[Re-posting my reply to the original post on groups.io]
> On May 19, 2021, at 12:03 AM, N1RM - Rick Miller <r...@milr.com> wrote: > > I put SN122 through its initial paces today. Here are some of observations: Thanks, Rick. My comments below. > 3. The BNC connectors protrude farther out the back panel than the K3, and > look a little strange to me. (But who really cares what the back panel looks > like!) Unlike the K3, the five BNC connectors on K4 have bushings that are used to physically and electrically secure the connectors to the rear panel. This is part of the overall noise-reduction strategy. It also provides very rigid mounting for the RF board. > 2. The interior is very interesting. Most parts appear to be very cleanly > integrated. The CPU has a bit of a "tacked on" appearance. I applaud > Elecraft for not trying to design their own high performance processor board, > but the interface cabling looks a little ad hoc. It all works, but I have to > wonder how it would survive getting knocked around enroute to a Dxpediton. Our goal here was to be able to adapt to future single-board-computer technology rather than be constrained to what's available today. Swapping boards would be a matter of adjusting mounting screw locations on the replaceable adapter bracket and at worst, replacing a couple of cables. > > 3. The front headphone jack was completely dead on my radio, but the rear > headphone jack was fine. It was pretty easy to figure out how to release the > front panel (thanks to Wayne's excellent video on the 3D model of the K4). > The front headphone jack attaches to its circuit board with a socket that > plugs onto a 4-pin header. That connector was completely off the header.... We're going to improve the mating connectors. Thanks for finding and reporting this. > > 4. The pushbutton switches on the front panel are much more solid, with > better tactile feedback than the K3. I like them much better. This is due to our use of real tact switches beneath the rubber in the K4. The K3 (and our other products with rubber switch matrices) uses carbon-dot contacts that rely on hysteresis in the rubber itself. > 3. Tx audio compression seems to be very weak compared to the K3. Even at 30 > (max setting), it seemed to do less than a setting of 10 on the K3. It might > need some DSP attention. Agreed. This is on our list. > > 4. Most of the UI is absolutely great... > > 5. The spectrum display system is a work of art... > 6. Data and CW decoders can run simultaneously on the A and B VFO > frequencies... Thanks for these observations :) > > One weird thing: > 1. I noticed very shortly after I turned the radio on for the first time (AF > gain at zero, no antenna connected) that I thought I had a ringing in my > ears. When I turned off the radio it went away. It wasn't loud, it just > felt like a very slight case of tinnitus. It was sort of like one of those > high pitched tones that you try to guess if it's there during a hearing test. > I noticed that it seemed to come and go as the display came up and went away. > (I resisted the urge to hold my finger up and down as it came and went :) > Then I noticed that it got fainter if I turned the display brightness down. > Just to be sure I wasn't imagining it, I hooked a microphone up to my PC and > Audacity, held it in front of the display, and then powered up the radio. I > could see nothing in the time domain, but when I ran a spectrum on it, there > was a very distinct spike at 10 kHz. The spike disappeared with the radio > off. The "ham demographic" probably includes very few who could hear it, but I'm one of them. Just to put it in proper perspective, I'm that guy who during sound checks in church says "where is that squeal coming from?" and everyone else looks at me like I'm nuts. It's just barely on the edge of being annoying, but there is hopefully something that can be done to mitigate it for those of us that can still hear weak 10 kHz audio. My guess is that it is a DC-DC boost converter somewhere in the display with a ringing inductor. We'll definitely investigate whether it's a DC-DC converter on the front panel board or within the LCD itself. If there's a way to suppress the 10 kHz a bit, we'll find it. > > Bottom line: > While very reminiscent of the K3, this is NOT a K3. It sounds better on Tx > and Rx and its UI is a whole new animal for Elecraft (in a good way!). It has > far more connectivity and control options than the K3, which means you will > have to invest some time to learn how the K4 thinks and acts. I waited > exactly 2 years (to the day!) for this radio, and I can say that it was > certainly worth it for me. Congratulations to Wayne and the whole Elecraft > team for getting this radio out under some really tough conditions. Appreciate the feedback! 73, Wayne N6KR ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
