Anthony L .Ferguson wrote:
Greetings,
I would like to enlist suggestions from the group for help. I have a
project on my mind and has been bothering me for a while. In the area
I live there is a need of a simplex repeater. I know that the term
SIMPLX REPEATER is not a true repeater, but a message store and
forwarding device using either a carrier operated relay (COR) or
carrier operated squelch (COS) controller.
Just a simple question: If the solution is a simplex repeater, what's
the problem? ;-)
I can't think of many situations where a real duplex repeater wouldn't
work better than a store-and-playback simplex system.
My Ideal suggestion for a controller is either the BD VA10 or the
NHRC 3+ controller. The controller is the brains of the entire
system, allowing analog information to be stored on the ISD chip then
dumping the stored information to the transmiter. The controller is
needed for CWID to be legal on the ham bands.
There are other ways to do this -- heck some of the OM's here probably
built store and forward voice stuff with tape recorders back in the
day -- but what you're describing would work.
Now with that all behind us on the controller.I would like some
suggestion on types of commerical radio gear that may be easily
converted to 2 meters or 440 Mhz.
You have looked at the Repeater-Builder website that goes with this
mailing list, right? Also, there's the Batlabs website for Mother M
(Motorola) gear, and various others scattered around.
I see Ebay is flooded with all types of stuff that looks like it
should work for my project. I see listings for GE Phoenix mobile
radios, GE master Excutive II , Delta and Ranger. I don't want to
stop with just GE so I must include Motorola also.
Those will all work. It's just a matter of how easy and finding the
right documentation. The radios you mention there are all relatively
old. Many people like using a little bit newer synthesized stuff, but
it takes a slightly different skillset -- radios like the Motorola
GM300's with the right accessory connector on the back are dirt-simple
to interface to a controller or other device via that accessory
connector, but you have to learn the secret handshake to get
information on the programming software and cables.
The reason is that technically Motorola sells those tools for about the
cost of a small third world country's debt to the World Bank to
commercial radio folks so they want to make sure us hobbyists are not
out there selling copies and/or cutting into their sales of such tools
to government, etc. They'd prefer you take the radio to someone with a
legal copy of their software to work on it, of course... so the usual
disclaimers apply here. And truthfully if you've never done it before,
sending the radio to someone that knows what they're doing for the
programming is a fine option if you don't care to learn it. Finding
someone nearby who can show you how (in good Ham elmer tradition) is
better. Depending on your personality type, learning it through online
documentation and trial-and-error may be your style, or whatever... you
probably get the idea here.
I'm confused on something, and hopefully someone will guide me in the
right direction. I'm not sure which is needed to complete my Simplex
repeater station, minus the controller. I see all the stuff listed on
EBAY from GE and Motorola like transceiver and repeaters. Which do I
need ? The transceiver or the repeater or both?
Are you sure you understand that a simplex repeater really isn't a
repeater? It's a single radio with a storage device for the audio. You
talk into it, unkey, and it plays back the message. A real repeater is
a receiver and transmitter that operate at the same time (usually
through the same antenna, but they don't have to) and what it's
hearing is retransmitted to your end-users immediately. To do this
requires things like duplexers (or vertical separation of vertically
polarized antennas - there's a chart for different frequencies here on
Repeater-Builder for the minimum vertical distances for various bands,
but unless you're going up above UHF, plan on having a tower for this
tactic...), high-quality feedline (to avoid desense), and if you're
putting the repeater at a shared transmitter site, things like
isolators, and possibly band-pass cavities, depending on the RF
environment at the site.
I simply want to know my options before I start digging in my wallet.
I know the controller is first and that is my goal first.
I wouldn't buy the controller first. If you can't get the radio working
you have a controller that is useless.
I think that commerical gear would be the best choice due to it being
built a bit better to handle the load of usage while in service to
the community.
You'll get various opinions on this, but most of the people that build
systems that just work day in and day out would definitely agree.
The
