Bitcoin donations to: 1CE9UfWJcHBYkWPns7iqBqZgKhd5xfqEaM thanks!
Buy Bitcoins easily by clicking HERE and get $10 in free bitcoins!

Web hosting in Iceland - OrangeWebsite.com

Author Topic: Preppers Calling Frequency.  (Read 10676 times)

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2502
  • SMeter: +58/-2
    • View Profile
    • Radio Preppers
Re: Preppers Calling Frequency.
« Reply #45 on: May 01, 2017, 02:38:22 PM »
Thanks Scarr, I need to allocate a couple hours to research this...  :)

Gil.

cockpitbob

  • Administrator
  • Hero Member
  • *****
  • Posts: 1057
  • SMeter: +28/-0
    • View Profile
Re: Preppers Calling Frequency.
« Reply #46 on: May 02, 2017, 09:31:22 AM »
Thanks Scarr, I need to allocate a couple hours to research this...  :)

Gil.
Ditto.  Those charts will take some learning to interpret, but I bet there's real valuable info in them.

scarr

  • Newbie
  • *
  • Posts: 15
  • SMeter: +2/-0
    • View Profile
Re: Preppers Calling Frequency.
« Reply #47 on: May 02, 2017, 05:29:54 PM »
foF2 is the Critical frequency in a given location - the highest frequency you can knock straight up and have it come straight back down, vital for deciding on NVIS regional comms. I've kept an eye on it lately and the frequency is rarely going near 7MHz - meaning if you want local HF comms, you've got to decide between 80M or 60M.

From foF2, a rule of thumb is that the Maximum Usable Frequency will be three times foF2 - so if foF2 is hovering around 5MHz and it's daylight in Europe and North America, well - generally - no point trying to cross the pond on 10 Metres, your best bet is likely to be ~20M.

The VOACap page is really useful for calculating likely condx between any two points on various bands. Just feed in the locations and to be honest, for the most accurate prediction - put the sunspots at zero. The (11) sunspots we have at the moment are miniscule and have little if any impact on the solar flux level. SF is at 75 at this moment - from the last solar minimum, I remember that figure dipping into the 60's. In short, that means forget the higher HF bands.

This all goes back to something gil and others have said - if people just expect to fire up a HF rig in a SHTF situation and talk with little or no experience - forget it.

The charts aren't 100% necessary, but they inform operational experience - e.g. if I'm on 40M at 1PM local and I'm hearing no Irish or UK stations, but Germany is booming in, I know foF2 is less than 7MHz.

If we ever have to use HF in a scenario where mains is out, spending time listening first is going to be vital - when you've decided on where you'd like to contact, you've got to figure out what's happening with the bands before keying. No point blasting 100W into the ether on 20M when 5W on 80M will get the desired result. Power could be precious.
« Last Edit: May 02, 2017, 05:51:05 PM by scarr »

Pensioner Prepper

  • Newbie
  • *
  • Posts: 6
  • SMeter: +0/-0
    • View Profile
Re: Preppers Calling Frequency.
« Reply #48 on: August 04, 2017, 06:29:05 AM »
I wondered if anything yet has been desided for a 80m Prepper calling frequency. If not I will throw my hat into the ring and suggest 3.675 USB for UK inter G and parts of mainland Europe.

 My group would be willing to do some testing to see if this frequency is suitable.

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2502
  • SMeter: +58/-2
    • View Profile
    • Radio Preppers
Re: Preppers Calling Frequency.
« Reply #49 on: August 04, 2017, 08:25:20 AM »
Quote
suggest 3.675 USB for UK inter G and parts of mainland Europe.

Are there any digital modes around there?
Otherwise, I wonder if 3685 would rhyme better with 7185...
Nobody is using 7185 USB yet, so maybe concentrating on it now would be better, then we can move on to 80m once there is traffic on 40m...
What do you think?

Gil.

Pensioner Prepper

  • Newbie
  • *
  • Posts: 6
  • SMeter: +0/-0
    • View Profile
Re: Preppers Calling Frequency.
« Reply #50 on: August 04, 2017, 11:28:49 AM »
I will give it a try. Will sit on 3.685 for a week and see if is used for any regular nets. Will let you know. Have been monitoring 7185 USB and putting out the occasional call with no response thus far.
There being no NIVS on 40M it is hard to work inter G on this frequency. Larry
« Last Edit: August 04, 2017, 11:45:43 AM by Pensioner Prepper »

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2502
  • SMeter: +58/-2
    • View Profile
    • Radio Preppers
Re: Preppers Calling Frequency.
« Reply #51 on: August 07, 2017, 01:36:52 PM »
Quote
There being no NIVS on 40M it is hard to work inter G on this frequency.

There has to be some going on... I know this is no longer Florida, but I've experienced some here, from near Lille to England.

Gil.