Using a broken R-7000 HF with a tuner

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mancow

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I have a Cushcraft R-7000 vertical HF antenna but the control box that contains the toroids is broken. One of the toroid coils shattered and there is some corrosion inside as well.

I was looking at the Force12 flagpole antennas and it got me thinking about using what is left of the R-7000 since the rest of the hardware and traps appear to be just fine.

What would be the result if I ground mounted this thing wihout the control box and fed it directly with coax. I was thinking of making a rolled up coax balun and then connecting it all to my Z-11 Pro tuner.

The thing would be 24 feet tall but how would all the traps play into all of this?

Would it be worth the effort?
 
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prcguy

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If you put the Z-11 tuner at the base of the antenna in place of the original balun, it will probably work as good as original within the ham bands and it will also tune out of band. If you put coax between the tuner antenna you will start incurring losses.
prcguy
mancow said:
I have a Cushcraft R-7000 vertical HF antenna but the control box that contains the toroids is broken. One of the toroid coils shattered and there is some corrosion inside as well.

I was looking at the Force12 flagpole antennas and it got me thinking about using what is left of the R-7000 since the rest of the hardware and traps appear to be just fine.

What would be the result if I ground mounted this thing wihout the control box and fed it directly with coax. I was thinking of making a rolled up coax balun and then connecting it all to my Z-11 Pro tuner.

The thing would be 24 feet tall but how would all the traps play into all of this?

Would it be worth the effort?
 

mancow

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I was wondering about doing that too but the idea of running power and sealing it up seemed kind of like a pain.

What about a Hustler 6BTV? Maybe I should just order one of those and be done with it. Do you have any suggestions for a decent vertical. I know they are all a compromise but I think that's my only option here. The trees just aren't far enough apart for a decent dipole and there is just too much noise nearby. The neighborhood predates buried services so I have that to deal with. I was hoping a vertical might help to cut down on that.
 

prcguy

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I had a GAP Titan and can't recommend that POS. I have a Cushcraft MA5V on my office and can't recommend that when a B&W style T2FD horizontal at 30ft works much better. I did have a 20ft tall 1.5" dia vertical mast fed with an SGC tuner in the center of a bonded metal roof 125ft X 225ft and it seemed to work well on 40m and up for DX, but no NVIS coverage at all. Ground wave was good on that out past 50mi but it was dead from 75mi to a few hundred mi. Otherwise everyone I know who has any sort of full size dipole, G5RV or similar and a vertical (R-5, R-7, R-7000, Hy-gain 14AVQ, 18AVT, Butternut, you name it) has had grim results comparing them and the dipole type always seems to win for both DX and local use, except for local 10m where nearly everyone is vertical polarized.
prcguy
mancow said:
I was wondering about doing that too but the idea of running power and sealing it up seemed kind of like a pain.

What about a Hustler 6BTV? Maybe I should just order one of those and be done with it. Do you have any suggestions for a decent vertical. I know they are all a compromise but I think that's my only option here. The trees just aren't far enough apart for a decent dipole and there is just too much noise nearby. The neighborhood predates buried services so I have that to deal with. I was hoping a vertical might help to cut down on that.
 

mancow

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Well hell...

I may just drink beer by the fire pit in the back yard with the 817 on a collapsible whip and say F it.

:(
 

dkostrey

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Why not contact Cushcraft and see if you can order the parts you need. It may be cheaper than buying something new.
 

mancow

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I may do that. I just figured they would want some outrageous amount for the box but I guess it never hurts to ask.
 
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