Hmm, interesting, 4 dB MDS improvement and the gain of the preamp is 15-20 dB i think. Spontaneously this is a lousy preamp or I had too much too drink during Saturday dinner.
Correction to W0SD: The FT-1000D DO have a preamp, about20 dB gain. Check the schematic and you will see. When you turn switch to IPO it kicks out the preamp. Then turning it further to 6 dB etc etc you switch in attenuation in 6 dB steps. IMO this was soo stupid, instead I did modify my FT-1000D NOT to turn off preamp but just use the atennuation steps. Easy to do, just look at the schematic. By using the 6 12 18 dB attenuation steps I easily can improve the IMDDR3 when needed. My modified FT-1000D has about 92 dB IMDDR3 at a MDS of about 142 dB 2 kHz spacing. Not too shabby, and I don´t have to "ride the" RF gain. Also I don´t get fatigued by strange pink or whatever noise. Soo here we have a radio ( K3 ) with 135 dB MDS and you guys are going to lower the gain! In my head something is totally wacky here. / Jim SM2EKM ------------------------ drewko wrote: > Regarding the preamp: MDS measurements show a better (S+N)/N with the > preamp on, approx 4 db improvement in MDS on my K3 on 40m. A similar > improvement is obtained by setting the ATU to BYPASS. > > The macro to toggle Preamp+Bypass is SWH19;SWT24; for anyone who wants > to try it. It may be useful for weak signals. You do have to remember > to toggle it (the ATU) back on when you transmit though. > > 73, > Drew > AF2Z > > > On Sat, 19 Dec 2009 10:27:16 -0600, Ed W0SD wrote: >> It has been my experience over the years to "NOT" use the pre-amp on any >> HF radio unless you are out of audio gain. The FT-1000D did not have a >> pre-amp and the only place for me it was lacking was 10 meters. For me >> I just don't hear more at 10 meters and down with a pre-amp. For me it >> just brings the noise up with the signal. The only place I have seen a >> big benefit from a pre-amp is above 28 mhz. Obviously the K3 benefits >>from a pre-amp on six meters. >> Ed W0SD > ______________________________________________________________ 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
