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The eco-4 shivley antenna, with Mystery Ports

Posted: Sat Jun 30, 2018 9:16 am
by abwdvm
We got it down, it's a two bay
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Mystery port... Spooky
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Re: The eco-4 shivley antenna

Posted: Sat Jun 30, 2018 10:00 am
by RGORJANCE
From what I see, that looks like a patch covering possible lightning strike damage. I doubt if the interior ever got cleaned. There are probably carbon deposits inside all of the lines. The only thing to do is to take that section apart and inspect the inside. If there is damage that is not repairable, you will need to get an exact length to replace it. That could reveal a lot more carbon thru the other sections requiring a significant amount of time to clean, inspect and repair as necessary.

It might be more expensive to buy a new antenna, but on the other hand, it will be all new and won't have the "used-damage repaired" and possible hidden damage issue to deal with.

That repair job is, in my humble opinion, pretty crude.

Fossil

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sat Jun 30, 2018 10:10 am
by ncradioeng
I think the mystery ports you refer to are the disconnected heater feeds.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sat Jun 30, 2018 10:36 am
by RGORJANCE
Hmmmmm. I might be losing it in my old age. I could swear that I only saw two pictures when I looked at the post earlier.......and I assumed that the patch was on an interbay line. Sorry 'bout that! :shock:

You might want to pull the bullets out an look up inside the interbay lines for any possible pitting/carbon deposits before you reinstall it....just as a "cya" check. Lots easier to clean/fix on the ground than up in the air.

Fossil

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sat Jun 30, 2018 4:05 pm
by Deep Thought
Yeah, that antenna is supposed to have deicers (as noted by ncradioeng above) and the cut-off electric feeds for them are what those "mystery ports" are.

That antenna is pretty old and doesn't owe anyone anything at this point.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sat Jun 30, 2018 4:42 pm
by TPT
Houston--we have a problem!!!

Compiling these threads, you have a sick ECO-4 and are moving to a new tower requiring 295 feet of transmission line (1 5/8th foam proposed), for an ERP of 3600 watts. Now the antenna is down you see it is a two bay--not a four bay.

OK--Antenna gain for a two bay Shively llisted at .99
So 3,636 watts required into the antenna (top of the pipe)
Loss in the 295 feet of feedline is 605 watts;
Therefore you need 4,241 watts out of the ECO-4

Not likely.

If you purchased a new 3 bay antenna, your transmitter would be required to put out about 2700~2800 watts. Check ERI, SWR or Jampro.
Note this is well within the capabilities of a Nautel VS2.5, which is rated up to 2800 watts. The ECO-4 probably can be re-tuned to produce 2700 watts, so should be good for a while. But it is no longer supported, and eventually it will die. The Nautel, I believe, costs in the range of $13K.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sat Jun 30, 2018 4:55 pm
by TPT
Now--if I am confused, and 295' is the coax length at the present installation you just took apart--then this explains the 3" coax. With those parameters, the transmitter power out required is 4,087 watts. Still marginal.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sat Jun 30, 2018 7:28 pm
by Deep Thought
We don't know if the TPO was 3.6 KW or the ERP was 3.6 KW. Either way this has turned into a situation where someone who knows what they are doing really needs to take over. No disrespect to the OP because we all had to start somewhere, but there are too many "gotcha" variables here.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sun Jul 01, 2018 8:44 am
by TPT
Putting on my legal hat--I wonder if they have applied for an STA to remain silent while the new owners makes these changes. A day or so outage isn't a problem, of course. But this project looks like it may go on for a while--well past the 30 days the Commission wants to see an STA for either a temporary site or off-air.

When we did a "drop and flop" back in 2004, we were off two days while the old tower came down & the new tower was built 3 feet away. Gave us some time to check out our 4 bay, which had been up 15 years at that point. Then in 2012 we moved off a rented site to a new tower--350 feet away.
Had to abandon the antenna because the tower crew wouldn't climb the old tower. However, we were already on the air from the new site with a kilowatt before we hauled the ECO-4 out. But we had planned both moves well ahead of time.

I realize sometimes circumstances throw a whole series of curve balls. Last year, about this time--we were talking with a local church that owns a class A on a possible relocation to our tower. Come August the pastor is at our door-steaming--since his landlord allowed the AC to die on their equipment shelter. Killed his transmitter. Working with his engineer got him back on the air at reduced power--with a 1977 vintage antenna--at my site under an STA in a week. But his engineer has been in the business since the 60's, so we had a plan in place.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sun Jul 01, 2018 1:59 pm
by kkiddkkidd
Deep Thought wrote: Sat Jun 30, 2018 7:28 pm We don't know if the TPO was 3.6 KW or the ERP was 3.6 KW. Either way this has turned into a situation where someone who knows what they are doing really needs to take over. No disrespect to the OP because we all had to start somewhere, but there are too many "gotcha" variables here.
I firmly concur. As Deep iterated, absolutely no disrespect intended but this project is not something that I would have wanted to take on as a novice (and possibly even as an intermediate) engineer.

Advice from forums is a very good learning tool but this TX site has more than enough problems and "gotcha" variables to make this 30+ year vet a little nervous if I were the site engineer trying to move a system on the spur of the moment.

Don't be a hero and then compound your problems by making poor decisions based on forum advice while trying to reuse worn out junk. The chances of a positive outcome for you or your employer are slim to none. The chances of great heartache and strife are great.

To recap, your TX is no longer supported, the TX is probably too small to _reliably_ make licensed ERP with the existing antenna & line, the antenna is damaged, both the antenna and TX are OLD, IF you reduce the cable size to something reasonable, the tx will almost certainly never make ERP with the existing antenna.

It may have been mentioned before, but you are aware that moving a broadcast transmitter site requires an FCC construction permit?

Regards,

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Sun Jul 01, 2018 2:58 pm
by abwdvm
Thanks you all for all the information. It has really been a great help.

Passing the unvarnished truth to the boss.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Mon Jul 02, 2018 3:42 pm
by Nathaniel Steele
I don't envy you. I assume this was an AS-IS Where-IS sort of deal? Your'e In Texas right? IF you want assistance, I know someone I could refer you to. I have no Idea what his schedule is right now and it may not work for him but I'd be happy to pass off his info in a PM. I know he's pretty good with those ECO boxes, I think he still helps a client in CO with them from time to time. He can also assist with the FCC paperwork, filing, and studies.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Mon Jul 02, 2018 4:09 pm
by abwdvm
Thanks, we have an FCC attorney, and that part i don't have to worry about. We might interested in someone who knows the ECO hardware.

Re: The eco-4 shivley antenna, with Mystery Ports

Posted: Tue Jul 03, 2018 9:40 am
by Nathaniel Steele
I sent him links to your threads, sounds like he's out of town this week, but he said he'd look it all over. Maybe he'll register and post or PM you, or I can put you in touch otherwise. He did ask where in Texas, he's up in the panhandle.