise timing information for the CW beacons sent by various amateur radio satellites?
Thanks and 73, Douglas KA2UPW/5
On 01/27/2019 13:14, Douglas Quagliana wrote:
I am looking for exact dit time, dah time, intra-letter timings,inter-letter timings and inter-word timings for CW beacons from amateur radio satellites. For example, AO-999, dit time 52 milliseconds, dah time 156 milliseconds... and so on.
Is there a comprehensive list that gives precise timing information forthe CW beacons sent by various amateur radio satellites?
My guess is that no one has even considered such a thought. mSec is not exactly the most common timing for CW speed - WPM is. You might state what you are trying to accomplish.
Hi Jim, Yes, WPM is the standard, but WPM alone doesn't tell you exactly how long the dits, dahs and delays are (see, for example, Farnsworth).
What I am trying to do is determine if a given recording has any CW telemetry in it and at what frequency, not just to get the telemetry but also to perform Doppler measurements. For example, HO-68 sends the CW telemetry and it always starts with "BJ1SA XW XW" and always ends with "XW XW". These are always sent at the same speed with the same spacing. The telemetry values in between change, obviously, but you can calculate a minimum and maximum amount of time for the telemetry to be sent so you can place some limits on how long after "BJ1SA XW XW" you should find the trailing "XW XW". If you see both of these, then you know that you have found CW telemetry from HO-68. Even if the signal is too weak to get all of the telemetry, you could still use the frequency that you found "BJ1SA XW XW" for Doppler measurements.
But in order to get a computer/DSP algorithm to look for "BJ1SA XW XW" you need to specify exactly how long each dit, dah and delay lasts so that the computer knows what to look for. The more accurate the measurements of dits, dahs, and delays, and the longer the CW sequence that you know for sure, the further into the noise you should be able to detect the CW signal. Now for HO-68, it looks like a dit is 80 milliseconds, dah is 240, and the delays are 80, 400 and 720 milliseconds. I found these timing values and I was hopeful that someone had compiled a list of CW timings for other satellites that send CW telemetry. I hope this explains my request. 73, Douglas KA2UPW/5
On Mon, Jan 28, 2019 at 2:21 PM Jim Walls [email protected] wrote:
On 01/27/2019 13:14, Douglas Quagliana wrote:
I am looking for exact dit time, dah time, intra-letter timings,inter-letter timings and inter-word timings for CW beacons from amateur radio satellites. For example, AO-999, dit time 52 milliseconds, dah
time
156 milliseconds... and so on.
Is there a comprehensive list that gives precise timing informationfor
the CW beacons sent by various amateur radio satellites?
My guess is that no one has even considered such a thought. mSec is not exactly the most common timing for CW speed - WPM is. You might state what you are trying to accomplish.
-- 73
Jim Walls - K6CCC [email protected] Ofc: 818-548-4804 http://members.dslextreme.com/users/k6ccc/ AMSAT Member 32537 - WSWSS Member 395
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (2)
-
Douglas Quagliana -
Jim Walls