80m yagi and 20m quad fix

12 Jul 2014 by sm0w, No Comments »

Last week to get ready for the IARU contest (we operated as SK9HQ) I spent most of the week at the station doing maintenance. During spring we lost the 6 element 20m quad. Rotator stopped working and coaxial was broken in the tower. Also I needed to get the 80m yagi hooked up again, getting a new feedline up the tower and also a new control cable for the relay boxes on each of the elements of the yagi. On Monday last week I climbed the 45m self supporting tower that holds the 80m yagi. Brought up the coaxial and control cable from the ground with the help of the ground crew SM0T and SM0IMJ. I made a new break out box for connecting the various cables up in the tower. Made all connections in the break out box and then connected the 7/8" coaxial with a short piece beteen the balun in the antenna and the top of the tower. Both cables was turned few turns around the mast pipe. Made a short video from the top of the tower.

And here is the first test turning the yagi with the PST110D-PRO rotator in the evening..

On wednesday we brought the broken Prosistel PST-71 rotator down from the tower.. It seems they have a serious problem with the potentiometer. We have had issue with this several times now on several rotators, some how the potentioneter is mechanically damaged, maybe their alignment is bad.. The thing that pisses me off is that you have to bring the whole rotator down to ground to be able to change the potentiometer. Its a big job since they are heavy! I just realilized this is the 4th time. The 40m Quad also stopped working in the winter and i figure its the same problem again since thunder is not an issue in the winter here.. Alot of wasted work.. 

I changed the Potentiometer in the rotator, picture of that in the gallery below.. And myself together with Dag SM0KDG got the rotator back in the tower, unfortunately changing the potentiometer caused a problem with the bolt that goes to the rotator top clamp and mast tube to eliminate torque slipping in the clamp. Another stupid Prosistel problem that you can not dynamically tell the rotator box that the specific voltage coming back from the pot is a certain direction. This can be done with for instance the Green Heron rotator box but I think it is stupid you have to buy a expensive extra box when Prosistel should rethink their rotator box instead..

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OJØR Market Reef

OJØR Market Reef

OJØR is my callsign during visits to the barren rock of Market Reef in the middle of the Baltic sea. [&hellip