HA6SST
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« on: September 10, 2007, 09:44:48 AM » |
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I'm trying to resolve a timing issue in a transceiver transmit/receive circuit. Please could someone give me the width of a dot in milliseconds for the following speeds:
5 wpm 10 wpm 15 wpm 20 wpm 25 wpm
There's no point giving me the width for speeds faster than this because I struggle to hit 20 wpm. I am therefore going to set the speed control for a maximum of 25 wpm.
HA6SST
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KB1OOO
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« Reply #1 on: September 10, 2007, 10:02:53 AM » |
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A word is 50 "elements", i.e. the number of elements in the word PARIS. Dot is 1 element, dash is 3 elements, between character spacing is 1 element, and between word spacing is 7 elements. So formula for 1 element (dot) in ms is 60000 -------- wpm * 50 Here's a reference if you want to read more: http://www.ac6v.com/morseaids.htm73, Marc
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KB1OOO
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« Reply #2 on: September 11, 2007, 05:56:00 AM » |
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just a correction on my description: *intra* char spacing is 1 elment and between character spacing is 3 elements.
Marc
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WQ3T
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« Reply #3 on: September 11, 2007, 08:34:44 AM » |
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I timed my dit on my oscilloscope at 62 mS with keyer set at 20 WPM. I haven't tried other speeds.
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KB1OOO
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« Reply #4 on: September 11, 2007, 10:53:44 AM » |
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Is it too difficult to plug into the forumla, which reduces to
1200 ----- wpm
and gives:
5wpm -> 240ms 10wpm -> 120ms 15wpm -> 80ms 20wpm -> 60ms 25wpm -> 48ms
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WQ3T
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« Reply #5 on: September 11, 2007, 11:44:35 AM » |
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I suppose you always trust cash registers to figure your correct change also. I figure the change in my head and tell the cashier how much change I need. Then when the cash register displays the same amount, I say, "The cash register is correct". My 62 mS timing was something I measured myself, not depending on someone else's formula. I think the formula is off by 2 mS. Can you prove otherwise?
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KE3WD
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« Reply #6 on: September 11, 2007, 12:07:30 PM » |
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Like 2mS differential is consequential...
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HA6SST
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« Reply #7 on: September 11, 2007, 02:09:37 PM » |
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Thank you for all the replies. A formula of 1200/wpm is easy to remember, all I need to do now is cure my problem of a shortened first dot when the transceiver changes over.
On with the struggle!!
HA6SST
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KB1OOO
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« Reply #8 on: September 11, 2007, 08:20:20 PM » |
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Sorry, I didn't mean to come off as a jerk. I just wasn't understanding why my original post wasn't clear.
Marc
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WQ3T
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« Reply #9 on: September 12, 2007, 10:40:59 AM » |
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You did reduce the fraction to make it simpler to use. I haven't seen any jerks- just guys helping out each other.
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KE3WD
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« Reply #10 on: September 12, 2007, 11:00:31 AM » |
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>>by HA6SST on September 11, 2007
"Thank you for all the replies. A formula of 1200/wpm is easy to remember, all I need to do now is cure my problem of a shortened first dot when the transceiver changes over."<<
You might want to take a look at QST magazine tests, both for your rig and others, before you drive yourself crazy here.
That first dit length is indeed problematic for many, if not most rigs.
QST typically publishes an oscilloscope graph of the first dit element length for every rig tested.
Almost all of them are shortened to some extent.
Another test where TenTec and Elecraft transceivers often come out doing better, just another reason that they are loved by serious CW ops I guess.
--KE3WD
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KE3WD
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« Reply #11 on: September 12, 2007, 11:05:03 AM » |
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BTW -- Shortened first dit in QSK will likely not be a problem at all with the speeds listed here.
Somewhere up past the 30WPM mark would be when the shortened dit can start proving problematic.
!
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W8ZNX
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« Reply #12 on: September 12, 2007, 03:57:27 PM » |
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im with KE3DW shortend dit should not be a prob most ops don't even notice it
if you rig does have a huge shortend dit prob on qsk how is it when you slow down rx tx change over
lots of ops use the qsk mode but do not realy run qsk style so a slower longer change over might work for you with out having to mess with your rig
by the way what kind of radio is it
also you might want to ask on the/your rigs user group and there is a yahoo user group brasspounders
my FT 102 has a chirp on first note after change over i just turned up the vox delay so it does not change over till i turn it over to the other station
for qsk work i have a old Ten Tec Omni D
yours truly Mac
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W8ZNX
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« Reply #13 on: September 12, 2007, 03:59:18 PM » |
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KE3WD not KE3DW mac
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KE3WD
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« Reply #14 on: September 12, 2007, 06:07:01 PM » |
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That's okay, Macs are allowed to make typos.
;-)
--Mac
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