Copyright 2020 Tri Town Radio Amateur Club- All Rights Reserved
Tri-Town Club Repeater146.805 Tri-Town WD9HSY/R PL 107.2
Picture Tour of the 2 Mtr Repeater
By Brian, WD9HSY
Welcome to the 2 Mtr repeater!
I’ll be passing along
credit to the rest of the repeater guys that have help keep this little monster up and running and were instrumental in putting it
up and on the air.
Lets start at the top!
Picture 1. Antenna
The 1st Pic is of the Decibel DB222 2 Bay Folded
Dipole antenna. This 2 Bay will be replaced with a 4 Bay version soon for more gain and more directivity. The Club has
the new 4 pole a Telewave ANT150-69. These are all Commercial Antennas, not the light weight Ham grade antennas.
2. Ground Block
We have ½ inch Hardline coming from the antenna to this copper plate grounding block. The grounding cable
and PolyPhaser are mounted here as well as the cabinet ground wire. From here there is a piece of ¼ inch hardline going into
the cabinet and the duplexers.
Picture 3. AC Power Conditioning
Dan, WB9ACN provided the AC / lightning protection
for the machine. This is the protection from lightning (PolyPhaser) and AC power surges. (Blue Thing!…. Hi -Tech
Inside the Cabinet!
Picture 1. The Radio, Duplexers, and Controller
The cabinet is dark and cramped
with wires here and there. The repeater consists of the Motorola Micor radio, power supply, repeater controller, and the duplexer.
The picture shows the general lay out. I have a fan blowing across the heatsink of the Micor that is above and out of the picture.
This is the back view (working end) of the cabinet.
It’s a little hard to see, but that shiny thing under the Motorola Micor
is the SCOM 7K repeater controller. It’s the heart of the system. This part controls the ID’s, timers, announcements,
autopatch, voice announcements, all the courtersy beeps. It gives the system its “personality.” If you have timed out the repeater,
the 7K got you! The last time I checked I had about 4-5 pages of programming for the 7K. It is programmed over the air
or by the telephone using DTMF tones. As an example I have to type this in to get the 7K to say, “This is the WD9HSY repeater”:
20 9000 MPW 15 9981 9988 9989 9985 9960 0565 0101 0335 0207 0431 0587 0377 0421*
Picture 2. The Power Supply
This is a 40-amp
power supply made from Motorola parts by Mike, WA9ZPM. This power supply has been running 24 hrs, 7 days a week, since the repeater
went on the air, more than 10 years ago. Mike wins another “Show and Tell” contest with this power supply. I have a feeling
this supply will still be here 10+ years or more! Thanks Mike!
Picture 3. Pre-amp and Duplexers
This is a tight
shot of the duplexers and the Pre-amp. The duplexers are the “Black Box" of repeater operations. These 4 “tanks” are mechanical
filters that tune to the receive and transmit freq. and allow the radio to transmit and receive at the same time. This prevents
the transmit from swamping the receiver. The preamp goes from the duplexers to the Motorola Micor and gives a boost to the incoming
weak incoming signal. Over the years we have had the preamp in and out of the system. Currently its out of the system
and the Micor is running on its own.