Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: Prev 1 [2] 3 Next   Go Down
  Print  
Author Topic: KX-3?  (Read 16953 times)
KF5KGN
Member

Posts: 1




Ignore
« Reply #15 on: June 08, 2012, 09:40:06 PM »

In spite of the vitriol, I found this interchange to be quite valuable in broadening my  perspective.     My thanks to the contributors.   Lips sealed
Logged
G7DIE
Member

Posts: 65




Ignore
« Reply #16 on: June 09, 2012, 02:55:13 PM »

Thats what I was talking about too? I was just pointing out that on 40 meters in Europe --------

--------- I have heard G4AKC and his buddies work pedestrian mobile from near the sea making reliable SSB contacts with very low milliwatt power,  however without the huge sea water advantage this would not be a  daily reality. 20 watts  regardless of where you are located is a very effective communication power limit that works well on all modes.


Like this:
Real HF Mobile group morning DX

That's me with 5W and a homebrew whip Wink
Logged
LA9XSA
Member

Posts: 376




Ignore
« Reply #17 on: June 10, 2012, 04:47:57 AM »

Thats what I was talking about too? I was just pointing out that on 40 meters in Europe as you well know,  your receiver faces this so called "contest" challenge on a daily basis plus the added penalty of facing extreme levels of signal levels from the shortwave broadcasters.
The broadcasters are above 7.200. The filters we're talking about here are more for rejecting a signal, say, on 7.060 while you want to work 7.030, right?

The KX3 even with its good roofing filters and performance has way too much  receiver performance than is really needed.
Why is it a problem that the receiver is "too good" for you? With the roofing filters and DSP you should be able to work stations that you otherwise might not hear due to strong stations nearby, or due to RFI. That station could hear your KX-3 perfectly because he
a) Has a low noise level and no nearby stations
b) Has a beam or phased array with wide nulls to reject the QRM
c) Is also working QRP
d) You are working QRO
Or any combination of a-d. It's simply not true that more money and weight should always be spent on transmit power. You need to balance transmit power, the antenna and receiver features. People who buy a KX-3 will want the most capable radio they can get per unit of weight, for backpack operation, while also being able to hold its own as a base station rig with an amp.

While Its nice what Elecraft have accomplished with the KX3's design, some simple question  can I operate all day on batteries and be heard is more of an important question than having the best receiver!
With its efficient and low power draw, yes you can operate on batteries all day and you can carry them with you too. And for a QSO to take place the guy/gal at the other end has to be heard by you too, so a good receiver is not a waste.

I dont know how  filters can prevent  EMC/EMI  or noise problems? I have never owned a radio that has a filter that can block man made noise?  There is nothing you can really do about noise problems in big cities. The EMC regulations need to be enforced and tightened up. I can walk down the road into any store and see equipment for sale from China that has fake EMC stickers on them that dont meet any EU EMC standards. The KX3's roofing filters cant help much here, the roofing filters are there to protect the front end not filter out noise.
Of course it would be nice if you can hunt down all sources of RFI in the neighborhood, but some of that RFI presents itself as a strong narrow signal - perhaps repeated as harmonics up the band - and with a sharp filter you can at least cut that away and work between those harmonics.

Its not what can and cant be done with 5 watts or QRP. The question is simply what is  an effective level of power for  reliable communications?  5 or 10 watts   is not  an effective communication power output for SSB for most  land based hams. If you operate from near the sea side sure it can be very effective. We dont all have the luxury of operating from  piers looking over sea water. I have heard G4AKC and his buddies work pedestrian mobile from near the sea making reliable SSB contacts with very low milliwatt power,  however without the huge sea water advantage this would not be a  daily reality. 20 watts  regardless of where you are located is a very effective communication power limit that works well on all modes.
My point is that 20 watts isn't effective either, for most land based hams, if by "effective" you mean it guarantees communications in a the intended area on HF. You need hundreds or thousands of watts to near-guarantee voice communications at the ranges that HF hams usually operate. And even with full legal limit, there are some hams who live in areas where HF sometimes is almost completely dead and linked repeaters or satellites is the only way to operate for any long distance work.
In the post I replied to you claimed that military research had shown that 20 watts was enough for anyone on HF; I asked for documentation of this, and pointed out that it's a compromise and that the communications requirements for a military manpack are more modest than what most hams want to do, and that the logistics situation and style of use is different. Also I pointed out that also military manpacks have a modular build-up with optional external amplifiers. I can't see that you've addressed these questions in your post.

I dont need 100 watts for portable operation, if I needed 100 watts or more I would just get into my car and connect the antenna!
If you want near-guaranteed effective communications on all modes you need more than 100 watts actually. I've operated a kilowatt portable station a couple of times at field day, and at the worst time of night you need all that power to work SSB somewhat effectively - yet some bands are dead at that time no matter how much power you try to use.

Most people dont walk to their QRP operating sites!
They roll there with their mobility scooter? Why do you keep touting a 20 watt HF manpack as all the radio anyone would ever need if you just drive to your operation site anyway? You could just bring a generator and a kilowatt power amplifier.

Rather than an HF manpack, I would compare the KX-3 to the radios that special forces operators would use deep inside enemy lines. Rather than just talk to other companies and battalions in the brigade's area of operation, and be continually supplied by batteries through the supply lines, it is meant for longer distance communications, and has to be smaller and more battery efficient.

I think manpacks are cool, partly because I'm a bit of a military nerd, but the point remains that the KX-3 is designed exactly to be a trail radio that you carry with you for longer trips, and I would suppose that most people who want one intend to carry it in their backpacks.

If the KX3 was a true portable radio, a 100 watt amp should not even have been offered!
That's like saying that if the KX-3 was a true portable radio, a battery charger wouldn't have been offered - only a solar panel. In fact, that the 100 watt amplifier is offered as an extra rather than being built in, shows that it is indeed intended as a portable radio, because you can leave the 100 watt stage at home if you like. It just shows that it's made to possibly be your only radio, in contrast to the single-band CW only tuna tin QRP sets that are as light as possible but require the operator to work much harder and perhaps are locked to a very narrow frequency range.

The popularity of 20 watt to 50 watt amps for  the FT817 is testament to this fact.
Yaesu doesn't offer an amp for their FT-817, so that proves that the FT-817 is truly portable yet the KX-3 isn't because Elecraft offers an amp for it? If that's what you meant it's rather silly. The main problem with the FT-817 for portable operation is its current draw; the KX-3 is more economical with the current due to its more modern circuit design.

Lots of external amps out there, no need to be tied to the Elecraft 100W model.
Well on this I agree.
Logged
AA4GA
Member

Posts: 120


WWW

Ignore
« Reply #18 on: June 10, 2012, 09:28:41 AM »

In Europe on 40 meters CW, we dont have to wait for contest weekends really to test our receiver, thats our standard operating environment. The number of receivers  that can handle  the CQ WPX on CW on 40 meters in Europe is a very   small.   Any radio with a poor 2nd order intercept point or poor IMD dynamic range wont cope well in Europe.

...

The point still remains that with simple antennas, and portable operation most front ends can cope well enough unless the receiver is totally useless. The KX3 even with its good roofing filters and performance has way too much  receiver performance than is really needed.

Which side of your mouth should we be listening to?

QRA?
Logged

W7ASA
Member

Posts: 267




Ignore
« Reply #19 on: June 17, 2012, 09:53:19 PM »

The KX-3 is a 10 Watt transceiver that is rather well suited for remote operations, though I am cetain that it's fine in the ham shack and local picinic table as well. //I'd LOVE to have one in MY ham shack right now!//  Grin

Doubling output power only equals 3 dB. In practical application, that is only one half of one S-unit at the receiving station's end. It's basically undetectable in the operator's headphones, though some may claim that they are able - with effort- to detect a 3dB difference.  

I've done a LOT of long range/low power HF communication from extremely remote areas of the world, both professionally and as a ham and cannot forsee any engineering, practical or tactical reason to add a 20 Watt amplifier to a 10 Watt transceiver to gain only a HALF of an S-unit (3 dB). This is not worth the extra space, expense & power requirement.  

As for extras, I want:

Every receive filter, noise damper and etc. that I can get (I listen far more than I transmit - which is good advice in life too... ;^)  

Automatic antenna coupler.
 
Internal rechargeable battery for use with folding solar panels (in addition to external packs that work at low temperatures)

I won't use their front mounted paddle, as I don't usually operate where there are tables and prefer my own, leg mounted variant, so that I can just sit where I am able.

>>> I would love to have it's case be a watertight, protective case with ROUNDED corners, like my personal KX-1 (pics at: QRZ.COM and my callsign.)

73 de Ray
W7ASA ..._ ._
« Last Edit: June 17, 2012, 09:58:30 PM by W7ASA » Logged
ZENKI
Member

Posts: 980




Ignore
« Reply #20 on: June 18, 2012, 02:38:24 AM »

Location, Location Location.

If I could do that well with a FT817 from my inland location, I would pull all my towers and beams down. I then would sell all my amplifiers.

Its unfortunate that real estate that is close to the  water is so expensive and full of QRM.

There is also a couple of VK stations who operate mobile also near seawater. These two stations are  heard regularly on 20 meters. On one occasion the VK3 mobile was stronger than VK3MO who uses 20 elements on a 200 ft tower.
There is no doubt that operating near seawater combined with vertical antennas and the Brewster takeoff angle  make it the most effective way of operating with simple antennas and low power.

 The seawater advantage  has been demonstrated on many occasions now by the "team vertical" and other near saltwater dx'peditions. Height might equate to a mighty signal, however there is no doubt that seawater and vertical antennas are a dynamite combination for good signals on HF. In my work I had the opportunity to use a Navy Vertical Log periodic  that was well over 500 ft long  and its last element was right over the saltwater. What this antenna heard was truly impressive. Switching over to a horizontal tilted LPDA that was on the same site and the signals just disappeared.




Thats what I was talking about too? I was just pointing out that on 40 meters in Europe --------

--------- I have heard G4AKC and his buddies work pedestrian mobile from near the sea making reliable SSB contacts with very low milliwatt power,  however without the huge sea water advantage this would not be a  daily reality. 20 watts  regardless of where you are located is a very effective communication power limit that works well on all modes.


Like this:
Real HF Mobile group morning DX

That's me with 5W and a homebrew whip Wink
Logged
ZENKI
Member

Posts: 980




Ignore
« Reply #21 on: June 18, 2012, 03:13:09 AM »

Thats what everybody says, "its only 3db" Try getting 3db from a portable antenna! Well if you add 3db from the extra power, 2 db from tuner loss, and a few more db from low antennas and the total loss looks dramatic. The only 3db is the simplest way to try and help overcome some of the losses that you cant control. 3db on the receiving makes a huge difference when your signal is weaky squeaky.

Well the KX3 would have been a better radio with a 20 or 30 watt PA. It could have been a 2 stage PA that operated QRP when using  internal batteries, and high power on an auxiliary LIPO battery packs. Just look at the number of FT817 users who are looking for a decent amplifiers. If Elecraft did their market research well they would have discovered that most portable operators were looking for something a bit more than 10 watts that integrated into a nice  small package. The Military HF manpacks like the Tadiran Manpacks make excellent ready to go HF radios. The Tadiran  HF 6000 is just a fantastic radio to use portable. The KX3 could  have been built into a similar option using a high tech plastic case with extra batteries. 20 watts of output is standard output power on most Mil manpacks for  very good reasons. The mil manpacks have no issues with battery power. Modern battery backs can deliver the power needed. 4 X Dewalt  drill 18 volt 4ah XR would easily deliver the power. Thats almost 300 watts of power in a very light package. These 4 batteries and 20 watt KX3 could have easily  fitted into small plastic manpack case with a auto-tuner. If you wanted to use the KX3  you would simply slide it out of the manpack case. This kind of setup would have been far more popular than the  KX3  in its current form.

Judging by the sale numbers so far the KX3 is going to be a huge hit. The 100 watt PA just looks messy. I would rather just use a FT857 than lugging a KX3 and a 100 PA around.  Even a Icom 706 is much neater and more portable than a KX3 with its 100 watt PA. A HF manpack configuration would have been hugely popular with  EMCOMM and MARS and most other hams. I know a lot of hams who XYL's will not allow them to have  HF radio in their car with the associated porcupine needle on the roof. A HF manpack that could be thrown in the boot with a telescopic antenna would have  been an allowable and popular option  for semi mobile operation.


We can go on and on with ideas,  if you are member of HFPACK you  will find that manpack pedestrian mobile operation is humungous in its popularity.  Its the biggest ham radio group on yahoo groups.
Elecraft have their own ideas and that is their right,  however many of their ideas products are not what dedicated HF packers want. I will buy a KX3 just for tracking down QRM and doing antenna work etc and I am sure thousand of other hams will do the same. The Elecraft will be a huge a success for Elecraft. I personally think if Yaesu updates the FT817 and delivers the new version with  say 20 watts and a manpack integration kit it will outsell and be twice as popular as the current FT817. Yaesu just need to do its market research well and it will have winner on its hands.

I have  2 K2's one which has is the 10 watt battery kit. I am very happy with the K2's performance. I also have several HF manpack radios and they are the most convenient  and fun to use. Find a ham antenna tuner that can tune
a end fed wire properly with high efficiency! A manpacks antenna tuner will just about tune an antenna nail with good efficiency. They also handle long wires very well unlike like ham grade tuners.






The KX-3 is a 10 Watt transceiver that is rather well suited for remote operations, though I am cetain that it's fine in the ham shack and local picinic table as well. //I'd LOVE to have one in MY ham shack right now!//  Grin

Doubling output power only equals 3 dB. In practical application, that is only one half of one S-unit at the receiving station's end. It's basically undetectable in the operator's headphones, though some may claim that they are able - with effort- to detect a 3dB difference.  

I've done a LOT of long range/low power HF communication from extremely remote areas of the world, both professionally and as a ham and cannot forsee any engineering, practical or tactical reason to add a 20 Watt amplifier to a 10 Watt transceiver to gain only a HALF of an S-unit (3 dB). This is not worth the extra space, expense & power requirement.  

As for extras, I want:

Every receive filter, noise damper and etc. that I can get (I listen far more than I transmit - which is good advice in life too... ;^)  

Automatic antenna coupler.
 
Internal rechargeable battery for use with folding solar panels (in addition to external packs that work at low temperatures)

I won't use their front mounted paddle, as I don't usually operate where there are tables and prefer my own, leg mounted variant, so that I can just sit where I am able.

>>> I would love to have it's case be a watertight, protective case with ROUNDED corners, like my personal KX-1 (pics at: QRZ.COM and my callsign.)

73 de Ray
W7ASA ..._ ._
Logged
LA9XSA
Member

Posts: 376




Ignore
« Reply #22 on: June 18, 2012, 07:30:46 AM »

Since you haven't addressed it further, I suppose you've abandoned your position that the KX-3 doesn't need any roofing filters or other advanced receiver features, but it appears you still somewhat maintain that 20 watts on HF is enough for everyone.
Thats what everybody says, "its only 3db" Try getting 3db from a portable antenna! Well if you add 3db from the extra power, 2 db from tuner loss, and a few more db from low antennas and the total loss looks dramatic.
A whooping 57 instead of a 58! You yourself decried the lack of adherence to science, but as I mentioned above this is one of the main scientific arguments against your opinion.
A portable antenna with 3db gain gives you 3db more on BOTH receive and transmit, without having to use more batteries or having a heavier PA stage.
There is of course a limit to how good, elaborate and heavy a trail antenna can be, but a ham can operate more leisurely than a military manpack operator who is potentially subject to enemy direction finding and attack, and runs along with his platoon commander during attack and withdrawal relaying orders and calling in fires. The manpack can also be connected to fixed antennas (old army buddies tell about tuning up guard rails and using power lines as signal reflectors), but that is mainly for short- and moderate distance NVIS work.
The only 3db is the simplest way to try and help overcome some of the losses that you cant control. 3db on the receiving makes a huge difference when your signal is weaky squeaky.
At best it might turn an impossible signal into one which is a pain to copy, perhaps a step up from a 21 to a 31 signal report? You still need a good operator and good antenna system on the other end. If I was to bother with an amplifier, I'd want at least 50 or 100 watts. It would be more to lug around, but at least I can leave it at home if not needed.
Well the KX3 would have been a better radio with a 20 or 30 watt PA. It could have been a 2 stage PA that operated QRP when using  internal batteries, and high power on an auxiliary LIPO battery packs.
As I said it's a tradeoff between weight and power. For a trail radio, at one point you have to draw the line at how much minimum weight and power draw you'll accept. To prevent the 30 watt PA stage from drawing power while dormant, you could have a mechanical switch or relay, but at that point the transistors, heat sinks, etc. are just dead weight for the operator. Why not have this extra PA stage as a plug-in external module that you can leave at home if you don't need it?

Amplifiers for the FT-817 are somewhat popular, but they tend to be in the 50 or 100 watt size due to the decibel-related discussion earlier. The interest in these is due to people who bought an FT-817 as an affordable entry level radio that could do every mode and band and want more power for stationary operation, and perhaps want to homebrew to save money or to practice their electronics skills for fun. Some of the amps are lower power than 50 watts due to cost and ease of homebrew. Another consideration is that the FCC doesn't allow commercial sale of these QRP-to-QRO amplifiers in the US because they can be abused by illegal CB operators.
The Military HF manpacks like the Tadiran Manpacks make excellent ready to go HF radios. The Tadiran  HF 6000 is just a fantastic radio to use portable. 
In PRC configuration it weighs about 4 kg, right? That's not too bad for a PRC. But a KX-3 weighs just 0,7kg. And an FT-857 gives you 100 watts on HF, 50 watts on UHF and VHF, more modes, at 2.1 kg - leaving about 2kg for LiPo batteries and antenna. Also you can't use the HF 6000's encryption and frequency jumping features in the amateur service anyway. It looks like a cool radio for HF pedestrian mobile, but it's a different use than the KX-3's market segment.
The KX3 could  have been built into a similar option using a high tech plastic case with extra batteries. 20 watts of output is standard output power on most Mil manpacks for  very good reasons.
And those reasons are not DX work. When the military works DX they usually use hundreds and thousands of watts in vehicle mounted radios, or use satellites or aircraft relays, because you can not depend on a 20 watt manpack for HF DX. (Note that you can use it for DX with good propagation or efficient digital modes, but they would not dependon it.)
The mil manpacks have no issues with battery power.
Because batteries are charged in vehicles or with power generators at command posts, and if needed spare batteries are carried up to the radio operator.
Modern battery backs can deliver the power needed. 4 X Dewalt  drill 18 volt 4ah XR would easily deliver the power. Thats almost 300 watts of power in a very light package. These 4 batteries and 20 watt KX3 could have easily  fitted into small plastic manpack case with a auto-tuner. If you wanted to use the KX3  you would simply slide it out of the manpack case.
Well precisely! As I said you can go ahead and build a manpack with it. You can build a nice bicycle mobile too. But if you forced everyone to to carry around a larger PA stage and batteries, it would be less modular.
This kind of setup would have been far more popular than the  KX3  in its current form.
Why? Since it's so easy to build it into a manpack, there's no need to make a separate manpack model. Also many of the manpack fans like to use genuine military PRCs due to the military history aspect of it.
I would rather just use a FT857 than lugging a KX3 and a 100 PA around.
Sure, if you always work 100 watts, and don't need the more advanced SDR features and usability of the KX-3.
A HF manpack configuration would have been hugely popular with  EMCOMM and MARS and most other hams.
If you're sure about that, someone is sure to build one then.
I personally think if Yaesu updates the FT817 and delivers the new version with  say 20 watts and a manpack integration kit it will outsell and be twice as popular as the current FT817. Yaesu just need to do its market research well and it will have winner on its hands.
The main complaints about the FT-817 is that it draws more current than it would if made with more modern design, and that it's highly menu driven and difficult to use. I would think a new version or inheritor for the FT-817 would - if it takes the market research into account - consider a similar direction as the KX-3 with SDR, lower current draw, better filters/DSP, a better user interface, lower weight, and perhaps built-in PSK-31 decode/encode.
For Yaesu's part, the sort of manpack or car portable radio you're calling for is probably more adequately adressed by a new version of the FT-897.
Logged
AA4GA
Member

Posts: 120


WWW

Ignore
« Reply #23 on: June 18, 2012, 02:49:21 PM »

Thats what everybody says, "its only 3db"
That's because it is only 3dB!

Quote
2 db from tuner loss,
Sounds like you need a better tuner.

Quote
Well the KX3 would have been a better radio with a 20 or 30 watt PA.
Not for me, it wouldn't - why should I have to pay for something in both dollars and weight that I (and most folks who operate at accepted QRP levels) would never use?

Quote
If Elecraft did their market research well they would have discovered that most portable operators were looking for something a bit more than 10 watts that integrated into a nice  small package.
I think the apparent large number of early sales of this radio proves their market research was just fine.

Quote
The Military HF manpacks like the Tadiran Manpacks make excellent ready to go HF radios. The Tadiran  HF 6000 is just a fantastic radio to use portable.
ZZZZZZZzzzzzz...then buy one!

Quote
This kind of setup would have been far more popular than the  KX3  in its current form.
I doubt that is true - why do you think it is?  I have been on the KX3 Yahoo group since its inception and almost no one has been whining about needing an additional 3dB of transmitter power.

Quote
Judging by the sale numbers so far the KX3 is going to be a huge hit.
Exactly - and this comment effectively contradicts your previous comments.

Quote
if you are member of HFPACK....Its the biggest ham radio group on yahoo groups.
Nonsense.  I only had to look as far as the FT817 group to find one that was bigger than "hfpack"...I would not be surprised if there were others.

I'll repeat my question:  QRA?
Logged

LA9XSA
Member

Posts: 376




Ignore
« Reply #24 on: June 18, 2012, 06:01:17 PM »

By the way, not just the larger PA stage and heat sink in a 30 W KX3 would be dead weight if not needed - the internal tuner and SWR bridge would most likely have to be beefed up too, to handle more power. All this means more weight.
Logged
W8JX
Member

Posts: 6431




Ignore
« Reply #25 on: June 18, 2012, 06:03:14 PM »

By the way, not just the larger PA stage and heat sink in a 30 W KX3 would be dead weight if not needed - the internal tuner and SWR bridge would most likely have to be beefed up too, to handle more power. All this means more weight.

And more power to run it too even at reduced output.
Logged

--------------------------------------
All posted wireless using Win 8.1 RT, a Android tablet using 4G/LTE/WiFi or Sprint Note 3.
ZENKI
Member

Posts: 980




Ignore
« Reply #26 on: June 19, 2012, 02:03:54 AM »

You creating imaginary scenarios that do not occur under real QRP conditions when working DX.

Since you haven't addressed it further, I suppose you've abandoned your position that the KX-3 doesn't need any roofing filters or other advanced receiver features, but it appears you still somewhat maintain that 20 watts on HF is enough for everyone.

###Yeah you dont because the average ham who works portable is using marginal antennas, in real life you only need 70Db IMD dynamic range and thats easily achievable with no roofing filters. The Elecraft K3 is a radio where most of
its optional roofing are just a huge waste of money. The IMD dynamic range data supports this conclusion. You chasing performance that is not needed. The only people who need narrower roofing filters than normal are hams running big antennas. In case you forget direct sampling receivers like the Perseus and Winradio G31DDC achieve better performance without roofing filters.

###20 watts is a very effective power level for QRP, portable and emergency operation. Does it take  the place of 2 kilowatts absolutely not, there is a thing called the laws of physics! All I am saying a lot more hams would
enjoy QRP and portable operation if they used a decent power level like 20 watts, and this is especially so on SSB.

Every
Thats what everybody says, "its only 3db" Try getting 3db from a portable antenna! Well if you add 3db from the extra power, 2 db from tuner loss, and a few more db from low antennas and the total loss looks dramatic.
A whooping 57 instead of a 58! You yourself decried the lack of adherence to science, but as I mentioned above this is one of the main scientific arguments against your opinion.
A portable antenna with 3db gain gives you 3db more on BOTH receive and transmit, without having to use more batteries or having a heavier PA stage

## Most QRP signals are not 5/8 and 3 db can make a huge difference to the signal to noise ratio.
You are right again  about 3db working on RX/TX however most people cant errect 3db gain antennas for portable or QRP operation. The 3db gain is really more for the relief of the RX station who has to
cope with inadequate ERP from weak QRP stations. QRP stations dont have difficulty copying stations running 1kw. 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.
.
There is of course a limit to how good, elaborate and heavy a trail antenna can be, but a ham can operate more leisurely than a military manpack operator who is potentially subject to enemy direction finding and attack, and runs along with his platoon commander during attack and withdrawal relaying orders and calling in fires. The manpack can also be connected to fixed antennas (old army buddies tell about tuning up guard rails and using power lines as signal reflectors), but that is mainly for short- and moderate distance NVIS work.

## 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. A radio like the FT857 makes a more convenient portable 100 stations than two boxes
and tons of cables hanging all over the place. You must love chaos in your ham radio style. HF manpacks are elegant in their packaging and effectiveness.

The only 3db is the simplest way to try and help overcome some of the losses that you cant control. 3db on the receiving makes a huge difference when your signal is weaky squeaky.
At best it might turn an impossible signal into one which is a pain to copy, perhaps a step up from a 21 to a 31 signal report? You still need a good operator and good antenna system on the other end. If I was to bother with an amplifier, I'd want at least 50 or 100 watts. It would be more to lug around, but at least I can leave it at home if not needed.

## 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.

Well the KX3 would have been a better radio with a 20 or 30 watt PA. It could have been a 2 stage PA that operated QRP when using  internal batteries, and high power on an auxiliary LIPO battery packs.
As I said it's a tradeoff between weight and power. For a trail radio, at one point you have to draw the line at how much minimum weight and power draw you'll accept. To prevent the 30 watt PA stage from drawing power while dormant, you could have a mechanical switch or relay, but at that point the transistors, heat sinks, etc. are just dead weight for the operator. Why not have this extra PA stage as a plug-in external module that you can leave at home if you don't need it?

##Trail radio? I doubt that most KX3 users will have QSO's when trail walking. With the "smarts" built into the KX3 it would be easy programming job setting the PA bias level for the best efficiency at the nominated power output. Besides like I said a two stage PA  5 watts driver with next stage being able to be switched in our out. This can easily be done without too much trouble. The problem is that ham designers always take the laziest and simplest way out ratherthan being brilliant in the practice of RF design. AEG Manpack is well over 30 years old  and puts all these techniques into practice.

Amplifiers for the FT-817 are somewhat popular, but they tend to be in the 50 or 100 watt size due to the decibel-related discussion earlier. The interest in these is due to people who bought an FT-817 as an affordable entry level radio that could do every mode and band and want more power for stationary operation, and perhaps want to homebrew to save money or to practice their electronics skills for fun. Some of the amps are lower power than 50 watts due to cost and ease of homebrew. Another consideration is that the FCC doesn't allow commercial sale of these QRP-to-QRO amplifiers in the US because they can be abused by illegal CB operators


## Then you get inconsiderate hams using illegal CB amps causing excessive amount of IMD or splatter. The FT817 is already a radio that causes excessive IMD because its PA is such a poor design. Adding
 a CB amplifier or some other homebrew sollution just causes excessive interference. There is not much difference between the price of a FT817+amplifier and a FT857, you kidding yourself with this argument.
 The FCC rules have changed for low drive amps in the ham service.
.
The Military HF manpacks like the Tadiran Manpacks make excellent ready to go HF radios. The Tadiran  HF 6000 is just a fantastic radio to use portable. 
In PRC configuration it weighs about 4 kg, right? That's not too bad for a PRC. But a KX-3 weighs just 0,7kg. And an FT-857 gives you 100 watts on HF, 50 watts on UHF and VHF, more modes, at 2.1 kg - leaving about 2kg for LiPo batteries and antenna. Also you can't use the HF 6000's encryption and frequency jumping features in the amateur service anyway. It looks like a cool radio for HF pedestrian mobile, but it's a different use than the KX-3's market segment.

## you heading off at  tangent that is not related to the ham radio service.  The essential point is that a ham solution can packaged in the same way without all the mil specs. If the KX3 was built into a manpack configuration
with all accessories and a 20 watt PA it will be lighter than any current mil spec manpack. Hams dont need radios that 4 wheel mil vehicles can drive over. Mil HF manpacks can deliver all these features plus mil specs in a tiny package.  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 can grab a man pack radio and  a piece of wire in my pocket and be out of the door of my house in 30 seconds.  You not being realistic in your arguments here, the  HF manpack  solutions kills
some clumsy ham radio design like the KX3 especially the KX with a amplifier and all its accessories.


The KX3 could  have been built into a similar option using a high tech plastic case with extra batteries. 20 watts of output is standard output power on most Mil manpacks for  very good reasons.
And those reasons are not DX work. When the military works DX they usually use hundreds and thousands of watts in vehicle mounted radios, or use satellites or aircraft relays, because you can not depend on a 20 watt manpack for HF DX. (Note that you can use it for DX with good propagation or efficient digital modes, but they would not dependon it.)

## You have incorrect views of the role of long distance HF communications in the military service. Your views are incorrect about long range HF manpack use in the military service. Special forces and reconnaissance  units use HF manpacks for long range communications on a daily basis.  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.

The rest all interesting counter points of view. Mine is just an opinion, and I have no intention going into the ham radio business.  The point remains that those who design these clumsy ham radio products do not do a good job when
thinking about how these product will be used.  I can make do with any radio, just as hundreds of hams do in field days around the world. I know many hams who still use TS520's with the inverters for mobile and portable operation. They are more than happy with such horrid solutions. We will use what we think is best and if its a KX3 for many so  be it, all I am saying is that its far from ideal,,, thats all.  My opinions might be a teeny weeny minority and  thats all it might ever be, its an opinion nonetheless .
Most of these products are poorly thought out and  those who actually operate with this style of operation  m
Logged
K0JEG
Member

Posts: 672




Ignore
« Reply #27 on: June 19, 2012, 05:57:46 AM »

The Military HF manpacks like the Tadiran Manpacks make excellent ready to go HF radios. The Tadiran  HF 6000 is just a fantastic radio to use portable.

Just looking at that radio's spec sheet I have to think the cost is much more than the casual portable/QRP operator is willing to spend. Plus I see what looks like some very expensive connectors that won't be available at the local Radio Shack in a pinch.

Here's a site selling one for $9,800! http://tinyurl.com/6n63b7m Granted, it's "fully loaded" but still...

Of course, if you're out there every weekend you might be able to justify the cost. I'll keep saving my pennies for a KX3 though.
Logged
LA9XSA
Member

Posts: 376




Ignore
« Reply #28 on: June 19, 2012, 07:06:34 AM »

Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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.
Quote
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?

Quote
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.

Quote
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

Quote
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.

Quote
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.
Logged
N2EY
Member

Posts: 3909




Ignore
« Reply #29 on: June 19, 2012, 10:53:12 AM »

Well the KX3 would have been a better radio with a 20 or 30 watt PA.

No, it wouldn't.

Higher power would increase the price and decrease battery life.

In amateur circles, 5 watts output or less on CW is QRP. So most QRP rigs are designed to give that much plus maybe some more.

The Military HF manpacks like the Tadiran Manpacks make excellent ready to go HF radios. The Tadiran  HF 6000 is just a fantastic radio to use portable.

But what does one cost? A KX3 with ATU, roofing filter and mike is less than US$1300.

How does an HF 6000 perform in AMATEUR service? For example, does it have full QSK on CW?

The KX3 could  have been built into a similar option using a high tech plastic case with extra batteries. 20 watts of output is standard output power on most Mil manpacks for  very good reasons. The mil manpacks have no issues with battery power. Modern battery backs can deliver the power needed. 4 X Dewalt  drill 18 volt 4ah XR would easily deliver the power. Thats almost 300 watts of power in a very light package. These 4 batteries and 20 watt KX3 could have easily  fitted into small plastic manpack case with a auto-tuner. If you wanted to use the KX3  you would simply slide it out of the manpack case. This kind of setup would have been far more popular than the  KX3  in its current form.

No, it wouldn't. The amateur market is very different from the military market. The things you propose would greatly increase the price without improving the overall performance.

The KX-3/amp concept isn't that you cart them around. It's that you have the amp at home and use the bare KX-3 in the field. That way the same rig does two jobs.

73 de Jim, N2EY
Logged
Pages: Prev 1 [2] 3 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!