RG-8X or Better?

[RadioDitch]

Looking for some guidance, as this is kind of a unique situation. I'm trying to determine what the best grade coax would be to use for a 1500ft run down a mountainside. This would be for VHF, ***receive only***, with a genuine Stationmaster at the summit and Motorola Maxtrac at the bottom.

My main concern would be signal loss. Granted, I know it wouldn't be HUGE in this situation, but the less, the better. Price/ft is not an issue. So would RG-8X cut it? Or is there a much better option that isn't total overkill?

Thanks in advance gents.

 

[mmckenna]

Oh, hell no. Are you serious, or just pulling our leg(s)?
65dB of loss just in the cable. SIXTY-FIVE. You'll get nothing measurable out the end. In fact I'd go as far as to say that the leakage through the shield would provide more signal than the antenna would supply to the radio. Probably by a long shot.

Money's not an issue?
Times Microwave LDF6-50A would only loose about 2/3rds of your signal to cable losses. Only looking at somewhere around $15.00 a foot, or $22,500 just in the cable. Of course laying that cable directly on the ground will eventually destroy it, but money isn't an issue, right? It'll come on huge reels that will likely be delivered by an 18 wheeler. Got a forklift? It'll weigh tons and dragging it across the ground will probably destroy it. It's air core, so any damage will let the water in, so you'd need to pressurize it.
Of course you could step up to hard line, lots of flange/bullet connections, lots.... Gotta be straight run. Several hundred thousand to start.

Running coax 1500 feet isn't the way to do this.
What you do is mount the radio at the base of the antenna and feed the audio to your shack via something much more appropriate for for long haul. Like twisted pair telephone cable. Outdoor type, ariel, gel-filled. Using a tone remote set up, you could even do channel steering. Fiber optics would work better, no risk of attracting lightning. IP radio link would probably be a better way to go. Get a couple of point to point links and put a PC up at the radio. Stream the audio.....

 

[n0nhp]

Running 120 Volts up the mountain and stringing audio back down will be about the only way to get any usable signal at all at 1500 feet.
On VHF anything over 50' will be a total exercise in futility with RG8x.
The best antenna and receiver in the world will not work at these distances.

Bruce

 

[bharvey2]

1500' ? Is that a typo? I don't know of a type of coax that you can use that will be able to carry a decent signal that far. If you've got your heart set on cabling I'd go with what mcmenna mentioned and use fiber. At that distance, multimode should still work. Otherwise, go wireless. In any case, you'll need to convert your audio signal to a streaming format. However, if your creative you might find some way to transmit audio over fiber like this: Mic and Line-Level Fiber Optic Audio Extender Kit

Either that of get a really powerful amp and BIG speakers and put them on top of the hill. You're neighbors won't be happy though.


bharvey2

 

[kayn1n32008]

Hmmm... This sounds familiar... Someone has asked this very question before...


Sent from my iPad using Tapatalk

 

[Voyager]

Put the Maxtrac at the top of the mountain and run a DC or Tone (preferably tone) remote line (same as telephone line) to the bottom. It will be much less expensive in the long run (pun intended), and will actually WORK.

Even using Heliax that is a lot of loss.

 

[zz0468]

G-line would work, but then you'd have the expense of the launchers, and poles in to suspend the line above the ground.

Any other cable intallation will require distributed amplifiers along the way. You'd be better RF linking that distance.

 

[KC4RAF]

1,500 foot run of coax?!?!

And reference to loss, "Granted, I know it wouldn't be HUGE in this situation,..."; the loss will BE HUGE!!!
Fiber optics is about the only way to go and not suffer a big dent in your bank account. A couple of other mentions were posted that will work, but more cost involved.

 

[RadioDitch]

As insane as it sounds, and believe me, I'm well aware it very much does, it's not a joke. It's an interesting and VERY unique situation.

Basically the aim is to establish a permanent mountaintop antenna install for our campsite. It's intended for receive only, between 144MHz and 163MHz. The aim is to monitor both 2m, AAR band, and NOAA. There is no commercial power, and no telephone lines available at the location. This is an extremely remote part of the Berkshires. The run would have to be 1500ft from the summit at 2160ft ASL, down the mountain to our camp.

Honestly, I failed to realized it would be as huge as a 65dB loss. This isn't my strong part in the hobby.

So knowing now that there's no commercial power, and a tone link isn't an option with the total lack of utilities...any other suggestions?? I'm open to everybody's experience and knowledge...

 

[mmckenna]

Well, you were willing to run coax, so why not run some twisted pair phone wire, multi-mode fiber? Either one would be cheaper than coax.
Power will need to be addressed no matter what you do. Running coax would need a preamp at the antenna to get something useable down the coax. Powering a tone remote or fiber transceiver won't take a lot of juice. This is the exact situation where solar is ideal. Also, if it's only for during camping trips, you could probably haul up enough battery power to run everything for a few days.
It doesn't require any commercial utilities (phone co. or electric utility)

This isn't an uncommon situation. There are plenty of radio sites that I've been to that have no commercial services available. Solar is getting very common, and many just use propane thermo-electric generators as back up. Point to point radio links can take care of the connection. I've even been to sites where the phone company just laid direct bury phone cable on the ground. It ran from the bottom of the hill to the peak.

Coax isn't the answer. Even if it was, you'd need to line power amplifiers, like the cable TV companies do.

 

[mass-man]

no commercial power...then look into a small solar power setup! A 1500ft coax run will never give you satisfactory results.

 

[mmckenna]

So, this isn't scalable to what you want, but it's a prime example of how it's done. This is a remote AT&T cell site at about 10,000 feet elevation in far eastern California. Probably a full 6 months out of the year it's only accessible by snowcat or helo. Full LTE site, microwave backhaul. Large solar array for primary power and a 6000 gallon supply of propane for the generators. There is NO electric or telephone utility at this site. In fact, it's probably 20 miles to the closest pole.

You could do something similar, obviously a MUCH smaller scale.
Simple Harbor Freight solar panel with battery back up to power everything.
Use a tone remote set up to connect to the radio.
Run 1500 feet of direct bury rated telephone cable down to your camp.
Tone remote base at that end, plus whatever you need to power it.
You don't need phone company dial tone to make a tone remote work. You just need a pair of wires from point to point.

 

[Voyager]

+1 on the solar.

 

[n5ims]

Instead of running that 1500' of RG-8X, just put this on your radio. You'll end up with less loss. Save money to boot!

202113 BNC Male Dummy Load/Termination (High Performance 0.5 Watt (1%)

 

[cmdrwill]

"For receive only". Run the speaker into a 8 ohm to 600 ohm transformer at the radio and the 600 ohm telco type cable to your listening post......

 

[n0nhp]

Wouldn't work for the NOAA but for 2M, I would just get a dual band that you could throw into crossband remotely.

Bruce

 

[Voyager]

Another option would be a passive repeater - basically a yagi aimed toward the house connected to the vertical antenna. It's lossy, but likely not as lossy as a 1500' feedline.

 

[mmckenna]

He'd need a crap load of gain to do that, probably some amplification. Adding amplification adds the risk of it starting to self oscillate.

 

[zz0468]

A remote radio on a wireline or rf link is what he needs.

 

[majoco]

Hmmm. I'll enquire from a friend how he does his link. All his radios are down the yard in a shed and he has a WiFi link back to the house. He's an IT guru so it's not surprising. He reckons he can select his scanners and listen to them while soaking in the bath.... not a pretty sight!