Hi Ken, I will look next week-end if DATA mode is usable with VOX? If i remember correctly, this was the (only) reason i choose USB mode(?)
As i said before, the 3dB variation with output power in certain circumstances, when DF= ~ 0Hz is only a "minor" problem; i work with that since March 2008. I was just curious to know the cause of this "selective" effect with some "particular" JT65 tones. Just a precision, this level variation is also perfectly perceptible with the MON(itor) output of the K3... Very pleased to meet you in this forum and i enjoy to see you soon in the JT65 windows! (May be before my "forced" Winter break!) 73 QRO de Rudolf, HB9ARI Ken Roberson wrote: > Rudolf, > > We have worked many times on JT65A , I also use a K3. > I operator in the Data mode , ( setup data mode for USB ) > and have had no problem for about a year. > I think this is the best way to run data modes. > I set the shift at 1250 hz and the BW at 1200 HZ. > The JT65 software only looks at 1200 hz bandwidth. > This works for me. > GL 73 Ken K5DNL > > ------------------------------------------------------------------ > > > --- On Wed, 11/11/09, hb9ari <hb9...@bluewin.ch> wrote: > > >> From: hb9ari <hb9...@bluewin.ch> >> Subject: Re: [Elecraft] JT65A output power variations. >> To: "Elecraft-forum" <Elecraft@mailman.qth.net> >> Date: Wednesday, November 11, 2009, 9:59 AM >> Hello Matt, >> >> Yes, TX EQ is flat. I've tried to compensates >> with TX EQ, but i've all "reseted" to "flat". >> >> Thank you for this indication. >> >> 73 QRO de Rudolf >> HB9ARI >> >> Matt Zilmer wrote: >> >>> Since you're using USB, you might want to be sure you >>> >> have the TX EQ >> >>> "flat". Or use DATA A, where the EQ doesn't >>> >> apply. >> >>> 73, >>> matt W6NIA >>> >>> On Wed, 11 Nov 2009 11:28:36 +0100, you wrote: >>> >>> >>> >>>> Hi Julian, >>>> >>>> Thank you for your fast answer! >>>> A 1st point, as with the FT857, i'm using >>>> USB mode for JT65A. For the filter used, >>>> i ordered a 8 poles 2.8k with my K3, >>>> but i'm not sure if the 5 poles 2.7k "original" >>>> and always installed as FIL2 is not >>>> selected during TX???; next week-end, when >>>> active at my "external" shack, i will look how >>>> to remove the 2.7k filter, as i've also problem >>>> with center filter when i adjust the HI LO >>>> filter controls; when the 2.7k filter is >>>> >> (automatically) >> >>>> selected, i've a big discontinuity with >>>> >> filter setting. >> >>>> As you say, i will look if the 2.7k is not >>>> >> selected >> >>>> during TX. I read also the "problems" when in >>>> DATA A mode, but as said, i'm working in USB >>>> (as recommended for JT65A for all RF bands) >>>> and VOX work at perfection too. >>>> >>>> My best 73, Rudolf >>>> HB9ARI >>>> >>>> PS As i expect to get 50W output when i set >>>> the control to 50W, i've adjusted the audio input >>>> level for max bars on ALC. For PSK31, i work >>>> with ~ 10 to15W max for 100W selectes with >>>> the control and "local" receiving give me an >>>> >> "acceptable" >> >>>> -24 to -28dB IMD. >>>> >>>> >>>> Julian, G4ILO wrote: >>>> >>>> >>>>> hb9ari wrote: >>>>> >>>>> >>>>> >>>>>> Hello, >>>>>> >>>>>> As i use principally JT65A (snice ~ >>>>>> >> 2years), >> >>>>>> i've remarked transmit output power >>>>>> >> variations >> >>>>>> depending where the audio is located in >>>>>> >> the waterfall, >> >>>>>> as i'm not speaking English, it's >>>>>> >> difficult to explain correctly; >> >>>>>> if i'm ~ in the middle of the waterfall (~ >>>>>> >> 1200Hz) >> >>>>>> i get over 3dB in output power variations; >>>>>> >> for an expected >> >>>>>> 50W output power, between some tones of >>>>>> >> the JT65A >> >>>>>> modulation, the output level can vary from >>>>>> >> 20W >> >>>>>> to 60W; if i'm working away from the >>>>>> >> "middle", >> >>>>>> variations are lower and acceptable but >>>>>> >> most >> >>>>>> of time, "central" frequencies are >>>>>> >> used... >> >>>>>> I've always worked with this "problem" as >>>>>> >> i >> >>>>>> expect some AGC effect by the receiving >>>>>> >> side... >> >>>>>> I would appreciate to have an explanation >>>>>> of this effect. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>> This topic has been brought up before in the >>>>> >> context of RTTY. The reason is >> >>>>> that there is no automatic level control in >>>>> >> DATA A mode (or rather, there >> >>>>> is, but it is very slow acting to avoid >>>>> >> causing IMD on PSK31 signals) so >> >>>>> there is no compensation for ripples in the >>>>> >> roofing filter passband. It has >> >>>>> been suggested that the problem is less when >>>>> >> using the 8-pole SSB roofing >> >>>>> filter as it has less ripple than the standard >>>>> >> 5-pole filter. >> >>>>> The output should not vary as much as you >>>>> >> suggest while working within the >> >>>>> normal passband for JT65A operation so I'm >>>>> >> wondering if you have correctly >> >>>>> adjusted the audio input level in DATA A to >>>>> >> get 5 bars on the ALC scale. >> >>>>> This will not prevent the power varying for >>>>> >> different tones during a >> >>>>> transmission but it should help maintain a >>>>> >> constant average level when >> >>>>> working at different places within the >>>>> >> passband. >> >>>>> ----- >>>>> Julian, G4ILO. K2 #392 K3 #222. >>>>> * G4ILO's Shack - http://www.g4ilo.com >>>>> * KComm - http://www.g4ilo.com/kcomm.html >>>>> * KTune - http://www.g4ilo.com/ktune.html >>>>> >>>>> >>>>> >>>>> >> ______________________________________________________________ >> >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:Elecraft@mailman.qth.net >>>> >>>> This list hosted by: http://www.qsl.net >>>> Please help support this email list: http://www.qsl.net/donate.html >>>> >>>> >>> >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> > > > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
