coryb27

It's not just wanna-be repeater users either. I was running some tests with two of my radios today. Some guy got on and told me I needed to be "OFF HIS FREQUENCY" by 6:00 PM because him and his friends have a conversation every Monday through Friday starting at 6:00 PM on that frequency.
 
I was a hot second away from using a very poor selection of words to remind him that these are "public" airways and no one has priority unless there is emergency traffic and if the frequency was in use... he could just pick another one.
 
Best part... I listened in on the 6:00 PM convo... they are talking about what they like on their salad. What restaurants have the best salads and salad bars. Dude was going to be in such and such a place tomorrow and wanted to know if anyone know where he can get a good salad... especially with good ranch dressing.
 
Glad they consider a dinner salad priority traffic and tell others to get off "their" channel. Good grief.

As long as the duplexer covers that frequency range you can tune it any way you like. I have tuned a duplexer to work like a combiner for 2 transmitters. Works great as long as you include isolators in your design.

As long as the duplexer covers that frequency range you can tune it any way you like. I have tuned a duplexer to work like a combiner for 2 transmitters. Works great as long as you include isolators in your design.

In VERY general terms, more cavities = more isolation. Larger cavities generally have a better efficiency - ie: less loss through the duplexer for equivalent isolation achieved.
 
As Berkinet mentioned, the higher quality duplexers involve a combination of bandpass and reject technology. Lower cost "notch" style duplexers are usually limited to 65 to 75 dB of isolation between transmit & receive. Notch duplexers suffer in high power use, and they won't filter out other nearby transmitters very well (They are designed to only "notch out" the transmit frequency of the machine they're used on).
 
Good duplexers have high isolation, low loss, low noise, and can handle high power. They'll also use quality components, and will be built to handle large swings in temperature without de-tuning.

I build repeaters, tune duplexes, transmit combiners and I have no idea what you are trying to say here.... What?

Sounds like a kid I once heard say he put 7.5" pistons in his 6 cylinder Mustang engine to get higher compression for his supercharger... and now it runs 9 seconds in the quarter. I never laughed so hard in my life.

Well, since it is usually better to learn how to fish than to have to buy fish... Try starting with the Wikipedia. Another excellent source for repeater information is Repeater-Builder.com. Here is a page from them on duplexers.
 
But, to get you started... very basically, each cavity performs one of two functions. It either:
Filters out everything except a specific frequency (a notch filter) Filters out just a specific frequency (a band-pass filter) As you add more cavities (I.e. the more times you filter the signal) the effect of the filter becomes more pronounced. The low cost, so-called mobile, duplexers consist of only notch filters - 3 for receive, 3 for transmit. The transmit cavities (attempt to) filter out any signal other than the transmit frequency. The receive cavities do the opposite, filtering out everything except the receive frequency.  Adding a band-pass filter will boost the effectiveness of the duplexer. For example, a receive band-pass cavity would be turned to attenuate the transmit frequency.  Note that most high-end and commercial duplexers consist of both types of cavities.

You will not have any issues at all, i have commercial pairs way closer then that and combining TX.

The 1225s are indeed solid serviceable repeaters with built-in controllers. However, they have a seriously bad habit of blowing the final PA amplifier. They work best when run at half their rated power on a 50% duty cycle.
 
However, before you buy a 1225, I would strongly suggest looking at a MTR2000. This is a solid piece of equipment, also with a built-in controller. It has no bells and whistles, just 100% duty cycle ability at the rated power.  On a good day you can get a MTR2000 for near the same price as a 1225. Unlike the 1225s, the MTR2000 can be rack mounted. OTOH, it does not come in a neat little metal box like the 1225s. Also note, you will probably have to buy a duplexer. But, a basic mobile unit, like the one included in the 1225s, won't set you back very much.

Hey Howie, welcome.
 
Unfortunately, we don't publish specific repeater information in the public forums, to prevent unlicensed users from abusing the service.  I can tell you that between the "Maps" feature and the directory, it looks like there are potentially several that serve your area.
 
If you haven't created an account on www.mygmrs.com, you will need to in order to access the directory.  It is a separate login from the forums.  Once,you are logged in, look at the "Maps" and search the directory, include the whole state and sort by city.  You should be able to see the same repeaters that I do.

I think that's the goal. Don't want everyone and their mom with an MXT115 bought at Cabelas/Bass Pro just randomly picking the repeater channel and going for it. 

I might add that GMRS has tolerances as far as frequency that are far lower then most HAM gear. With GMRS being smack in the middle of the part 90 portion of the band it is important to maintain some type of standard as to not cause interference to the adjacent service. Requiring a type accepted and certified transmitter is the best way to do this.

@berkinet wins the prize for being the first to notice. 

I think Corey hit the nail on the head. You get what you pay for. I see this in my field for work daily. Customers put in a radio system on cheap then complain. It doesn't matter if it a garage GMRS repeater of a full blown countywide TLMR system. If you cheap out on features, option, subscribers, shelters, etc stuff will not meet your expectations. I have some cheap GMRS mobile radios and use them for what they are, being a cheap radio I can throw out. My go to radios cost over $5000 each but I use them for public safety along with my hobby stuff. There are alot of reasonable priced part 90 radios on the market and with some education can be very nice GMRS rigs. 

As a side thought, if GMRS is something you enjoy and plan to keep using save you penneys and purchase a new part 90 radio with real features and the ability to program 1000 channels any way you like. Yes these radios can be priced from 300 to 800 but well worth it. I have several HAM rigs in the 800 to 3000 range, an Aeroflex service monitor that costs me many thousands, its my hobby and I invested it. I would love to see anybody find 1 case of the FCC tracking down somebody and issuing a fine for using part 90 gear because its not going to happen. Calls to the FCC will get you a response like, so long as we are not investigating you for other violations your part 90 radio is just fine. I have run into FCC field officers at commercial tower sites and have addressed the question in person showing them my GMRS setup (Motorola XPR5550 with handheld control) and the response was, that's a nice radio. YOU GET WHAT YOU PAY FOR plain and simple, cheap is cheap for a reason.....

You are asking a lot for 150 bucks, quality components and engineering cost money. The small profit margin would require every GMRS license holder in the US to purchase several 150 dollar radios just to recover the engineering costs let alone the rest of the expense of bringing a product to market. Its simple economics and GMRS is to little of a market share to invest in.

Well, let's see. If every active GMRS licensee  (the FCC says there are 56,338 of us) bought 1 radio at $150 ea. that would net $8.4M. Then, let's assume retailer profit is 40% (66% markup).  That leave $100 per radio ($5.4M total) to the manufacturer (we won't worry about any wholesalers, etc. here).  
 
Now, I'll take a wild guess and say it would cost $200k to design a radio from scratch (I.e. not base it on any existing product) and another easy $200k to setup the manufacturing capability.  That brings the manufacturer's gross income down to an even $5M.
 
Next, let's guess each radio costs $50 to manufacture, and another $10 to box, warehouse and ship.  That is a cool $2.8M and the manufacturer is now down to $2.2M. Note that if this was the only product of its type, the manufacturer's costs would be much higher.
 
Next, in order to get 56,000 people to buy this radio you have to advertise. Easily $0.5M and throw in another $0.5M for promotion, trade shows, etc. Now we are down to $1.2M. Taxes, overhead, retirement plans, health insurance would likely add another $2M and we end up with a nice profit of $1,000,000.00  IF every single GMRS licensee actually bought one. The real number is likely to be under 10%. But, let's be generous and say it would be 25%.  So, after all this work the net profit is going to be around $200,000 and would result in a totally saturated market for years to come. And, don't forget you have to either pay off your investors or the bank, or have had the cash to finance this on your own.
 
And, THAT is why you do not have the perfect GMRS radio being sold today for $150.

Hey, the two tin cans worked. Hickam AFB, 1964. Had two tree forts. (No, not sissy tree houses) other side of the alley, 150 ft apart. They worked!
Dang, tried to get them to bedroom windows, couldn't keep the string tight.

As a side thought, if GMRS is something you enjoy and plan to keep using save you penneys and purchase a new part 90 radio with real features and the ability to program 1000 channels any way you like. Yes these radios can be priced from 300 to 800 but well worth it. I have several HAM rigs in the 800 to 3000 range, an Aeroflex service monitor that costs me many thousands, its my hobby and I invested it. I would love to see anybody find 1 case of the FCC tracking down somebody and issuing a fine for using part 90 gear because its not going to happen. Calls to the FCC will get you a response like, so long as we are not investigating you for other violations your part 90 radio is just fine. I have run into FCC field officers at commercial tower sites and have addressed the question in person showing them my GMRS setup (Motorola XPR5550 with handheld control) and the response was, that's a nice radio. YOU GET WHAT YOU PAY FOR plain and simple, cheap is cheap for a reason.....

As a side thought, if GMRS is something you enjoy and plan to keep using save you penneys and purchase a new part 90 radio with real features and the ability to program 1000 channels any way you like. Yes these radios can be priced from 300 to 800 but well worth it. I have several HAM rigs in the 800 to 3000 range, an Aeroflex service monitor that costs me many thousands, its my hobby and I invested it. I would love to see anybody find 1 case of the FCC tracking down somebody and issuing a fine for using part 90 gear because its not going to happen. Calls to the FCC will get you a response like, so long as we are not investigating you for other violations your part 90 radio is just fine. I have run into FCC field officers at commercial tower sites and have addressed the question in person showing them my GMRS setup (Motorola XPR5550 with handheld control) and the response was, that's a nice radio. YOU GET WHAT YOU PAY FOR plain and simple, cheap is cheap for a reason.....

As a side thought, if GMRS is something you enjoy and plan to keep using save you penneys and purchase a new part 90 radio with real features and the ability to program 1000 channels any way you like. Yes these radios can be priced from 300 to 800 but well worth it. I have several HAM rigs in the 800 to 3000 range, an Aeroflex service monitor that costs me many thousands, its my hobby and I invested it. I would love to see anybody find 1 case of the FCC tracking down somebody and issuing a fine for using part 90 gear because its not going to happen. Calls to the FCC will get you a response like, so long as we are not investigating you for other violations your part 90 radio is just fine. I have run into FCC field officers at commercial tower sites and have addressed the question in person showing them my GMRS setup (Motorola XPR5550 with handheld control) and the response was, that's a nice radio. YOU GET WHAT YOU PAY FOR plain and simple, cheap is cheap for a reason.....

As a side thought, if GMRS is something you enjoy and plan to keep using save you penneys and purchase a new part 90 radio with real features and the ability to program 1000 channels any way you like. Yes these radios can be priced from 300 to 800 but well worth it. I have several HAM rigs in the 800 to 3000 range, an Aeroflex service monitor that costs me many thousands, its my hobby and I invested it. I would love to see anybody find 1 case of the FCC tracking down somebody and issuing a fine for using part 90 gear because its not going to happen. Calls to the FCC will get you a response like, so long as we are not investigating you for other violations your part 90 radio is just fine. I have run into FCC field officers at commercial tower sites and have addressed the question in person showing them my GMRS setup (Motorola XPR5550 with handheld control) and the response was, that's a nice radio. YOU GET WHAT YOU PAY FOR plain and simple, cheap is cheap for a reason.....

You are asking a lot for 150 bucks, quality components and engineering cost money. The small profit margin would require every GMRS license holder in the US to purchase several 150 dollar radios just to recover the engineering costs let alone the rest of the expense of bringing a product to market. Its simple economics and GMRS is to little of a market share to invest in.

You are asking a lot for 150 bucks, quality components and engineering cost money. The small profit margin would require every GMRS license holder in the US to purchase several 150 dollar radios just to recover the engineering costs let alone the rest of the expense of bringing a product to market. Its simple economics and GMRS is to little of a market share to invest in.

You are asking a lot for 150 bucks, quality components and engineering cost money. The small profit margin would require every GMRS license holder in the US to purchase several 150 dollar radios just to recover the engineering costs let alone the rest of the expense of bringing a product to market. Its simple economics and GMRS is to little of a market share to invest in.