Merv, My experience with the FT-1000D was that the S-meter didn't start to move until the actual signal strength reached S-5 or so. But yes, I believe you when you say that the switching power supply creates a lot of noise, and the one in the FT-1000D doesn't.
73, Erik K7TV ----- Original Message ----- From: "Merv Schweigert" <k...@flex.com> To: "Milt, N5IA" <n...@zia-connection.com> Cc: <elecraft@mailman.qth.net> Sent: Monday, May 11, 2009 4:14 PM Subject: Re: [Elecraft] K3 Power supply > Milt, N5IA wrote: >> >> ----- Original Message ----- From: "Merv Schweigert" <k...@flex.com> >> >>> I started to try and find the problem and using another >>> receiver I find the Astron SS-30 is generating all sorts of noise. >>> I have used this supply for some time and have not noticed the noise >>> before. >> >> Merv, >> >> For weight considerations, the SS-30 supplies were selected for the >> Ducie Island expedition this past year. >> >> This problem you mention, or a very similar one, was evident during >> the VP6DX expedition from the time that Robin started making tests >> while underway on the Braveheart from ZL to FO. >> >> We added extra filtering internally. >> >> We grounded extensively. >> >> We cleaned the case cover screw holes both on the main chassis and on >> the cover to improve bonding to the cover. We were never able to make >> them clean. All supplies performed in the exact same manner. >> >> We were float charging small batteries to keep the K-3s and the >> ancillary equipment running while the gensets were being refueled and >> having oil changed. The extra capacitance of the battery helped with >> the DC filtering but most of the stuff was of a frequency that the >> battery and other filtering could not remove. And we couldn't keep it >> inside the case. >> >> The fact remains that the harmonics of the switcher were a very real >> problem for us, especially on the lower frequency bands. The most >> annoying situation was the harmonic signal moving around, slowly up >> and down the band such that we could not avoid it at times when we >> were in the middle of a tough one on 160 and were trying to dig it out >> of the noise floor. We had to wait until the birdie slowly slithered >> on by or many times I just reached and turned the SS-30 off during a >> difficult contact. >> >> 73 de Milt, N5IA > The noise floor with the switchers has always been a problem, but the > increase is what was > bugging me, and happy to have it confirmed that they are somewhat > incurable, thought it was just me, > have done about all that Milt describes and still has noise. > The past couple days its has just increased by 2 DB on the meter, in > other words on 20 meters > the K3 is hovering around s4 to s5 noise floor, compared to turning off > the switchers and K3 > and listening on a Ft-1000D it has a noise floor of S0. > I guess its back to an old transformer supply, had been trying to stay > away from that due to the > shipping weight etc. Thanks for all the input. > 73 Merv KH7C >> >> > > ______________________________________________________________ > 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
