also there is the NXR-710 that replaces the TKR-750
----- Original Message ----- From: Maire-Radios To: [email protected] Sent: Thursday, March 25, 2010 9:56 AM Subject: Re: [Repeater-Builder] Re: opinions for a public safety repeater look at the new version of the TKR-740 the NXR-700 repeater it is the way to go and get the ver 2 software. John 727-441-3250 ----- Original Message ----- From: skipp025 To: [email protected] Sent: Thursday, March 25, 2010 8:37 AM Subject: [Repeater-Builder] Re: opinions for a public safety repeater > "Jed Barton" <j...@...> wrote: > Hey guys, > Need some input here. I'm putting together a public safety > repeater for my local FD. It's going to be really simple. > Given the reliability factor, we're going with a Kenwood. > Here's the million dollar question, i need some input. How > about a kenwood tkr750 or a tkr740. I've run several 750s with > great results. I have not played with the 740, but i know it > has an amazing receiver, but yet only pushes a few watts. > Any suggestions for a good amp, perhaps Cresend i think it is. > Thanks, > Jed Hi Jed, The Kenwood TKR-750 and TKR-740 are both great Repeaters. The TKR-750 also has an amazing receiver. Proper setup of the receiver should normally include the front end pre-selector alignment using a special coax cable jig assembly and a tracking generator properly configured and installed onto the PC-Board matching input and RF sample port/jack. Most people and Dealers tend to do the more casual "peak for max signal" method, which results in very usable but not the absolute best sensitivity and performance. I'm very much amazed how many repeaters we service with rather odd looking (on the test equipment) "tweak and peak" front end alignment(s). So be sure to ask any Dealer what and how they prepare your equipment before they send it to you. The TKR-750 is more of a self contained ready to use repeater with a lot of built in features. Very popular for operations toward the 50 watt power level. The TKR-740 is more of "system repeater" meaning... how many owners often use them with external Power Amplifiers and Controllers. The TKR-740 has much less power output and normal operation assumed by most people is to include an external RF Power Amplifier. If you need to bark higher than a 50 watt signal onto the air the most popular method is to include (and use) an external RF Amplifier. You can save quite a bit of serious money by using the same external amplifier configuration with a TKR-750 Repeater and a higher drive (input) level External Amplifier. There's nothing in stone about driving an external high power RF Amplifier at the 25 to 50 watt level compared to spending a lot more money on a low drive level amplifier. TPL, Cresend and TE can and will sell you higher drive amplifiers for much less money and you end up with pretty much the same end product. In the hopefully rare case where an external amplifier might fail, continued repeater operation at the 25-50 watt power level is quite usable versus the very low power output of the 740 repeater. There can be different advantages to using the TKR-750 or the TKR-740 Repeater. cheers, skipp skipp025 at yahoo.com www.radiowrench.com
