[Elecraft] RTTY vs. PSK31 (was: OT - 73 Magazine (was H mode mixer))

[Old Man]

In my humble opinion, I would say PSK, generally, has it "all over" RTTY. 
Communication can be maintained with very marginal signals, and very nearby 
signals (unless they are "dirty" or overpowering the receiver's AGC system). 
I have used a lot of RTTY systems over the years and they require MORE 
bandwidth, more power for effective communication (generally), and subject 
nearby signals more interference (generally).

The largest "bug" I have found in the PSK system is that it is "mangled" by 
propagation phase shifts caused by auroral disturbances even though audibly, 
the signal sounds "OK".
I consider this acceptable as it (PSK31) seems to "get through" much more 
efficiently than RTTY with less power.  Speed in this case not a factor in 
keyboard to keyboard QSO's.

I can see no sense in using MORE bandwidth than a PSK31 signal to convey 
normal QSO information.  Other modes capable of data and image communication 
in addition to normal keyboard QSO's wind up being gross "overkill" and use 
spectrum space a lot more inefficiently.  Spectrum space for CW, digital 
modes is "shrinking" from demands made for voice and wide data modes. 
Therefore it would behoove us to contrate our efforts on the narrowest 
digital mode that will give satisfactory communication in these days of 
decreasing spectrum space.  An amazing amount of use is being made of just a 
3-5 Khz. "sub band" for PSK operations on most bands from 80-10 meters.  It 
amazes me why this mode isn't replacing RTTY, and remains a popular FSK 
mode.  It would be like comparing effectiveness of SSB voice mode to the 
older AM voice mode.  I can't see people changing over to AM, even as a 
"fad", over SSB operations.  It's starkly obvious which is generally 
superior!

My "two pennies" worth on this thread.

73,

Sandy W5TVW


----- Original Message ----- 
From: "Brian Lloyd" <brian-wb6rqn at lloyd.com>
To: "J F" <phriendly1 at yahoo.com>
Cc: "Elecraft Discussion List" <elecraft at mailman.qth.net>
Sent: Tuesday, May 15, 2007 1:09 PM
Subject: [Elecraft] RTTY vs. PSK31 (was: OT - 73 Magazine (was H mode 
mixer))


>> Whether is PSK or another protocol, is to be
>> seen. Judging by the numbers of participants in RTTY
>> contests these days, it is a fast growing segment.
>> Change is good, unsettling yes, but the possibilities
>> are worth the uncertainty...
>
> CW remains a mainstay because it is an efficient mode. You can 
> communicate with very low power levels which makes QRP reasonable.  RTTY 
> is not nearly so efficient and requires much more energy per bit  to get 
> good copy. It forces you into more QRO operation. PSK31 is as  narrow as 
> CW which lets you use narrow filters to lower the noise  energy in the 
> passband. It also incorporates forward error correction  which allows it 
> to still give good copy with very marginal signals.
>
> Now that is not to say that PSK31 is the be-all and end-all for  casual 
> QSOs but I personally think that it is the first of some very  interesting 
> modulation schemes that will provide the same level of  performance as CW. 
> And since new hams don't have to know the code  anymore ...
>
> 73 de Brian, WB6RQN
> Brian Lloyd - brian HYPHEN wb6rqn AT lloyd DOT com
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 
> 269.7.1/805 - Release Date: 5/15/2007 10:47 AM
>
>