Radio Preppers

General Category => New To Radio => Topic started by: new2ham2020 on September 10, 2020, 04:00:02 PM

Title: Newbie Transmit/Receive Range (distance) question
Post by: new2ham2020 on September 10, 2020, 04:00:02 PM
Hi,

I'm completely new to HAM/"Amateur" radio and I'm thinking of getting into the hobby for disaster preparedness (probably an extended "grid down" scenario where phones and the Internet don't work and maybe an electromagnetic pulse has damaged repeater infrastructure).

My use for HAM would be long-distance voice communications, between fixed locations (as much as 1500-2000 miles apart, in the Lower 48 states).

I would be transmitting and receiving from either:
Northeast Washington to either Northeast Indiana or Southwest West Virginia (appx. 2000 miles)
Northeast Washington to Southern California (appx. 1500 miles)
Northeast Indiana to Southwest W. Virginia (appx. 400 miles)

I have read conflicting information about the ability of HAM radio to transmit over long distances and be received clearly.

Some websites indicate HAM can reach thousands of miles away, but only under certain atmospheric conditions or using 3rd-party resources like repeaters and the Internet. Others say it can reach 100-600 miles more likely (without repeaters). I don't want to have to rely on other people's infrastructure for my communications, or else I would probably buy a satellite phone.

Would HAM actually be reliable and predictable to have the signal travel that far and be clearly understood by the recipient, without using other infrastructure?

What would I likely need in order to do that? Would I need a massive antenna tower at each end (100'+ in height)?

If you could provide me any more information that would be helpful, I would appreciate it!
Thank you so much for taking the time to read my post.
Title: Re: Newbie Transmit/Receive Range (distance) question
Post by: JS6UEY on September 10, 2020, 06:43:01 PM
"1500-2000 miles apart", "voice communications", "reliable", "predictable"?  Yikes....

The US military had to use circus tent sized antennas with +kilowatt transmitters, dedicated field of operators, ionosounde and scientists to maintain that kinda network.  Despite the movies, it's highly unlikely an average bunch of hams could replicate.

IMHO, low rate data might be doable.  With good planning, proper antennas & newer protocols (like JS8Call) a group of learned ham's could pull it off 'fairly' reliably.

73's
Scott
JS6UEY

Title: Re: Newbie Transmit/Receive Range (distance) question
Post by: gil on September 14, 2020, 04:54:04 AM
Hello.

It is possible, though it won't be 100% reliability. I would use two antennas, a vertical and an inverted V. You would need to use different bands as well: 80 and 40m on the inverted V, and 20/30m half-wave end-fed verticals. Your maximum height would be 15m then, and you can use a Spiderbeam mast for that. You'd use 40/80m for evening/night and 20/30m for day comms. Do not expect to make contact every time, though in a few years the return of the solar cycle will help a great deal. As Scott mentions, using the JS8 digital mode would help a great deal, or for a much simpler solution: Morse code using CW! Output power isn't a major factor here, propagation is... I would be happy with 5W CW or 30W SSB. If you have good charge capabilities go with a 100W radio, but pick one with a low receive current draw. It can be done semi-reliably, even with a modest installation. I used to have daily chats with Ray (radioray) from Florida to Virginia using CW, and rarely did we not make contact, and that was using 5W, sometimes as low as 100mW.

Gil.

Gil.
Title: Re: Newbie Transmit/Receive Range (distance) question
Post by: KE5ES on July 10, 2023, 07:37:27 PM
I found that a dipole pointed in a general direction also helps.  An example is this video:  https://youtu.be/4qle_lWTrpc
With one leg high and the second leg under it the path is directional.  With one vertical and the second horizonal in the direction of your intended contact it may work.  For best results experiment.  See what works best for you and your environment.  I have used the Buddipole antenna with one straight up and the second pointed, with a compass, at the azimuth my target is at.  Good luck!!!
de KE5ES