KD4BBM-6
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This page is about my high APRS Digi, KD4BBM-6.  [Updated 1/16/2006]

First, about the site.  It's 1400' up the WTVJ, NBC Channel 6 Tower in South Dade.   It shares a rather small cabinet with the SFFMA 147.00 MHz and the WT4X 442.350 MHz Repeaters.   As you can see here, the radio is a GE Phoenix and the TNC is a KPC-3+ with version 8.2 firmware.  This radio holds up well in a high RF area.    The TNC is THE choice today for Wide Digi's.   It's ability to cut down on needless duplication of packets has cut way down on useless traffic.

The entire tower is fed by a UPS and generator, so there are no provisions for back up power within the rack.   The antenna is a very heavy duty quarterwave on the NW leg at about 1400'.   This puts it at about 60' above the cabinet on 1/2" Heliax.  Also in line is a 2m BandPass filter.  I plan to upgrade this to a better one at some point.  Nothing indicates that it's needed, but since there's a full power FM broadcast antenna on the opposite leg, I figure any out of band suppression will help.   The output power was set to 35 watts.

The range so far has been impressive.  I've seen connections to Jacksonville up for hours.   I've been told it's been heard in Texas.

My thanks to George, WT4X and WTVJ.

Here are some pics from our recent trip up the Channel 6 tower in Homestead.    

The digi. Here's the radio and TNC in the cabinet.   Yes, there is corrosion.   While the cabinet is waterproof, the ocean air at 1400' does have a big effect on anything electronic.   It's the black radio (GE Phoenix) and black TNC (KPC-3+).  The rest is the SFFMA 147.000 Mastr 2 Repeater.  Here's how they're connected.

 

The APRS antenna is at about 1500'.  It's the unity gain heavy duty ground plane antenna above the two UHF yagi's

This is George, WT4X, at the front of the rack where the Digi, the 442.350 and 147.00 are located. Wt4x01.jpg (37607 bytes)  

George on the left at the front, me on the right changing antenna connections.Wt4x02.jpg (48891 bytes)  

Here are the settings I use on my Wide area Digi on the channel 6 tower:

Updated as of 1/14/2006.   Details of the tower trip available here at the SFFMA site.

8BITCONV ON
ABAUD 2400
AUTOLF ON
AX25L2V2 ON
AXDELAY 0
AXHANG 0
BEACON EVERY 10 min
BKONDEL ON
BLT
1 EVERY 02:01:00
2 EVERY 01:00:10
3 EVERY 02:00:00 STARTING AT 00:01:00
4 EVERY 02:00:00 STARTING AT 00:31:00
BREAK OFF
BTEXT !2532.42NT08028.10W#PHG5760/W-R-T-FL ray@kd4bbm.com
BUDLIST OFF NONE
Link state is: DISCONNECTED
CANLINE $18 (CTRL-X)
CANPAC $19 (CTRL-Y)
CD SOFTWARE
CHECK 0 (disabled)
CMDTIME 1 (1 sec)
CMSG DISC
COMMAND $03 (CTRL-C)
CONLIST OFF NONE
CONMODE CONVERS
CONOK ON
CONPERM OFF
CPACTIME OFF
CR ON
CRSUP OFF
CSTAMP OFF
CTEXT APRS Digipeater UI frames only. Disconnecting
CTRL A OFF B OFF
CWID EVERY 0 (disabled)
CWIDTEXT DE KD4BBM
DAYTIME 05/28/04 16:55:56
DAYTWEAK 8
DAYSTR mm/dd/yy hh:mm:ss
DAMA OFF
DAMACHCK 18 (180 sec)
DBLDISC OFF
DELETE $08 (CTRL-H)
DIGIPEAT ON
DWAIT 0
ECHO ON
ESCAPE OFF
FLOW ON
FILTER OFF
FRACK 4 (4 sec)
FULLDUP OFF
GPSHEAD
1 $GPGGA
2
3
4
GPSINIT
HBAUD 1200
HEADERLN OFF
HID OFF
HTEXT
INTFACE TERMINAL
KNTIMER 15 min
LEDS ON
LCOK ON
LFADD OFF
LFSUP OFF
LLIST OFF NONE
LT
1 !2532.42NT08028.10W#PHG5760/W-R-T-FL CH 6 TWR ray@kd4bbm.com
2 !2532.42NT08028.10W#PHG5760/W-R-T-FL ray@kd4bbm.com
3 !2532.42NT08028.10W#PHG5760/W-R-T-FL SouthDade FL
4 !2532.42NT08028.10W#PHG5760/W-R-T-FL Ch 6 Tower FL
LTP
1 APRS VIA WIDE,WIDE,GATE,GATE,WIDE
2 APRS VIA TRACE,TRACE,TRACE,TRACE
3 APRS VIA TRACE4-4
4 APRS VIA WIDE3-3
LTRACK 0
MONITOR ON
MALL ON
MAXFRAME 4
MAXUSERS 1
MBEACON ON
MCON OFF
MCOM ON
MHEADER ON
MRESP ON
MRPT ON
MSTAMP OFF
MXMIT ON
MYCALL KD4BBM-6
MYALIAS WIDE
MYDROP 0
MYNODE KD4BBM-7
MYPBBS KD4BBM-1
MYREMOTE 4BBM
NDWILD OFF
NEWMODE ON
NOMODE OFF
NTEXT
NUMNODES 0
PACLEN 128
PACTIME AFTER 10 (1000 msec)
PASS $16 (CTRL-V)
PASSALL OFF
PBBS 100
PBFORWRD NONE EVERY 0 (disabled)
PBHEADER ON
PBHOLD ON
PBKILLFW OFF
PBLIST OFF NONE
PBLO NEW VARIABLE
PBPERSON OFF
PBREVERS ON
PERSIST 63 (25%)
PID OFF
PMODE CMD
PTEXT
REDISPLA $12 (CTRL-R)
RELINK OFF
RETRY 10
RING ON
RNRTIME 0 (disabled)
RTEXT [deleted for security]
SCREENL 0
SENDPAC $0D (CTRL-M)
SLOTTIME 10 (100 msec)
START $11 (CTRL-Q)
STOP $13 (CTRL-S)
STREAMSW $7C (|)
STREAMCA OFF
STREAMEV OFF
SUPLIST OFF NONE
SWP 17,17,108
TELEMTRY 0 (disabled)
TRACE OFF
TRFLOW OFF
TRIES 10
TXDELAY 30 (300 msec)
TXFLOW OFF
UNPROTO APRS VIA WIDE,WIDE,TRACE
UIDIGI ON RELAY,WIDE,TRACE,FL
UIDWAIT OFF
UIFLOOD WIDE,30,ID
UITRACE TRACE,30
USERS 1
XFLOW ON
XKCHKSUM OFF
XKPOLLED OFF
XMITLVL 268
XMITOK ON
XOFF $13 (CTRL-S)
XON $11 (CTRL-Q)

Old settings (before 1/13/2006)

INTFACE TERMINAL
CD SOFTWARE
BEACON EVERY 10
BLT 1 EVERY 02:01:00
BLT 2 EVERY 01:00:10
BLT 3 EVERY 02:00:00 START 00:01:00
BLT 4 EVERY 02:00:00 START 00:31:00
BT !2532.42NT08028.10W#PHG5760/W-R-T-FL rvaughan@gate.net
CMSG DISC
CTEXT APRS Digipeater UI frames only. Disconnecting
HEADERLN OFF
HID OFF
LT 1 !2532.42NT08028.10W#PHG5760/W-R-T-FL CH 6 TWR rvaughan@gate.net
LT 2 !2532.42NT08028.10W#PHG5760/W-R-T-FL rvaughan@gate.net
LT 3 !2532.42NT08028.10W#PHG5760/W-R-T-FL SouthDade FL
LT 4 !2532.42NT08028.10W#PHG5760/W-R-T-FL Ch 6 Tower FL
LTP 1 APRS VIA WIDE,WIDE,GATE,GATE,WIDE
LTP 2 APRS VIA TRACE,TRACE,TRACE,TRACE
LTP 3 APRS VIA TRACE4-4
LTP 4 APRS VIA WIDE3-3
MAXUSERS 1
MYCALL KD4BBM-6
MYALIAS FL
MYREMOTE 4BBM
RTEXT wouldn't you want to know
UIDIGI ON RELAY,WIDE,TRACE,FL
UIFLOOD WIDE,30,NOID                (I need to change ID to NOID on the digi)
UITRACE TRACE,30
UN APRS via WIDE,WIDE,TRACE
XMITLVL 268
ABAUD 2400

An important correction:

I notice on your page http//www.rayvaughan.com/kd4bbm-6.htm

You show UIFLOOD WIDE,30,ID

Please note that on Bob's APRS page http//web.usna.navy.mil/~bruninga/aprs/fix14439.html he reccomends that you set that to NOID

FIXING THE ID/NOID DIGIPEATERS One thing that is quite broken in the APRS network are the large number of digipeaters that are incorrectly set with the UIFLOOD parameter of "ID" set. This setting forces an unwanted DIGI ID into every packet transmitted by that digi at the expense of obliterating any prior useful PATH data. Thus in areas with "ID" set, no path can arrive at any receiver with its FIRST-digi-used callsign intact. Thus we cannot trace packets to where they entered the network, and users have no flexibility in path choice for their specific applications. Please read why this is so important. To help APRS users find out which digipeaters are improperly set with the UIFLOOD, ID parameter, we searched the net and came up with a list of Apparent ID-Digis

Do you agree with that statement, and if so, will you update your page?

Thanks!

Brian L Short

Kcaprs.org

"Shorty" – KCBS

On Feb. 24, 2007, the digi was removed from the tower.   We found water damage from Hurricane Wilma finally did it in.

Damage inside the KPC-3+.   Hard to see from this angle, but water entered via the unused coaxial power connector.  Damage appears to be limited to the connector only.

 

This is the inside of the GE Phoenix Radio.   Heavy water damage as the water was driven well into the radio through the connector slots.  There may have been some arcing between the first and second pins of the left connector.   When you look at it carefully, you can see a water line where the water stopped.

 

This is the radio connector at the back of the TNC.   The DB-9 connector shows serious corrosion but the connections were still working.   Power is delivered to the TNC using this connector.

When the replacement unit goes back up, I'm expecting to use a Kantronics KPC+ and a Kenwood TM-271a radio.   The modification for the radio is here: 

http://www.washcoares.org/tm-271-packet-mod.html

Last update: 01/14/08 13:11

Except for portions owned by others, Copyright: Ray Vaughan, 2008

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