Power vs Range.

[TNFrank]

We all know that antennas play a big part in fars that you get. Also, generally speaking the more power(watts) you push the more fars you get. My question is On HF if you use less power will you be able to talk more locally? I hear stations on 10M SSB that come in clear all across the country but stations talking back in AZ. are either very faint or not heard at all. If those stations decreased their power would they come in more clearly locally or would the skip still make them hard to pick up? 

Also, what about antennas, would a vertical bring in close by HF stations better than the Inverted V or an EFHW sloper? 

I'd like to try and make a QSO with POTA stations I hear in AZ. and CA. but when I tune to their frequency I hear nothing. So should I try to pick up a vertical to use or is HF just not going to allow local QSO's.

[SteveShannon]

2 minutes ago, TNFrank said:

My question is On HF if you use less power will you be able to talk more locally?

If you’re unable to contact nearby stations, it’s NOT because you have too much power. Instead, it’s because of the propagation pattern of your antenna. 

 

[SteveShannon]

12 minutes ago, TNFrank said:

Also, what about antennas, would a vertical bring in close by HF stations better than the Inverted V or an EFHW sloper? 

Yes, probably, but raising your wire antennas higher will usually flatten the pattern also.

[TNFrank]

So a higher antenna would help bring in closer stations on HF then. I can't really go much higher than the 15' tripod I have but I wonder if a vertical on that 15' tripod would help with close range HF.  I'd also like to dig out my RT95 and put the 70cm short vertical I have up on the tripod and get it up nice and high to see what kind of simplex contacts I can make on 70cm. Thanks for the reply. 

[SteveShannon]

Just now, TNFrank said:

So a higher antenna would help bring in closer stations on HF then. I can't really go much higher than the 15' tripod I have but I wonder if a vertical on that 15' tripod would help with close range HF.  I'd also like to dig out my RT95 and put the 70cm short vertical I have up on the tripod and get it up nice and high to see what kind of simplex contacts I can make on 70cm. Thanks for the reply. 

Yes, a vertical on that tripod, assuming it has the necessary ground plane, would probably help. 

[TNFrank]

What about a QRP HF radio through the same antenna set up(i.e. EFHW or Inverted V at 15')? I know I'd still RX the same since I have no control over the transmitting stations and their power output but with 5w of output on my end would that let close by HF stations hear me better or would propagation be the same no matter what?

[Northcutt114]

3 hours ago, TNFrank said:

What about a QRP HF radio through the same antenna set up(i.e. EFHW or Inverted V at 15')? I know I'd still RX the same since I have no control over the transmitting stations and their power output but with 5w of output on my end would that let close by HF stations hear me better or would propagation be the same no matter what?

Propagation is going to be the same no matter what. The only thing on HF that is going to help you with nearby stations outside of ground wave propagation is going to be an NVIS antenna setup. Because of the angles involved and the distances traveled, you're going to have stations in the skip zone that you just can't hear with any other kind of antenna. 

The one time I did manage to activate a park, I picked up a guy on ground wave that was roughly six miles from me. Everybody else was over 500 away.

[WSEZ903]

I rarely hear Az station when doing POTA.  I did twice, once at Table Mesa and the other operator was across the highway.  The other time I was at the wildlife are off of the 85 in Buckeye and I heard some guys from Az talking.  Not sure where they were at.  Yesterday there was about 4 different people from Az talking and I could not hear any of them but the propagation was sending me to the North West and East.  It varies all the time and through out the day.

[SteveShannon]

2 hours ago, TNFrank said:

What about a QRP HF radio through the same antenna set up(i.e. EFHW or Inverted V at 15')? I know I'd still RX the same since I have no control over the transmitting stations and their power output but with 5w of output on my end would that let close by HF stations hear me better or would propagation be the same no matter what?

No, reducing your power would not do anything to improve your reception by nearby stations.  Propagation doesn’t improve simply by reducing power. Ever. 

[WRYZ926]

A dipole, loop, or EFHW hung close to the ground will work good for NVIS which is what you want for close in stations on HF.  @TNFrank your dipole hung as a horizontal flat top at 6-8 feet should work fine for NVIS. Then you can get it up 16 feet or higher to work the far away stations.

My friend that lives in town always tries to work me when I do a POTA activation. I activated a park 20 miles away for the last couple of activations using a 1/4 wave vertical. My signal was skipping right over top of my friend. He could not hear me at all but was hearing every station that was working me.

[SteveShannon]

3 minutes ago, WRYZ926 said:

A dipole, loop, or EFHW hung close to the ground will work good for NVIS which is what you want for close in stations on HF.  @TNFrank your dipole hung as a horizontal flat top at 6-8 feet should work fine for NVIS. Then you can get it up 16 feet or higher to work the far away stations.

My friend that lives in town always tries to work me when I do a POTA activation. I activated a park 20 miles away for the last couple of activations using a 1/4 wave vertical. My signal was skipping right over top of my friend. He could not hear me at all but was hearing every station that was working me.

You’re right that NVIS is the way to make contact with people in your skip zone, but the problem with NVIS here is that although it works well for the lower HF frequencies, it becomes much more difficult as the frequencies increase, to the point where 28 MHz NVIS is very difficult. @TNFrank is limited to 10 meters for USB phone privileges. 

[TNFrank]

I'm working on my General. Once I get that and I can mod the QT80 for not only 20M but also 11M, 12M and 15M. 

I might try hanging my dipole 8' off of the ground using a north to south orientation to see if I can get more east to west contacts. 

[WSEZ903]

Get a little portable set up adn go out and have fun.  I find that there is just too much noise by my house for the HF.

[TNFrank]

Something else I figured out, even if I set up an NVIS antenna I'd still not pick up nearby stations unless they were also using an NVIS antenna. Both stations would need to run them. If only one has one it'd be a one way conversation because the station running a "normal" antenna would skip right over the NVIS station even though they would be picked up by the non-NVIS station.

[WRYZ926]

That's common especially if one station is using a vertically polarized antenna and the other station is using a horizontally polarized antenna. Same thing happens with VHF and UHF with different polarization.

 

[beerftw]

Propogation works independant of power, same with tropospheric tunneling. Without either power just allows pushing through nearby terrain and can increase transmit distance when skip or propogation is not happening. But when propogation or with vhf uhf tropospheric tunneling happens, the power output means little, you are not pushing your way onto the airwaves, but rather a hitchiker being carried through the atmosphere.

  I was literally talking with an old ham guy today, and he did say with the right antenna you could talk worldwide with a single watt so long as conditions were correct, but might not be able to talk to anyone local without decent power output.

[SteveShannon]

16 hours ago, TNFrank said:

Something else I figured out, even if I set up an NVIS antenna I'd still not pick up nearby stations unless they were also using an NVIS antenna. Both stations would need to run them. If only one has one it'd be a one way conversation because the station running a "normal" antenna would skip right over the NVIS station even though they would be picked up by the non-NVIS station.

I think I shared this with you before, but if not I apologize.  This is the Marine Corps Antenna Handbook.  It does a great job explaining antennas, propagation, frequencies, and distances at a level that I think most people can understand.  For instance page 117 is the beginning of a chapter on NVIS and how it can be used to achieve continuous communications at distances that would otherwise fall within the “skip zone”.  

https://www.marines.mil/Portals/1/MCRP 3-40.3C With Erratum z.pdf

Here’s a snippet: 

To communicate over the horizon to an amphibious ship on the

move, or to a station 100 to 300 kilometers away, the operators

should use NVIS propagation. The ship’s low take-off angle

antenna is designed for medium and long-range communications.

When the ship’s antenna is used, a skip zone is formed. This skip

zone is the area between the maximum ground wave distance and

the shortest sky wave distance where no communications are possi-

ble. Depending on operating frequencies, antennas, and propagation

conditions, this skip zone can start at roughly 20 to 30 kilometers

and extend out to several hundred kilometers, preventing communi-

cations with the desired station.

NVIS propagation uses high take-off angle (60° to 90°) antennas to

radiate the signal almost straight up. The signal is then reflected

from the ionosphere and returns to Earth in a circular pattern all

around the transmitter. Because of the near-vertical radiation angle,

there is no skip zone. Communications are continuous out to several

hundred kilometers from the transmitter. The nearly vertical angle

of radiation also means that lower frequencies must be used. Gener-

ally, NVIS propagation uses frequencies up to 8 MHz

[TNFrank]

Seems like an NVIS antenna with a QRP HF radio would be very useful for short range(out to 300 miles)communication. This would be much more effective than VHF/UHF. 

[SteveShannon]

1 minute ago, TNFrank said:

Seems like an NVIS antenna with a QRP HF radio would be very useful for short range(out to 300 miles)communication. This would be much more effective than VHF/UHF. 

It all depends on what you’re doing.  There’s always some kind of compromise.  NVIS is great for communicating on HF from a mostly fixed place to another mostly fixed place, but because it’s HF it requires a large antenna placed mostly parallel to the ground.  
VHF/UHF allows for very clear voice and data mobile communications.  If you can place a repeater high enough you can communicate voice and data and even video over a hundred mile radius using very small radios and antennas.