Station Master repair

[VK5IR]

Hi guys. After a bit of advice from those in the know.

Today's planned antenna maintenance has now turned into operation Station Master restoration. The bottom has broken from the base.

I'm sure I'm not the only person to have had this problem, so how have you guys fixed it?

[VK6ADF]

Hi Theo, I have not had that happen to me because I don't have one, but it looks like possibly a plastic conduit type insulator with the ali tube in it. If it is a standard conduit size you could try this type of thing.

conduit.jpg (9.93 KiB) Viewed 11084 times

Should be available at any electrical supply place, Bunnings maybe etc etc. Just an idea.

[VK5PJ]

Hi Theo,
get the brave pills out...

drill out the two rivets holding the coil in place on the base plate, unsolder the SO-239 from the fly wire if not broken already, angle the mast section so you can slide the bracket up and off the mast.

Get out your favourite wire bush and give the bracket a clean up.

use a hack saw or Stanley knife to slice along the broken grey conduit fitting and try to lever it off, try not to damage the orange conduit in the process. Now the orange conduit is not designed to be exposed to UV so it may be quite brittle, this might be the place where it all comes undone as if it is brittle the repair might be a waste of your time.

Phil, vk6adf has already identified the part you need and of course some conduit glue to keep it in place. Looking at the state of the SO-239 coax socket, I would look for a new one, either another nut locking one or a 4 screw panel type and use some pop rivets for it.

Find some steal wool and clean up the coil around the tap point and where it attaches to the base plate.

once happy put the plate back on and see how it fits...

I have done one before a long time ago, it was not as sad as yours so it was much easier to work with. Sorry to say yours might be a bit past its use by date but a bit of careful metal work might give it a few more years.

Regards,

[VK6ZFG]

Hi Theo

The plastic components consists of electrical u/g conduit and plastic electrical conduit to threaded adaptor. Conduit size is determined by outside diameter. eg 20mm, 25mm, 32mm etc. Old imperial sizes were 5/8", 3/4", 1" etc but these are no longer available.

[VK5IR]

Thanks for all your help guys. Hopefully I can get all the plastic/conduit off at the bottom and might try to replace new for old.

[VK6ZFG]

Hi Theo

Just one other thing. The orange electrical conduit is intended for heavy duty use and grey for normal use and as a result the orange has a thicker wall than the grey. You will need to use the orange again to avoid getting a sloppy fit. 25mm orange electrical conduit provides good fit for 3/4" dia tube but I suspect in your case you might need the next conduit size.

[VK5IR]

Thanks Igor.

I've found the parts I need - a grand total of $14 from Rexel. I just hope I can remove the existing orange conduit without too much trouble. Knowing my luck its probably been glued to the bottom element on the inside.

[VK4GHZ]

Knowing my luck its probably been glued to the bottom element on the inside.

Theo, what about running a Stanley knife blade down the tubing, and peel it off along the split.
Might be easier than trying to slide it off?
Glue or no glue!

[VK3ALB]

There's no need to replace the tube. It's fine inside and underneath the faded outer coating. Just replace the bottom support. As for weather proofing, leave the underside open to the air. You can see how the silicon on the underside trapped moisture. If the underside is open moisture will drain away nicely.

[VK2TS]

Beware using orange conduit as it is not UV resistant. It appears whoever mnanufactured these things originally wasnt aware or ignored that fact. Now thats In built limited life span using that stuff. It is designed to be buried and as such not receive any UV from the sun. I would replace it with grey conduit which is designed to hold up to UV for a much longer time.

Cheers

[VK6ZFG]

Unfortunately the grey conduit has a slightly larger bore than the orange so the fit will not be as good. It does not seem to last much longer than the orange under U/V in any case. Best solution is to use the orange conduit (prefarably new) and paint it with a long lasting UV resistant paint. Spray tin paints generally will usually not last too long but better than no paint. My latest preference is for "Killrust" type paints as these seem to have a longer life.

[VK2TS]

Unfortunately the grey conduit has a slightly larger bore than the orange so the fit will not be as good. It does not seem to last much longer than the orange under U/V in any case. Best solution is to use the orange conduit (prefarably new) and paint it with a long lasting UV resistant paint. Spray tin paints generally will usually not last too long but better than no paint. My latest preference is for "Killrust" type paints as these seem to have a longer life.

Yes but one can buy conduit terminators for the grey conduit as the outside diameter is the same. Internally yes the wall thickness is thinner so one would need to sleeve the aluminium to make up the difference. Orange conduit in sunlight is a definite no no And painting conduit is possible if you use the correct primer and paint designed for painting plastic ie: for automotive applications such as plastic bumpers. Wrong paint and it will just peel off.

Cheers

[VK6TU]

In the past I had a station master in the Pilbara for a long time even though the Orange conduit is affected by the UV it is only used as a insulator and in every antenna I have seen the orange conduit has not broken, just faded, even after the aluminum has been bent by a cyclone the conduit has not broken.

Stick to what has been used as it is the right size for the tubing no extra sleeving required and has worked well for many years 30+

73 from Michael
VK6TU

[VK5IR]

Thanks for all your help and advice guys. This combined with some advice I received on FB has helped me a lot.

The Station Master rebuild is complete and I am almost done tuning it. I just need a little more time to get the job done and although I could put her up in the air as is, I'd prefer to work on shifting the dip down a little bit more. I'm sharing this here for the main reason that when I started doing this job, I basically didn't know where to start and I know there will be others in a similar boat so i hope this is of some benefit.

I have quite a few before and after photos posted on FB which you can find here:

https://www.facebook.com/media/set/?set ... 070e23dc0a

No Facebook logon on account is required to view this album.

[VK7DB]

To get the match a bit better on 10m, you can make another tap on the coil similar to what you use to feed it with, and use it to shorten the coil. Juggle element length, top tap point and feed tap point and you can achieve a near perfect match.
Something like this http://www.vklogger.com/forum/viewtopic ... 673#p17956

[VK4LA]

looks like your station master has seen better days , but its repairable ,if you findout anywhere that supplies the grey insulator with the thread that screws threw the mounting bracket ,please let me know.
as all i used was a slightly longer peice of insulated white pvc and used 2 small screws , 1 on each side the the bottom mounting bracket to insulate the vertical elelent from shorting out ...oh and do ya self a favor ..cut the old u-bolts off and buy new ones ....lol
cheers mate and good luck ok ..
Rob vk4la

[VK6ZFG]

I have successfully made use of plastic/nylon cable glands to provide support and insulation on antennas. They nowdays come in all sizes and are readily available and provide a convineint way of getting the job done. For the staion master one could be used for the top support and another at the bottom. The use of conduit can thus be eliminated.

[VK2ZIW]

The Station Master has many dis-similar metal problems!!!

The connector, brass, onto aluminium - disaster #1
The coil to baseplate screw, steel - disaster #2
The coil to radiater steel screw - disaster #3
The connector wire to coil, brass and steel - disaster #4

http://www.unixservice.com.au/hamradio/ ... Master.JPG

Hopefully. a bit better

[VK3DXE]

Has anybody had any experience with dismantling the base section of a Station Master MKII? I have one that was full of water (now drained), but would like to get right inside to ensure no further issues with corrosion, and possibly tweak it of use on other bands.

I've been able to remove the seal/spacer from the top part where the radiator emerges from the base, but no luck removing the bottom part to see what's inside.

I couldn't find a pic of the MKii on the web, but did come across this in my searches for it All I can say is ignorance can cost you a lot of money

http://www.ebay.com.au/itm/Sirio-SD-Dip ... Sw0vBUk31k

[VK5IR]

if you findout anywhere that supplies the grey insulator with the thread that screws threw the mounting bracket ,please let me know.

G'day Rob

The adapter is Clipsal part no. 263/32GY and is called a "ADAPTOR PLAIN TO SCREWED, PVC, FITTING, CONDUIT, 32MM, GREY" and the nut is Clipsal part no. 260/32GY and is called a "LOCK RING, PVC, FITTING, CONDUIT, 32MM, GREY".

I found them at Rexel but you should be able to find other suppliers. A Google search of those part numbers will find a few results for you.