You creating imaginary scenarios that do not occur under real QRP conditions when working DX.
Really? Such as? I gave an example of a situation where your signal is below marginal, where 3 db more might make the contact possible but still really hard.
My example of going down from 58 to 57 is not from DX work. If you want to be 58 or 59 on SSB DX you don't work 5, 10 or 20 or 30 watts with marginal antennas. Then it's more like going from 54 to 53 when you go from 20 to 5 watts.
Yeah you dont because the average ham who works portable is using marginal antennas, (...) The only people who need narrower roofing filters than normal are hams running big antennas. (...)
You're welcome to make an argument that the receiver is good enough without extra filters, or that it would be better to use a different receiver architecture, but tying it so strongly to transmitter power level as you do does not make sense.
It seems you still haven't addressed the counter-arguments to this - the QRP operator, even with a compromise antenna, could have a high noise level and hear adjacent stations or narrow RFI sources that would be helped by the roofing filters. Also some hams like to work QRP non-portable, go portable with elaborate antenna systems, etc.
20 watts is a very effective power level for QRP, portable and emergency operation.
That's a bit like saying that an AK-47 is a very effective submachine gun.
20 watts is not QRP by definition; this limit is of course arbitrary but you have to draw the line somewhere. QRP is more about being efficient than effective. I would not trust my life to a 20 or 10 watt HF radio in an emergency any more than I would a 5 watt HF radio.
Does it take the place of 2 kilowatts absolutely not, there is a thing called the laws of physics!
Thank you for this admission. I guess we don't need the documentation I asked you for where you claimed that the military had found out that 20 watts was enough on HF SSB in any situation - because this documentation appears to not exist, whether classified or publicly available.
Most QRP signals are not 5/8 and 3 db can make a huge difference to the signal to noise ratio.
Actually many successful QRP contacts might end up around 55 to 59+ somewhere because some operators only have patience for working the stations they hear well - without knowing their power level. (I almost never identify /QRP even when running QRP.) A 3 db gain won't turn an impossible SSB contact into an easy one, but as I said it might elevate it from impossible to still very difficult.
QRP stations dont have difficulty copying stations running 1kw.
They can if the QRP station has more QRM, QRN and RFI to deal with than the QRO station, or if the 1kw station has a compromised high-loss antenna and makes up for it with more power delivered to the antenna system.
Again QRP operators like being legends in their own minds and fail acknowledge the tremendous job done by the receiving stations excellent low noise QTH, huge antennas and huge power. Please give credit where credit is due.
I see QRP operators complimenting and thanking their counterpart quite often. If you're operating portable QRP with a compromised antenna, and adverse propagation, the other person's antenna, receiver features and operator skills are doing much of the heavy lifting. But note that the QRO station's linear power amplifier doesn't make it hear the QRP station any better.
A manpack configuration is a flexible and more convenient setup than carting around bits of this and that like you will have to do with the KX3.
Are you seriously trying to say that a whole manpack - whether it's 4 or 10 kg - is more modular than a smaller and lighter radio that can be built into a manpack? That Elecraft should force their customers to bring out their powertools and soldering irons to rebuild it into a trail-friendly QRP radio?
People who go hiking for many days want to save as much dead weight as possible, because they need to carry their food and survival gear.
A radio like the FT857 makes a more convenient portable 100 stations than two boxes and tons of cables hanging all over the place.
Of course, which is why I said it, if you mostly work 100 watts anyway; but if you only need 5 or 10 watts, you can't leave the excess weight and power draw at home with a FT857; with a KX-3 you can.
You must love chaos in your ham radio style. HF manpacks are elegant in their packaging and effectiveness.
It's not difficult, given time and and a simple power tool to mount the KX-3 into a frame and construct a manpack around it. If demand is high, somebody will offer it for sale or build it themselves.
Your lack of experience at using this power is clearly showing. Try it some day with your big beam. Call a station with 100 watts and then reduce your TX power down to a level of 20 watts. Almost 100% of station will not even
mention that your signal has dropped.
I've run both QRP and high power club stations. The signal level difference between 5 and 20 or 10 and 20 is smaller than the decibel difference between 20 and 100. In the same post you manage to say "3 db can make a huge difference to the signal to noise ratio." Another contradiction you make.
The reason I personally wouldn't bother with anything less than a 50 or 100 watt PA, is that I would want the extra weight to have a noticeable effect, at least an order of magnitude.
All you will end up with the KX3 is box thats full of messy pieces of equipment, wires and inconvenient battery packs and amplifiers. The combined weight of all these items in the messy configuration will weight more than your worst case scenario.
I see you're worried about too much cable salad - but some HF manpacks are indeed constructed as modules and since the KX-3 is a kit, you could also just buy a bigger enclosure, mount your PA stage inside it, and cut holes in it for the connectors. But you'd still have to make the same electronic connections inside this box, and then the question arises - why not just mount a K3 and and a battery on a pack frame and call it a day? I mean since milspec ruggedness isn't something you care about in a military manpack?
You have incorrect views of the role of long distance HF communications in the military service.
Citation needed. You claimed that the military found a 20 watt HF manpack on SSB to be enough for dependable communications (documentation which you haven't shown). You seem to reject that a manpack user would have different communications requirements and circumstances and than a backpacking radio amateur.
Special forces and reconnaissance units use HF manpacks for long range communications on a daily basis.
As far as I know, they use encryption, frequency jumping and digital communication with power-efficient modes, and can use external amplifiers if they want. For longer distance communications they are limited by the same propagation that HF amateurs are limited by, but thanks to relays, they aren't necessarily dependent on a dependable HF path from point A to point B to exist, but can communicate via various ground stations, naval vessels, E-8 JSTARS
While there is no doubt that other services like satellites is reducing the dependance on HF service, long range HF communication is still well integrated in the military forces of the world.
Sure, but they don't exclusively rely on SSB manpacks.
The FCC rules have changed for low drive amps in the ham service.
When did they start type-approving them? I haven't kept current on that it seems.