Kanonkop maintenance 20191019
Meetup at gate (at tar road) +_ 09:00.
Drove up.

Measured Power and SWRs
Batteries 13.3V and 13.2V
Power Supply Unit right 26.64V
Power Supply left (DC to DC) 13.7V
Power Supply RHS against rack (DC to DC) 13.8V (Negative grounded on rack)
Between Duplexer and Heliax 10W SWR 1.4
Between T4002 and circulator 30W SWR 2
Between Circulator and Band Reject Filter 16W SWR 1.7
Between Band Reject Filer and Duplexer 13W SWR 1.4
Tested Heliax and Antenna
Used hand radio as source
Bottom 6W SWR 1.4
Removed antenna and replaced with dummyload
Bottom 6W SWR 1.4
Top 5W SWR 1
Reconnected antenna
Top 5W SWR 1
The 2 stage circulator was retuned to correct SWR problem (145.750 before -1.2dB SWR 2 after tuning -0.38 dB SWR 1) The first cap in circulator is suspect.
Bandreject (Notch) filter on 146.2375 was measured and the one nut was tightend
The duplexer was measured and retuned to get a beter insertion loss on 145.150 (before -1.95db after -0.74db) (One cable in harness was found to be wrong length and was replaced)
Wideband bandpass filter was measured. This was connected between cavity bandpass filter and preamp. Moved to be between circulator and bandreject filter.
Cavity bandpass filter was retuned for beter pass band. (before -5.71dB after -4.6dB)
Tested gasfet preamp (145.150 +16 dB)

All equipment was labeled with measurements.
Repeater sensitivity measured -0.4uV
Everything reinstalled and some final measurements
Between T4002 and circulator 30W SWR 1
Between ciculator and Wideband bandpass 27W SWR 1
Between wideband bandpass and band Reject filter 12W SWR 1
Between band reject filter and duplexer 11W SWR 1
After duplexer, just under 10W
Sensitivity after duplexer 0.3uV

Tested UHF dipole antenna on side of building (good strong signal to 438.800)
Cleaned up and drove down +_ 15:30.
Summary
More thinking will need to be done about Heliax state.
TX side: losses was improved and corrected, but with the introducing of the wideband bandpass in the correct place, no power was gained.
RX side: removed wideband bandpass (2.2 dB improvement), returned cavity bandpass (1.1 dB improvement), retuned duplexer (1.2 dB improvement) Total 4.5 dB improvement
TODO:
Investigate Antenna options
Decide on Feeder
Think about linking
Retuned Wideband bandpass Filter to have less loss on 145.750 (currently -2.7db)
Move preamp before cavity BP filter. (This would just make more sense to amplify, before filter)
Remove one can from Cavity BP filter, retuned for 145.750 and replace wideband BP filter. (Will make about 1.2db more sensitive on RX and about 2dB less loss on TX)
Service UHF
Repeater Status Report 20191015
Good evening. The latest status report for your reading pleasure.
Repeater Status Report 20191008
For your reading pleasure, the latest status report here is. Enjoy it you will. ๐
Repeater Status Report 20191001
Good afternoon!
Here’s yesterday’s report for your reading pleasure.
Repeater Status Report 20190924
All I shall say is that it was Heritage Day. ๐
Repeater Status Report 20190917
This should have been posted last night but one of our naughty dachshunds grabbed my specs off the bedside table yesterday afternoon and chewed them to bits. Fortunately, I had an emergency pair at work.
Repeater Status Report 20190910
Repeater Status Report 20190903
This should have been posted yesterday – apologies.
Constantiaberg maintenance 20190831
On 23/24 July the Motorola repeater was damaged in a storm. It is suspected that the repeater was damaged by static from lightning.

On 26 July Jan ZS1VDV and Paul ZS1V investigated and found the repeater damaged. The repeater and duplexer was removed. The antenna SWR (1:1.03) was checked.
In the following weeks a new install was planned:
- a backup repeater serviced by Verstay (ZS1VDV, ZS1V)
- correct length coax acquired (ZS1VDV, ZS1YT)
- duplexer tuned (ZS1VDV, ZS1V)
- circulator tuned (ZS1VDV)
- power supply connector replaced (ZS1V)
The morning of 31 August started at 06:00 with the last few tests of the configuration. Backed all equipment and tools. Left for site around 07:30
Repacked all into 4×4 vehicle at ZS1DDK.

On site around 10:00



Installed duplexer (Decibel Products 6 can). It was tuned to -2.04 dB insertion loss on RX, -2.5 dB insertion loss on TX, and -115 dB isolation between RX and TX). Next was the installation of the rack mount power supply (13.82 V) and Vertex VXR 9000 (sensitivity set to 0.25 uV) repeater.

SWR was rechecked between repeater and circulator, circulator and duplexer as well as after duplexer, all was found to be perfect flat (1:1.05). The power output after the duplexer is 14W.

A few test contacts was made to confirm all working.
Packed all equipment and boxes and returned home at around 11:30
A quick lunch sponsored by ZS1DDK was enjoyed at Peddlers on the Bend.