75 Baud does require as you would expect wider filters, which means signal
to noise ratio is 2.2 dB lower than the same signal at 45.45 baud. This may
not sound much but on a marginal signal the difference in character error
rate is about 5 times. The character error rate vs signal to noise ratio is
an exponential function. An extra 2dB of SNR will make a noticeable
difference. Yes 2dB extra signal strength will substantially reduce the
repeat rate.
However it is multipath propagation that really does for 75 baud compared to
45.45 baud. Often multipath has differential delays that will take out 75
baud while 45.45 will carry on without any problem.
73 David G3YYD
-----Original Message-----
From: RTTY [mailto:rtty-bounces@contesting.com] On Behalf Of Ken K6MR
Sent: 15 September 2017 03:32
To: RTTY Reflector
Subject: Re: [RTTY] Contest this weekend
I wish we would all use 75 baud all the time. what a rush!
And as long as we're talking RTTY contests this weekend, don't forget the
NCJ RTTY Sprint Saturday evening. Yes, it's a bit weird, but all you need
is a radio and you (well for RTTY just a bit more). No internet required!
Put those S&P skills to good use!
Ken K6MR
From: Bill Turner<mailto:dezrat@outlook.com>
Sent: Thursday, September 14, 2017 19:11
To: RTTY Reflector<mailto:rtty@contesting.com>
Subject: [RTTY] Contest this weekend
Just a reminder of the BARTG 75 BAUD Sprint contest this coming weekend.
This contest starts on SUNDAY (not Saturday) at 1700 UTC and runs for four
hours.
Rules at:
https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fs3.spanglef
ish.com%2Fs%2F7850%2Fdocuments%2Fcontests%2Fsprint75%2Frules%2Fcurrent%2Fbar
tg%2520sprint%252075%2520rules.pdf&data=02%7C01%7Ck6mr%40outlook.com%7Ce81dc
3b8ffc0479940ca08d4fbdf0ca5%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C1%7C636
410382778598252&sdata=5n7PMSR7nrhg4zoKiezTub7tqkG4u6vZsUdTcGoQy5Y%3D&reserve
d=0
Time at:
https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.bartg.o
rg.uk%2Fsprint75contest.asp&data=02%7C01%7Ck6mr%40outlook.com%7Ce81dc3b8ffc0
479940ca08d4fbdf0ca5%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6364103827
78598252&sdata=r7goY%2FQUVZfGoHrK26QSQ0yUK4aelL1lcp2TcceZwjQ%3D&reserved=0
A great, fun contest, one of my favorites. Don't forget to change MMTTY and
2Tone to 75 baud!!
See you there!
73, Bill W6WRT
_______________________________________________
RTTY mailing list
RTTY@contesting.com
https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.conte
sting.com%2Fmailman%2Flistinfo%2Frtty&data=02%7C01%7Ck6mr%40outlook.com%7Ce8
1dc3b8ffc0479940ca08d4fbdf0ca5%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C
636410382778598252&sdata=HTCwc%2BE%2FFCYCws3ruApzxFTzz5p%2BoVLNNc8kKM9vv4U%3
D&reserved=0
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|