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 <[email protected]> wrote: > From: hb9ari <[email protected]> > Subject: Re: [Elecraft] JT65A output power variations. > To: "Elecraft-forum" <[email protected]> > 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:[email protected] > >> > >> 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:[email protected] > > 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
