mingus repeater site review & introduction to allstar · 5/20/2020 · what equipment is...
TRANSCRIPT
May 2020 Tech TalkMay 2020 Tech Talk
Mingus Repeater Site Review & Mingus Repeater Site Review & Introduction to AllstarIntroduction to Allstar
bybyDoug - NO1DDoug - NO1D
Tonight’s AgendaTonight’s Agenda● Overview of equipment installed at the site● 2019 and 2020 Projects completed● Challenges – High RF fields, desense issue from YCSO
● 2m and 70cm Repeater Status● 2020 Projects being planned● Linking – What is Allstar all about
What equipment is installed @ MingusWhat equipment is installed @ Mingus
● 2m Repeater● 70cm Repeater● APRS digipeater● 70cm Control● 220 Mhz Repeater● WinLink Digipeater – offline 5/16● MARS Repeater – offline 4/20● Various controllers, power supplies,
cellular router and networking
Tower ViewsTower Views
2019 Quick Review2019 Quick Review● New crystals for Daniels MT2 Rx/Tx
● Replaced Yaesu VX7k with Daniels
● 2m Site Survey, performance measurements
● Repair of VHF Amplifier(s)
● Refurbish of Link Systems RLC4 controllers
● Deployment of Cell Router, Allstar controller, new controller interfaces
● Solid State Relays for remote control ops
● Replacing defective APRS radio
● Tests with new Filters
● Linking 2m, 70cm & Allstar● Creating W7EI Hub Node (more
later)● Procurement of many spare modules● Hut Cleanup, Fan/Cooling, Temp
Sensor● Grounding improvement● Tower work including 70cm antenna,
2m antenna
Why Swap to a DanielsWhy Swap to a Daniels● Better front end selectivity for
improved Rx performance● Chassis based, ease of module
replacement to reduce downtime● Higher MTBF – fewer parts● Lower power consumption● Two chassis from Squaw we could
re-use● Simplier, cleaner interface w/
controllers which we had for remote control
Daniels RxDaniels Rx● Dual Helical BPF in
front end w/ LNA● 2nd IF Helical Filter● TCXO version here
Daniels TxDaniels Tx● TCXO version● 4W out max● Helical Filter
Daniels AmplifierDaniels Amplifier
● Takes up dual slot in backplane● Wideband simple design; tunes
in Ham Band● Thermal controlled● 30W out, 4W in● This is early design VT2,
currently running VT3 module
Crystals & SynthesizersCrystals & Synthesizers
You’ve heard of You’ve heard of Bugs in HW?Bugs in HW?
High RF Fields !High RF Fields !
The YCSO Desense ProblemThe YCSO Desense Problem● Very High RF Field Site
– You see 0dBm (1mW) sigs at Antenna feedlines on VHF !
● YCSO 120ft away● NOAA Wx 120ft away
– 24x7x365 transmissions
● MMRG 100ft away● Airband 120Mhz thru 138Mhz● Several VHF Ham Repeaters on Mt.● DTV at 170Mhz● High Noise Floor
● Random desense● YCSO has to be transmitting● Weak signals primarily
affected– Occasionally hits strong
signals into Rx
● Zero desense w/ antenna disconnected
Many Attempts Many Attempts were madewere made
● Terminated all unused feedlines/antennas
● Improved Grounding● Measured Duplexer again● Tried Several BPF designs on Rx
– Home Brew, 800Kc, 400Kc– Measured 1dB Blocking Range on Rx;
about 130Kc
● Installed OCI 2m BPF on antenna; brute force !
● Incremental improvements, however problem persisted
Identified… we believeIdentified… we believe● Terminated MARS feedline, desense
problem went away● Isolated intermittent and oxidized
feedline; duplexer to bulkhead● Desense did not require MARS
repeater to Tx ! ● Suspect IMD generated from high
RF hitting PA– No circulator/isolator in Tx path– Mobile duplexer, poor rejection
● MARS team is looking to upgrade their equipment
A Detailed Site Survey looking for IMD productsA Detailed Site Survey looking for IMD productsIs high priority. We need to get to root-cause!!Is high priority. We need to get to root-cause!!
Current 2m/70cm Repeater Current 2m/70cm Repeater StatusStatus
2m2m● Audio bit low; adjust● Address squelch tail noise;
Rx open on release of PTT● Unique tone from 70cm● Add back BPF/LNA to Rx
path for increased Rx performance
70cm70cm● Duplexer found intermittent● Currently 17W; increase to
25W - 30W● Audio level adjustment(s)● Replaced Lightning Protection● Control Channel work● Add BPF/LNA to Rx path
2020 Projects2020 Projects● Hut Painting and Sealing
– Before Monsoon Rains !
● IMD Site Survey Report● 220Mhz Allstar Controller● Centralized Power supply
– Rework old breaker panels
● Add site Wx station● WinLink (under review)
● Removal old unused antennas off tower
● Grounding Measurements and Improvements
● Possibly Diplex APRS w/ 70cm for vertical separation
● Re-aim Control Channel yagi
LinkingLinking● Today’s Capabilities
– 2m and 70cm (no Allstar)– 2m w/ Allstar– 70cm w/ Allstar– 2m & 70cm w/ Allstar
● Two RLC4 controllers provide powerful audio switching matrix for linking
● Many points of audio adjustments :-(
So What’s AllstarSo What’s Allstar● Voice Over IP (VOIP)● Network of Repeaters,
Base Stations, Radio-less nodes & Hubs
● Based on OpenSource Asterix PBX software
● Supports EchoLink
● Can replace legacy repeater controllers
● Interfaces to variety of radios/repeaters– Many many models
● Great for Linking repeaters● Runs on variety of HW; rPI
series my favorite
Hardware ExamplesHardware Examples
Links Links mademade
Management Management InterfacesInterfaces
Management InfoManagement Info● Daily emails me a
connection log– Tracks node ID and IP
● Immediate notification if tunnel is lost
● SSH up to site allowing access to RLC controllers
Current Linking PolicyCurrent Linking Policy● Anyone can connect to W7EI Hub
(46005)● No inbound connections to node at
site (49941)● Can create white/black lists for
connection policy (not currently used)● Tech Committee member must
configure audio mux on RLC controllers– 70cm typically patched to Allstar
● Let us know if you want a link connection made
● 60’s Net – 2m ● TGIF Net – 70cm
● Note: EEE During emergencies may link 70cm (2m) to another machine to expand coverage area and support EM comms
Want to build a node ?Want to build a node ?● RPI3B+, good 5v supply● DMK Engineering URIx
– USB cable from rPI to URIx
● HamVoip Software Distro– 8G Micro SD card
● Home Brew Cable– DB25 to Radio– Tx, Rx audio– COS– PTT
● Can use almost anything for radio– Even Baofeng series
● Can work over WiFi– I like Ethernet however
● Register with AllStarLink.org for node number
● HamVOIP vs. ASL– Registration differences
● Contact me if you have questions
VVARA Allstar FuturesVVARA Allstar Futures● Possibly replace old RLC
controllers and go direct to Allstar– Eases automation of linking– Direct control over audio
levels– Voice ID – Special Announcements
including Wx/Fire alerts ?
● Add in 220 machine for Rodney KI6FH– More linking
possibilities
ThanksThanks● Thank you for your patience while we maintain club
machines and continue to improve performance at our site(s).
● Email: [email protected]● Tel: (978) 602-5487 (emergencies please)