The disasters of the October contest

Building the station

The 432 Mc station

Trouble with 3 cm TWT high voltage

The 3cm TWT high voltage connector finally gave up. It was necessary to push the pins into the recepticle before applying mains power.

Not always a pin made good contact and this caused some trouble.

After a few hours the HT power supply started smelling badly and a "hissing sound"came out of it.

This smelled like real trouble again.....(and was)

 

 

 

 

 

 

 

 

The resistors around the C1 / C2 Darlington circuit where burned.

One resistor was gone for ever, the others looked burned, but still functioned OK.

The whole,circuit was repaired, tested and put in operation again.

Still "hissing sounds" were coming out of the HT supply. Afetr close examination it was found out that the HT connection was causing the noise.

The connector was not used anymore and all pins were just put in the femele connector. To "tighten"them they were wrapped with isolation tape.

This "isolation tape" did not isolate at all. The glue on the tape was causing a relatively low resistance path between the pins, causing arcing.

So we took the tape of and continued without problems.

 

 

 

 

 

 

Hans, PE1CKK busy repairing the Darlington circuit of the 3cm TWT HT power supply.

It took approx. 1 hour to get everything working again.

 

 

 

 

 

 

 

 

 

 

 

The final set-up of the HT connection. Approx. 4 kV is present on the wires.

It was the only way to be active on 3cm.

Now we DO need a new connector.....

 

 

 

 

 

 

 

 

 

6 cm power failure

During the May contest we had some troubles with 6 cm  (see Mistakes, 6cm trouble).

However at that time nothing serious was found.

This time the power output was almost gone.

A thorough investigation took place and it became clear that a voltage connection to one of the amplifier stages was interrupted.

After some soldering all was OK again and the unit could be mounted again near the dish (in pitch dark, rain and strong winds).

 

Ron, DL3BPC inspecting the 6cm transvertor unit.

 

 

 

 

 

Hans, PE1CKK making the necessary repairs.

Note the modern glasses he is wearing. They suit him well.....

He borrowed these glasses from Henk, PA0C.

Henk did forget to bring his glasses so a new pair was bought by Hans for the tremendous amount of Euro 2.99.

So the "bold guys" of this contest group shared the glasses when it was necessary to see something small.

(We are really getting old.....)

 

 

 

 

 

 

23 cm PA explosion

The West PA did explode with a big bang. The HT voltage short-circuited somewhere.

The PA was taken apart, various changes were made, but no 100% certainty could be achieved with regard to the cause of the fault.

A second try resulted in an ever louder bang and brigth flash....

This PA was beyond repair for the moment.

We had to continue with the spare one.

 

 

 

 

 

 

 

Missing packet link antenna

The antenna for the packet link was forgotten. A pity, because in May Marko had done his best to make us a new one.

So we had to improvise again.

A broom-assisted-antenna was put in place. Without difficulty we could reach the 70cm tower by packet and were able to exchange the sked information.

 

 

 

 

 

 

 

 

Building the station

The 432 Mc station

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