The 447.775 MHz Repeater

The KA1RCI Repeater Network

447.775 / 442.500 with PL 67.0 - Established 2004

Lincoln - Rhode Island

Scroll to the bottom for latest updates from July 2010

Back Ground / History from '04 to '07

2004 marked a great deal of changes to the repeater network. Major upgrades to the 223.960 and 449.325 system including a new powerful FF-800 controller along with a move to a prime site with 350 foot towers in Johnston, RI. The move to Johnston left a few vacant repeater antennas on the 80 foot Lincoln tower so I decided to build some new 440 and 900 MHz repeaters to warm up those antennas!

Here are several photos of the various stages of the temporary repeaters during the construction phase.

(click on images to enlarge)

The three photos above show 447.775 online using a pair of Kenwood TM-V7A radios while I was building the permanent repeater RF units and having the new UHF duplexer tuned for my frequency.

(click on images to enlarge)

The four photos above show the 100 watt VHF duplexer running the 146.460 / 147.460 repeater while the large duplexer is being tuned for the new input frequency. The other photos show 146.460 and 927.500 on the air using a pair of Kenwood TM-241A's and a set of Motorola GTX radios. You can also see the new 447.775 duplexer in the bottom and the small blue rack tuned and ready for the new UHF RF units. The 223.960 and 449.325 rack is in the back ground also getting an upgrade with a new link radio and the new FF-800 controller.

The replacement transmitter for the 447.775 repeater finally arrived after weeks of waiting and I was able to pull together all the components for the 146.460 / 447.775 / 927.500 Repeaters. In these three photos the repeaters are "on air" with a combiner allowing both the VHF and UHF repeaters to share the small antenna for testing. The 900 MHz repeater is still only running on a small mobile antenna while I wait for the final frequency pair so I can have the duplexer tuned.

(click on images to enlarge)

447.775 modifications made in 2006

After running in the small rack for several months I was able to locate a very nice commercial rack cabinet that would be able to hold all the hardware for the three Lincoln repeaters 146.460 / 447.775 / 921.6125 however it was a few feet too tall to fit in the space that I had available in the repeater shed.

My brother-in-law Scott came to my rescue again and was able to cut the cabinet down just small enough to squeeze into the space available in the repeater shed while still leaving enough room inside the rack to accommodate all the hardware.

(new lager rack photos here)

447.775 Rebuild Project Fall of 2007

With so many other repeater project all going on at the same time, I must have been crazy to rip apart a repeater that was working perfectly but that is exactly what I did when the opportunity to move the 447.775 Lincoln repeater down the road a few miles to a much better site.

I stared by removing the existing 447.775 duplexer, radios, and power amplifier out of the 146.460 / 447.775 / 921.6125 rack cabinet at the Lincoln site and dragged all that hardware back to my QTH to get started rebuilding everything in a smaller cabinet.

(new cabinet photos here)

Since I have been enjoying such great success using the older Kenwood commercial TK-30 series radios in repeater service on the 147.075 and 147.390 projects I decide now would be a good time to swap out the commercial Icom radios with some TK-30 series Kenwood radios.

(new radio photos here)

I also decided to get two additional band pass cavities for the duplexer, the two additional cavities that I had added to the 224.040 repeater made such a dramatic improvement I got in touch with my friend Jag and ordered two new band pass cavities for the 447.775 repeater. Jag had built the original 447.775 / 442.775 Bp/Bp duplexer for me back in 2004 which was working perfectly but I wanted to make sure there was enough isolation and filtering for the more RF rich environment at the new site.

(original four cavity duplexer photos)

(new band pass cavity photos here)

You just never know how these project are going to unfold once you get started and then the "might as well" philosophy kicks in and you start upgrading things just because you are tearing everything apart. The original 447.775 transmitter power amplifier fit perfectly in the smaller rack cabinet that I had built the new 444.500 repeater in and that big hole in the back of the rack had been bothering me for awhile so I moved the big flat UHF PA back into that smaller cabinet and purchased a new rack mounted PA for the 447.775 project.

Jag does it again!

New custom phasing harness for the JAG duplexer - July 2012

This repeater rebuild it still ongoing and the page is currently...

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