Practical comms fixes.

[Ogri the trog]

I guess my query is aimed at Lightspeed, though I am happy if anyone else has something to throw into the pot. I have read the forum articles and I am really trying to understand what I need to do to improve both myself and my kit. I'm a stubborn old goat, getting a bit long-in-the-tooth to learn lots of new stuff and I'm not really in any position to buy loads of new kit just for the occasional weekend playing!

Last weekend I was out in the Mountains, trying to get comms with a number of mates - we were all using either Baofeng or Retevis hand-held units on PMR channels with a variety of aerials, some static and some roving. Distances varied up to about 6 miles but we were among some pretty big hills.

The major problem as I saw it, was that at no time did everyone get comms together - some had contact with others and some could hear but not reply (rather the reply was not being heard by the first transmitter) and others barely heard anything all day.

We know that locations were not always ideal - some were close to steep mountain sides and some were away from crests of high ground, but they were generally open in the direction we wanted to transmit & receive. One location was using a 6 meter mast with an Omni directional (I think) aerial - barely made any difference when they changed to using a hand-held unit.

We had a laugh and messages got through by either relaying via one or two others or mobile phones (when they had signal), and we are all wondering what we could do to get better at it.

So, if you'll humor me...
Could we have done better if we had made some Dipole aerials and slung them into the trees? If we did, how can we be sure that they are all "tuned in" to the same channel/frequency?

Is there any element of "bend" to the radio waves to go over hill tops or is it straight line and nothing else?

Is there a range of frequencies that would penetrate the hills and dense woodland any better than others without us all having to pay someone to sit an exam and then forever being on someones "list".

Should we just resort to developing telepathy as a more rugged communication system?

Thanks for any help you can offer.

Ogri the trog

[harrypalmer]

At a very basic level your hand helds are not much more than line of sight, the signal goes straight up (which is why we can talk to the ISS) but does not really 'bounce much as high frequency short wave does. A better antenna will help a lot but don't expect too much from these rigs certainly in woodland and mountains.

If you get your foundation license you can then access repeater stations and kick your signal on and in a group situations your group can use 'talk through' to keep in touch.

What sort of rigs are you running? Also take a look at RAYNET, you don't need a license to join and you will learn a lot, I enjoy my times with them http://www.raynet-uk.net/

Look forward to talking to you in the future

73

[Ogri the trog]

Thanks Harry,

You may have hit the nail on the head - that I am expecting too much from cheap equipment - and I'm in no financial position to buy a lot more kit as I mentioned. I was after some practical hints to get the absolute best from what we have - Baofeng UV - 5's, UV 82's and Retevis units with combinations of little mag mount roof top aerials and standard screw in types.

I've looked at Foundation Licencing but that still wont change the equipment, though I understand about accessing different frequencies and repeaters.

I have had one experience with Raynet, but I'm sad to say it left a very sour taste - not something I'd want to pursue if there was any other way of doing things.

Thanks for your reply, I appreciate your information,

Cheers

Ogri the trog

[harrypalmer]

Don't knock the UV5's, I've got Icom and Yaesu which cost a LOT more but offer little in way of improvement...the frequencies your using are limited in range end of story. Sorry about your poor experience with RAYNET, not always like that.

[Lightspeed]

Ogri:

No disagreement with anything HP has advised.

Re Baofeng UV5rs: Yes they are pretty much line of sight. But in hills line of sight can be a significant distance. My location is around 1500ft ASL, and my un-played with UV5r can reliably reach a repeater that is sited more than 80 miles from me. So, its not necessarily the equipment.


How to maximize inter-connectivity:

All stations to be set to EXACTLY the same frequency
All stations to hold their radios upright ti ensure all signals are vertically polarised.
All stations set deviation to WIDE,
All sations to set power to High
All stations to set CTCSS and DTS to ZERO = Off.
All stations radios to be set to the lowest possible squelch level.
Over-ride squelch when listening for distant stations.
At UHF and VHF frequencies, often moving just a few feet will greatly change signal strength.
All stations to have Roger-bleep turned-on. This can help make others aware that there are transmissions, even if they cannot hear spoken word, as the tone burst will often get through.

Assign one of the stations as Network control, with responsibility for coordinating communications across the group, and coordinate times for each unit to check in.

Example of Net Control communication:
Net Control<< This is Lightspeed listening for Harry P>>
Net Control<<Nothing Heard. Can any other stations hear Harry?>>
OGRI REPLY: <<Hi Lightspeed, Ogri here, Confirming that I can hear Harry>>
Net Control: << Thanks Ogri, Please confirm if he is OK and if he has any message for us>>
OGRI: <<Ogri calling Harry P. Lightspeed has asked me to relay request if you are OK or have any message to pass back?>>
OGRI: << Ogri calling Lightspeed. Harry OK. No messages to pass>>
Net Control: Thanks Ogri, all understood.
Net Control: This is Lightspeed listening for Mary>>

...and so on.

Re the mixed bag of transceivers in use in your group, beware that the super cheap Baofeng BF888/777 type equipment is lower powered than a UV5r, and that these units must be accurately set up to match the exact same frequencies and modes of the rest of the group. For these low cost machines, that setup is through a computer over a USB interface cable.

Degree of bend? At VHF and UHF virtually no bend in signal pathway. But look out for aircraft flying overhead. Often signals will reflect back off aircraft fuselages to extend range. There's also a phenomenon called knife edge reflection in which occasionally signals will bend back earthwards over ridgelines. I've never experienced the latter myself, but its well documented.

It is unlikely that full cost Ham gear is going to greatly improve comms among your group. However most current Yaesu equipment has a transponder system that informs when stations are in reach of one another...that could be a handy feature if you are looking for a hot spot from which to transmit.

[Ogri the trog]

Thanks Lightspeed and Harry again

Exactly the sort of thing I was after. I'll make sure our handset's all match your recommended settings (though the Roger bleep might take a little getting used to!) and I'll look into PC programs and interface leads.

A number of the group are "Ex mil" so we have some idea about comms procedures along with "Lost comms" and relaying messages.

Thank you for taking the time to reply, I really appreciate your help.

ATB

Ogri the trog

[harrypalmer]

A lot of hand helds like the Baofeng/Icom/Yeasu and more can be programmed from the keypad but its easier to use

http://chirp.danplanet.com/projects/chirp/wiki/Home if you have hams in the group get one of them to use the chirp software and save an 'image' which can then be easily loaded to many of your other radios so your all 'speaking from the same page' so to speak.