First off, I am not using an amplified speaker; it is a National Receiver speaker from circa 1950's. I have used it with my FT-847 for years before getting the K3 (#4340) in 2010. Never popped like the K3. In fact none of the ham radios that I have owned since my first one in 1958 ever did this (so much for your theory this is common).
Its not a thump on my K3, it is a sharp POP. Sometimes a double POP-POP. You can duplicate what is sounds like by applying 24vdc, momentarily, to any common 4 or 8-ohm speaker. If it doesn't destroy the speaker coil in the process it will give you a very loud sharp pop! The internal speaker also pops at start up. In the headphones it is also there but not as loud. Audio gain control has no effect on it. My home theater 200w receiver does have a low thump in the speaker when turned on, but not a sharp pop, and not as loud. I haven't mentioned this until this thread came up, but I was certainly alarmed the first time I turned on the radio. MY power supply is a 50amp Astron analog supply - if that matters. Again neither the FT-847 or FT-817 exhibit any sound when turned on except radio noise and/or signals. Some have suggested turning off the speaker. Well, that is kind of hard since the mini-phone plug has wires directly to the speaker coil. Again it is a plain speaker - no amplifiers. The only way for me to mute the radio is to make a 555 timer to control a relay to disconnect the speaker during start up. But that will not silence the snap at shut down. I guess if it irritates me enough I can mount a switch on the speaker to disconnect it (providing I remember every time I turn on/off the radio). This is all I am going to say on the subject. I will leave it in Elecraft hands at this point. Ed - KL7UW ---------------------------------------- Message: 18 Date: Sun, 4 Sep 2011 14:16:46 -1000 From: David Herring <d...@ah6td.com> Subject: Re: [Elecraft] K3: switching on click -- One wonders... To: Elecraft Reflector <elecraft@mailman.qth.net> Message-ID: <bf2d16a2-72fc-497b-a6bf-141e22ba9...@ah6td.com> Content-Type: text/plain; charset=us-ascii Hi All! I know we've milked this one quite a bit, but I do have a point to make that I think will frame this "power-on thump" issue in a little better light... First off, I have K3 #3019 and there is a very detectable power-on AND power-off thump in the built-in speaker and in the cans. I don't have external speakers so I can't say about that. BUT, what I wanted to point out is that this behavior, this power-on and power-off click or thump is widespread and not strictly a K3 problem. While there are others on this list with way more experience in the field of audio, I can say that in my younger days I was very much an audiophile. I can tell you with certainty that all the high end audio equipment I owned (and wished I owned!) thumped when powering on and powering off. Outside of my own equipment, I have worked mixing boards and commercial sound systems which all thumped on power-on/off. Some loud enough to nearly blow your hair off. I have even witnessed this in concert halls -- I'm thinking, as one example, of the Pacific Amphitheater one night in LA which very clearly had the power-on/off thump. I can think of others probably if I worked my brain cell really hard. The point is that this phenomenon seems to be part and parcel of the powering-on and powering-off of solid state audio amplification. As this exists in the high quality and commercial equipment I've had the pleasure of working with, I don't feel it detracts from the K3. I think the K3 is actually in pretty good company. I know that being common doesn't make it right...but it probably does indicate that most in the business don't regard it as particularly important. IMHO if it costs more than a nickel to fix, I wouldn't bother. However I understand that others, perhaps with amplified speakers, are well within their rights to feel differently. :-) Alrighty then...back to the honey-do list... 73 & Aloha, Dave AH6TD 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-? DUBUS Magazine USA Rep dubus...@gmail.com ====================================== ______________________________________________________________ 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
