Need recommendation for repeater

[DanOfWA]

Looking for a recommendation on a low cost repeater

Operating on 70cm using 5 specific frequencies
Looking for a repeater to cover them all over a 5 mile area

Hopefully easy to set up/take down as it will be used at different events

Needs to be reliable and low cost (funds come from donations)

Any suggestions ideas are welcome.

Dano

 

[nd5y]

It's not possible for one repeater to work on 5 frequencies at the same time.
A repeater needs two frequencies, an input and output.
To cover 5 channels you would need 5 repeaters and 5 frequency pairs.
This won't be cheap. Reliable repeaters are not cheap.

 

[Thunderknight]

Dano, do you mean able to operate on any of 5 pairs, one at a time, or all 5 at once?
For the former, depending on the total spread, you *might* get away with one duplexer, but likely will end up with more than one.
For the latter meaning (all at once), that is five repeaters.

 

[wrath]

Well you can find some used old Motorola gear and build one , or probably the cheapest pre-made I know of would be bridge Com, but the repeater is actually the cheap part , the controller, the cans , the tuning of the cans , a set of batteries if this thing is going to be portable are going to cost big money , and don't forget getting all the paperwork in order ,the repeater needs coordination and it needs the frequency pair used to not be in use any closer than 100 miles , there is a lot that goes into this that is time consuming and budgeting nightmare and if the frequency pairs you have in mind are not available to you because of location or conflict the whole thing goes bad , if you have not done this before and are inexperienced you probably need to hire a consultant to flesh this all out for you every step of the way on paper before you make any purchases , going to a ham fest and buying the equipment to make one is the easiest part ,getting it legal and on the air can be a challenge and a half, especially for a mobile repeater,another big cost can be the portable tower to put the antenna on at varied locations .

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[kayn1n32008]

To cover 5 channels you would need 5 repeaters and 5 frequency pairs.
This won't be cheap. Reliable repeaters are not cheap.

It is quite possible to have a portable repeater operate on multiple pairs with only one duplexer.

Years ago I built 2 VHF portable repeaters out of Icom mobiles for a government entity. They were programmed to operate on 12 or 13 different pairs. They had 5.26MHz split on every pair, and fell with in 1MHz of spectrum. 153.xxxxMHz TX and RX was 5.26MHz higher. Programmed it to transmit with 5w at the antenna port on the duplexer. The repeaters used Sinclair mobile duplexer, and had a Zetron community tone panel, power supply and could operate on 110v AC or 12v DC.

I do not believe the OP wants to use all 5 pairs at the same time, likely he want to be able to select a single pair depending where he wants to set up the repeater.

Even using a Sinclair 4 cavity BpBr ResLoc(Q3220), the OP should be able to easily pass 5 unique UHF pairs, with out significant loss.


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[DanOfWA]

Thanks for the replies so far

looking to have 5 pairs available at the same time for 5 diff 'departments'
since power is available it doesn't have to be mobile - just moveable - we have a 'tower' to use (20ft)

Trunked was looked into but the sticker shock was - uh - mind blowing

Inquiring so as to know what minimum equip is needed - repeater/duplexer/etc
don't want to just duplicate what already have 4 more times but find a way to 'minimuze the parts' to get it done

the organization already has 1 repeater (licensed/equip) for a freq pair but is looking to expand to cover all 5 freqs used to make comms easier - (up to 40 handhelds in use during event)


And then price out the equip needed to make it happen

 

[SCPD]

Hey Dano
.
I am not sure what you mean by the five frequency coverage- it is a bit unusual to have one system cover that many frequencies simultaneously- like others have said. A radius as small as you want to cover doesn't seem to be too difficult; even for the simplest of repeaters--- It is unusual you'd want a repeater for so small a area when simplex might do very well.
.
All that aside, how do you plan to use this system? Is the repeater to be located on an elevated site, as in line of sight to the mobiles? Will it have to talk thru buildings, thru foliage? And of course, what is your budget...?... quite a few variables to consider, and it is hard to give a definitive answer on what you have provided.
.
All that being said, I have a suggestion for something to consider. This is about the simplest, most inexpensive repeater- and I have had real life experience with it.** I hesitate to suggest this for I know the hoots and hollers it will produce... but I have had remarkable success with it- all things considered. It is a:
.
"SainSonic RPT-12D Two-way Radio Repeater Box for Two Motorola Transceivers, Station"
.
This is a simple audio controlled interface for two transceivers...... twenty-some dollars from Amazon. It is anything but a full fledged repeater- and limitations on such a system are beyond the scope of my missive. However:
.
I will tell my experiences and let the readers draw their own conclusions.
.
Awhile ago I purchased a box full of BaoFeng UV5 transceivers for work. After handing them out, sometimes multiply, there was still quite a few left in that box. Ever-the- curious, I had seen that SainSonic interface on Amazon and, bought one on a lark (no taxpayer's money, this one, guys.) About 2 miles from my lab is an unused hilltop antenna ranging site with an equipment shed and AC power. I took two of the BaoFeng transceivers up there, connected them with the interface, placed them in the shed- using battery pack eliminators and an AC power supply-- and I connected each transceiver to separate external antennas. These antennas were simple quarter wave verticals; the receive, on the top of a 20 foot tower- the transmit, just outside the shed door. Every thing from there is line of sight for at least 5 miles. The frequencies I chose were 408.xxx In, 418.xxx Out - mirroring the amateur 440 band. About as simple a setup you could ask for.
.
The Results?
.
It was hardly a Motorola repeater- But, and that is a "but' with an exclamation mark (!)- it did work surprisingly well. Of course there were things to adjust, as there always are- and your mileage may vary (YMMV- I like that abbreviation )
.
Okay, (laughing)... let the criticism begin... I can hear the rumblings already. But Dano, you asked for suggestions- and I work in the concrete-practical.... and here is one.....Good luck Cowboy!
.
................................................CF
.
.
____________________________________
** this was but an experiment- it was on the air long enuff to prove its worth-- now its all back in that box,
I also realize this is not the standard in/out, off set frequencies- etc... standards to gov. channels...

 

[kayn1n32008]

Thanks for the replies so far

looking to have 5 pairs available at the same time for 5 diff 'departments'
since power is available it doesn't have to be mobile - just moveable - we have a 'tower' to use (20ft)

Trunked was looked into but the sticker shock was - uh - mind blowing

Inquiring so as to know what minimum equip is needed - repeater/duplexer/etc
don't want to just duplicate what already have 4 more times but find a way to 'minimuze the parts' to get it done

the organization already has 1 repeater (licensed/equip) for a freq pair but is looking to expand to cover all 5 freqs used to make comms easier - (up to 40 handhelds in use during event)


And then price out the equip needed to make it happen

DMR is something to consider. Two repeaters will give you 4 talk paths. Getting 2 repeater to play nice in the same site is going to be a lot easier than trying to get 5 repeaters to play nice together.

It is also going to be expensive to get 5 repeater to pay nice together at the same time. Just the filtering alone will cost thousands if not tens of thousands of dollars

5 repeaters for 40 radios also seems way out of proportion. I could see needing 5 repeater for say 400 radios, but not 40.

I would suggest DMR for a few reasons.

1 Two talk paths per repeater pair. Two repeater will give you 4 simultaneous talk paths. Plus you can also have talk groups, allowing a massive number of potential user groups that you can load evenly on the 4 talk paths.

2 It is pretty trivial to get 2 repeaters, using very close pairs, to use the same antenna. A good duplexer (Sinclair ResLoc Q3220 or equivalent) a two port transmit combiner, and a 2 port receive multicoupler.

3 By buying DMR portables from Kenwood, Tytera, or Connect Systems Inc you can replace your analogue radios fairly economically.

This would likely be cheaper than trying to build a 5 channel repeater system.

A 5 channel repeater system will likely cost, if done half assed right, on the VERY low end, probably $40,000 not including feedline, tower and antenna.


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[rescue161]

DMR is something to consider. Two repeaters will give you 4 talk paths. Getting 2 repeater to play nice in the same site is going to be a lot easier than trying to get 5 repeaters to play nice together.

It is also going to be expensive to get 5 repeater to pay nice together at the same time. Just the filtering alone will cost thousands if not tens of thousands of dollars

5 repeaters for 40 radios also seems way out of proportion. I could see needing 5 repeater for say 400 radios, but not 40.

I would suggest DMR for a few reasons.

1 Two talk paths per repeater pair. Two repeater will give you 4 simultaneous talk paths. Plus you can also have talk groups, allowing a massive number of potential user groups that you can load evenly on the 4 talk paths.

2 It is pretty trivial to get 2 repeaters, using very close pairs, to use the same antenna. A good duplexer (Sinclair ResLoc Q3220 or equivalent) a two port transmit combiner, and a 2 port receive multicoupler.

3 By buying DMR portables from Kenwood, Tytera, or Connect Systems Inc you can replace your analogue radios fairly economically.

This would likely be cheaper than trying to build a 5 channel repeater system.

A 5 channel repeater system will likely cost, if done half assed right, on the VERY low end, probably $40,000 not including feedline, tower and antenna.


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I agree with everything that kayn1n32008 said. I am running 5 repeaters right now on two separate antennas, a 5-channel combiner and a multi-coupler. It was not cheap, but it works great. The repeaters that I have connected together are two P25 Quantars, one DMR XPR8400, one Bridge-Com BCR-40U and one Kenwood TKR850. In the beginning, I had only two repeaters using their own antennas with separate duplexers, but I like to experiment, so I started playing with different duplexer arrangements. Using duplexers to combine things sometimes works okay, but the losses add up very quickly. Here is a link to a 5-channel combiner that works much better than back-to-back duplexers.

Sinclair TJ3215 UHF Combiner, 5 channel, 7" cavity-ferrite, dual stage isolators | eBay

 

[kayn1n32008]

That is likely a decent price for a 5 channel transmit combiner. Q3220 duplexer $1500, 5 repeaters at $1200-2200/ea(mobile based repeaters will NOT cut it), receive multicoupler @ $500-$1000, 5 repeater controllers @ $200/ea, 5 20A powersupplies @ $200/ea, misc parts and cabling $100-$200. If you do not get very close pairs, dump the duplexer and add a bunch of money for a second antenna, feedline, and filtering the receive side. If all your frequencies are really close together, you are looking at $24000 easily, some others will likely add other things i have overlooked. Like a receive pre-amp. Potentially you may need external amplifiers, depending how big an area you need to cover because the transmit combiner will be 3-6dB of loss all on its own, add 1dB for the duplexer then add feedline losses.

Going DMR will save money on hardware, better than 50% cheaper, momey saved can be spent on DMR portables...

 

[kayn1n32008]

http://www.ebay.com/itm/Kenwood-UHF...211237?hash=item1c5b5266e5:g:uAgAAOSwwbdWI9ie

This is a steal of a deal, for really old trunking technology. The transmit/receive filtering is probably worth more, new, than what they are asking for the whole 10ch repeater system.

 

[Project25_MASTR]

Dan, what will likely fit your needs the most effectively is DMR. The reason I say that is you get two time slots on a single channel pair (two simultaneous talk paths) so it is a little more efficient compared to traditional analog setups.

You have stated that you need 5 "channels" and will only have 40 radios on the system. What you should really be saying is you require 5 talk groups and will have up to 40 radios on the system at once. Now if transmissions are kept to the bare-necessities (~20-30 second exchanges) and planned traffic essentially correlates to everyone checking in every 20 minutes (which is average for a public service event IME) system will be handling roughly 90 calls an hour. We can then take that information and plug it into the Engset formula and come up with a Grade of Service (GoS) of 11% (probability of both time slots being used at any given time). Factor in a majority loading on a single talk group (say 60%) and the average grade of service actually drops to 5% (totally acceptable levels) There are many more factors that come into play such as talk group loading that can make this number even smaller.

So it would be doable on a two slot DMR system. Of course, the most efficient way is to randomly assign the available time slot (versus assigning primary on one time slot and the other 4 talk groups on the other) and that can actually be done using a process called pseudo trunking. Benefit, it's low cost compared to true trunking and can be done with only one repeater. Motorola has an option for it called Capacity Plus, Hytera calls their version XPT, Simoco calls theirs Simple Repeater Dual Slot (though unlike Motorola and Hytera which can have multiple repeaters on this function, Simoco can only have one). I believe Simoco's option is the lowest cost as they include it in all of their Xd products at no additional cost (but like I said, limited to 1 channel, two slots).

 

[Raccon]

Hytera XPT is a trunking system. Pseudo-trunking in their DMR Tier II system is just called pseudo-trunking by Hytera.

 

[lmrtek]

I think what you need is a digital repeater.

That way every department will have their own talk group

Moto turbo is your best bet