[Moon-Net] TS-2000X SSB TX Output Power Ramping

Edward R Cole kl7uw at acsalaska.net
Wed Nov 9 01:53:40 CET 2016


Paul,

Be sure to report back the results of using the 
TS2000X ACC2 with JT65 on 2m-eme.  I suspect a 
few seconds ramping of audio input will not 
affect performance as the JT65 tone groups are 
repeated several times during a 50-second Tx sequence.

As SDR technology is increasingly used for radios 
there should be better design to accept digital 
modes.  I had the FT-847 from 1998 to 2012 and 
using the DATA jack was simple for interfacing 
audio and PTT/CW keying. Mic input was 
disconnected and audio output was fixed amplitude 
low-level perfect for driving a soundcard (levels 
set with dialog windows in the computer).  My 
computer had spkr, mic and line-in jacks for the 
internal s/c. so I used spkr and line-in.

I think Elecraft has thought out digital I/F as 
well as anyone.  K3 has internal audio isolation 
transformers with both line-in and 
line-out.  Plus it provides RS-232 port for PTT 
keying by use of DTR and/or RTS.  Mic is 
disconnected in DATA modes which there are four 
types selected by menu.  DATA-A is used with 
digital computer modes.  So no computer I/F is 
required. The new K3S provides either USB or 
RS-232 jacks, so even the soundcard not needed 
when using USB line.  But the K3 (and K3S) both 
forgot providing direct IQ access from the 
SDR.  The newer KX3 does provide IQ baseband I/F 
but still requires a soundcard ADC to convert to digital IQ.

In time the mfrs will accommodate digital modes 
better.  Design is still driven by HF concerns, 
not VHF/UHF/satellite/eme.  But some are 
realizing many high-end radio purchasers are 
using the radios for these frequencies and 
modes.  Also specialty mfr's are making SDR's and 
transverters incorporating the desires of their customers.

73, Ed

At 01:01 PM 11/8/2016, Paul Andrews wrote
>John,
>
>Good to know. Â  I successfully used the AFSK 
>Input port on my previous radio the FT-847. Â  I 
>think Yaesu did a better job. Â  The AFSK input 
>was not subject to speech processing or front 
>panel microphone level control. Â  It was a 
>clean way to interface the SignaLink. Â  Â 
>Obviously, I didn't expect that the TS-2000X 
>ACC2 input would have this issue. Â  I will 
>operate 2M EME with this TX ramp up just to see 
>if it affects the quality of my QSOs. Â  The TX 
>level ramp is kind to SSPAs. Â  Your 8877 is a 
>very resilient amp. Â  SSPAs are subject to 
>damage for over drive. Â  This ACC2 interface 
>problem may actually help protect the SSPA. Â  We'll see.
>
>73 - Paul - W2HRO
>
>
>Â Â
>
>On Tue, Nov 8, 2016 at 3:00 PM, John Regnault 
><<mailto:john.regnault at btinternet.com>john.regnault at btinternet.com> wrote:
>
>Paul,
>
>Â
>
>I have used several TS2000 (X) both for EME and 
>FSK441 meteor scatter over 12+ years.
>
>I have been aware of this issue for many years 
>and just do not use the ACC2 port. The mod looked like a major nightmare!
>
>I run an external sequencers which in turn 
>switches the TS2000 to TX and I use the mic input for all modes.
>
>Like Joe K1JT has said ‘NO PROCESSOR’ and 
>further I would say reduce the audio drive until 
>you have almost no alc. Overdrive and clipping 
>‘does’ affect the quality of a JT65 
>transmission. Poor(clipped, compressed, 
>overdriven) JT65 transmissions decode badly!
>
>Â
>
>Over 3000 JT65 EME QSO’s and over 1000 FSK MS 
>QSO’s driving a 8877 amplifier and the only 
>thing that has gone wrong is oxidised crimp connections on the power lead.
>
>Â
>
>73
>
>John G4SWX
>
>Â
>
>Date: Tue, 8 Nov 2016 09:53:03 -0500
>
>From: Paul Andrews <<mailto:w2hro.fn20 at gmail.com>w2hro.fn20 at gmail.com>
>
>Subject: [Moon-Net] TS-2000X SSB TX Output Power Ramping
>
>To: Moon-Net <<mailto:moon-net at mailman.pe1itr.com>moon-net at mailman.pe1itr.com>
>
>Message-ID:
>
>Â Â Â Â Â Â Â Â Â Â Â Â Â 
>Â 
><<mailto:CAOsf+NQYZazuD2kjTz3HfLQonjD7Eohx23M1LeRaX45cYd+ABA at mail.gmail.com>CAOsf+NQYZazuD2kjTz3HfLQonjD7Eohx23M1LeRaX45cYd+ABA at mail.gmail.com>
>
>Content-Type: text/plain; charset=UTF-8
>
>Â
>
>Kenwood has reported that TS-2000X TX Output 
>Power Ramping when using the ACC2 interface is a 
>real bug / "feature" affecting early models.
>
>My radio is SEPT 2001.  This appears to be a 
>relatively rare bug unless many operators just 
>haven't seen it because they use the front panel 
>microphone jack and not the ACC2 interface.
>
>Â
>
>This bug affects only SSB transmissions originated from the ACC2 port.
>
>FM is unaffected.  WSJT transmissions using the 
>front panel Microphone jack are unaffected.
>
>Â
>
>Kenwood sent me the detailed factory authorized upgrade procedure.   I
>
>have the procedure document in PDF form and will 
>provide it to anyone who asks.  Is there a good 
>place that this procedure could be posted for all interested to review?
>
>Â
>
>The fix is not trivial.  The easy part is 
>removing 1 resistor and adding 
>another.  Removing and replacing a 150 pin SMD 
>IC chip is a little more complicated and then 
>the final step is a full upgrade of CPU and DSP 
>firmware.  At the end of the procedure Kenwood 
>writes, "when complete - no adjustments are needed".  :)
>
>Â
>
>It appears that this TX power ramping is written into the DSP.
>
>Kenwood could have offered this as an 
>option.  The idea of "soft start" for audio 
>digital modes is interesting.  This "soft start"
>
>could be easily written into WSJT and could 
>minimize the TX power overshoot problem that SSPA owners worry about.
>
>Â
>
>I have decided (like others) that this 2 second 
>TX power ramp is actually a very valuable 
>"FEATURE" because it helps treats solid state 
>amps kindly by avoiding the abrupt 0 to 100% output transition or
>
>overshoot spikes.   Hey - I'm making lemonade out of lemons.   I have
>
>not tested to see if this TX Power ramp exists 
>on 70cm or 23cm.  I'll be testing soon.
>
>Â
>
>Thanks for all your responses to my original 
>question.  In summary, 2 moon net readers knew 
>this was a TS-2000 bug and had experience with 
>it.  10 others had not experience this issue.
>
>Â
>
>73 - Paul - W2HRO
>
>Â
>
>
>
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73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
Dubus Mag Business e-mail:
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