I don't know what's still available, but some time ago I ordered spares of what I expected might wear out, mainly encoders and pots. They're all fairly generic, so even if Elecraft no longer sells the

I also just did the manual calibration. However, there doesn't appear to be a way to display the new calibration values. Even saving and restoring the configuration did not work, nor did cycling the p

The internal protection diodes are probably intended only for ESD protection, and can't handle much current. The TVS diodes, on the other hand, can handle lots of current, which is probably necessary

I hadn't run the TX gain calibration in almost 2 years on my K3. I was seeing some significant power overshoot when I changed bands, up to 126 W when set to 100 W. After the first transmission, it alw

In CW contest operation, I've never see the temperature get much above 60 C. I have, however, tested the fans at maximum speed. You will know if they ever reach that speed, and there better not be any

#kpa1500

That is true. The K3(S) will display its own output power. Unlike the KXPA100, of course, the KPA(1)500 has it's own display. 73, Scott K9MA

You would have to be a serous masochist to lug a K3 and the battery very far on your back or bike. I just use the KX2 barefoot for that sort of thing. 73, Scott K9MA

I've used both the KX2/KXPA100 and K3 for portable operation. I don't think there is much difference in power consumption, but the K3 is a lot easier to use, has a better receiver, doesn't require con

I know they're not popular, but I recommend an external tuner located at the end of the wire. The only exception might be if the coax is short and the wire is NOT a multiple of a half wave. In either

It's also probably a bad idea to try to use a power combiner with internal ATU's in the amplifiers, unless you can make absolutely sure they both use the same settings. Better to use a single tuner AF

Lack of active cooling suggests that the loss can't be large: a 1dB loss would be about 300 W. The manual definitely should specify equal cable lengths. 73, Scott K9MA ---------- Scott Ellington --- v

I would be concerned about that, too, especially with all those toroidal inductors supported only by their leads. (And Elecraft recommends against using adhesives, as it can detune them.) Since the K3

I have plenty of them, but not on the K3. Many of the cables to the desktop computer, for example. However, my antennas aren't far away, and I shunt feed the tower on 80 and 160. 73, Scott K9MA

I think it would take extreme amounts of RF in the shack to require ferrite chokes on any of the K3 cables. My shunt fed tower is only 10 meters from the shack, and I know there's a lot of RF flying a

Thanks, Bob. I didn't think to look at the amplifier manuals. That all makes perfect sense, as the K3 uses those pins for other functions, and connecting them to the amplifier would make a mess of thi

All filters have phase shift. The important thing is how that phase shift varies across the passband. Filters with nearly linear phase shift produce minimal distortion of the signal, because linear ph

I did not know about the unconnected pins. Though I can see why, based on the K3 schematic, I don't know why they weren't just left open at the KPA500/1500 end. RFI perhaps? Or maybe, with a long cabl

Hi Tony, Well, that's one way to cut down on the fan noise! Unfortunately, my shack is already in the basement, and I don't think putting the amplifier above my head in the dining room would be popula

Of course, the power supply goes by the amp. The ACC cable has the DB15HD connectors, with all 15 pins connected. The longest ready-made cable I can find that I would trust is 10 feet from Winford. An

Hi Lou, I would locate the power supply near the RF deck, so DC power cables won't be an issue. It would indeed take a lot of copper to make a 20 foot DC cable! 73, Scott K9MA