Remote "tower" for my loop

[Blueliner]

I am only a now and then SWL guy. I use a MLA-30+ loop on a short pole outside the walk out basement wall and a SDR that seems to pull in just "OK". Also have a Grundig Satellit 800 Millennium, and a Radio Shack DX-394 that I use now and then.

The house is built into a fairly large hillside that faces NE so the upside of the hill, about 20 to 25 feet higher before it levels off, blocks everything except the N to NE direction. Not sure if this is part of a reception problem but suspect it is. I'm in a rural area so "neighborhood" noise isn't an issue. My utility lines are all buried from the road to the house as well.

I was thinking of erecting a short tower, maybe 20 feet high at the top of the hillside and running coax down to the inlet at the house. This would put my loop in a line of sight range of 360 degrees. The top of the hillside is one of the higher spots around this area so I hope raising the loop this way will allow better reception generally. I see old TV towers at auctions fairly regularly, some with old rotators still attached that if working, might be an added benefit for a loop antenna for SWL?

Here's my question:
The distance from the proposed tower base to the basement wall inlet will be in the range of 40 to 50 feet. It is a steep hillside covered in ivy, so buried cable isn't really necessary. IF this is even feasible, what type of coax cable is recommended and is 50 feet going to degrade signal strength enough to negate the higher up loop?

Hope this makes sense.

 

[K4EET]

I am only a now and then SWL guy. I use a MLA-30+ loop on a short pole outside the walk out basement wall and a SDR that seems to pull in just "OK". Also have a Grundig Satellit 800 Millennium, and a Radio Shack DX-394 that I use now and then.

The house is built into a fairly large hillside that faces NE so the upside of the hill, about 20 to 25 feet higher before it levels off, blocks everything except the N to NE direction. Not sure if this is part of a reception problem but suspect it is. I'm in a rural area so "neighborhood" noise isn't an issue. My utility lines are all buried from the road to the house as well.

I was thinking of erecting a short tower, maybe 20 feet high at the top of the hillside and running coax down to the inlet at the house. This would put my loop in a line of sight range of 360 degrees. The top of the hillside is one of the higher spots around this area so I hope raising the loop this way will allow better reception generally. I see old TV towers at auctions fairly regularly, some with old rotators still attached that if working, might be an added benefit for a loop antenna for SWL?

Here's my question:
The distance from the proposed tower base to the basement wall inlet will be in the range of 40 to 50 feet. It is a steep hillside covered in ivy, so buried cable isn't really necessary. IF this is even feasible, what type of coax cable is recommended and is 50 feet going to degrade signal strength enough to negate the higher up loop?

Hope this makes sense.

Based on your MLA30+ loop antenna, it appears that your SWL interest lies between 500 kHz and 30 MHz. Using Times Microwave LMR-400 as your coax, 50 feet only has 0.359 dB of loss with an SWR of 1.5:1 at the highest frequency of 30 MHz. With the same parameters but using Belden 9258 RG-8X for the coax, you are still only looking at 0.879 dB of loss. Both types of non-bury coax would be acceptable with LMR-400 being the least lossy of the two. Use the following calculator if you want to change the type of coax.

Coax Loss Calculator | KV5R.COM

Let us know if you have any questions.

 

[Blueliner]

Yes, my SWLing is mostly in the BC bands, 500KHz to 30MHz. But who knows what may come along in the future? Scanner, CB, no telling. You really helped with answers on the question of loss over the estimated length, thanks for that and thank you for addressing my rather beginner type questions.

Since posting this original thread was looking on line for antenna rotators, the kind used for TV. The old school standbys like Channel Master with fairly reasonably priced but sturdy models are all sold out. Only Chinese TV antennas with what appears to be inadequate rotators are available. Comments on Chanel Master's site all lament the unavailable or sold out situation that now seems to date back a couple of years or more. Wonder what has happened there?

 

[tuihill]

Yes, my SWLing is mostly in the BC bands, 500KHz to 30MHz. But who knows what may come along in the future? Scanner, CB, no telling. You really helped with answers on the question of loss over the estimated length, thanks for that and thank you for addressing my rather beginner type questions.

Since posting this original thread was looking on line for antenna rotators, the kind used for TV. The old school standbys like Channel Master with fairly reasonably priced but sturdy models are all sold out. Only Chinese TV antennas with what appears to be inadequate rotators are available. Comments on Chanel Master's site all lament the unavailable or sold out situation that now seems to date back a couple of years or more. Wonder what has happened there?

I've seen some antenna rotators for RV roofs that are compact and 12 volts.

 

[MDScanFan]

Before building anything, my recommendation is to test reception at the bottom and top of the hill to see if it makes much of a difference. This should be easy to try given your radios and the MLA-30 can be run on batteries. For the frequencies you listen to the hill might not make much of a difference.

The type of coax used for reception at these frequencies is basically inconsequential. RG-6 is one low cost option.

 

[tuihill]

It is my understanding from reading past forums elsewhere that these HF loops perform better near ground level than elevated too high above the surface. Don't remember why.