Batboard

Anybody know what models of this repeater are FCC certified for the VHF band and what power levels they come in ?

Someone told me that there is no fcc certified VHF version that is capable of being set down to no more than 6 watts power output.

A lot of the new VHF public safety fcc licenses are only for 12 watts erp and with a 3 dB gain antenna this does not leave a lot of equipment available for putting up a legal repeater, so can anyone tell me if there is a 1225 repeater certified for this low of a power level in the VHF range ?


Mike

The "RKR1225" is available in VHF with a low power transmitter of 1-10 watts.

But I would NOT recommend that unit for public safety applications.

The MTR2000 is what you really need.

OK RKR1225, the photo I had of it was so poor that it looks like RHR.

Too late to get a real repeater now as they already purchased it. All I've received is bad reports on this repeater, it's only going on a 8000 foot mountain.

Well that is better if it is certified to go that low in power.


Mike

Are there other repeaters on that same mountain?

Yes a bunch of VHF forest service and one VHF fire department. I have nada to do with it, I am only checking as requested by another site owner who has the FD equipment.

Also how well will it work with an added pre-amp, that is correct an added pre-amp, he is worried about all the added amps etc. causing interference to the FD equipment.

Another thing which I don't think will work is they want to also use it for page outs and as I remember from my days at motorola designing paging transistors we usually recommended 500 watts ERP or more in VHF just to get reliable pages out to 25 miles, I'll assume the laws of physics have not changed any since 1997.



Mike

With the other VHF equipment at the same site, you are going to want to add lots of filters. A “crystal filter” would be the best option. But no filter will protect the actual repeater internal parts from receiving interference from the other equipment at that site.

http://www.com-rad.com/xtalfilter.htm Crystal Filter Maker Link

The RKR1225 is a GR1225 repeater in a rack mountable housing. These units do NOT like heavy duty work. Even at 1 watt @ 50% duty cycle, that repeater is going to get eaten up. If it is not to late, spend the extra $ on the MTR2000.

500 watts for paging is great, but the PS freq coordinators do not issue licenses with that much power unless you can REALLY justify it. Good antenna selection and proper site selection are the keys to good signal propagation.

P.S. to run an VHF RKR1225 @ 500 watts your looking @ $7000.00 just for the amp. (TPL 2-4 watt in with 500 watts out. Part # PA3-2AG-HMS)

mike m wrote: Also how well will it work with an added pre-amp, that is correct an added pre-amp, he is worried about all the added amps etc.
causing interference to the FD equipment.

Pre-amps are great, but remember filtration!

The RKR1225 is simply an R1225 transceiver in a rackmount box that includes a switching power supply and a fan. The RKR1225 package has space to install a mobile notch duplexer and/or a multi-tone controller. The same transceiver is available in a desktop package as the GR1225.

Although it is a low-tier, economy-grade repeater, the R1225 is a lot of value for the money. Standard features include Morse ID, courtesy beep, wide/narrow band operation, and PL/DPL with reverse burst/turnoff tone. It is available in either 1-10 watts or 25-45/50 watts, on both VHF and UHF. All models are FCC type-accepted for Part 90.

I have four units in service right now, three on VHF and one on UHF. The UHF repeater is on solar power and has been running 24/7 for more than a year, with no problems at all.

The R1225 is rated for continuous duty at the 25 watt level, but it will cut back on power automatically on high temperature or high VSWR. I am replacing the R1225s with MTR2000s because I need the additional power and sensitivity, but I still think the R1225 is suitable for many uses.

I have no say in what the other tenant does so it's to late to buy anything eles also I was only checking up on this rptr for the tech who maintains an adjacent buildings FD RPTR.

The other tenants tech is 200 miles away from this site and he asked me to find out any info that I could on this new rptr.

Sensitivity wise how how does it stand up to say an old Micor ComuStation RPTwith the pre-amp option as this is what it is replacing and I can't find a link to this rptr on Motorolas web page.


Mike

The MICOR station receiver is probally one of the best receivers for a conjested site. The R1225 radio is a good receiver but needs a Cavity filter on the receiver at the least on a conjested site.

Most sites use a Receiver antenna system and that gives a lot of seperation and filtering.