Hello group. HELP I just received a call from a group running a hospital in Haiti who needs radio. They had old Motorola ps50 which I was able to find batteries and get them sent down late last week. Apparently they are not working as well as they expected. Due to short communication time and since they are very busy there I was unable to communicate to them today that no radio by it self would have the 5+ mild range they are looking for. I don’t think any are Hams and am unsure about any repeaters in the area,(if so are they operational)
Any ideas from the listers about a radio (8) I could purchase and get to them?
Have looked at the Cobra LI-7200 which may be close to their needs but not sure. I don’t even think my 2m ham handheld will give the range they think they need without a repeater.
What are your thoughts???
If their location warrants it (there is somewhere nice and high), and power is available, why not just get them a repeater?
2 GMRS radios wired together could make a cheap but ghetto GMRS repeater.
Find two mobile radios that work on GMRS bands (eBay can probably help with this) and hook it up, wire the accessory ports together so one radio’s squelch detect line goes to the other radio’s PTT line, and the audio lines are connected. Or just plug the RX radio’s audio port into the TX radio’s mic port and set TX radio for VOX. Result is a simple cheap ghetto repeater with no hangtime, ID or courtesy tone, but it WILL repeat.
For power, just get a 12v battery charger or transformer wired up in parallel with a car battery. As long as the charger doesn’t overvolt too much or produce much noise, you have an instant cheap UPS for the thing.
Then include a couple of consumer level FRS/GMRS portables that support repeaters (motorola makes a few) and they’re good to go*.
Note- I don’t know what radio licensing is like in Haiti, if GMRS frequencies are allowed for use in Haiti, or if they’d need a license to use them. This post reflects a quick and dirty and cheap way to get them going.
The cheap (bubblepack) radios he’s talking about cannot use a repeater, anyway.
The only practical method is going to be a manned relay station at height.
Legalities:
CONATEL NOTICE The National Council of Telecommunications (CONATEL) hereby notifies the general public, and those particularly impacted, that following the widespread damage caused by the violent earthquake of January 12, 2010, a satellite office of CONATEL was installed at Number 97 of the Avenue Panaméricaine in Pétion-Ville with the goal of assuring the continuity of its work. This arrangement will allow, among other things, better coordination for establishing a temporary emergency telecommunications network in Haiti. Consequently, all concerned are asked to contact CONATEL at the above mentioned address between 9 AM and 1 PM and throughout the day at the following telephone numbers: (509) 3454-0541, (509) 2516-0000 or (509) 3702-1414, or at these e-mail addresses : techommunication@yahoo.fr or info@conatel.gouv.ht, before any use of telecommunications equipment or the spectrum resources. We hope to avoid interference problems and possible conflicts between the incumbent operators established in Haiti and those who are newly operating in this unusual circumstance. The National Council of Telecommunications (CONATEL), while thanking the telecommunications service providers for all their efforts to keep their networks operational despite the widespread damage that has been noted, takes this opportunity to offer its sympathies to the families of the victims of the earthquake. Port-au-Prince, January 20, 2010 Montaigne Marcelin
Director Général
Here is a ‘bubble pack’ repeater capable radio. The store is out of stock of them at the moment; Mot makes a few more which show up on their (motorola’s) site, but I have to run in a second and no time to look them up.
I saw that notice too, that’s geared toward ham radio users who want to obtain reciprocal licenses for operation in Haiti. It would probably be wise for the hospital to contact CONATEL and ensure that a GMRS repeater wouldn’t interfere with anything.
What I had mainly meant tho was that in the USA the FRS/GMRS bands are reserved for FRS/GMRS users. Aside from the licensing requirement (which I’m sure nobody would bother enforcing if there was an earthquake here) one can use a FRS or GMRS radio without worrying about causing problems for anybody other than other FRS/GMRS users.
In Haiti on the other hand, the 462 and 467MHz frequencies used for FRS/GMRS may be allocated for something else, IE government, military or business use, and putting up an (American) GMRS system may cause problems for Haitian systems that are actually supposed to be using those frequencies.
A good comparison is the European PMR446 radios- operating right around 446MHz, PMR446 provides a nice equivalent to the USA’s GMRS. However while PMR446 may be used freely in Europe without a problem, in the USA a PMR446 user would be inside the 440MHz amateur (ham) band which of course requires a license, and is also used by military radar systems. A European user who brings his PMR446 radio to the USA and starts using it could inadvertently cause problems for a 440 band ham radio repeater, I wouldn’t want our friend in Haiti and his hospital to create the same problem for someone else down there.
Having a receiver in close proximity to a transmitter will “desense” the receiver.
A speaker level audio signal applied to a microphone input will overdrive the transmitter’s audio circuit, causing the re-transmitted signal to be distorted and unintelligible.
This makes the approach inappropriate for a mission-critical application where there are lives involved.
A better option would be a simplex repeater, or any VOX-enabled FRS/GMRS radio with a digital voice recorder connected between the mic and speaker ports of the radio. Placed high enough, should provide a decent and usable coverage area. A single 12 Volt battery should provide weeks of service.