Base Station Setup: antenna first

[Radiomatrix]

I have lugged around my Base station stuff for 40yrs, including mast, thick coax, and A-99 antenna.
I am trying to find a suitable location for the antenna/mast but a little hesitant attaching a bracket to the house so a possible location for the mast is a wooden structure 12ft from the house.

Questions:
*Can i run coax down from the antenna, into some electrical conduit underground to the house?
*Can the coax enter the house through the same electrical conduit shared by 110vac that powers the outside outlets or will having coax right next to romex coming thru the wall cause some evil interference?
*Is it possible to paint parts of the A-99 black?

More questions coming soon. Thanks!

 

[mmckenna]

Questions:
*Can i run coax down from the antenna, into some electrical conduit underground to the house?

You can, but you would want to use direct bury rated coax, even in conduit. Water -will- collect in the conduit. Doesn't matter how well you seal it, it will find it's way in. Standard coax sitting in water long term will become an issue. The jacket will break down and the water will destroy the cable.

*Can the coax enter the house through the same electrical conduit shared by 110vac that powers the outside outlets or will having coax right next to romex coming thru the wall cause some evil interference?

NEC code violation to do that. Needs to be in its own conduit.
Good coax with 100% shield should be OK in close proximity to 110v AC wiring, but it's a good idea to keep things apart.

*Is it possible to paint parts of the A-99 black?

With non-metallic paint.

More questions coming soon. Thanks!

 

[Radiomatrix]

You can, but you would want to use direct bury rated coax, even in conduit. Water -will- collect in the conduit. Doesn't matter how well you seal it, it will find it's way in. Standard coax sitting in water long term will become an issue. The jacket will break down and the water will destroy the cable.



NEC code violation to do that. Needs to be in its own conduit.
Good coax with 100% shield should be OK in close proximity to 110v AC wiring, but it's a good idea to keep things apart.



With non-metallic paint.

THANK You!.... Bury rated coax: does it still need to be in conduit or it is just a good idea?

I have read stuff about the length of coax until my eyes bled. If less than 50ft are we good?

I just googled direct bury coax and got stuff for satellite or cable TV coax.
Can you throw out some brands and specs please!

I should have mentioned but when I went back to edit a few hours later, the EDIT window had expired ( WHY DO THEY DO THAT ON THIS BOARD WITH SO MANY OLD FARTS HERE LIKE ME?) ....Anyway, I have a President Washington Base Station that I sent away to President for tune up and checkout. AM/SSB radio. I want to set it up with my A-99. I am working ever so slowly on my Technician's license and may probably try and use the same setup for my first HAM setup as well-----SOOoooooo, I guess the COAX should be good enough for both...????

Electrical code violation: CHECK thanks...( I should have known that.) I have to drill a hole in the wall before the wife get back home on Sunday!

 

[mmckenna]

THANK You!.... Bury rated coax: does it still need to be in conduit or it is just a good idea?

"direct bury" rated coaxial cable has a water displacing gel in it that will keep the water out if the jacket gets damaged.
Often the bigger issue is caused by rodent damage, or damage from sharp rocks.
You could certainly direct bury the cable and be OK, but it may eventually get gnawed upon by some subterranean rodent.

But, ya' gotta dig the hole to put the coax in. And you want it deep enough that it doesn't get easily damaged. PVC conduit is cheap and easy to work with. It adds a layer of protection to the cable -and- if you upsize the conduit a bit, it makes it easy to install more cable if you need it.

Personally, I wouldn't put all the effort into digging a trench and NOT throw in at least one run of conduit. The real cost is in the labor, not in the conduit.
I did something similar in my back yard about 12 years ago. I needed to run a cable for the sprinkler controls. I dug a trench and laid in a 3/4" PVC electrical conduit for that wire. I also dropped in a 2" PVC conduit for "future" use. Sure enough, a few years later I wanted to run some coax back into the yard for a shortwave antenna. All I had to do was pull it through the conduit and I was done.

I have read stuff about the length of coax until my eyes bled. If less than 50ft are we good?

That is something you need to decide. For CB use, you don't need super high grade coax to get good performance. Most coax works pretty well at 27MHz without a whole lot of loss.
All coaxial cable has some amount of loss.
Longer coax has more loss than shorter coax.
Higher frequencies will suffer more loss than lower frequencies.

You can play around with this online calculator and try different coaxial cable types to see what the loss will be like.
-Remember, loss works both ways. More loss will result in less power getting to your antenna. It'll also result in the same amount of loss in getting signals FROM your antenna to your radio.

Every 3dB of loss is half your power. If you are running a bone stock CB at 4 watts, and you have 3dB of loss in your coaxial cable, only 2 watts will make it to the antenna base. Same works in reverse, half the received signal will be lost….

Just make sure whatever cable you get is rated for direct bury. Also make sure that you use a big enough conduit. Pulling a run of LMR-400 through a 1/2" conduit is going to be difficult. 3/4" conduit would be hard. Go large, conduit is cheap….
Also, either install the cable before putting on the connectors, or make darn sure you figure in the size of the connector when sizing the conduit.

I just googled direct bury coax and got stuff for satellite or cable TV coax.
Can you throw out some brands and specs please!

Times Microwave LMR type cables with the -DB suffix. LMR-400DB would be a pretty good cable for CB use. If budget is tight, LMR-240DB would work pretty dang well.

LMR-400-DB | Times Microwave Systems

LMR 400 50 ohm coax cable for Direct Burial with UV Resistant jacket. Better bending and handling than smooth wall or corrugated hardline cables.

timesmicrowave.com

LMR-240-DB | Times Microwave Systems

LMR 240 50 ohm coax cable for Direct Burial with UV Resistant jacket and watertight braids. Better bending and handling than smooth wall or corrugated cables.

timesmicrowave.com

I should have mentioned but when I went back to edit a few hours later, the EDIT window had expired ( WHY DO THEY DO THAT ON THIS BOARD WITH SO MANY OLD FARTS HERE LIKE ME?) ....Anyway, I have a President Washington Base Station that I sent away to President for tune up and checkout. AM/SSB radio. I want to set it up with my A-99. I am working ever so slowly on my Technician's license and may probably try and use the same setup for my first HAM setup as well-----SOOoooooo, I guess the COAX should be good enough for both...????

I'm not up on those CB antennas, but I ~think~ they can be retuned for the 10 meter band. The performance from the coax standpoint between CB and 10 meters is going to be close enough.

If you plan on running VHF or UHF, then you want a good cable. The LMR-400 would be my choice if a dual band VHF/UHF radio is in your long term plans.
Or, install a large enough conduit that you can pull through multiple runs of cable.

Electrical code violation: CHECK thanks...( I should have known that.) I have to drill a hole in the wall before the wife get back home on Sunday!

Yeah, those pesky codes….

 

[Radiomatrix]

"direct bury" rated coaxial cable has a water displacing gel in it that will keep the water out if the jacket gets damaged.
Often the bigger issue is caused by rodent damage, or damage from sharp rocks.
You could certainly direct bury the cable and be OK, but it may eventually get gnawed upon by some subterranean rodent.

But, ya' gotta dig the hole to put the coax in. And you want it deep enough that it doesn't get easily damaged. PVC conduit is cheap and easy to work with. It adds a layer of protection to the cable -and- if you upsize the conduit a bit, it makes it easy to install more cable if you need it.

Personally, I wouldn't put all the effort into digging a trench and NOT throw in at least one run of conduit. The real cost is in the labor, not in the conduit.
I did something similar in my back yard about 12 years ago. I needed to run a cable for the sprinkler controls. I dug a trench and laid in a 3/4" PVC electrical conduit for that wire. I also dropped in a 2" PVC conduit for "future" use. Sure enough, a few years later I wanted to run some coax back into the yard for a shortwave antenna. All I had to do was pull it through the conduit and I was done.



That is something you need to decide. For CB use, you don't need super high grade coax to get good performance. Most coax works pretty well at 27MHz without a whole lot of loss.
All coaxial cable has some amount of loss.
Longer coax has more loss than shorter coax.
Higher frequencies will suffer more loss than lower frequencies.

You can play around with this online calculator and try different coaxial cable types to see what the loss will be like.
-Remember, loss works both ways. More loss will result in less power getting to your antenna. It'll also result in the same amount of loss in getting signals FROM your antenna to your radio.

Every 3dB of loss is half your power. If you are running a bone stock CB at 4 watts, and you have 3dB of loss in your coaxial cable, only 2 watts will make it to the antenna base. Same works in reverse, half the received signal will be lost….

Just make sure whatever cable you get is rated for direct bury. Also make sure that you use a big enough conduit. Pulling a run of LMR-400 through a 1/2" conduit is going to be difficult. 3/4" conduit would be hard. Go large, conduit is cheap….
Also, either install the cable before putting on the connectors, or make darn sure you figure in the size of the connector when sizing the conduit.



Times Microwave LMR type cables with the -DB suffix. LMR-400DB would be a pretty good cable for CB use. If budget is tight, LMR-240DB would work pretty dang well.

LMR-400-DB | Times Microwave Systems

LMR 400 50 ohm coax cable for Direct Burial with UV Resistant jacket. Better bending and handling than smooth wall or corrugated hardline cables.

timesmicrowave.com

LMR-240-DB | Times Microwave Systems

LMR 240 50 ohm coax cable for Direct Burial with UV Resistant jacket and watertight braids. Better bending and handling than smooth wall or corrugated cables.

timesmicrowave.com

I'm not up on those CB antennas, but I ~think~ they can be retuned for the 10 meter band. The performance from the coax standpoint between CB and 10 meters is going to be close enough.

If you plan on running VHF or UHF, then you want a good cable. The LMR-400 would be my choice if a dual band VHF/UHF radio is in your long term plans.
Or, install a large enough conduit that you can pull through multiple runs of cable.



Yeah, those pesky codes….

Codes were all weitten in blood at some point, good thing we have them.

i must thank you for taking the time to post such a thoughtful response.

one inch electrical conduit be sufficient? 1.5” (future proof)?

 

[slowmover]

DAVIS BuryFlex Is what a number of us CB’ers have used with good results. In stationary and mobile (given its physical limits). Nice noise rejection in big truck mobile where I had a 25’ run.

I wouldn’t want to have to replace in a base station scenario any more often than necessary.

.

 

[mmckenna]

Ooops, forgot to include the link for the online coax cable calculator:

Coax Calculator

 

[mmckenna]

Codes were all weitten in blood at some point, good thing we have them.

i must thank you for taking the time to post such a thoughtful response.

one inch electrical conduit be sufficient? 1.5” (future proof)?

The common UHF male connectors are almost 0.8 inches in diameter. The internal dimensions of Schedule 40 1" PVC conduit is 1.004".
It'll fit with the connector on, but it's going to be close and probably a bit difficult.

If you can install your own connectors and just pull the coaxial cable through, that will make things a lot easier. It'll reduce the size of conduit you need if you can just pull the cable only. If you need to keep the connectors on, it's going to need to be a much larger conduit.

I pulled a lot of cable in my younger years, and when you approach the fill capacity of the conduit, life gets hard. Pulling all the cables through at the same time is the easiest way to do it. If you try to pull them one at a time, they often get wound around each other and you'll end up pulling it all out.

Planning is important.

 

[wjm1129]

Jefatech has good coax also with free shipping.

 

[Radiomatrix]

Jefatech has good coax also with free shipping.

They are in Maryland. Thanks!

 

[Radiomatrix]

Jefatech has good coax also with free shipping.

My wife is visiting a few miles from this place in NH!

 

[Radiomatrix]

I have a telescoping mast. It has a bracket that is attached to a structure then the mast is attached to that. What do people do with the bass of the mast?

 

[Radiomatrix]

The common UHF male connectors are almost 0.8 inches in diameter. The internal dimensions of Schedule 40 1" PVC conduit is 1.004".
It'll fit with the connector on, but it's going to be close and probably a bit difficult.

If you can install your own connectors and just pull the coaxial cable through, that will make things a lot easier. It'll reduce the size of conduit you need if you can just pull the cable only. If you need to keep the connectors on, it's going to need to be a much larger conduit.

I pulled a lot of cable in my younger years, and when you approach the fill capacity of the conduit, life gets hard. Pulling all the cables through at the same time is the easiest way to do it. If you try to pull them one at a time, they often get wound around each other and you'll end up pulling it all out.

Planning is important.

LRM-400 from what i have read is difficult to work with. Also looking at LRM400uf…

i can add my own connectors.

when the cable enters and exits a given run of electrical conduit, especially on the open end, are there grommets or fittings for the ends or do you just fill with silicon?

 

[prcguy]

LRM-400 from what i have read is difficult to work with. Also looking at LRM400uf…

i can add my own connectors.

when the cable enters and exits a given run of electrical conduit, especially on the open end, are there grommets or fittings for the ends or do you just fill with silicon?

You can't prevent water from entering and filling up underground conduit, its useless to try and seal it. I've run miles of cables in underground conduits that will soon fill with water and no companies I know of use direct burial cable inside conduits. Yes the cables will sit submerged in water at some point, no it doesn't affect anything, at least over 30-40yrs that I have seen.

 

[mmckenna]

LRM-400 from what i have read is difficult to work with. Also looking at LRM400uf…

Direct bury rating needs to come first. They don't make a direct bury rated ultra flex cable. The direct bury rated has a solid center conductor and it has a larger minimum bend radius, but it works fine with standard sweep elbows for electrical conduit.

i can add my own connectors.

when the cable enters and exits a given run of electrical conduit, especially on the open end, are there grommets or fittings for the ends or do you just fill with silicon?

As prcguy said, it won't keep water out. It does not hurt to install something to keep bugs and debris out, however. There are specific conduit sealing compounds made that will keep critters out. Silicone would work if that's what you have.