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Author Topic: 5W to Nowhere?  (Read 14736 times)
KF5KCA
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Posts: 74




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« on: August 30, 2017, 01:09:37 PM »

Hello, fellow Ham friends!

My apologies upfront for the confrontational subject line, but a I have to draw you ‘all in somehow  Grin

I have asked this exact question in another thread before, but it got somewhat drowned out by the topic of using an FT-891 for portable work, rather than a KX2.

However, my question is still open and I have not really gotten any good answers. So, here it goes:

I can watch videos of folks having fun with 5W portable QRP on Youtube all day long using end-fed wire antennas. However, I can also watch videos about folks shooting hoops across an entire basketball field with their back turned to the hoop. Needless to say, that the Youtube video documenting the success of shooting that hoop is probably "take number 396". Do I have to expect the same "success rate" with a 5W QRP radio unless I live in the Cascades or Rocky's above 8k feet of elevation?

The curious element of these videos is that most people are literally SOTA activators, or somewhere on the beach (or cliff), using salt water amplification. I won't have access to either on a regular basis as I am in central Texas.

To provide a little more context, I would like to limit the scope of this question to portable operation, SSB phone and digital modes. Of course, CW would be far more efficient, especially when atmospheric or geographic conditions are not favorable. However, there is currently no way for me to fit a reasonable amount of practice into my schedule.

I am also aware that mother nature can be extremely helpful with QRP propagation, but that is also a less than reliable factor. So, folks saying “I have made tons of contacts using QRP”, please do put your answers into the context of someone trying to get into portable HF radio for ongoing weekend fun.

Now, I (obviously) know that I am not going to make contacts on a 5W QRP rig with the same ease and success as someone with a 120ft antenna tower, beams and 600W of power. However, my question is really if I should brace for this to be an extremely frustrating exercise, or if I can expect some rate of success and joy (being that I do not live in the Alps or Bahamas).

Any input from those using QRP on a regular basis is greatly appreciated!

Thank you and 73!

Oliver
KF5KCA
« Last Edit: August 30, 2017, 01:11:49 PM by KF5KCA » Logged
KC4ZGP
Member

Posts: 1637




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« Reply #1 on: August 30, 2017, 01:41:25 PM »



I am not a regular QRPer but I was able to get to California from Georgia on 1 1/2 watts, Morse, 21.105MHz
in my novice days in the early nineties. The antenna was a quarter-wave ground plane up about sixteen feet.

It is possible. One QRP contact was it. I didn't keep at it. Good luck friend.

Kraus

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K0UA
Member

Posts: 1456




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« Reply #2 on: August 30, 2017, 02:02:16 PM »

My experience is you can expect some success rate with 5 watts SSB.  You can expect one helluva lot greater success rate with 5 watts cw, and one helluva lot greater success rate with 5 watts of one of the weak signal digital modes than CW.  The difference is about 10db each time. So not doing CW will be a real drag compared to 5 watts SSB.

  That said, you will make contacts on 5w SSB with compromise antennas.  Then there will be times you yell, scream and pitch a fit (this can be helpful in cold weather outings), and you STILL cannot make them hear you.  Then you go to 25 or 50 watts, and somehow magically they pull you out. You gotta remember THEY are doing all the work NOT you.  You will be a little pissant station way down there in the noise with 5 watt SSB and a lousy antenna.

 BUT, all that said, think about this.  Say you are on your home 100 watt station and you contact someone with an S9 signal. Good copy both ways.  Now on that same station, you go to 5 watts.  Another way of saying 5 watts is +37 dbm.  37 decibels greater than a milliwatt.  The milliwatt is a standard, so we often rate station power in decibels greater or smaller than a milliwatt.  Ok, your 100 watt station is +50 dbm.

 So you have a gain or loss of 13 db from the 100 to the 5 or the 5 to the 100.  Just 13 little DB you say?  Now if we are using the OLD S meter standard of 6 db per S unit, which most modern rigs don't use any more, our hypothetical 100 watt S9 signal just dropped a little over 2 S units.  lets call it 6 1/2 s units now.  Still a fairly good signal right?.  Most modern rigs use a standard nearer to 3 db per S unit.  I don't know why. But If you have one of the more modern rigs like I do, they tend to give inflated S meter readings.  So in this case we would have dropped a bit over 4 "S units"  so lets say S 4 1/2 is where you are now.  Ok?  

Well, your signal is definately a bunch weaker, BUT you are still being heard... Now comes the rub..you go out and drape a wire over a limb.  Well I can tell you from experience you are liable to be down at least 10db unless you home station antenna system really sucks, and more like 20db. Now your 5 watts is down in the dang noise.  Still there, but very weak.  And remember your QSO partner is the guy with a nice 3 element beam and at least 100 watts pointed in your direction that was shoving an S9 signal down your way. Now he is having real trouble even hearing you.

 But all is not lost.  There are people on the band with better signals than him by far.  Lots of guys with signals that would have been 10 or even 20 db over S9 back on the home station, and even out in the boonies are still squirting respectable signals your way, and hearing pipsqueak signals from you too.

 So you see when you operate portable with small power and compromise antenna's, you are cutting out the lower tier of folks just like you and you are communicating with the more towards the top tier of stations.  Now maybe it isn't all as bad as I laid out here, and you WILL make contacts.  Just not as many as you would at 25 or 50 or 100 watts.  And yes it can be a little frustrating at times.  You must "work" harder for each contact.  And you QSO partners must "work" a lot harder.

IF you operate CW, you will have at least a 10db advantage over SSB right off the bat.  That alone can be the difference in a nice chat, and a quick "yeah I heard you sorta of" SSB contact.  If you work JT65 or even FT8, you have another 10db over CW.  Yeah the digital modes require a laptop and an interface. AND the laptop need to be synchronized with NTP protocol. Not as big a deal as some make it out to be, as you can sync it before you go on the outing. Or if need by, you can tune WWV and synch it by hand to withing 1 second or less, and that will get you by.


So, I am not trying to talk you out of that 5 watt radio that you primarily are going to use on SSB, but there is a reason MOST QRP ops use cw or digital. But you will suffer some disappointments, but every QSO you do complete will be that much sweeter, and you can have  a good number of QSO's with 5 watts SSB if you try.
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KF5KCA
Member

Posts: 74




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« Reply #3 on: August 30, 2017, 02:17:32 PM »

[...]
It is possible. One QRP contact was it. I didn't keep at it. Good luck friend.
Kraus

Kraus, thanks for the feedback!

Oliver
KF5KCA

[...]
So, I am not trying to talk you out of that 5 watt radio that you primarily are going to use on SSB [...]

James, I know exactly what you are trying to talk me into...... When is that new rig of yours arriving?  Grin

Thank you for the in-depth answer! I think focusing on digi modes maybe an option, but then the question is why would I go with a tiny 5W rig since I have to lug extra equipment anyways?

Thank you!

Oliver
KF5KCA
« Last Edit: August 30, 2017, 02:22:49 PM by KF5KCA » Logged
W9IQ
Member

Posts: 1712




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« Reply #4 on: August 30, 2017, 02:18:11 PM »

The correct reference for the unit is dB, not db nor DB.

- Glenn W9IQ
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- Glenn W9IQ

I never make a mistake. I thought I did once but I was wrong.
K0UA
Member

Posts: 1456




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« Reply #5 on: August 30, 2017, 02:36:09 PM »

[...]
It is possible. One QRP contact was it. I didn't keep at it. Good luck friend.
Kraus

Kraus, thanks for the feedback!

Oliver
KF5KCA

[...]
So, I am not trying to talk you out of that 5 watt radio that you primarily are going to use on SSB [...]

James, I know exactly what you are trying to talk me into...... When is that new rig of yours arriving?  Grin

Thank you for the in-depth answer! I think focusing on digi modes maybe an option, but then the question is why would I go with a tiny 5W rig since I have to lug extra equipment anyways?

Thank you!

Oliver
KF5KCA

I am thinking Monday or Tuesday.  Some laptops are pretty small. A signalink is not very big either.  And the FT891 has a USB port for rig control.  So a laptop with 2 USB ports would work pretty well.  Or learn CW.. All you need is your ears, and a little set of paddles or a straight key.  Not much gear at all.. But like I said, don't let me talk you out of the 5W SSB idea if that is what you want to do. It is all just a matter of a few dB's.  (Thank you Glenn)  Smiley  
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KM4DYX
Member

Posts: 63




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« Reply #6 on: August 30, 2017, 02:37:33 PM »


I can watch videos of folks having fun with 5W portable QRP on Youtube all day long using end-fed wire antennas. However, I can also watch videos about folks shooting hoops across an entire basketball field with their back turned to the hoop. Needless to say, that the Youtube video documenting the success of shooting that hoop is probably "take number 396". Do I have to expect the same "success rate" with a 5W QRP radio unless I live in the Cascades or Rocky's above 8k feet of elevation?

To provide a little more context, I would like to limit the scope of this question to portable operation, SSB phone and digital modes. Of course, CW would be far more efficient, especially when atmospheric or geographic conditions are not favorable. However, there is currently no way for me to fit a reasonable amount of practice into my schedule.
 

Any input from those using QRP on a regular basis is greatly appreciated!

Thank you and 73!

Oliver

KF5KCA


I'm 100% QRP. Have been since I got my ticket 2 whole years ago. Just came in from the back yard where I was operating "back yard portable" i.e., battery power, wire antenna. (2 element wire Yagi Uda inverted V.)

You can look at my 20 M WSPR spots on the WSPR map page. Things were doing so well that I dusted off the mic and made two phone QSOs, S51DX Slovenia, and LZ55UPB, Bulgaria. 5 Watts.

Anything you want to know just ask.

73,
Al
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WD4ELG
Member

Posts: 183




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« Reply #7 on: August 30, 2017, 02:55:12 PM »

Al, well done.

And as usual, your results prove what we already know...it's the antenna that makes the difference with QRP.  Your antenna is way superior to a wire over a limb.  Possibly 10-15 dB, depending on the wire over the limb and the length and the height of the limb and lack of radials.
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KM4DYX
Member

Posts: 63




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« Reply #8 on: August 30, 2017, 03:04:32 PM »

Al, well done.

And as usual, your results prove what we already know...it's the antenna that makes the difference with QRP.  Your antenna is way superior to a wire over a limb.  Possibly 10-15 dB, depending on the wire over the limb and the length and the height of the limb and lack of radials.

Thanks. I'm pretty pleased with that antenna. A couple weeks ago I had it turned around the other way and uploaded Winlink email through XE3N in Cancun.

Yup. Antenna, antenna, antenna.

73,
Al
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WD4ELG
Member

Posts: 183




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« Reply #9 on: August 30, 2017, 03:19:26 PM »

I will add that I have worked a lot of DX QRP with hamsticks on the car and end-fed half waves on limbs.  But...it was ALL CW or digital, the conditions were good (sometimes the sunspots were great, other times I was using the grayline, other times there were no other stations calling or very quiet band). 

I have had the most success on 40 at night and 20 at sunset, regardless of sunspots. 

Of course, lots more DX using the hexbeam QRP!
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WB6BYU
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Posts: 17184




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« Reply #10 on: August 30, 2017, 04:08:48 PM »

It can be rewarding.  And it can be frustrating.  Sometimes both at the same time.

But there were times when I had that experience running 100W of SSB on 75m...

While most of my work has been CW, I've had some memorable SSB contacts, too.


The most important thing is to use an effective antenna.  That doesn't mean you need
a 120' tower, but at least as good as a dipole, and at a reasonable height for what you
are trying to work, even if that is only 20 - 30'.  A short end-fed wire draped over a
couple bushes and fed without and adequate ground system isn't going to cut it.
That doesn't mean it has to be expensive, but you don't want one of those "magic"
antennas that is more about marketing than actual performance.

Be creative with your antennas, and make best use of the resources and supports
you have available.  The 40m 2-element wire yagi isn't that much more difficult to put
up than an inverted vee (it just needs some sort of spreader, or a second support)
Be prepared to take advantage of salt water, tall trees or hilltops when they present
themselves.  (Actually it isn't the altitude, but the ground slope, that makes the
difference, so you may find that the side of a smaller local hill gives some improvement.)

Also, study the current propagation conditions to make sure you are using the best
band for the occasion, whatever you want to accomplish.  Use VOACAP to check
what bands are open to your target area at what times of day.  (You can set the
power level, antenna, and mode to match what you are using.)

Understand how vertical and horizontal polarization perform from your own location
for different distances.  The ground conductivity will give you a hint, but doing your
own experimentation will be even better, even if that means you need to put up
two antennas and switch between them while comparing signals.


That still doesn't guarantee that you'll be able to work every station you can hear,
but it will help you make the most of your low power and help reduce the frustration.
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KF5KCA
Member

Posts: 74




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« Reply #11 on: August 30, 2017, 04:35:36 PM »


I'm 100% QRP. Have been since I got my ticket 2 whole years ago. Just came in from the back yard where I was operating "back yard portable" i.e., battery power, wire antenna. (2 element wire Yagi Uda inverted V.)

[...]

73,
Al

Al,

That is encouraging information, thank you!

Oliver
KF5KCA
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KF5KCA
Member

Posts: 74




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« Reply #12 on: August 30, 2017, 04:44:20 PM »

It can be rewarding.  And it can be frustrating.  Sometimes both at the same time.
[...]

Dale,

Thank you very much for the comprehensive summary! Lots of good info.

My overall goal is to decide between the KX2 and FT-891 (different thread). One of the decision points is the ability to have fun with 5W. From responses so far it sure seems that there is good opportunity, so my quest is not over, yet.  Smiley

Best and 73,

Oliver
KF5KCA
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AA4PB
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Posts: 14359




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« Reply #13 on: August 30, 2017, 05:22:26 PM »

Your operating technique can make all the difference. You'll not usually have much success by jumping in the middle of a big pile up running 5W and trying to compete with 100 other stations who are running 100W or more to efficient antennas. However, if you can catch the DX before all the other stations show up or you can wait until the pile up fades away, you have a better chance. Another trick is to study the DX station's technique (i.e. does he keep calling stations farther up or down in freq) and then placing yourself on the most likely next frequency. Look for stations who are putting in a strong signal at your location because they are likely running 100W or more so you will be much weaker coming back to them. Calling weak stations is not as likely to result in a contact unless you know they are QRP. The key to working QRP is to spend a lot of time listening and making your calls at the appropriate time.
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Bob  AA4PB
Garrisonville, VA
KF5KCA
Member

Posts: 74




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« Reply #14 on: August 30, 2017, 05:56:51 PM »

Your operating technique can make all the difference. [...] The key to working QRP is to spend a lot of time listening and making your calls at the appropriate time.


Bob,

I can deal with that. That actually sounds like fun and challenging. My concern was that making contacts would be a 1/1000 chance, which would have resulted in frustration on my end. Like I mentioned earlier, 5W QRP being a viable option is making my quest of picking between my radios of choice harder-- again. I was kind of hoping for folks to completely push back on 5W QRP and tell me that there is no excitement to be had, or that it is only for die hard mountain goats or folks that cherish Sisyphean tasks. Then, the dice would have rolled in favor of the FT-891 in a heartbeat. Alas, now I am back to the drawing board.  Grin

Thank you for your feedback!

73,

Oliver
KF5KCA
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