K3 SSB Power Control and ALC Metering
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K3 SSB Power Control and ALC Metering
 
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Michael,
I also see the exact same symptoms you describe below. This is after implementing Wayne's procedures 'to the letter.' Firmware V2.38, K3 S/N 775. 73, Kam N3KS Thanks for the detailed information. However, this is not my problem. The most severe problem I have is: a) the output power spikes and overshoots in CW or SSB or FM as you adjust the power control, so it is not advisable to use a sensitive, i.e solid state power amplifier with the K3. Especially not one needing less than 50W of drive. It needs a fast responding meter to see it. A work around is to set the power without the amplifier in circuit, speak or key to let the spike happen, then switch on the PA and not adjust power or mode afterwards. Does this not happen to anyone else? A lesser problem is: b) that the power output is unstable once set in SSB mode, showing variations of around 50-100% in the peak output depending on the power output setting. This is when set up as described. It is only really visible with a peak reading power meter. _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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Yep, my recently factory re-done K3-100F #309 also has RF output power spikes upon first key down or first SSB word spoken. The spike appears to be at fully 120 watts when rig is adjusted to 50 watts. When oh when will this rig be at least half way done? 73, Charles Harpole [hidden email] > From: [hidden email] > To: [hidden email] > Subject: [Elecraft] K3 SSB Power Control and ALC Metering > Date: Wed, 24 Sep 2008 22:35:12 -0400 > > Michael, > > I also see the exact same symptoms you describe below. This is after > implementing Wayne's procedures 'to the letter.' Firmware V2.38, K3 S/N > 775. > > 73, > Kam N3KS > > Thanks for the detailed information. However, this is not my problem. > > The most severe problem I have is: > > a) the output power spikes and overshoots in CW or SSB or FM as you adjust > the power control, so it is not advisable to use a sensitive, i.e solid > state power amplifier with the K3. Especially not one needing less than 50W > of drive. It needs a fast responding meter to see it. > > A work around is to set the power without the amplifier in circuit, speak or > key to let the spike happen, then switch on the PA and not adjust power or > mode afterwards. > > Does this not happen to anyone else? > > A lesser problem is: > > b) that the power output is unstable once set in SSB mode, showing > variations of around 50-100% in the peak output depending on the power > output setting. This is when set up as described. It is only really visible > with a peak reading power meter. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > 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 Elecraft mailing list Post to: [hidden email] 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 |
Re: K3 SSB Power Control and ALC Metering
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In reply to this post by Kamal Sirageldin
This reminds me of the IC706 (I think) which has a spike leading edge which shuts down an Alpha (which has protection circuits) but not a Heathkit for instance. Or is it just the power control itself which is faulty?
David G3UNA > > From: "Kamal Sirageldin" <[hidden email]> > Date: 2008/09/25 Thu AM 03:35:12 BST > To: <[hidden email]> > Subject: [Elecraft] K3 SSB Power Control and ALC Metering > > Michael, > > I also see the exact same symptoms you describe below. This is after > implementing Wayne's procedures 'to the letter.' Firmware V2.38, K3 S/N > 775. > > 73, > Kam N3KS > > Thanks for the detailed information. However, this is not my problem. > > The most severe problem I have is: > > a) the output power spikes and overshoots in CW or SSB or FM as you adjust > the power control, so it is not advisable to use a sensitive, i.e solid > state power amplifier with the K3. Especially not one needing less than 50W > of drive. It needs a fast responding meter to see it. > > A work around is to set the power without the amplifier in circuit, speak or > key to let the spike happen, then switch on the PA and not adjust power or > mode afterwards. > > Does this not happen to anyone else? > > A lesser problem is: > > b) that the power output is unstable once set in SSB mode, showing > variations of around 50-100% in the peak output depending on the power > output setting. This is when set up as described. It is only really visible > with a peak reading power meter. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > 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 > ----------------------------------------- Email sent from www.virginmedia.com/email Virus-checked using McAfee(R) Software and scanned for spam _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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In reply to this post by Charly
I tested my rig using dummy load and scope. My rig is serial 1198, using
f/w 2.38 and dsp 1.90. I don't see any spike in output. On cw the o/p power on key down is initially about 95% of the set value and then rises to the set value. I tested this on all bands using 51w o/p. On ssb the peak power occasionally exceeds the set value but very slightly, maybe 5% or so. I tried changing the power setting but got the same result. I did however notice that the needle on my analog power meter (Diamond SX200) overshoots the set power - this appears to be a function of the dynamics of the meter movement. Graham G3TCT ----- Original Message ----- From: "Charles Harpole" <[hidden email]> To: "Kamal Sirageldin" <[hidden email]>; <[hidden email]> Sent: Thursday, September 25, 2008 3:48 AM Subject: [Elecraft] K3 RF-out spikes,was: K3 SSB Power Control and ALC Metering Yep, my recently factory re-done K3-100F #309 also has RF output power spikes upon first key down or first SSB word spoken. The spike appears to be at fully 120 watts when rig is adjusted to 50 watts. When oh when will this rig be at least half way done? 73, Charles Harpole [hidden email] _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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Hallo Graham,
thank you for looking at this with a scope. Did you try changing the power level while you were in SSB at lowish power, e.g. from 30W to 35W? This (at least it used to) usually caused my K3 to settle in on a power level which tended to be between 3db and 10dB lower than requested. The effect was stronger at lowish power levels, e.g. 30W, than at higher levels, e.g. 90W. Did you change the power level request while in the RX and/or TX states? My work around, was to set up the power level in CW (or TUNE) and then not touch the PWR knob while in SSB. The more recent firmware versions have improved quite a bit, but the effect never really disappeared totally. This being said, I haven't had a chance to test the very newest firmware yet. vy 73 de toby -- DD5FZ (ex 4n6fz, dj7mgq, dg5mgq, dd5fz) K2 #885, K2/100 #3248, K3/100 #67 _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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Hi Toby
I've just tried it at 30w and it behaves sensibly whether I adjust o/p in rx or tx. There's a slight "wobble" in output power as I adjust it (visible when running carrier) but only a few percent. I tried all powers from 3w to 100w on 80m and 15m. And it also produces the same peak power on ssb as near as I can tell. I haven't noticed any change in this area from firmware changes. Hope this helps. Graham ----- Original Message ----- From: <[hidden email]> To: "Graham Kimbell (G3TCT)" <[hidden email]> Cc: <[hidden email]> Sent: Friday, September 26, 2008 10:53 AM Subject: Re: [Elecraft] K3 RF-out spikes, was: K3 SSB Power Control and ALCMetering > Hallo Graham, > > thank you for looking at this with a scope. > > Did you try changing the power level while you were in SSB at lowish > power, e.g. from 30W to 35W? This (at least it used to) usually caused > my K3 to settle in on a power level which tended to be between 3db and > 10dB lower than requested. The effect was stronger at lowish power > levels, e.g. 30W, than at higher levels, e.g. 90W. > > Did you change the power level request while in the RX and/or TX states? > > My work around, was to set up the power level in CW (or TUNE) and then > not touch the PWR knob while in SSB. > > The more recent firmware versions have improved quite a bit, but the > effect never really disappeared totally. This being said, I haven't > had a chance to test the very newest firmware yet. > > vy 73 de toby > -- > DD5FZ (ex 4n6fz, dj7mgq, dg5mgq, dd5fz) > K2 #885, K2/100 #3248, K3/100 #67 > > > _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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Hello Graham,
thanks for taking another look. It sounds like your K3 is behaving correctly. I hope to update my firmware before the big RTTY contest this week end, which means I could check my K3 (again) as well. If I still see any errors, then one can assume that it likely is not a bug in the firmware. Very interesting indeed... mni tnx es vy 73 de toby -- DD5FZ (ex 4n6fz, dj7mgq, dg5mgq, dd5fz) K2 #885, K2/100 #3248, K3/100 #67 _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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Hi all!
I a have the same problem with my K3 S/N 1577, V2.38. DSP1.90 spikes are visible on all bands specially on SSB first second transmitting! It is very interesting indeed.... 73, E72X,
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Some spike, some don't. Charles Harpole [hidden email] > Date: Fri, 26 Sep 2008 05:41:47 -0700 > From: [hidden email] > To: [hidden email] > Subject: Re: [Elecraft] K3 RF-out spikes, was: K3 SSB Power Control and ALCMetering > > > Hi all! > > I a have the same problem with my K3 S/N 1577, V2.38. DSP1.90 spikes are > visible on all bands specially on SSB first second transmitting! It is very > interesting indeed.... > > 73, > E72X, > > > > > dj7mgq wrote: >> >> Hello Graham, >> >> thanks for taking another look. It sounds like your K3 is behaving >> correctly. >> >> I hope to update my firmware before the big RTTY contest this week >> end, which means I could check my K3 (again) as well. If I still see >> any errors, then one can assume that it likely is not a bug in the >> firmware. >> >> Very interesting indeed... >> >> mni tnx es vy 73 de toby >> -- >> DD5FZ (ex 4n6fz, dj7mgq, dg5mgq, dd5fz) >> K2 #885, K2/100 #3248, K3/100 #67 >> >> >> _______________________________________________ >> Elecraft mailing list >> Post to: [hidden email] >> 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 >> >> > > -- > View this message in context: http://n2.nabble.com/K3-SSB-Power-Control-and-ALC-Metering-tp1117009p1120761.html > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > 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 Elecraft mailing list Post to: [hidden email] 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 |
Re: K3 RF-out spikes, was: K3 SSB Power Control and ALCMetering
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In reply to this post by E72X
Notice that Graham mentioned that his 'peak reading meter' indicated
overshoot, but that no overshoot was seen on an oscilloscope. If your only indication is from a peak reading meter, that may be an anomaly of the meter and not any problem with the K3. Most reports of 'overshoot' that I have read about on this reflector have been observed with some type of peak reading meter. 73, Don W3FPR e72x wrote: > Hi all! > > I a have the same problem with my K3 S/N 1577, V2.38. DSP1.90 spikes are > visible on all bands specially on SSB first second transmitting! It is very > interesting indeed.... > > 73, > E72X, > > > > > dj7mgq wrote: > >> Hello Graham, >> >> thanks for taking another look. It sounds like your K3 is behaving >> correctly. >> >> I hope to update my firmware before the big RTTY contest this week >> end, which means I could check my K3 (again) as well. If I still see >> any errors, then one can assume that it likely is not a bug in the >> firmware. >> >> Very interesting indeed... >> >> mni tnx es vy 73 de toby >> -- >> DD5FZ (ex 4n6fz, dj7mgq, dg5mgq, dd5fz) >> K2 #885, K2/100 #3248, K3/100 #67 >> >> >> _______________________________________________ >> Elecraft mailing list >> Post to: [hidden email] >> 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 - http://www.avg.com > Version: 8.0.169 / Virus Database: 270.7.3/1693 - Release Date: 9/26/2008 7:35 AM > > Elecraft mailing list Post to: [hidden email] 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 |
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Hi, Spikes are visible on both power meter on K3 and I can see on external Watt meter including "error message" from automatic amplifier which get response - Overdrive Input is to high! I am forward message from Elecraft support! it is helpful to press TUNE when the rig is first switched on, for the quickest and most accurate RF output on later transmissions in SSB, CW, or data modes. E72X, Gordan,
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In reply to this post by dj7mgq
Toby
A couple of thoughts - have you looked at the power supply regulation - it might be reacting badly to the sudden key down. The other thought is whether RF is getting into something - this can cause all manner of strange effects, I've even had multimeters giving nonsense measurements through RF pickup. Otherwise it may need to go back to Elecraft as it could be a component failure. Good luck Graham _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Re: K3 RF-out spikes, was: K3 SSB Power Control and ALC Metering
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In reply to this post by G3TCT
I wonder if this thread is related to the thread about TX Gain
calibration, from which it seems to have forked. If the TX gain calibration hasn't been done properly, or the conditions are not similar (e.g. the PA is not providing a 50 ohm resistive load, or there is a significant operating temperature difference), the power produced by setting the gain based on the gain calibration could well differ from that demanded, until the rig has had time to measure the actual power and correct. The only way of going straight to the right power without overshoot or undershoot is to have gain calibration measurements that are accurate and cover all possible factors that affect gain. -- David Woolley "The Elecraft list is a forum for the discussion of topics related to Elecraft products and more general topics related ham radio" List Guidelines <http://www.elecraft.com/elecraft_list_guidelines.htm> _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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