GB7WIN Crab Wood, Winchester

GB7WIN was commissioned on 23rd March 2025 as a joint project between Alan G8IPG and Jason M0MZF on the radio site at Crab Wood, Winchester, IO90hb as part of South West Hampshire Raynet's wider project to provide digital voice and data services to amateurs across the wider area. Thanks to Matt 2E0HKD for his continuing involvement in BPQ node configuration!

Live traffic monitor at http://gb7win.ddns.net:50650
Get on WhatsPac :) http://whatspac.m0ahn.co.uk:88/

Current and planned ports

Port	Frequency	Antenna	NinoTNC Mode	ERP / Dev.	Status	Neighbors	WebSDR
2	144.9375MHz 12.5KHz FM	V Omni 3dBd 40mAGL	0101 QPSK 3k6 IL2P+CRC	14dBW 2.4KHz	active	GB7RDG GB7BSK GB7WOD GB7BDH	SUWS
4	70.4875MHz 12.5KHz FM	V Omni 0dBd 7mAGL	-	-	considered	GB7EBN? GB7BSK?
6	50.650MHz 12.5KHz FM	V Omni 0dBd 40mAGL	1011 QPSK 2k4 IL2P+CRC	13dBW 2.4KHz	active	GB7BDH GB7RDG	Wessex
7	432.650MHz 25KHz FM	V 180° 5dBd 7mAGL	-	-	considered	GB7IOW? GB7SOU?

Coverage Maps

Simulations from radiomobileonline; Outstation antenna 12m AGL; Strong signal 15dBuV/m, Weak Signal 3dBuV/m, Path “reliability” 95%

2m plot, 4dBi antenna	6m plot, 2.2dBi antenna

Technical

Hardware

Modified Comet GP-15N @ ~40m AGL / ~200m ASL, 55m Andrews LDF7-50A, 14dBW ERP
Raspberry Pi 5 / Raspberry Pi OS (Debian Bookworm) / 256GB NVMe SSD
Meanwell HRP-100-12 PSU
GPIO Relays for remote power switching, Dallas 1-wire temperature sensor for radio
External 12V switched power & USB for future expansion
2m: Motorola GM380 (data in / flat audio out)
6m: Alinco DR-M06TH (modulator / discriminator tapped)
2x NinoTNC A4 v3.42 firmware
CM108 on NinoTNC RX audio tap for 1k2 AX.25 decode (Direwolf 1.7)

LinBPQ

Version

G8BPQ AX25 Packet Switch System Version 6.0.24.69 March 2025 (G8BPQ beta)

Last updated

Fri 2025-04-18 18:43:40 BST

Global

;T3=540                 ; L2 validation timer - increase from default 180 (3min)
;IDLETIME=2700          ; L2 idle link shutdown timer - increase from default 900 (15min)
MINQUAL=50              ; Minimum quality to add nodes to the table
L4COMPRESS=1            ; Enable compression on L4 links
NODESINTERVAL=60        ; Broadcast / expect nodes every 60min
OBSINIT=6               ; Initial OBS counter for an added node
OBSMIN=4                ; Minimum OBS number to select broadcasted nodes
L3TIMETOLIVE=25         ; L3 maximum hops count
L4DELAY=10              ; L4 delayed ACK timer
L4RETRIES=6             ; L4 retry count, default=3, increased to 6
L4TIMEOUT=120           ; L4 Timeout increased to 2min
PACLEN=236              ; Max out NETROM frames

Routes

ROUTES:
M0MZF-1,192,2
GB7WOD,192,2

; Prioritise RDG on 6m
GB7RDG,192,6
GB7RDG,191,2

; Prioritise BDH on 6m
GB7BDH,192,6
GB7BDH,191,2

;GB7BSK,192,2
;MB7NPW,192,6
***

RF Ports

PORT
  PORTNUM=2
  ID=144.9375MHz/Nino-0101/QPSK/3k6
  M0LTEMapInfo=RF,144.9375,QPSK,3600,3600,Mixed
  TYPE=ASYNC
  PROTOCOL=KISS
  KISSOPTIONS=ACKMODE
  COMPORT=/dev/tnc-2m
  SPEED=57600
  TXDELAY=100            ;msec, Seems OK for a relay-switched 857d
  TXTAIL=1               ;msec, Needed to prevent NinoTNC sending 30msec tail
  FRACK=7000             ;msec, Busy channel, 7sec ACK timeout
  PACLEN=236             ;bytes, 236 is max for a NETROM frame
  MAXFRAME=4             ;no., Default frames before ACK
  RESPTIME=600           ;msec, Delay time before L2 ACK (256*8)/3600=568
  SLOTTIME=100           ;msec, Wait time before checking PERSIST again
  PERSIST=51             ;255/(# hidden stations on link - 1) but we can hear everyone
  DIGIFLAG=0             ;Don't digipeat (=1 all, =255 UI only)
  QUALITY=10             ;Nodes heard on this port get this quality
  MINQUAL=50             ;Therefore do not broadcast nodes heard on this port
  NODESPACLEN=160        ;Keep NODES broadcast shorter to help decode
  QUALADJUST=100         ; % by which to reduce quality if the best neighbor is on the same port, needs tuning
  NONORMALIZE=1          ;Disable node quality normalisation algorithm
  IGNOREUNLOCKEDROUTES=1 ;Locked routes only
ENDPORT

PORT
  PORTNUM=6
  ID=50.650MHz/Nino-1011/BPSK/2k4
  M0LTEMapInfo=RF,50.650,QPSK,2400,2400,Backbone
  TYPE=ASYNC
  PROTOCOL=KISS
  KISSOPTIONS=ACKMODE
  COMPORT=/dev/tnc-6m
  SPEED=57600
  TXDELAY=180            ;msec, DR-M06 takes ~150msec to key up
  TXTAIL=1               ;msec, Needed to prevent NinoTNC sending 30msec tail
  FRACK=4000             ;msec, Needs tuning
  PACLEN=160             ;bytes, 236 is max for a NETROM frame
  MAXFRAME=4             ;Default no. frames before ACK
  RESPTIME=900           ;msec, Delay time before L2 ACK (256*8)/2400=853
  SLOTTIME=100           ;msec, Wait time before checking PERSIST again
  PERSIST=255            ;255/(# hidden stations on link - 1) - but we can hear everyone
  DIGIFLAG=0             ;Don't digipeat (=1 all, =255 UI only)
  QUALITY=10             ;Nodes heard on this port get this quality
  MINQUAL=50             ;Therefore do not broadcast nodes heard on this port
  NODESPACLEN=160        ;Keep NODES broadcast shorter to help decode
  QUALADJUST=100         ; % by which to reduce quality if the best neighbor is on the same port, needs tuning
  NONORMALIZE=1          ;Disable node quality normalisation algorithm
  IGNOREUNLOCKEDROUTES=1 ;Locked routes only
ENDPORT

Other FAC'd equipment on site

MB7UUW APRS Digipeater, 144.800 MHz
GB7CW DMR Repeater, South West Cluster, DVU48 439.600 MHz -9MHz, CC5, Slot 1 TG 9 Local, Slot 2 TG 950 Cluster

UK Packet Network Wiki

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