DATE

SITE

PERSON/S

ACTION

23 December 2010

Lady's Slipper

ZS2AAW

PIC Interface
Pull-up resistors fitted on the PIC interface that controls the Link/Repeater disconnections and HF rig.  This was to correct a construction error where the door alarm, mains fail alarm and HF Rig active line were not pulled up, so caused toggling alarms and had to be remotely disabled.  The PIC does not have internal pull-ups on all IO pins, so they must be added externally.

Tha mains fail alarm is yet to be commissioned - I did not have cable at hand to run to the AC DB outside the container where the mains fail relays reside.  Door alarm works now though.

HF system interface, Repeater/link interface with PIC card, HF Rig, CIV interface:

Repeater/link interface with piggy-back PIC control card

22 December 2010

Elandsrivier WiFi

ZS2AAW, at the QTH of ZR2LLD

New connection
Llise, ZR2LLD was connected to the ZS2R-3 WiFi "repeater" running at Allan's QTH.  SIgnal levels -77dBm, all OK.

21 December 2010

ZS2AAW

ZS2AAW

HF Balun constructed
The Travelling wave HF antenna at Slipper requires a 5:2 voltage ratio (= ~6:1 impedance ratio) balun, which is detailed on the website http://www.paws.dircon.co.uk/draka.htm  ZS2AAW eventually got to construct one using a purpose-bought T200 ferrite core from the SARL swopshop pages.  Thanks to ZS2DL for the tip on the local source!

Balun Completed:

Inside view:

20 December 2010

Uitenhage WiFi/APRS

ZS2AAW, Roland

Antenna bracket
Cherry-picker used to re-align the antenna offset bracket back to original orientation.  The feeders are also taken across to the building at high level, no longer in the grass, to ensure they are not damaged by maintenance staff clearing brush.  Once back in place, the Slipper link is resurrected, with -68 to -72dBm signals again.  WiFi service re-established at about 10h30 for those using the Uitenhage access point.  Thanks for your patience with this long outage.

18 December 2010

Mount Rd

-

Mains Supply Failure
Mains Supply lost in large areas of Port Elizabeth.  Because the WiFi box at Mount Rd is not yet on inverter supply off the standby battery, the central hub went down at 17h50 Saturday evening.

Power and services restored 20h05

17 December 2010

Farmcomm 

ZS2Q, ZS2AAW

Repeater donated
A Storno 9000 complete repeater, with duplexer was crystalled, aligned and deliverd to ZS2Q for use by the Farmcomm neighbourhood watch as a community repeater.  
Serial number F6509 003245
TX Power 15W out of duplexer (max 27W)
RX sensitivity -117dBm
Fitted with CTCSS tone panel - Idylltek RP-176 supplied by HRO
Installed at ZS2Q for soak test, copied and worked from Broadwood with ease

13 December 2010

Uitenhage WiFi/APRS

ZS2GH, Roland

Antenna pole base replaced
Gordon advised that the steel base had to be replaced on site, which was done by Roland the contractor.  This has resulted in the WiFi antennas shifting, so they will need to be re-panned and tightened into postiion again.  An appointment is made for later that week.

9 December 2010

Grahamstown

ZS2AAW

Re-instate ZS0GHT Node/APRS/Digi
The "Storno PC" and 9k6 backbone are re-installed en route back from a saltmine trip to EL.  The 9k6 has never operated as a backbone to Slipper, and it was successfully implemented today.  This only after the Slipper 9k6 end was finally commissioned using Tait T800 equipment recently.  

A shelf was mounted for the TNC's and keyboard, and the previous 1200bd UHF Backbone rig removed.  At some future date a 434.800 APRS rig will be fitted in its place.  The 144.800 VHF port was commissioned, and the filters aligned accordingly.  The packet rig has a notch on 145.150MHz to prevent desensing the VHF repeater receiver, and the VHF repeater TX has a notch on 144.800 to prevent desense of the packet RX.  The only missing filtering is a notch on the packet rig on 145.750, to also prevent desense of the packet from the VHF repeater output.  But it is considered an acceptable risk to allow the VHF repeater to desense the packet port, since the APRS port can tolerate some limitations while the VHF network is busy.  It is NOT considered acceptable however for the APRS port to desense the VHF repeater, and this has been achieved my means of the notches used.

(from L to R)  The VHF, 9k6, [future 434.800] and Storno PC 

8 December 2010

Buffelsnek (Plett)

ZS2AAW, ZR2AAS, Angel, Craig

Repeater site completely re-installed
The Plett repeater has been off the air for months thanks to Switchmode Power Supply interference with the landlord's repeater.  A new Unit was purchased and taken to site for commissioning.  However the landlord informed me that the whole site was being refurbished, and that the mounting board onto which the Storno's were mounted was being removed.  We were to please make another plan for the Amateur equipment.  (only 2 days' notice!)

A scrap 19" open frame was assembled, and three Storno brackets fitted horizontally, similar to Kareedouw repeater site.  The new 48-24V PSU was affixed to a DIN rail, along with three load circuit breakers.  Filters and repeater equipment on site would have to be mounted onto the frame somehow, and the frame placed according to the lardlord's room layout wishes.   Extra DIN rail, bolts and nuts, hardware etc, were all taken along.

Job accomplished by 2pm - not bad!

What it was beforehand:

What it looks like now:

The filters mounted at the rear:

The new DC-DC Converter (48 to 24V)

The following were noticed for future attention:
The UHF link yagi to Swartberg has HIGH SWR - change antenna
The VHF Repeater exhibited a bad connection in the internal multiplug - no TX deviation...
The antenna feeders need to be properly made off when the frame is fastened in place.

26 November 2010

Lady's Slipper

ZS2AAW

HF Rig reinstated
The Icom IC-718 was returned to site today.  The advanced PIC control interface was also installed as part of the conference network.  This allows remote control of the IC-718 using DTMF, which is decoded and converted to the Icom CI-V protocol and sent to the rig.  The setup now has two PIC's on site, one dedicated to the switching of repeaters and the other to the HF rig control.  The following codes are now in use:

7001 1 - VHF Repeater disconnect
7001 2 - UHF Link disconnect
7001 3 - FRN interface (soundcard) port disconnect
7001 4 - BBS PC ZS0NTP power off (remember to switch back on...)
7001 5 - WiFi power off (remember to switch back on...)
7001 6 - HF Rig power off (remember to switch back on...)
7001 7 - Door alarm (switch off and on again to reset after closed)
7001 8 - Battery volts (reply in CW)
7001 9 - Mains Fail alarm

7000 1 - HF Patch - RX Only (permanently keys the rept network)
7000 2 - HF Patch - 2-way interactive (dependant on HF squelch setting)
7000 3 - AUX 1
7000 4 - AUX 2
7000 5 - AUX 3
7000 6 - AUX 4
7000 7 - Icom HF Rig Control
7000 8 - Shack temperature (inside) reply in CW
7000 9 - Not used (HRD active detect)

HF RIG CONTROL:
The HF rig can be patched to the Coastal Repeater Network using the 70001 and 70002 codes above, with the usual * to connect and # to disconnect.
The Icom frequency control can be done as follows:

MEMORY CHANNELS:
send 7000701 to select memory channel 1
send 7000702 to select memory channel 2

DIRECT INPUT:
send 70007 mmkkkhh to set to the desired frequency, where m = MHz (two digits required), k = kHz and h = Hz digits.  A total of seven digits required. e.g 
7098kHz would be:  700070709800
10.123MHz would be:  700071012300

HAM RADIO DELUXE:
Set up a new Rig to control in HRD - click on "Connect"
select "New"
Company: Icom
Radio: IC-718
COM Port: Remote
Speed: 19200
CI-V Address: 5E (default)
Flow Control/Interface Power: tick only DTR (VERY important, since this enables the equipment up on slipper, and ticking RTS will place the HF rig in permanent TX)

Now create the remote connection:
IP Address: 10.0.0.60
Port: 7805 (default)
Username: zs2pe
Password: zs2pe
Save these settings
Click on "Connect"
You will get a welcome window from Lady's Slipper if you have connected successfully

Com Port: Com 1
Optional PTT (TX) Configuration - DE-SELECT this
Click on OK

You will get a screen replica of the HF Rig.

AUDIO CONNECTIONS:
The HF audio can be monitored in three ways:
1) on 438.800MHz UHF using full duplex, permanently keyed when HRD is activated
2) on 145.700 and the repeater network if coupled using 70002 above
3) on Skype

Using Skype - search for ZS0NTP and request contact details.  Email ZS2AAW and inform him, and he will remotely allow you onto Skype, whereafter you can connect and hear audio.  To transmit, either click on the "TX" button (top RHS), and speak into your Skype microphone, or key up on 438.800MHz UHF in the Slipper coverage area and simply talk.  This duplex link will key the HF transmit when it gets incoming signals, even though it permanently transmits the HF receive audio as soon as an HRD connection is made (yes, this is one of those items controlled by the "DTR" line).  The 438.800Hz link will also key up when the 70002 patch is selected.

8 November 2010

Lady's Slipper

ZS2AAW

VHF Repeater reinstated
The repaired Kyodo repeater and VHF Packet unit were re-fitted on site.  The KPC9612 cable was resoldered for RX audio on pin 6.  

ZS2ABZ was copied flawlessly on 144.625 MHz.  

7 November 2010

ZS2AAW (at home)

ZS2AAW

Kyodo VHF Repeater from Slipper
Checks on the bench show intermittent TX PA output, but consistent drive to the PA module.  Any amount of tapping or knocking does not induce the fault.  Eventually it refuses to fail, so the fault cannot be located.  Decision was taken to swap the PA modules from the Packet and Voice repeaters around, to get the 700 repeater back on-air.  TX output (capable of 70W) is set to 25W.  DC Power fuse is already soldered in.  Modification done to bring out the repeater squelch pot onto the rear panel in place of the Speaker jack.  (Was internal to the unit, so could not be adjusted without removing and opening covers)

Later on inspection, the power control transistor Q603 is seen to have possible heat-induced dry joints.  These are re-soldered and this unit fitted to the Packet rig.  Soak test on TX shows perfect performance, so it will go back to site for evaluation.  TX output set to 10W.  DC Power fuse already soldered in.  This unit needs to have EPROMS programmed for 144.800MHz

The KPC9612 is opened and the VHF 1200bd equalisation jumper J1 is found NOT to be in the default fitted position to disable equalisation.  It is refitted onto both posts and the unit will be tried again.  ZS2ABZ WX station transmissions appeared to be QRT, but a wrongly configured Antenna c/o relay was the cause - permanently pulled in thanks to J1 on the Kyodo rear panel being fitted (swapped PA stage, remember!).

Note: Discriminator audio is available on the Kyodo on pin 6 of the 37 pin connector.  At present, de-emphasised RX audio is being used.

LATER:
It was found that the TNC refuses to decode the ZS2ABZ weather station on 144.625, even though the signal is good.  The Kyodo RX incorporates a Bucket-Brigade Device audio delay line in the receive audio path to remove the squelch tail noise burst from the end of received audio.  This means that the audio is further shaped, which also accounts for the slightly more muffled sound on these Kyodo repeaters.  This added roll-off appears to play havoc with 1200 bd data.  

The Discriminator audio point on pin 6 was then tried, and the KPC9612 configured for SOFTWARE DCD since this is a permanently unsquelched audio point.  The equalisation jumper was set back onto partial equalisation, since this Discriminator point is not de-emphasised.  It will be run like this on trial.

3 November 2010

Longmore

Lady's Slipper

ZS2AAW

Solar Power Problems still
Watching the APRS beacon from Longmore shows it is off the air every night, so there are still DC problems on site.   A replacement setup comprising solar regulator and load disconnect module was organised and tested by ZR2JH at the saltmine.   This replacement was taken to site and fitted.  The original one was removed for further tests at the workshop again.  The battery indicator was once again black - flat.  Only about 10 minutes spent at the site, just a quick visit

145.700MHz Repeater
Return trip was via Lady's Slipper - the VHF repeater transmitter is dropping out, while the VHF RX and UHF link remains active, so the actual TX must be at fault.  Equipment used is the Kyodo KG110 50W VHF Repeater.  Sure enough on site, the PA output meter shows power dropping off intermittently.  The complete unit is removed for inspection and repair.

Also removed is the identical VHF Packet unit, since it could be used for spares as a last resort.  The Kantronics KPC9612 is also removed, because this TNC and the Kyodo RX are not matching up too well - I notice VHF packets are not decoded by the TNC.  Plan is to set them up at home and monitor ZS2ABZ's WX station off-air for test purposes.

17 October 2010

Longmore

ZS2AAW

Solar power problems?
VHF repeater 145.625 has been off the air for some weeks.   Suspicion was the solar regulator being faulty and that the battery had died.  

On arrival, the repeater was indeed dead, but the link was still running.  The Deltec battery showed a black indicator = FLAT.  Solar regulator was cycling between "charged" and charging, battery seemed high impedance, because the volts rose and fell too easily.  

There are three 70W solar panels.  Tested them: single panel = 3.7A short cct current.  The double panel = 7A short cct, so they are all OK.  Solar regulator main fuse (32A) found to be blown.  Did a jippo repair with spade connectors and an automobile fuse (only 15A).  BUT the regulator keeps the batteries in boost mode, way above 14V.   A solid KLAP of the regulator on the shelf sorts out the stuck relay problem, and it now cycles in and out of boost mode properly.   From boost to normal at 14V.   From normal to "charged" at 13.5V

Swapped the battery for a charged one brought from home, with a green indicator.  Will take the flat one back for recharging and testing

Investigate the repeater - found an open-cct main supply fuse inside the chassis - went o/c due to heat on the fuse end-caps solder.  Resoldered and refitted, and the repeater is fine again.

Re-installed the APRS Digi on 434.800MHz, after it was removed for repairs post the 2010 VW Rally.  This Digi's beacon will be monitored on Ui-View to see if the DC is lost on site again.

15 October 2010

Saltmine (re Buffelsnek)

ZS2AAW

Site power supply
Sourced a commercial DC-DC converter at reasonable cost.  Item is the MeanWell SD-150C-24, which will provide 6.3A at 24V DC from a 36-72V source, ideal for 48V sites like Buffelsnek and soon-to-be Brenton.  I have ordered one such device to test at Buffelsnek.  If it works without causing interference to the Eskom VHF Repeater, we will prepare for another purchase for Brenton when the site upgrade goes ahead.

4 October 2010

Saltmine (re George)

ZS2AAW

Repeater site move
I was also informed that the existing George repeater site (Eskom) is to be discontinued, since all the Eskom equipment is now located in the Sentech 3rd party building.  Negotiations were initiated with Sentech in 2003 (around the time we obtained permission from them for Brenton site) to move the Amateur equipment into the 3rd party building, but were never concluded.  The contact, Dawie, has since retired, so we will have to start from scratch with the current transmitter manager in George.

Site to be de-commissioned:

The future location, pending negotiations:

In order to limit space required on the tower, a single dual-band antenna will be used for both VHF repeater and UHF duplex link, fed with 7/8" heliax feeder to minimise losses over the fairly long feeder length

4 October 2010

Saltmine (re Buffelsnek)

ZS2AAW

Site power supply
Had another call from Bart Saayman to inform me that the new DC-DC converter as sent to George for installation at Buffelsnek repeater site, also exhibits the supply rail interference on the Eskom VHF repeater, so the site could not be re-instated.  Bart suggests we run with a mains PSU for now, or source a different make/design of DC-DC converter.  

Agreed, so the site remains off-air

3 October 2010

Lovemore Heights

ZS2AE, ZR2SAM, ZS2AAW

WiFi site still down
Went to site to investigate the loss of WiFi service:

It appears there has been some lightning surge damage to the LAN barrel connector in the equipment cabinet inside the building.  The offending tailpiece and barrel connector shwon above were removed, the CAT5 screened cable connector was also blackened, but was brushed up and plugged directly into the Power-Over-Ethernet adaptor, and the site came alive again.  Amazing that the wifi equipment up top, and the DC power supply down below seem to have survived this damage...

Note that the Power-Over-Ethernet is passive, and uses the unused cores 4-5 and 7-8 to convey the 18V DC.  Each pair is paralleled and carries the GND and +18V supply rail per pair.  Over long lengths of CAT5 cable, the volts loss is reduced by using a pair in parallel.  In our case, the tower alone is 35m tall, add to that the run to the building and into the equipment cabinet inside, and we have about 50m of cable.  We lost one of the conductors when the finger was burnt off, so possibly lost reliable DC supply to the box

BUT, also present in this extender barrel connector was a lot of water, so there is also a water ingress problem on the CAT5 cable - possibly caused by a damaged outer sheath on the tower.

The CAT5 connector will be replaced ASAP, and the barrel connector changed to an in-line lightning surge protector, tied to the local and rather substantial station earth bar present in the cabinet already.  We will also inspect the CAT5 cable on a nice still summer's day...

30 September 2010

Lovemore Heights

ZR2JH

WiFi site down again
Wireless connectivity lost from Lovemore again - Asked Jacques to please power off-on the installation to reboot.  System did not restore this time...  

ZS2AAW is away on leave in Pretoria, back on the 2/10, so will have to wait until then.  Possible power supply or motherboard problem?

29 September 2010

Lovemore Heights

ZR2JH

WiFi site down
Wireless connectivity lost from Lovemore - both the backbone link and the Access Point appear to be off the air.  Asked Jacques to please power off-on the installation to reboot.  System came back OK.

September 2010

ZS2AAW QTH

ZS2AAW, ZS2AE

Standby diesel generator capability
Changes being done at the QTH of ZS2AAW for automatic diesel standby generation.  Major power re-routing meant that the mains supply to the QTH was off all afternoon.  Since the ADSL router, Firewall machine and Ethernet switch are not on UPS at the moment, meant that the internet connectivity to the WiFi network was also down during this outage time too...  Sorry!!
Plans are to re-instate the UPS feature once the automatic diesel standby generator has been completed - this will mean that in the event of mains failure or load shedding, the UPS will take over.  If the UPS time runs out, the generator will be configured to get going before the UPS fails, and keep the whole system alive.  (Someone needs to fill the diesel tank every now and then...)
This feature makes us load-shedding proof, because Mount Rd also has battery plus diesel backup, Lovemore and Slipper have massive battery backup, and Uitenhage has a small amount of battery backup.

30 August 2010

WiFi Network

ZS2AAW

Internet connectivity down
11h42 appears that IP connectivity through ZS2AAW to the ADSL connection from Mount Rd was lost.  Winbox connections from the WiFi side show no reason, but slow response.  
Power off-on reset at ZS2AAW Wifi installation cures the problem.  Suspected IP address clash on the local LAN after the ZS0GHT Node PC is brought up on the LAN for configuration purposes.  (A LAN card was added to this Node PC to facilitate file transfers to it, since it has no USB ports, and only a Stiffy drive plus 500MB HDD...!)
Service restored at about 17h15

29 August 2010

Workshop

ZS2AAW

ZS0GHT Node PC
(Pentium-1 motherboard, with 32MB RAM (!!), on-board VGA, 500MB HDD, and 24V DC power supply, running Win98)
HDD scanned and defragged, cleared of unnecessary FBB software files etc
Ui-View32 is loaded, and the old unregistered Ui-View16 is removed.   Registration codes as obtained long ago finally used to unlock the full 32bit program.  Digipeat paths edited, and UI-Digipeating reconfigured to follow the new-N Paradigm, using WIDE1-1, WIDE3-3 paths.  Beacons edited to plot the digi correctly
AGW-PE .exe file also updated to the 2005 version
AGW Ports renamed to the new frequencies of 144.800MHz, 439.850MHz, 434.800MHz
DigiPlex configuration also updated to show the new radio ports
9k6 tests done to Slipper from the Node PC to test all configurations
The link from Slipper to Governorskop will now run at 9600 baud, the old 438.275MHz 1200baud "backbone" and forwarding channel is no longer required, and will be de-commissioned.  (Forwarding happens via the wifi network using telnet, direct to Jhb)
Unit left on soak test using 9k6 backbone from Slipper to ZS2AAW workbench

Pentium PC built into Storno Repeater casing

26 August 2010

Governorskop

ZS2AAW

Replace battery bank
Old 24V battery removed due to "popped tops" (positive plate growth pushing the covers off).  A replacement bank was installed, connected and commissioned.  Battery stand and floor cleaned.  Cells are nicely numbered 1-12.  Old cells delivered to Battery Centre PE for recycling.

Packet backbone 9k6 Storno 9000 installed, but could not be commissioned due to missing TNC-radio cable.  
Removed the Packet PC for fan replacement (worn bearings) and for updating the Ui-View to the registered 32-bit version, and for configuration to meet the new N-paradigm APRS digipeating
Removed the Packet VHF Storno (144.675MHz) for channel change to 144.800MHz as per the APRS standard.

25 August 2010

Lovemore Heights

ZS2AAW

WiFi Access Point
For unknown reasons, the access point went off the air on Wednesday evening at 18h30.  Link to Mount Rd also disappeared, so it appears the site locked up.
Quick visit to power off - on the WiFi box cured the problem, site online again at 07h10

19 August 2010

Lady's Slipper

ZS2AAW

439.850MHz 9k6 Packet Port
Replace T857 UHF Exciter with suitably modified module, to enable the 9600 baud UHF Packet Port on 439.850MHz.  Workshop tests had identified the low pass filter in the Exciter modulation path to be preventing correct wideband data modulation.   Filter removed, and deviation set using the KPC9612 9k6 output level pot to 3kHz.   Two-point modulation setup also performed to ensure correct low frequency response.

?

Saltmine

ZS2AAW & Bart Saayman

Buffelsnek interference
Had a call from Bart - he is on site at Buffelsnek tracing interference.  Seems the DC-DC converter is still generating mush interference on the Eskom repeater.  Asked him to please disconnect and remove the DC-DC converter.

Site is therefore off air.  DC-DC converter collected and a replacement handed over at George Eskom Offices on 12 August 2010.  To be fitted at their convenience.

24 July 2010

Longmore

ZS2AAW

145.625 Rally Repeater
Emergency site visit on the 24th July to replace 100Ah battery after failure during the 2010 VW Rally comms.  Extensive use and insufficient solar input caused battery exhaustion.  
While on site, the 434.800MHz APRS Digipeater was also investigated and found to be faulty - no decode.  Removed for repair.  (This will also alleviate load on the batteries)

20 July 2010

Kareedouw

ZS2AAW

Re-install VHF Repeater as repaired at home

Replace RX end-fed antenna with similar design.  N-type to PL259 adaptor was badly corroded
Check TX antenna for moisture, all OK

Site is now 100%

15 July 2010

Longmore

ZS2AAW

145.625 Rally Repeater
Old sealed battery had cracked and failed.  A replacement Dixon 100Ah battery is fitted. 
Solar input still appears to be OK

7 July 2010

Kareedouw

ZS2AAW

145.725 Repeater
VHF repeater receiver audio out of IF found to be faulty - coupling cap has dried up, causing low level audio & noise into control card = open squelch condition due to lower noise voltage in squelch circuit.  Cap replaced, all audio levels lined up perfectly thereafter, and squelch is working fine again.

5 July 2010

Kareedouw

ZS2AAW

UHF Link to Buffelsnek front end found to be faulty - replaced at home.  Tantalum DC supply decoupling cap in front end also replaced as a routine change.

4 July 2010

Kareedouw

ZS2AAW

Tests done from the mobile going past the mountain:

VHF Repeater control card appears to have blown chips - no squelch tail on VHF, but responds to 7250 from VHF side OK.  Responds to 7251 from VHF side OK.  Left disconnected at 7250 because of open squelch interference the previous week.

4 July 2010

Buffelsnek

ZS2AAW, ZS2VS & family

Link to Swartberg - antenna heliax shortened and new female connector fitted.  VSWR good.  RG213 male-male fly lead fitted to Storno link (heliax used to go direct onto the Storno - difficult to work with).  Tested 6254 - responded OK, but with lots of 100Hz hum

DC-DC Converter fitted.  Runs off 48V supply now.   Tested power-off-on cycle @ 48V supply breaker & starts up OK, but 7750 comes up disconnected.  Recover mains PSU.

Tested tones to 6750, 6752, 6753 - all OK.   7004 broken up.

Site working 100%

19 June 2010

Kareedouw

ZS2AAW

Site appeared deaf from PE

UHF Link to Slipper - All OK.
7251 responds.  
Signal RX is good on handheld. 
VSWR OK at 1.1:1; 
TX power 1W

UHF Link to Buffelsnek - RX DEAF:  >-80 dBm to open RX!  Removed for repair
Antenna OK, RX signals good from Buiffelsnek.  
VSWR 1.4:1
Tones at 7750, 6750, 6752, 6753 all OK
7004 still broken up (poor signal from George to Brenton on UHF)

VHF Repeater
All OK
But RX Antenna is Open circuit - VSWR > 3:1 ...!!
TX Antenna is not great at 1.7:1
RX is end-fed white antenna - replace
TX power 8W thru filters - OK
RX Squelch threshold 0.3uV thru filters - OK

19 May 2010

Cradock

ZS2AAW, ZR2JH

Tower work

Heliaxes totally loose – cable ties perished.  Temporary fix done using more cable ties…

VHF Packet Storno removed and brought back to change channel to 144.800MHz

22 April 2010

Mt Kempt

ZS2AAW, ZS2JM

UHF Link 438.600MHz

Fit unit as prepared in PE – old one had crystal problems.
Check all signals to Governorskop and Nqamakwe – all OK

4 April 2010

Kareedouw

ZS2AAW

?

30 March 2010

Kareedouw 
(on return trip from Brenton)

ZS2AAW

Local RF tests from N2

RX on 438.775 not working at all
Checked on +/- 20kHz in case of major drift, still nothing - link RX is therefore faulty
7252 only responds from VHF or Slipper side...?

(Site was visited later, link removed for repair & replaced by Benjamin later still)

30 March 2010

Brenton

ZS2AAW, ZS2AAS

Met Andre Crous (Eskom George) at site for access

UHF Link to George:
Re-install link
Antennas measure OK, VSWR ~ 1.4:1
BUT
Poor UHF signals from George on 438.725MHz
Checked with a second antenna at ground level - still bad.  Can trigger DTMF 7254 with a handheld, but no signal strength coming back.  Because of this, the George - Brenton signal gets flattened by local telemetry transmissions nearby, even with loose squelch.
Left link to George disconnected .  Squelch set flat-out again

UHF Link to Plett works fine, signals are good

30 March 2010

Buffelsnek

ZS2AAW

DC-DC Converter replaced.  BUT new one smoked!
Fitted mains PSU for now

Checked all RF parameters - links x2 and repeater all OK, or close and aligned OK

UHF Link to Swartberg antenna/coax is full of water.
All joints on tower checked.  Heliax male has water in it, but the tailpiece male and antenna seems dry!
Tailpiece is ~2.5m long
Maybe replace tailpiece and yagi?
Left bottom end open to drain

All other antennas measure OK

Action items:
1)  Replace DC-DC converter 48-24V
2)  Refit UHF Link antenna connector
3)  Replace yagi & 2.5m tailpiece if necessary

Notes:
[old DTMF card in VHF repeater]
[Eskom control cards in UHF Duplex link & Swartberg link]