> So using multimulticarrier soundmodem with a
> YaeComWood + 1kW PA will
> only heat your ham shack without other useful effect.
Negative.
The grounded-grid PA's have no negative effect on SNR if tuned right
(tuned for peak power). Those PA's have better lineariy than the 100W
push-pull trans
The other problem is linearity of the whole chain. The subcarriers get
mixed not only in the PA, but in the receiver, sound card etc., which
may be interpreted as increased noise on the decoder side. The average
YaeComWood was not designed with this in mind. Voice SSB modulation is
roughly similar
.com/group/DXandTalk
- Original Message -
From: "Roger J. Buffington" <[EMAIL PROTECTED]>
To:
Sent: Sunday, March 18, 2007 4:50 PM
Subject: Re: [digitalradio] Re: MPSK vs OFDM vs MFSK for HF High Speed Data
> Danny Douglas wrote:
> >
> > The best answer is
Danny Douglas wrote:
>
> The best answer is NO linears at all. Not gonna happen. But, in those
> countries whee no linears are allowed, things seem to work quite
> smoothly and operators get out and work DX better than most people
> here do.
>
> Danny Douglas N7DC
Well yeah. Countries in Euro
> when n becomes big, the ratio tends to 1/square(n)
> For example, for MT63 where you have 64 carriers in parallel,
> You transmit only 12.5 watts with a 100 watts maximum XCVR.
The same applies to the digi-sstv hamdrm/windrm modes. 30 to 60
carriers, crest factor (average to peak power) is ab
Danny Douglas
To: digitalradio@yahoogroups.com
Sent: Saturday, March 17, 2007 5:50 PM
Subject: Re: [digitalradio] Re: MPSK vs OFDM vs MFSK for HF High Speed Data
The best answer is NO linears at all. Not gonna happen. But, in those
countries whee no linears are allowed, things seem to work
D]>
To:
Sent: Saturday, March 17, 2007 10:30 AM
Subject: Re: [digitalradio] Re: MPSK vs OFDM vs MFSK for HF High Speed Data
>
> A bigger amplifier is the solution to that. It might bring some other
> amplifier technologies to the ham bands. Even with existing equipment,
> if
Although it was a decade ago that Tom Rink discussed the reasons for the
selection of various modulation schemes for Pactor 2, this modes still
seems to have the most success with throughput under varying conditions.
Pactor 3 enhances that even further, but with a dramatically wider
bandwidth.
ps.com
> Sent: Saturday, March 17, 2007 3:26 AM
> Subject: [digitalradio] Re: MPSK vs OFDM vs MFSK for HF High Speed Data
>
>
> Hi Bonnie,
>
> Thanks for initiating this discussion:
>
> Throw the prospect of incremental frequency shift keying into the mix
> for dis
e ratio is 1/8.
You transmit only 12.5 watts with a 100 watts maximum XCVR.
73
Patrick
- Original Message -
From: Bill McLaughlin
To: digitalradio@yahoogroups.com
Sent: Saturday, March 17, 2007 3:26 AM
Subject: [digitalradio] Re: MPSK vs OFDM vs MFSK for HF High Speed D
Hi Bonnie,
Thanks for initiating this discussion:
Throw the prospect of incremental frequency shift keying into the mix
for discussion; know a few are working on this mode(s)also.
The OFDM (AM-QPSK)+6dB better SNR may or may not be an issue...it
depends on usagethe usual HF near LUF versus
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