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Message |
    
Narf_edwards
Junior Member
Username: Narf_edwards
Post Number: 19
Registered: 3-2005
| | Posted on Tuesday, November 01, 2005 - 9:50 am: | 
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Do you think it is feasible for me to leave the shunt coil and cap out of the base of the Crossbow fiberglass halfwave I am restoring.I have added four 4.5 ft. radials at the top of the mounting bracket,but have not erected it to test yet.I need info on how to rewind a ferrite core to replace the old shunt coil...the old core was broken in two.If anyone can help me with the number of turns to wind the coil etc.I still have the cap that was in parrallel with the coil.
Any info would be of help
Thanx
Narf |
Marconi
Intermediate Member
Username: Marconi
Post Number: 468
Registered: 11-2001
| | Posted on Tuesday, November 01, 2005 - 3:51 pm: |
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Narf, the old original CLR II had a weak foil type coil on a round disk in the base that was used to match the 1/2 wave element. A later version was built to handle more power and it was just a simple small copper wire coil (3/4" with 4 or 5 coils as I recall). One end in the SO-239 and the other attached to the stub for the radiator. This was all mounted inside the same base of the antenna at the feed point just like the old model was.
I do not recall a cap in there, but maybe there is one. Wouldn't the cap have to also go to ground in there? I don't recall ground being in the base of the antenna unless one leg attached to the base of the SO-239. There was a small piece of PVC in there also, but I do not recall the part it played in this coil either. It may have been there to keep the base of the coil from touching the base of the SO-239. If I can find it around here I will let you know, but I think it might be trash. Sorry. |
Narf_edwards
Junior Member
Username: Narf_edwards
Post Number: 20
Registered: 3-2005
| | Posted on Wednesday, November 02, 2005 - 10:40 am: |
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I am thinking now that since I have this unit mounted on a 12' copper mast the antenna is essentially acting as a vertical diploe .With the shunt/loading coil not there it really just sending rf into the radiator and the ground planes/mast.I found some details to wind the toroid coil....12 turns primary and 3-4 turns secondary on a T50-2 core.Does this sound right?I am gonna take it apart and put this coil back in and check it out again.Hopefully,it will work
Thanx again
Narf |
