| Output Frequency: |
442.1750 |
| Input Frequency: |
447.1750 |
| Name: |
T.J. Molenkamp |
| Callsign: |
KC8LTS |
| CTCSS: |
123.0 Hz COR Active |
| Location: |
Detroit, MI |
| Controller: |
ICS Linker IIa |
| Receiver: |
Motorola Micor Spectra-Tac. TXRX Preamp |
| Exciter: |
Motorola PURC 5000 Paging Transmitter |
| Amplifier: |
Motorola PURC 5000 250Watt Continuous Duty PA |
| Power Output: |
200 Watts |
| Duplexer: |
DB Products DB-4076 BP/BR |
| Antenna: |
DB Products DB-408 6.6 dBd Antenna set for omni directional pattern |
| Powersupply: |
Rack mount 35 amp power supply for control receiver and remote base |
| Remote: |
Motorola 100 Watt Syntor X UHF radio set to 25 Watts. |
| Notes: |
6' tall rack mount cabinet, houses the transmitter, duplexer, controller, and receiver. Remote base and control receiver are in a separate 19 inch open rack along with the DCI filter and notch cavities for the remote base and the 220 repeater. The tower is 100 foot tree with a special made lubricant to deter squirrels from chewing the wires and feed line. It’s held very securely to the highest branch with extra strong 100 mile an hour tape straight from NASCAR. The remote base is not frequency agile but has 32 preprogrammed channels in it that can be remotely changed by DTMF commands. |
| History: |
This is version 2.31a. The repeater started as two 100 Watt Spectras tied together. The TX radio would get so hot set at 50 Watts with a huge fan on it that it would just lock up and stop transmitting. I had to put a relay on the ignition sense line to reset it, so that it would come back on line after getting hot. Even with that setup running a Comet GP-9 antenna it covered pretty well. Enough to get Jeff KB8SWR using it on his trips to town and invite me to join up with the CMAN group of repeaters in 2003. I then needed a good transmitter that wouldn’t burn up for the high usage airtime with the CMAN networked repeaters. I picked up a PURC 5000 transmitter and first installed this transmitter using a mid power UHF Spectra (which I think is Fred’s desk radio now) for a receiver. What a quirky setup this was. First the PURC burned up the GP-9 in the first week of use, so we had to get a commercial style antenna that would handle the power of the PURC. After replacing the antenna I had to deal with the less than selective front end of a mobile radio in duplex repeater service. Being in pager heaven downtown Detroit didn’t help any. Also the bouncy COR of the Spectra on receive gave tons of squelch crashes which were very annoying to listen to. Trying to keep the remote base transmitter out of the receiver and still keep good sensitivity was another big challenge. I finally gave up on that setup and retired the Spectra back to mobile service where it worked fine. I then got the Micor Spectra-Tac receiver made for repeater service, which has worked great since day one. Good learning experiences at the time. (Glad I wasn’t married at the time, as the wife would have killed me if I spent that much time with my repeater as I did during that period) |
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