Comments for Walkie Talkie Two-Way Radios

Comment on Long Range Two Way Radios by Admin

Admin — Mon, 16 Aug 2010 00:13:25 +0000

Hi Kevin. I live in Australia and I don’t know how many miles it is between your locations. But that is just one factor of many. The season of the year, the time of day… all of these make a difference to the Ionosphere – the upper levels of the air above our heads. It gets changed by electroromagnetic radiation from the sun, and that is affected by an 11-year sunspot cycle. ALL of these things can be factored into some intense calculations, but when it all comes down to the nitty gritty, it is really a matter of “suck it and see”. I would advise you to try the 80m band at night time, when atmospheric noises are at their lowest, and also give it a go on 40m both during the daytime and the night. You could try some of the new 60m band channels as well, if the ham you are trying to reach has them. See how you go with that. SSB needs a very good connection to work, whereas PSK31 will get through with a much weaker signal…just like CW (morse code) can usually manage. And as for antennas, a dipole tuned for the frequency you are going to use will be the best by far. For longer distances, get your antenna up high – more than 1/4 wavelength if possible. At lower heights it will act as an NVIS antenna, which sends the signal straight up – like hosing water into an umbrella above your head. This is good for comms for a local to a few hundred miles away. But not for DX. 73 David vk2dmh.

Comment on Long Range Two Way Radios by Kevin

Kevin — Sun, 15 Aug 2010 23:41:13 +0000

I am trying to figure out what would be the best amateur frequency to use for direct radio communication between central Indiana and central to northern Minnesota. A frequency that is least affected by sunspots, weather and daytime temperatures. SSB or PSK31 is ok, but can it be mobilized and could it run off a longwire or di-pole?
Thanks,
Kevin(N6FOZ)

Comment on Emergency Cellphones That Work Without Phone Towers Or Satellites by Admin

Admin — Sat, 24 Jul 2010 09:37:28 +0000

That’s right, it is a great idea. But it would also be great if everyone who goes to remote places had enough brains to take their own EPIRB – or, as as they are called now, a personal emergency beacon. These things use UHF to contact an overhead satellite. You have to be pre-registered with the service so they know who you are already, and they pinpoint your location to a few yards. Cost? Less than $500. It’s cheap insurance, considering a rescue probably costs tens of thousands of dollars… Maybe even more.

Comment on Emergency Cellphones That Work Without Phone Towers Or Satellites by diane

diane — Sat, 24 Jul 2010 08:57:38 +0000

Hi there. With all the people who get lost while out hiking, this is a clever invention- using mobile phones as short range two way radios. Makes me proud to be an Aussie. Hope this catches on.