Initial N0PKT Bristol Head Repeater Buildout Notes
The following components are those that will be used to build the allstarlink repeater on Bristol Head in Mineral County, CO. The exact location that this repeater will be placed can be seen on google maps
I have been working closely with the Mineral County Sheriffs office to build a system that is capable of reliable use by the public and for Search and Rescue (SAR) operations. The coverage area will be from Mineral County into Rio Grande County, parts of Hinsdale County and other surrounding areas. In a later post I will include a coverage map.
I have not included details about the feedlines in this post, suffice it to say that I am hoping to get feedline for both the UHF and VHF side donated from the Cheyenne Mountain Repeater Group in the form of 1/2” and 7/8” heliax.
Core Radio Components
MTR2000 40 Watt Radio
- Repeater PDF Info
- Ebay Reseller
- Power Requirements
- 8.5 AMP on TX
- 1.7 AMP on Stby
- 14.2 VDC
- Cost: $875
Rasberry Pi II Model B (1GB)
This will be the primary control device for everything. It will be responsible for not only APRS information relay but also control the repeater and allow for linking into the Fun Machine repeater system while also providing auto patch and reverse auto patch access.
- 32GB Micro SD Card
- Running DIAL for AllStarLink
- Power Requirements
- 2 AMP
- 5 VDC
- Cost: $49
RTL-SDR
- For APRS iGate
- Cost: $25
The RTL-SDR will interface directly with the Rasberry Pi, see notes below for APRS iGate.
URI (radio to pi interface and controller)
- http://dmkeng.com/URI_Order_Page.htm
- Cost: $69
Duplexer
- Ebay Reseller
- Cost: $175
Commscope DB420 (or equivalent for TX antenna)
- Antenna Farm
- Cost: $1625.00
Diamond X50NA Antenna (VHF APRS RX antenna)
- Cost: $100
Miscelanious Supporting Hardware
Power Control
The Power Controller will be controlled by the GPIO pins on the Rasberry Pi. it will consist of the following components, I will detail more in a followon posting.
- 4 Channel Relay Module with both NC and NO poles
- Amazon
- Cost: $6.99
- RasPi GPIO T-Cobbler
- Amazon
- Cost: $12.30
- High capacity relays
- Amazon
- Cost: $13.00
- Breadboard Jumpers
- Amazon
- Cost: $14.99
- Misc Informational Links to Similar Projects
Power StepDown Conversion and Source
This is a solar/battery/generator site, where the main feed will be a 48v feed. This feed will need to be down-converted to a 12v feed to power the Rasberry Pi and repeater.
- 48 > 12v StepDown Converter
- Amazon
- Cost: $50
- Battery Bank
- BWG 121000 x4
- http://www.bwgllc.com/products/bwg-121000-group-27/
- $150
- $150 shipping
- BWG 121000 x4
Mounting Hardware
The system will be mounted in a rack, assuming we will need minimal mounting items.
Power Consumption
| Device | VDC | Tx Amps | St Amps |
|---|---|---|---|
| Radio | 14.2 | 8.5 | 1.7 |
| Raspi | 12 | 2 | 2 |
| Power Control | 12 | 70mA | 70mA |
| Total | 12 | 10.6 | 3.8 |
Price List
| Device | Price |
|---|---|
| Repeater | $875 |
| Duplexer | $175 |
| Raspi | $49 |
| RTL-STR | $25 |
| URI | $69 |
| UHF Antenna | $1625 |
| VHF Antenna | $100 |
| UHF Feedline | $150 |
| VHF Feedline | $150 |
| Relay Box | $6.99 |
| Relays | $13 |
| Jumpers | $14.99 |
| T-Cobbler | $12.30 |
| Converter | $50 |
| Batteries | $750 |
| Rack Equipment | $200 |
| Total | $4265.00 |
Misc Applications
- QRadioPredict
- Used to simulate propogation
- AllStarLink Dial
- Runs on Rasberry Pi to create allstar controller and add other critical features
- Propogation Modeling
- Used to simulate propogation (online)
RasPi APRS iGate Buildout
- Some Directions
- klaibrate-rtl
- Generate a passcode:
- Code is included with pymultimonaprs noted in directions
It is CRITICAL to note that the GAIN needs to be adjusted to a value that the RTL-SDR supports, these values can be determined by running the rtl_test and then sampling to see what you get .