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Wadnobby
New member
Username: Wadnobby
Post Number: 1
Registered: 7-2010
| | Posted on Friday, August 27, 2010 - 10:42 pm: | 
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Hi there, I'm new to this forum and hoping to post this correctly.
I am in the process of restoring my old base station antenna bought from a neighbor in 1974. It has all the looks of a Super Penetrator, but not exactly.
The vertical is comprised of 5 sections, measuring 17'. It has four 8' radials, with a 10" sealed coil at the base, much like a Super Penetrator. There was no "top hat" when I bought it, but the holes are there for it. The plastic encased coil load was once Red in color, but sun faded now. The SO-239 is gold plated.
I did alot of DX'ing with this ant. and my old Lafayette HB-111 as a teen. Took the antenna and RG-8 off of the old family house after my Dad died a couple years ago, before we sold it.
Pretty sure it is a half wave, but I've seen conflicting info. about half, 5/8...and half over 1/4 wave. Anyway, looking forward to getting it back up on my house and on the air again. I'll be running barefoot on a Telsat 1240, to test the air again.
Thanks for looking at my post, and for any suggestions or info you may have. |
Mikefromms
Senior Member
Username: Mikefromms
Post Number: 1062
Registered: 6-2003
| | Posted on Saturday, August 28, 2010 - 11:26 am: |
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Four eight foot radials. Do they hang down in an angle like 45 degrees? If so, this might be what was known as the weeping willow ground plane.
Welcome a board. Check the archives. Lots of good reading. |
Tech833
Moderator
Username: Tech833
Post Number: 1856
Registered: 8-2002
| | Posted on Saturday, August 28, 2010 - 12:03 pm: |
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That sounds like an Antenna Specialist M-117 'Super Magnum' 1/2 wave. I have one in the boneyard here.
The trick with those was the 'radial tophat' on top. It had 4 aluminum wires that formed a sort of orb on top. The top of each wire was secured to the top of the antenna with a compression fit, but the bottom ends were attached with a plastic clamp, which always deteriorates and goes away. Won't make much difference anyway, so don't worry about it.
The red coil housing faded quick to a pink color, then developed micro-size cracks that absorbed moisture, so SWR would go up whenever it rained. If you plan to use it, seal the cover with epoxy resin and fiberglass cloth and finish it with some UV resistant paint.
Your radio 'Mythbuster' since 1998
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Wadnobby
New member
Username: Wadnobby
Post Number: 2
Registered: 7-2010
| | Posted on Saturday, August 28, 2010 - 6:47 pm: |
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Thanks Tech 833! Now that you mentioned "Super Magnum", that triggered my memory.
As for the coil load, there are no cracks evident after examination with a mag. glass. I was planning to use Krylon paint formulated for plastic to seal and refinish. Good idea or bad? Also, I have been cleaning the tarnished aluminum with a medium grit sanding block and Brasso for aluminum. The antenna was mounted to a chimney that exhasted the old oil furnace, so there is a great deal of residue to clean.
I'm sanding the coil load/radial mount bracket and plan to prime and paint with a good rust inhibiting paint prior to reinstallation. Is there any other sealing that should be done. The location for this is eastern Washington State.
I greatly appreciate any comments/suggestions. |
Tech833
Moderator
Username: Tech833
Post Number: 1858
Registered: 8-2002
| | Posted on Saturday, August 28, 2010 - 11:26 pm: |
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Watch the soot on and in it. Soot is carbon, and carbon is conductive. You have to clean it ALL out.
Whoever thought it was a good idea to invent the "chimney mount"??! I could just scream!
The Krylon treatment is a good idea. It will work for a short time until the paint oxidizes.
Your radio 'Mythbuster' since 1998
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Casey
New member
Username: Casey
Post Number: 1
Registered: 11-2010
| | Posted on Wednesday, November 17, 2010 - 3:05 am: |
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A little late on this topic, but, without the top hat pieces you might find it is a bit short to get a 1:1 swr.
Without the top hat you might have to extend the radiator up to 10" in length to see a flat swr.
I had to add 10" to the Penetrator to bring it back in tune when I lost all the 10" long top hat radials. |
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