[TenTec] OT: Question about TS-590 possible problem
k9yc at audiosystemsgroup.com
Mon Oct 8 16:20:50 EDT 2012
On 10/7/2012 1:10 AM, Rick - DJ0IP / NJ0IP wrote:
> We are simply asking for experience with the TS-590.
> I'm thinking the TS-590 is a random noise generator!
YES, it is. So is the Icom 7600. These are low cost, do-everything
wonders, and the design compromises to do everything at low cost results
in lots of broadband noise. There are good reasons why much cleaner
rigs like the Orion and K3 cost a lot more.
Below is a post by N6TV (top contester, owns several K3s) to the NCCC
reflector back in July. Note specifically the comments about the 590.
73, Jim K9YC
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On Mon, Jul 16, 2012 at 3:55 PM, KE1B <ke1b at richseifert.com
<mailto:ke1b at richseifert.com>> wrote:
OK, so now you've got my interest. Why would CW-QRQ (a *transmit*
function), cause RIT, IF SHIFT, etc. functions (all on the receiver)
to be disabled?
This is kind of a long and complicated story, and should probably move
to another reflector.
The original K3 firmware didn't have a CW jitter problem at speeds >37
WPM, but some K3s had a little chirp. Elecraft fixed the chirp by
changing the timing: they added more DDS "settling time". That fixed
the chirp, but introduced CW jitter (erratic CW timing at >37 WPM).
Then Elecraft added CW QRQ mode to fix the jitter, but this has the
noted restrictions, which are a side effect of locking the DDS. Other
radios like the TS-590S don't have the same issue because they use a
method of frequency locking that produces much more phase noise during
transmit (DDS without cleaning up the signal with a PLL).The Elecraft
engineers have decided it is far more important to have super clean
output, with some restrictions above 37 WPM, than to have noisy
jitter-free CW without restrictions at all speeds. These are difficult
engineering trade-offs. In densely-populated SCV, I think it is
especially important for all to have super-clean, noise-free, click-free CW.
Mon, Jul 16, 2012 at 4:05 PM, iain macdonnell - N6ML <ar at dseven.org
<mailto:ar at dseven.org>> wrote:
I think it's probably not necessary to enable this mode for
moderate-QRQ (~40wpm) if you don't
use QSK, although I haven't had any motivation to play with it....
I think you'll find that CW QRQ mode makes all K3 CW sound better, even
in semi break-in mode, especially at 40 wpm where a dot is only 30 ms
long. That's because CW QRQ reduces the TX DLY from 8 ms to 4 or 5 ms,
or from 26.7% of a dot length at 40 WPM to only 13.5 - 16.7% of a dot.
You really can /hear/ that, especially if your callsign starts with a
dot and you the VOX delay is set to drop out between every word.
Elecraft is aware of all these issues, and is trying to come up with a
new way to produce good, clean, jitter-free high speed CW without losing
RIT and IF SHIFT capabilities, but it's a tough problem and they may
never solve perfectly. In the mean time, they automatically turn CW QRQ
OFF and ON whenever you enable and disable RIT or SPLIT (when CONFIG:CW
QRQ is set to ON). Using contest logging software automatically to (1)
enable and move the RIT, (2) disable and zero the RIT, makes this less
cumbersome than pushing the radio buttons.
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