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Expense of Repeaters

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Is it just me not finding the right ones or right places or does everyone suffer the problem of repeaters being expensive to the point of being out of reach

for several years now i have run a very small group of people helping at events ( could be local or further afield )

the problem we have always suffered is our comms and we have tried so many different radios, sometimes begged borrowed etc just to try out so as to to try and get better comms ( only handhelds suitable for us as a general rule)

many many times on events we can end up several miles apart and as such comms lost completely which creates many issues for us

I know the simple answer is some form of potable repeater maybe even one that could be mounted into a car and positioned according to our needs for comms but as we are basically nothing more than a voluntary group who cater for mainly charities we have to maintain our our costs with any equipment we have so each member of the group is committed to buy there own stuff for the purpose of the group

with me being the main guy i have looked for repeaters which would cost me personally and can never seam to find anything even remotely close to a cheap way to get one other than the little black box that links two handhelds and to be honest i did buy one and it was a waste of time.

all i see are repeaters costing several hundreds to purchase even ones using old equipment or owner built using surplus equipment

ive even considered should i try to build one but when i look at gaining programming software , leads for linking two mobile units etc and make some sort of box for it all to go into and arials i end up finding even that route is too cost prohibitive.

licencing is not a problem as frequencies would be set to a suppliers licence under agreement

so is it just me that has this problem or am i missing something as to where people get them from at more sensible money

Thanks in advance 
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I'd be interested to know what you call "Sensible Money" and what sort of power you want to run.

Nick


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good one nick"Sensible Money". i would love for him to explain that one.

R.G TWO-WAY RADIO Elecctronic & consultant
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OK, so there has been no answer yet so I'll add this;

Radio's
I have been recently told by one of our members that now is a great time to find surplus radios in the US costing from $15-50 each.

Controller
I personally don't like the idea of using a simple cable to join the radios together unless the radio programming can provide both 'Watchdog' and Hang-Time' timers. For this reason, have a look at these controllers in the links section of this site:

Repeater Controllers - Hamfiles Links

Both are well under $50.

Duplexer
You'll need a duplexer unless you intend to make a cross-band repeater (which would complicate things considerably for your users). Although I've never used one myself (I've always been lucky enough to find a commercial device within my budget), this Youtube video may give you enough confidence to try a Chinese device that you can get pre-adjusted to your desired frequencies.

Repeater Chinese Made Duplexer Review - Youtube

$60-$70 Should buy you a 50W device and quite a lot less for a low power duplexer from eBay.

DC Power
Depending on your TX power output and your required run-time, Lead Acid or car batteries can do everything you need. A solar charger would be a great upgrade if you were into it.

Antenna
You could make one for a few $. Keep in mind that the larger diameter the vertical is, the greater the bandwidth (so a mobile whip is unlikely to cut-it). There are 1000's of designs for simple ground-plain antennas on the net.

Nick


If you find this site helpful, please try to upload something new (radio programming software or manuals/circuit diagrams etc.) and make someone else happy too. Please consider donating and help pay the bills, thank you.
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Thank you Nick
as for sensible money i just meant levels where myself footing all costing would be realistic for something that only serves a temp job from time to time
if we made money from what we do then there wouldnt be a cost issue but along will all other equipment we have to by personally such as keeping a  motorcycle on the road for the purpose and safety gear etc the radios part became a bug bugbear in the line up of equipment so have been on the lookout to attempt to find a way forward where im not paying out several hundred for a basic operational repeater than could still at least perform its intended purpose when needed.

your links are very useful and i already have one of those cheap duplexers which i bought several months ago with intent to take the route on trying to build myself but i then hit the problem of looking at other items and total costs will still adding up to several hundred pounds so thought i would post the topic above in the hope someone could at least point in right direction which you have done , what your saying there makes far more sensible costings than the costing i was coming up with so thank you very much, i will look into your info provided and hopefully maybe to take that as the route to get one built

Thanks Again
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Hi Nice111,

A couple of things suggest you're from the UK so the comment about radios in the US is of little help.

As you've already got the duplexer let me know what band/frequencies it's tuned to and I'll see if I can find anything in the radio dept. that may suite you.

Re the controller, I've built a couple of the VK5DJ's and can tell you they are bomb proof.

Let me look into it further and get back to you, I may be able to connect you with someone that can help.

Nick


If you find this site helpful, please try to upload something new (radio programming software or manuals/circuit diagrams etc.) and make someone else happy too. Please consider donating and help pay the bills, thank you.
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PM on it's way to you.

Nick
 


If you find this site helpful, please try to upload something new (radio programming software or manuals/circuit diagrams etc.) and make someone else happy too. Please consider donating and help pay the bills, thank you.
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The term low cost and repeaters are at the opposite end of the cost structure.  In what has been said so far is not going to bring things together for a solution.  A duplexer is a must for any repeater.  The big thing here is how much isolation it will provide to keep the TX frequency out of the receiver.  The next issue is how well shielded both the transmitter and the receiver are.  The shielding will effect how well the repeater will play.

Don't forget that a repeater uses 2 different frequencies.  One for receive and one for transmit.  The further apart these frequencies are, the less important the shielding is.  It also effects how well the duplexer will work and how big it needs to be.

A good duplexer that is set up for 0.600 KHz. separation will be much more expensive than one working with a 1 MHz. frequency separation.  Unless you can find a used one, your looking at something in the order of $1000.00 plus for a decent one.

Don't plan on using 2 portable radios for the transmitter and receiver.  They don't have any where enough shielding or frequency selectivity.  Plus there really is no way to connect them to the duplexer.

You should be using double shielded coax cables between both the receiver and transmitter and the duplexer.  Do not use any of the LMR series of coax cables.  These cables do not work well over time in a duplex type service that a repeater is.  Over time moisture manages to migrate inside the jacket of this cable and causes all sorts of noise problems.  This is due to the dis similar type of shielding materials used.  The inner shield is aluminum foil and the second outer shield is braided copper wire.  The 2 shields are touching each other so it doesn't take much to create some small amount of corrosion and now you have a diode junction that will create all sorts of RF noise under the right conditions.  This is a well documented problem when used for repeater feedline.

Your next issue will be choosing an antenna that doesn't cause noise problems when used in a repeater application.  Your choices are gain antennas and zero gain antennas.  In the repeater type application, your better off using a gain antenna.  Put it as high as you can and go from there.  The higher the antenna, the greater the range of coverage will be.

In reading what you have already posted, your not going to be happy with what I have said.  But these are the facts of life.  I would try and find someone in your area that can work with you and help guide you along.  Trying to do it on your own with no knowledge of how to do it or what you will need will only end up in an expensive failure.  Maybe looking around for a ham club near you and going to a couple of their meetings.  You should be able to have them point you to someone with the background that can help you.

Good luck on your project.

Jim

 
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I don't know if this will be of any help Nice111 (depending on your location)…

Yaesu Fusion (C4FM) repeaters were and possibly still are being sold/promoted at relatively low price.  They are dual mode, i.e., digital AND *** analog ***.  $500 is the average cost but you have to supply your own duplexer,
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If you already have a duplexer that's half the battle for a temp repeater. Pick up a cheap controller off ebay (ID-o matic) and you can interface just about any radios together. Maxtracs are cheap and reliable. Antenna can be made from coat hangers.
A repeater  can be as cheap or as expensive as your imagination can make it..
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