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--- site:rosston:224.2 [2018/01/12 22:00]
ke5gdb
+++ site:rosston:224.2 [2018/01/12 22:19] (current)
ke5gdb [224.2 Technical Specifications]
@@ Line 1: / Line 1: @@
 ====== 224.2 Repeater ======
-The KE5GDB 224.2MHz (pl110.9) repeater likely has the largest coverage area of all 220 repeaters in Texas. The repeater consists of a pair of Motorola CDM1550 radios, a 100 watt Henry amplifier, CX-333 antenna, and a Raspberry Pi running Allstar as a repeater controller. In addition, the Pi drives a Kenwood TM-V71a Remote Base.
+The KE5GDB 224.2MHz (pl110.9) repeater likely has the largest coverage area of all 220 repeaters in Texas with the antenna at 1500' AGL. The repeater consists of a pair of Motorola CDM1550 radios, a 100 watt Henry amplifier, CX-333 antenna, and a Raspberry Pi running Allstar as a repeater controller. In addition, the Pi drives a Kenwood TM-V71a Remote Base.
+{{:site:rosston:img_20170715_143302819_hdr.jpg?800|}}
 ===== 224.2 Technical Specifications =====
@@ Line 12: / Line 13: @@
 The repeater is run through the 220 port of a triplexer. The 2m and 440 ports are recombined with a diplexer and fed to a Kenwood TM-V71a. This setup makes use of all 3 bands on the CX-333, and provides remote base access as far south as Belton and Madison County and as far north as Oklahoma City.
-With the additional heatsink and forced air cooling, the CDMs have no issue running 100% duty cycle at the highest power possible, 28 watts. A DS18B20 temperature sensor was embedded in the radio heatsink. Over the course of several hours of continuous transmitting, a 25°C to 32.5°C temperature rise was recorded. This indicates CDMs may be able to run at the full-rated power as long as proper forced air cooling is used.
 Power distribution consists of an APC switched PDU and 3 independent supplies: repeater 13.8v (KPS-15), amplifier 13.8v (Astron), and Pi 5v (Monoprice 2.4A something).
@@ Line 20: / Line 19: @@
 {{:site:rosston:img_20170715_143533093_hdr.jpg?800|}}
+{{:site:rosston:20170122_182358.jpg?800|}}
 ===== Temperature Sensors =====
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 {{:site:rosston:img_20170923_161650465.jpg?800|}}
+===== Remote Base =====
+A Kenwood TM-V71a is connected to the Raspberry Pi with a USB-RIM. In addition, an FTDL USB-Serial cable allows control from the Raspberry Pi. The TM-V71a is fed into a diplexer, which is then fed to a triplexer, then to the CX-333. The diplexer/triplexer arrangement allows the single antenna to drive all elements of the 220 repeater and the remote base.
+A Python script was written to allow full control of the TM-V71a from the command line. DTMF control is planned, but not yet implemented.
+===== 220 CDM1550 Notes =====
+With the additional heatsink and forced air cooling, the CDMs have no issue running 100% duty cycle at the highest power possible, 28 watts. A DS18B20 temperature sensor was embedded in the radio heatsink. Over the course of several hours of continuous transmitting, a 25°C to 32.5°C temperature rise was recorded. This indicates CDMs may be able to run at the full-rated power as long as proper forced air cooling is used.
+To use the CDMs in the ham band, a few adjustments need to be made to the CPS and the tuning of the radio.
+First, modify your CPS per [[http://ccdx.org/zedyx/mods/CDM_Mods/CDM_OOB.htm|these instructions]] ({{ :site:rosston:cps_out_of_band.pdf |backup}}). The hex values you're looking for may be in a slightly different location (off by several bytes), but you should be able to locate and make it work.
+The radio only operates in 12.5KHz steps. In the event that you're programming to a pair that does not divide evenly by 12.5KHz, program the radio for the nearest channel and use the tuner to warp the reference oscillator to get it on frequency.
+Things to adjust:
+  * TX VCO Attenuator (for wideband use)
+  * Reference Oscillator (if not evenly spaced)
+  * Squelch Level

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