Wes Kenwood have delivered a very credible IMD performance from the new TS-890S and, indeed, even the TS-590s (especially the SG) are considerably better than the Elecraft offerings. All are 12 V radios, of course. I use a TS-890S with a KPA1500 and, while the combination is poorer in IMD terms than my 50-yo Collins S-line, it's a great deal better than many contemporary offerings. I don't anticipate parting with the TS-890S any time soon but, all things being equal, regard a K4 with good pre-distortion implementation as a deal maker in the not too distant future. Indeed, I might have waited for a K4 this time around, barring the shenanigans surrounding the K4 forum discussion and announcement.
Peter, VK6HP. -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Wes Sent: Friday, 30 August 2019 1:10 AM To: [email protected] Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband? Conrad and I have corresponded about this in the past. He is absolutely correct in worrying about the IMD performance of the K4. I bought my K3S after being disappointed with the K3 TX IMD and thinking that the FETs would be better. How wrong I was. IMD was no improvement and reliability was awful. At 50 VDC, they no doubt would be better but as long as Elecraft clings to "12-volt" radios, I'm afraid this will persist. Wes N7WS On 8/29/2019 5:04 AM, Conrad PA5Y wrote: > I have measured the TX IMD performance of my and 2 other K3S transceivers. In > my opinion it is not possible to have anything other than mediocre TX IMD > performance from a K3S or a K3 at ANY power level. I am so disappointed with > this aspect of the K3S. The mass market and cheap IC-7300 is better, > especially on 6m. In all other respects I am very impressed with the K3S. > > > The transverter output on 10m when set to 0.5mW has incredibly good IMD > performance so the problem is with the 2 PA modules. I have contacted > Elecraft and so far they have not offered me a satisfactory solution. I think > that I am going to go to the inconvenience of using an external PA on 6m. > > > The K3S has excellent TX composite noise all ruined by poor TX IMD. I can > easily see 19th and 21st order IMD components on 6m in the 90dB dynamic range > of my E4406A spectrum analyser - this rather negates the advantage to my > neighbours when I'm on SSB. For CW and Digimodes then the K3S is superb. If I > was contemplating the purchase of a K4 I would be asking Elecraft about TX > IMD from the hopefully new and improved TX amplifier chain. > > > Not a happy message but it's the truth. Yes I have the latest FW, yes I have > tried to reduce the gain from the driver using the settings in the FW yes I > maintain the correct voltage on the PA, yes I have late (not the latest) > revisions of the driver and final PA. I am using the 2 tone facility so there > is no question of external or maladjusted audio non linearity. The fact is > that it is poor. I also know what I'm doing. > > > Poor show Elecraft! > > > 73 > > > Conrad PA5Y > ______________________________________________________________ Elecraft mailing list Home: http://secure-web.cisco.com/1RrdgZXSnhmLAY_lbN4qKiWPuu_d2_Rin4oYknooNe9PoZH6r2XpnYKMxQFa0OuEy522SMlmuiZC_aIU-nwBLAJEn1QIUUWJ3rZuVONLvqLg5pu-VTOYl7EJtMst-SRfASbXOOdisf9JXYSscQjIOhaxZutHpCYe9bZPD7EujJ0QVEOLmJWfwksv6NXV-LTVJvKKEo2smKZXuZoeZW51AKEY5RU6dtPOb8xuGhmXpOI2V8DSD23MZTkWhwSUW9xaC2AVLZnCU8Az3n5Xt_Je4ub_N7kKtDCPQ20ZGd6Cxn65g012dejR1eZOwSipcWq9cbf31q06hgDt07nsGw6mXPlsR8yb28ku8Q6dPWim-bpCNp_KVXVi-CdyACLh36jnpeit36YqAULGO4codVPIZReBGa7Wssx9_2ldAqb1cRcztxD4SH0OewY4iLH61V5IAVPC4z42iHc2d9pztOxawHpY8KwbM17Z-TtetiL_T668/http%3A%2F%2Fmailman.qth.net%2Fmailman%2Flistinfo%2Felecraft Help: http://secure-web.cisco.com/1MNZxUEzTafvOANOXLoK_vJvodRC_LlCHQRTdRYGD7-6_4L92eD5UD-39n_HaXZZ1CApPLaKoApfn4GyixDVAsaNWGSrOr6T9t3iw0hworoMK2GxIPxBgfYR-ZZ6y3kYC5OCaXxxuDBIF2l6cZ41MxywuTfHOSAkwgl34jmlTbHi2j9jfPa_BdpzAYP3S2jI_xurncS4jTqpA3-G9p-cCZf9iwXx_wxcHSZD_3WXXVCkha8nwiFzX8cWorb92mnAV_p-PByPDWTNr9EjWhGl_J6gO3xGPUwMF-jnQvcTy5ExZ71v5alvt4ZeCFxHndULznDvk5y92Y3swuKfJGiREwGsVESRJg7YVY5-TwvLfTVwojZ3HUczDgBrv4733zgIIN1SixuHe1gYPaX-TrPcKf9O_Po28q4RdgI6U6Xp8Ezrd9SFLONsDDKq7j9pt1mGZuZNFaFyJPm-FmLOnh-0I-NRZgif44BaIY1nMKPZvUCY/http%3A%2F%2Fmailman.qth.net%2Fmmfaq.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 Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
