(this page)

REPEATER WORK (1975 - 1999)


A record of trips to/work at various repeater sites by PEARS members or helpers (reverse time order)


14 December 2009

Lady's Slipper


? (Can't remember what I did!)

19 November 2009



General RF Checks

Cradock UHF Link:
PIC Board & New DTMF card
TX Frequency 1kHz low, set to 0
TX dev 110mV OK
TX Power 2W - OK
VSWR 1.3:1 - OK
RX Dev 1.1V - OK
RX Frequency -72mV, cannot nett, no cap to remove.  Gives frequency 4kHz low - REPLACE CRYSTAL
RX sensitivity 1uV tight - OK

Mt Kempt UHF Link:
New DTMF card
TX VSWR 1.2:1 - OK
TX Power 1.5W - OK
RX Frequency -300Hz - OK
TX dev 113mV - OK
RX Dev 1.18V (bad pot) set to 1.14V - OK
RX Frequency -13mV, netted OK
RX sensitivity 1uV tight - OK

Slipper UHF Link:
Old DTMF card
TX VSWR 1.3:1 - OK
TX Power 2W - OK
TX frequency -1kHz, set to 0
TX dev only 3kHz, set to 3.5kHz - OK
RX dev 1.17V - OK
RX Frequency -2mV - OK
RX sensitivity 1uV tight - OK

VHF Repeater:
TX Frequency -300Hz, set to 0
TX Dev 115mV, set to 110mV
TX Power was 1W!, set to 12W (suspect pot) - OK
VSWR 2:1 into co-linear - BAD
RX dev 1.28V, set to 1.15V - OK
RX Frequency +17mV (1kHz low) set to 0 - OK
RX Sensitivity 0.6uV through duplexer & xtal filter - OK
First TX filter 11W out
Duplexer TX 4W out into antenna

VHF Packet:
TX Frequency -200Hz, set to 0
TX Power 10W - OK, 4W after filter
TX dev 103mV - OK
RX dev 1.16V - OK
RX frequency -10mV, set to 0
RX sensitivity (thru filters) 1uV with pot half way

UHF Packet:
TX Power 2W - OK
TX Frequency -1kHz - set to 0
TX Dev 97mV, set to 110mV - OK
TX VSWR 1.1:1 - OK
RX Dev 1.115V - OK
RX Frequency 6mV - OK
RX Sensitivity  0.7uV tight - OK

Battery electrolyte levels - half way - OK

18 November 2009

Mount Shepstone


Complete site installation (in the rain)

UHF Link
Storno UHF Link (ex Bedford) + antenna towards Cradock

VHF Repeater (new)
Storno VHF repeater (ex Slipper) + antennas x2
VHF TX Cavity filter

VHF repeater comms provided for Queenstown for the first time

17 November 2009

Mount Rd


Remove old site equipment at tank room:
Storno VHF Repeater
Storno UHF Link
Internal Mains PSU
1x TX Cavity filter
internal RX Crystal filter
UHF Link 3el Yagi
VHF TX Folded Dipole

5 July 2009 Longmore ZS2AAW, ZS2GV Digi installation
3 July 2009 Uitenhage ZS2AAW Wifi & Digi installation
2 July 2009 Lady's Slipper ZS2AAW Mains failure investigation
26 June 2009 Lady's Slipper ZS2AAW ?
15 April 2009 Longmore ZS2AAW, ZS2GV ?
7 April 2009 Lady's Slipper ZS2AAW Replace repeater after repairs
6 April 2009 Lady's Slipper ZS2AAW Repeater fuse failure (TX off air)
1 March 2009 Lady's Slipper ZS2AAW ?
21 February 2009 Lady's Slipper ZS2AAW Site re-installation
20 February 2009 Lady's Slipper ZS2AAW Site re-installation
19 February 2009 Lady's Slipper ZS2AAW Site re-installation


10 December 2008



VHF Repeater:
TX PA has burnt final transistor
Replaced PA board with spare
TX power 20W - OK
TX Frequency set to 0
TX audio levels OK @ 110mV for 3.5kHz dev
RX Offset set to 0
RX audio levels checked OK
Eskom control card fitted
TX seems a little prone to be spurious

UHF Link:
RX Frequency - adjusted to 0
RX Audio levels OK
RX Squelch 0.5uV
TX Power 2W
TX Frequency spurious - no centre frequency!
LINK REMOVED for repair

13 December:
Link repairs done in CT
Spare unit ex Buffelsnek F54064
Re-connected oven wires on SU602's
All adjustments done, used TX osc ex original unit to get on frequency
Swapped control cards - DTMF unit needed
Reset tone reply time & beep osc to default
Install IC socket to disable auto-disconnect (by removing CD4040 chip)

10 December 2008 Buffelsnek ZS2AAW Site maintenance
DC Supply u/s - Eskom batteries open cct?
Add another temporary bank in parallel, after permission from Bart Saayman

434.825MHz UHF Link:
TX -1.5kHz, set to 0
VSWR 3:1 - BAD
RX discr -8mV, set to 0
Audio levels all OK

438.775MHZ UHF Link:
TX -0.5kHz, set to 0
VSWR OK 1.4:1
RX discr 18mV, set to 0
Audio levels all OK

26 October 2008 Tygerhoek (Eskom) ZS2AAW, ZS2AE Move VHF repeater to Eskom site on a temporary test basis

TX power = 5W
TX Ant VSWR = 1.3:1
RX Threshold = 0.3uV
RX Ant VSWR = 1.1:1
Desense = 11dB's - BAD!

Later coverage tests are very disappointing, especially towards PE

2 October 2008 Mount Rd ZS2AAW 145.650 Repeater
VHF Repeater levels checked - "REPT MOD" not set correctly.  
Add 100k resistor in parallel with R809B to get sufficient gain for repeater thru mod setting (because RX level is now -10dBm, not 0dBm as designed)
September 2008 Mount Rd ZS2AAW Commission new site at Barracks building

Kyodo VHF Repeater:
Model KG110-15B50KBR, Serial number 502212
TX Power 25W
TX Deviation: 3.5kHz @ -10dBm 600 Ohms
RX Sensitivity 0.25uV; 0.5uV tight
RX Level: -10dBm for 3.5kHz deviation input

Tait T800 UHF Link:
TX power = 2W
Audio levels: -10dBm in & out for 3.5kHz deviation

VHF Repeater RX opened by Wifi interference - squelch tightened

VHF Duplexer fitted, single antenna - Colinear - VSWR - 1.2:1

Tait UHF Link modified to mute RX when TX'ing:
Bridge RX Disable A to Audio-2 in RX Module
Change jumper to select RX Disable
Bridge TX pin 5 to RX pin 7 on rack connectors

TX Still has Timeout Timer - to be disabled

UHF Link antenna Open cct - VSWR 2.5:1 - BAD

UHF Digi antenna OK, VSWR 1.2:1 - move link onto this antenna for the meanwhile

IRLP Computer fitted, but later removed for more config checks

22 July 2008 Noupoort ZS2AAW Brief Line-up checks

Cradock UHF Link:
TX Power 0.3W, set to 1W (max was 2W)
TX Frequency set to 0kHz
TX SWR good at 1.3:1
RX Frequency (discr) 0.007V, set to 0

Colesberg UHF Link:
TX Power 1W
TX Frequency ~2kHz off, set to 0
TX VSWR <1.2:1 - OK
RX Frequency 27mV, set to 0

Battery Bank both green
Volts held at 26V with Mains off - OK
Charge current 5A with mains back on - OK
Reduced to ~1A soon - OK

6001 was off - connected it again
8904, 8909, 6001, 6002 all respond

16 July 2008 Governorskop ZS2AAW Cradock UHF Link:
TX Frequency -2kHz, set to 0
TX Deviation 110mV for 3.5kHz - OK
TX Power = 3W - OK
VSWR = 1.2:1 - OK
RX dev 110mV for 3.5kHz - OK
RX Frequency -84mV (~4kHz low) Cannot adj to better than -45mV (2kHz low).  Cannot correct - no cap to remove - need to replace 438R750 Crystal

Mt Kempt UHF Link:
RX Dead
TX VSWR 1.3:1 - OK
Link removed for repairs

Lady's Slipper UHF Link:
TX Frequency -1.5kHz, set to 0
TX Power = 3W - OK
TX deviation 93mV for 3.5kHz - set to 110mV
VSWR 1.4:1 - OK
RX Frequency good at -7mV, set to 0
RX deviation low at 97mV, set to 110mV
(Slipper link RX discr at +16mV - OK)

Packet UHF Backbone Link:
TX -1.2kHz, set to 0
TX Power = 2W - OK
TX deviation 117mV for 3.5kHz, st to 110mV - OK
RX Frequency -27mV (~1.4kHz low) set to 0 - OK
RX deviation 110mV for 3.5kHz - OK
(Slipper link RX discr at +81mV - TX Freq needs to be checked at Slipper)

VHF Repeater:
TX power 8W, dropped away to 1W - bad power pot?
TX Frequency 0kHz off
TX deviation low, adjusted to 3.5kHz for 110mV
VSWR 2:1 - BAD
RX Level 115mV for 3.5kHz - OK
RX Frequency discr = -6mV - set to 0 - OK
Squelch set to 2 o'Clock gives 0.3uV thru crystal filter - OK

VHF Packet:
TX Power 11W - OK
TX Frequency -500Hz, set to 0
TX Deviation 108mV for 3.5kHz - OK
RX Frequency -2mV, set to 0 - OK
RX defviation 108mV for 3.5kHz, set to 110mV - OK
Antenna VSWR 1.5:1 - OK

Realigned all filters and duplexer

8 July 2008 Uitenhage ZS2AAW UHF Link
TX Link to 431.050 was 13kHz high
Could not nett onto frequency
Changed osc oven, XO663 module, then stopped working altogether!
Gave the crystal a flick and it came back to life - only 3kHz low!
Removed 10pF cap
netted onto frequency OK
Link TX Crystal thus FAULTY
14 June 2008 Buffelsnek ZS2AAW UHF Duplex Link:
TX Frequency 8kHz high - set to 0
TX Power 5W - OK
TX deviation 3.5kHz for 110mV - OK
RX frequency -30mV (1.5kHz low) set to 0
Squelch set to 0.5uV
RX deviation OK at 110mV

Swartberg UHF Link:
TX Frequency 6kHz high, set to 0
TX Power 3W - OK
TX deviation 3.5kHz for 110mV - OK
RX Freqeuncy 1.6kHz low - set to 0
Squelch 0.45uV tight - OK
RX Deviation 110mV for 3.5kHz - OK

VHF Repeater:
Installed old Buffelsnek repeater serial no F51239
TX Power direct = 11W
TX deviation high, set to 3.5kHz for 110mV
RX Frequency 2mV, set to 0
RX deviation high, set to 110mV for 3.5kHz
Squelch set tight
RX & TX antenna VSWR's OK <1.3:1
All filters aligned - 2x Aluminium, 1x TX Pass cavity
VHF TX power 6W into antenna

22 March 2008 Brenton ZS2AAW George UHF Link:
Repairs done:
Tantalum capacitor in exciter smoked
TX Switching transistor in PSU smoked as a result
TX VSWR 1.5:1

Buffelsnek UHF Link:
TX Frequency 3kHz low, set to 0
RX Frequency OK
RX Squelch 0.5uV
AF Levels OK

VHF Repeater:
TX Power 1W direct, 0.5W thru filter
TX Ant VSWR 1.3:1 - OK
TX Frequency OK
RX Ant VSWR 1.1:1 - OK
RX Squelch set to 1uV direct, 3uV through filters
RX Frequency OK

28 Fenruary 2008 Kareedouw ZS2AAW Installed temporary metro Ambulance repeater at Eskom site:
TX 154.150MHz
RX 147.100MHz

VHF Repeater:
Antenna VSWR was 3:1 - found water in ext connector to antenna
Remade heliax connector off and dried connections.
Re-used old antenna
VSWR now 1.4:1
TX power adjusted back to 15W direct (was 3W)
TX Frequency -180Hz - OK
TX Deviation OK
RX Sensitivity 0.2uV direct, 0.8uV thru filters (set tight) - OK
RX Frequency discr 1mV - OK
RX deviation OK
DTMF card no decode (old type) - FAULTY

Lady's Slipper UHF Link:
TX 3kHz low - set to 0
TX Power = 1W - OK
TX deviation OK
RX Frequency -26mV (-1.5kHz), set to 0
RX deviation OK
RX Squelch 0.6uV tight - OK
VSWR 1.3:1 - OK
set reply tones to 800Hz

Plett Link:
TX Frequency 200Hz high - set to 0
TX Power 2W, set to 1W
TX dev OK
VSWR 1.6:1 - not good
Set reply tones to 800Hz
RX Defv OK
RX Frequency -11mV, set to 0
RX Squelch 0.5uV tight - OK

17 January 2008 Uitenhage ZS2AAW, ZR2JH, Gordon Harris Investigate pole on new site for Wifi installation (manufacture brackets etc)


16 October 2007 Mount Rd Wifi ZS2AAW ?
18 June 2007 Uitenhage ZS2AAW UHF Link:
TX on 431.050 was 10kHz low
removed cap and retuned to frequency
Checked 431.100 - 1.5kHz low, adjusted to 0
Checked RX - both < 10mV, so adjusted OK
TX Power 1W - OK

No checks done on the repeater

17 April 2007 Cradock ZS2AAW Check link co-linear VSWR OK @ 1.2:1
Check 8 el yagi - VSWR OK @ 1.5:1
Link looks OK and works to 6001 & 6002, 8904, 8909, all OK
Other link specs are spot-on
Re-connect to co-linear and leave as it should be

No antenna: 7/8 heliax front LHS (closest to ladder)
TX Antenna: 1/2" heliax old type
8el Yagi: 7/87 heliax, front RHS

Changed antenna - VSWR still bad.  Leave for another day...

3 April 2007 Lady's Slipper ZS2AAW BBS Remove?
20 March 2007 Workshop ZS2AAW 650 UHF Repeater:
Serial no:  F51649
General checks
TX Power 10W
TX Frequency OK
TX Dev OK< set to 3.5kHz for 110mV
RX Squelch 0.5uV thru duplexer
RX Dev was low @ 550mV for 3.5kHz, set to 1.1V
Frequency error ~20mV, set to 0
RX Dev was high the next day - 1.3V, set back to 1.1V

Power Supply OK - regulating fine

16 February 2007 Kareedouw ZS2AAW UHF Link:
Test from the road en route to Plett repeater revealed the Plett link RX is u/s
So we stopped in at Kareedouw rather than go to Plett

Found the RX osc supply missing
PSU green LED also not lit
Switching transistor in the PSU is open cct
Replaced BC107 with same from spare rev 0 PSU
Then found that the RX Osc delay card had been shorted to earth and blew the BC107
Taped it up
Checked all tones - responded OK

VHF Repeater:
Set TX power down to 2W into VHF TX antenna because of 3:1 VSWR.  
Could not change antenna due to WX conditions - high winds.

Link to the West is now restored
All codes test OK down to Riversdale

Notice noise on the link signals from George into Brenton, may be a side lobe null at George because the link antenna is still pointing direct to Buffelsnek, and not to Brenton as it now runs

7 February 2007 Lady's Slipper ZS2AAW Checked 9k6 rig - no signals
Found that the 433.800 rig was using the 9k6 antenna!
Reconnected the 9k6 rig to the antenna
All OK again

Check audio & RF specs on UHF Link & Repeater - adjusted OK
Possible low deviation on RX Audio board - control was at max but level was 1.2V, so adjusted back to 1.1V
Replace audio board at a later stage

18 January 2007 Kareedouw ZS2AAW Buffelsnek UHF Link:
7252 no response (old board)
TX Power 1.5W
TX Frequency ~400Hz high, set to 0
TX dev spot-on
VSWR 1.5:1, not great
RX Squelch 0.7uV
RX Frequency 2mV - OK
RX devf 1.150V for 3.5kHz

Slipper UHF Link:
7251 responds OK
TX Power 1W
TX Frequency 1.8kHz low, adjusted to 0
TX Dev spot-on
VSWR 1.2:1 - OK
RX Squelch 0.7uV
RX Frequ -41mV, set to 0
RX dev 1.074V, adjusted to 1.150V - OK

VHF Repeater:
7250 responds OK
TX Power 15W direct, 10W thru filter
TX Frequency 200Hz low, adjusted to 0
TX dev OK
VSWR 3:1 - BAD
RX Squelch 0.15uV direct, 0.5uV thru filters - OK
RX Frequency -4mV, set to 0
RX dev 1.153V for 3.5kHz - OK
VSWR 1.4:1 - OK

7252 on Plett Link not responding (rev 0 card)
Swapped with repeater and swapped RX osc delay too
So now 7252 is a new card
Repeater 7250 does not respond now (so rev 0 card is faulty)
Removed NHRC board from repeater


21November 2006 Cradock ZS2AAW ICASA site inspection

VHF Repeater:
RX thru filters opens at 2.5uV - BAD
RX Frequency discr 10mV, set to 0
RX Dev high 1.27V @ 3.5kHz (left as-is)
TX Antenna VSWR 1.7:1 - BAD
TX Frequency 300Hz low - set to 0
TX Power 5W thru filters, 11W direct
TX Dev low - set to standard

UHF Link:
TX Power 0.3W @ 23.5V
4W @ 24.2V
Frequency 300Hz low - set to 0
TX Dev 3.5kHz OK
RX squelch OK at 0.5uV
RX discr -13mV, set to 0
RX Dev 1.18V for 3.5kHz - OK
VSWR 1.2:1 - OK

VHF Packet:
TX Power thru filter 4W
TX Frequency 0Hz off
TX dev limited @ 3kHz, nominal 2.5kHz
Cannot lift it higher than 3.5kHz limited
Set nominal to 3kHz, max to 3.5kHz
TX Audio board/modulator faulty
RX Frequency 2mV - OK
RX 741 op-amp was faulty - replaced
RX Dev 1.2V for 3.5kHz - OK
RX Squelch 0.5uV thru filters - OK
BUT Audio sounds distorted
Antenna VSWR 1.1:1 - OK

Batteries & floor need a good cleaning & bicarb treatment

Vacuum cleaner a good idea

15 October 2006 Tygerhoek (Eskom) ZS2AAW, ZS2AE Investigate for temporary VHF repeater
9 May 2006 Governorskop ZS2AAW Cradock UHF Link:
TX Frequency ~1kHz high
TX Power 3W
TX Dev 3.5kHz for 105mV
RX 8kHz low - removed 5p6 cap 
RX dev 1.1V for 3.5kHz - OK
RX Sensitivity 0.6uV tight
VSWR 1.2:1

Mt Kempt UHF Link:
RX 5kHz high (no cap fitted) - added 10pF cap
RX Sensitivity 1uV tight
TX 200Hz high - OK
TX power 2W
TX dev 104mV for 3.5kHz - OK
VSWR 1.3:1
[NO RX oscillator delay cct fitted]

Slipper Link:
Old DTMF card fitted
TX 1lHz low
TX Power 3W
TX dev 3.6kHz for 105mV, set to 3.5kHz
RX discr -11mV, set to 0
RX dev 1.1V for 3.5kHz - OK
RX Sensitivity 0.4uV not tight
VSWR 2.4:1 - BAD

VHF Repeater:
RX Frequency 2mV off - OK
RX dev 1.1V for 3.5kHz - OK
RX Sensitivity 0.2uV direct not tight
TX Power 9W direct
TX Frequency ~200Hz low at first, drifts on
TX dev was 115mV for 3.5kHz - set to 105mV
VSWR 2:1 into co-linear - BAD

VHF Packet:
RX 0mv off!
RX sensitivity 0.3uV threshold
RX dev 1.112V for 3.5kHz
TX Frequency 100Hz low
TX power 10W
TX dev 1.5kHz for 110mV, 3kHz max
set to 3.5kHz dev, 5kHz max
Then set TNC to 3kHz dev in calibrate mode
VSWR 1.5:1 direct to antenna - OK (2:1 thru filter)

UHF Packet:
TX Frequency 1.1kHz low - set to 0
TX power 2W
TX dev 3.5kHz for 110mV - OK
RX frequency -77mV off - set to 0
RX Dev 3.5kHz for 1.1V - OK
RX sensitivity 0.5uV - OK
VSWR 1.1:1 - excellent

Packet Digi re-programmed

27 April 2006 Buffelsnek






10 April 2006 Lady's Slipper ZS2AAW Roof


17 December 2005 Buffelsnek ZS2AAW VHF repeater replaced
serial no:  31978

Duplex UHF Link installed on 438.775MHz
serial no:  F61939
But this link exhibits audio problems...

This is to bring in the signals from Brenton, no longer links direct to George

16 December 2005 Brenton ZS2AAW, ZS2AE, ZR2AAS, ZS1PC New Repeater Installation

VHF Repeater serial no:  F54645
UHF Link to George serial no:  F63962
UHF Link to Buffelsnek serial no:  F52149

Complete installation from scratch


30 November 2005 Noupoort ZS2AAW Colesberg UHF Link:
Interference problems
Detune neutrodyne caps completely
Detune front end cap to give 5uV = 12dB SIJNAD
Gets rid of interference signal on 438.675MHz, but Colesberg still comes in OK

Batteries both green - OK
Holds DC volts OK on mains off

29 November 2005 Colesberg ZS2AAW UHF Link:
TX Power 5W
Frequency spot-on
Deviation ~6kHz max, 4.5kHz nominal (not great)
Adjusted R3/R4 (top one) to give nominal = 3.5kHz @ 110mV, max is now 5.5kHz - OK
RX Sensitivity & SINAD good at <0.4uV for 12dB
RX Audio levels fine
RX Frequency OK
Commands to Kramberg OK

Interference tracing:
440.000MHz - polled system, 1 outstation is spurious
interferes at Noupoort on 438.675MHz RX
Seems to be West of Colesberg
458.025 - same noise as Mt Kempt interference

29 November 2005 Kramberg ZS2AAW Changed PIC code to 8914
so 8914 6102 - Ham link
8914 6002 - Eskom (default)
Port #1 used for BUSY line

UHF Link:
TX Power 2W
VSWR 1.3:1
Antenna panned OK
Frequency OK, was ~400Hz low
RX Sensitivity >1uV - BAD
Adjusted front ends to get 12dB SINAD at 0.4uV
RX Frequency OK
Audio levels OK in & out
Respondes fine to DTMF commands via Colesberg

Lady's Slipper ZS2AAW Bush Fire

Site offline due to fires - no AC power
No damage to property
Power lines down for ~7 days
Removed BBS & Node PC for fan maintenance

Set up & got 9k6 radios working properly - was the roll-off on the Storno audio processor board
Removed the board and strapped it out
Also checked ZS2LR's SAATI modem to be OK

Configured additional APRS ports & fitted sound card

  1. 144.625
  2. 434.875
  3. 438.275
  4. 7.040
  5. BBS
  6. 433.800
  7. 144.800
  8. Loopback


16 September 2005 Kareedouw ZS2AE, ZS2AAW ICASA Inspection
Revealed a faulty yagi to Slipper
Antenna mounting re-hashed and improved with double supports
VHF RX and TX antennas added
Extra feedline added, but not through to container - need an additional 40mm pipe
19" rack left on site, ready for repeater/link installation

DC cable 6m
Link #1 M-M  5300mm
Link #2 M-M  4800mm
VHF TX M-BNC  3000mm
VHF RX M-BNC  4000mm

25 August 2005 Buffelsnek ZS2AAW DC System problems investigated
Charger left in boost mode
Batteries cooked dry, all over the floor
Charger boost threshold reduced to same as float to prevent a recurrence
Batteries filled
Pulls 1-2A only
Left to charge, but batteries are shot

~5 days later
Batteries went short cct, pulled volts down to ~16V, so load disconnected
ZS2AZR removed batteries, running on mains only

28 May 2005 Cockscomb ZS2ECH, ZR2RCG, Elly, ZS2AAW, ZS2R, ZS2AE, 2 labourers Hike

Too wet to lower the pole to replace the stay wires
Cleaned alkali deposit inside aluimium box, washed & treated with Tectyl
Replaced TX folded dipoles - water ingress
New TX folded dipole has poor VSWR - 1.9:1 - don't know why
New TX feeder RG213 into cabinet, direct to TX box
Link Yagi fitted, with new RG213 feeder & BMC connector
UHF Signals good
All feeders bandit-strapped to pole
Repeater fitted & running OK
Squelch set to 0.3uV
New gel battery fitted - 26Ah
RX antenna also not good on VSWR ~ 2:1

21 May 2005 Cockscomb ZS2AAW, ZS2AE, ZS2R Helicopter trip

Nico & Marie Dorfling on Kleinplaas, Tel 041 964 1007

Trip aborted quite dramatically due to wind on site whilst landed and offloading
Flight engineer left hanging after sudden take-off...

All tools, equipment unloaded on mountain, but no people
Rudi, ZR2RCG manages to cover and protect equipment
Organise a later hike to re-instate the repeater

10 May 2005 Cockscomb prep at home ZS2AAW RX Squelch line swings 0.765V closed, 6.82V open
RX Audio 1kHz tone @ 3.5kHz dev - HiZ = 0.679VAC, 5k = 0.368VAC
TX Audio (loaded) 11mV AC
Other levels
5kHz dev:  Loaded 500mV, Unloaded 913mV
3kHz dev:  Loaded 320mV, Unloaded 594mV
1kHz dev:  Loaded 117mV, Unloaded 220mV

TX as was
max limiting is @ 3.5kHz dev, up to 50mV
3mV = 3kHz
2mV = 2.2kHz

RX modification #1
re-instate C34 = 220n
Fit 10k preset across 12-13 (output)
take screened lead from wiper
set to 110mV for 3.5kHz dev (storno standard)

RX Sensitivity
Re-tuned osc/multiplier & front end
0.6uV = 12dB SINAD thru xtal filter
0.2uV 12dB SINAD direct to RX!
so 8dB loss thru XTAL filter...!!

TX modification #1
Audio in via 10K, then with 1k to GND and 0u47 coupling cap going to C9, C7 etc
Then set RV2 for 5kHz max
RV1 for 3.5kHz @ 110mV
No good - no pre-emphasis

TX modification #2
Re-instate 470R, remove mic, 10k, 0u47 etc as above
Audio in via 47k to pt 5, with 1k to GND (pt 6) as C1, C2 = 10u etc 
Remove C1 (2u2) and fit 1k in its place
Set gain RV1 to give 3.5kHz dev for 110mV i/p
Pre-emphasis now sounds fine - OK
Minimal loading of RX output now - with TX connected, level drops to 103mV

NEW battery purhcased - 26Ah for R336 at Batteries 4U, 35 5th Avenue, Tel 041 364 1241

13 May 2005 Uitenhage ZS2AAW UHF Link:
Ch1 TX 431.100 ~500Hz off, set OK
Ch2 TX 431.050 ~10kHz high!!   set OK
Ch1 & 2 RX both OK
Audio levels in & out both set OK

VHF Repeater:
TX 10W direct, 4W thru filter
Frequency OK
Audio levels OK
VSWR 3:1 into filter, 1:1 into antenna
Adjust cavity for best reject
VSWR 1.6:1 - OK
TX Power now 8W out of filter
RX antenna also 1:1 direct, 1.5:1 thru filter
Adjust RX cavity for best reject
RX Frequency OK
RX Audio levels 980mV for 3.5kHz, set to 1.1V
RX Squelch opens @0.3uV thru filter - good

Power Supply 27.8V - OK

12 April 2005 Mount Rd ZS2AAW Repetaer is off the air
Found the PSU unplugged
Checked all specs and adjusted where necessary
PSU is faulty - 39V output!  
Hum on TX

Removed for repairs

Returned to site and fitted internal mains PSU ex Riversdale
Hum cleared


? Governorskop ZS2AAW UHF Link antenna to Cradock bad
Removed and used 9600 Packet antenna

UHF Link antenna to Slipper has VSWR 2:1

UHF Link antenna to Mt Kempt OK

Cradock RX low

TX - changed osc oven (no trim range)

Adjusted to 2W TX

Must bring:
Drilled covers
UHF Yagi & bracket for Cradock
UHF Yagi & bracket for PE

? Cradock ZS2AAW UHF Link Omni antenna/feeder repairs:
Antenna changed - no difference
Feeder - still a problem
transferred to old 1/2" feeder - still no good
Tailpiece faulty - ZS2BW changed it later and fixed the problem
30 November 2004 Kramberg ZS2AAW Install UHF Link 431.075/438.675MHz to Colesberg into Eskom container as SATEPSA backup facility
DTMF code 7504
8904 6102 - Eskom Backup
8904 6002 - Normal Ham link

Take a look at Nico ZS4N's ham repeater next door
Motrola repeater RX gated audio found at J2-6 on main board, which also goes to the SG card bottom pin, and J4
Using the discriminator audio loads the squelch detector and opens the RX (previous problem noted by ZS2N)

23 October 2004 Swartberg ZS2AAW, ZS2AE, ZS1PC Complete installation

145.625MHz VHF Repeater supplied
Storno CQF614 25W
Serial no:  C40298
DTMF card 6254 * / #

431.150MHz UHF Link supplied
Storno CQF662 12W
Serial no:  C41894
With standard Eskom control card

1 September 2004 Colesberg ZS2AAW UHF Link:
TX Power 5W - OK
TX Frequenbcy +300Hz, left as-is
Deviation max  5.5kHz, nominal 3.5kHz - OK
RX Level 1.18mV - OK
Can't check point (a) as it is 0/-4dBm levels (reads ~480mV)
RX squelch set to 0.5uV
VSWR OK at 1.4:1
31 August 2004 Noupoort ZS2AAW Batteries bone dry
Filled them, but taking no charge
2x Willard truck batteries
Remove solar regulator & Transformer/bulb story
Fit "STORNO" charger
Re-wire DC blocks & breakers
Remove Renosterberg Link

Cradock Link:
RX sensitivity 0.5uV with tight squelch
RX Frequewncy -17mV, set to zero
RX audio level spot-on 110mV out on (a)
TX Frequency 3kHz high, set to zero
TX Power 0.6W, set to 1W
TX Deviation max 5.5kHz, set to 5kHz
TX Deviation nominal 3.3kHz, set to 3.5kHz
Reply tone frequency set to 800Hz
VSWR Cradock good at <1.2:1

Colesberg Link:
TX Frequency spot-on
TX Power 1W
TX deviation max 5kHz, nominal 3.7kHz, set to 3.5kHz
RX Frequency +17mV, set to zero
RX Deviation 70% 439mV - PROBLEM
RX Sensitivity 1uV squelch flat out
Changed the RX audio board SQ601, problem cured
RX Audio levels set to 1.1V, or 110mV out on (a)
Reply tone frequency set to 800Hz

Tests to 8909 and 8904 all OK

Repairs done to Cradock link as removed below
Audio board replaced from Renosterberg link
Now max deviation is 5kHz, nominal is 3.5kHz
Link can be returned to site (delivered 1/9/2004 to ZS2BW for re-installation)

31 August 2004 Cradock ZS2AAW UHF Link deviation max at 2kHz - AA601 faulty?
Removed link for repair
RX is spot-on
UHF Link antennas both faulty - low signals from Noupoort and Governorskop
Need to check 7/8" heliax for water (joint in ice tray outside)
Other 7/8" coax is know to be wet (joint closer to gland plate)
See if we can resurrect the unused 1/2" heliax that was wet before

Set IDMSG: idmsg via ZS0GHT-5;ZS0NTP-7,WIDE,WIDE


22 November 2002 Various ZS2AAW, ZS2AE, ZR2EY, ZS1SG Maintenance run - Southern Cape


Travel in convoy with Dave ZS1SG
Dave did maintenance on the Motorola linking equipment


ZS1SG changed out rack mounted Storno's with spares prepared by him


Change AC Power Supply

UHF Link antenna to Jonaskop - OK
UHF Link antenna to Geroge 1.3:1 - OK
VHF Repeater >2:1 - BAD
VHF TX power 9W
AF Levels adjusted

18 November 2002 Stilbaai ZS2AAW, ZS2AE, ZR2EY Maintenance run - Southern Cape

UHF Link:
Audio levels set (were out)
Frequencies good (set to zero)
TX o/p 3W tuined, set to 2W
VSWR OK at 1.1:1
Rev 0 PSU
3-way control card
serial number:  F57191

VHF Repeater:
TX o/p 15W, 11W out of duplexer
RX Frequency off - 3kHz low, set to zero
SIAND 12dB @ 0.4uV - aligned to 0.3uV
Squelkch set to 0.5uV, 0.55uV thru duplexer
VSWR good
Audio levels high - set to standard
Old Storno PSU
3-way control card

17 November 2002 Various ZS2AAW, ZS2AE, ZR2EY Maintenance run - Southern Cape


VHF Repeater:
Adjust squelch
IF Trimmed and balanced
SINAD tuned down to < 0.3uV for 12dB
RX Frequency OK
Audio levels lined up
Squelch set to 0.5uV thru filters
Antennae OK
TX Power 11W (small PA)

George UHF Link:
TX o/p 5W
Frequencies OK & set
SINAD checked OK
Audio levels set
VSWR good

Kareedouw Link:
TX o/p 1W
Frequencies OK, but set
SINAD OK at 0.4uV after alignment
Audio levels set
VSWR 1.5:1 (not great)

Charger cabled direct to DB and labelled
All equipment labelled etc



UHF serial no:  F57223
VHF serial no:  F56485

UHF Link:
TX way off requency - removed cap and adjusted back
TX o/p 5W
Audio Levels set
RX Off frequency - adjusted
SINAD OK at 0.4uV
Squelch set to 0.7uV
Old style PSU
20W PA stage
Burnt tantalum C27 4u7 35V
VSWR good at 1.1:1

VHF Repeater:
TX o/p 7W
Frequency OK
Audio levels set
VSWR 1.2:1
3 pole cavity filter
25W PA stage
Old style PSU
RX audio levels set
SINAD poor 12dB @ > 0.7uV, never better than 14dB!! (audio cct problems?)
IF not aligning properly
RX Ant VSWR good 1:1


VHF Repeater:
TX 15W
TX Frequency 2kHz low - adjusted
RX Frequency set
12dB SINAD for 0.3uV
Squelch set to 0.3uV
Audio levels set (were slightly low)

Stilbaai UHF Link:
RX Audio board faulty - replaced (RX level was max 400mV!)
SINAD OK at 0.45uV
Squelch set to 0.7uV
AF levels set
TX power 2-3W
TX Levels set OK

George UHF Link:
Replaced TX Audio board
Re-aligned Modulator (didn't help)
TX o/p 3W
TX Frequency OK
RX audio levels set OK

? Various ZS2AAW, June Poval Done on trip to Bloemfontein

Replace waterlogged UHF Link co-linear antenna
VSWR fine after that
Dried ouf all connectors
Signals tested OK to Queenstown and Grahamstown

Checked all parameters
Set up the audio through levels on the UHF Link
VSWR good
TX Output at 5W
Check RX frequency netting with 10.7 osc, adjusted on

No access - gate lock removed

13 June 2002 Cradock ZS2AAW ICASA Inspection:

VSWR's all OK

Changed UHF Link osc x2
TX was 6.5kHz low

Packet filter:
Tuned packet pass filter 3.5W TX output (was 2W)
Replaced squelch op-amp to correct RX LED
RX Frequency 1.6kHz high - netted OK
RX Squelch OK at 0.5uV

VHF Repeater filters
Sensitivity thru the filters was 5uV!
Re-aligned dB products filter, RX front end and 2x aluminium filters
RX sensitivity is now 1uV
RX Frequency spot-on
TX Frequency spot-on
TX Power is 8W after fitler
Re-align rejects on TX filter too

Tails required:
BNC to PL259 300mm - filter to tube
PL259 to N-type Male  700mm - tube to repeater


14 December 2001 Cradock ZS2AAW Maintenance Run

UHF Link:
TX frequency 5kHz low
TX Power OK @ 5W
Antenna VSWR BAD at 3:1
Water in 7/8 connector outside

Battery levels OK
VHF Repeater filters lined up
Packet filters lined up
TX power 3W out of filter
VHF Antennas all OK < 1.5:1

12 December 2001 Various ZS2AAW Maintenance Run

Coax clamps fitted
Check link specs & adjust
Ant VSWR 1.2:1
TX Power 2W
no RX frequency check (no 10.7 osc)

Dismantle meterbox & remove to Noupoort
Move link to cabinet inside Eskom AUX room
Re-route heliax & make up RG214 tail piece
Fit coax clamps on tower
12V DC trip switch fitted - power is from Exicom link
Re-jumper to IDF
VSWR 2.2:1 - BAD
TX Power set to 5W (was 3W)
No RX frequency check (no 10.7 osc)

PSU Burnt out
Solar regulator faulty
Colesberg link TX faulty (no output)
Re-fit Cradock link
Check Renosterberg link & nett frequencies
AC Cable required - 35m @ 1.5mm2

12 May 2001 Lady's Slipper ZS2AAW Sectional pole hold-down bolts
flats are 38mm
Stud dia 25.4 (1")
10 turns pitch = 32mm

Antenna checks:
UHF Packet backbone yagi 1.7:1
UHF Link colinear 2.5:1 - BAD
VHF RX colinear 1.2:1
VHF TX folded dipole 1.2:1

VHF Repetaer is now 4W after filter
144.625 re-notched
145.700 re-notched
Pass cavity retuned for min VSWR
Pass filters also retuned for min VSWR

2x stay pegs & concrete mix
Nuts, wood screws, perspex, door hook


13 July 2000 Colesberg ZS2AAW TX o/p 3W
Set frequency on (was -300Hz)
RX Netted
Squelch set to 0.5uV (was ~0.7)

DC PSU ex Spence fitted (solar site outside, panels stolen)
Charges at 4A










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REPEATER WORK (1975 - 1999)