Another which freq to choose/range question

[LakeMan2]

I know this question has been asked many times before. I have been doing a lot of research trying to decide what to do and have read through many posts like this one. The problem is that most posts don't have terrain details and I can't get a handle on how much LOS impacts transmission/receiving.

Most people ask about freq/range and the responses are "it depends". I get that. What I am having trouble with i show much it "depends" vs freq.

My situation is we have a lake cabin on a inland river/lake. We have kids that like to go canoeing/kayaking/fishing as well as some teenagers that are trying to convince us that they are old enough to take the ski boat out by themselves... I am trying to find a reliable means of communications with them in case if problems. It is a rural area and unfortunately cell phone service is non-existant on the shore/dock and spotty on the water. We had n issue late last year where the kids were out and the engine would not start. They had a cell, but we had problems getting calls to go through and being intelligible. It made the starting problem a whole lot more stressful for all involved. We have also had an issue where our youngest was out kayak fishing and the wind came up. He could not paddle back and had to paddle to the closest shore. He had a FRS/GMRS radio so he called us, but what we have is crap and I need to improve on that for that kind of situation. If he was a little bit further out we may not have heard him.

The part of the lake we are concerned with is long, relatively narrow (as lakes go, maybe ~200-300yrs wide) with steep high shore line. The surrounding topology varies of course but ranges from 20-80 feet above lake level. Unfortunately our cabin is not at the top of a hill but on the side (facing our cove). What ever we do we will have an antenna on a 40' tower. That will put the antenna above any nearby hills, but right at or slightly above more distant hills between us and various parts of the lake. Of course the problem is that the lake is in a "valley" of sorts"

I have two use cases. One is canoe/kayak which is short range 1 mile or less but I really wanted to go waterproof HT since they will get wet and likely will go in the water at some time. The second case is on the boat which would need 2.5-3 mile max range. Waterproof HT would be nice, but I could get away without a waterproof HT here.

I have looked at CB, marine VHF, MURS, FRS/GMRS, and a few others. Ham is not really an option because everyone in the family needs to be able to operate the radios. I don't see my wife or the kids getting their license. I would prefer to use one solution, but I am not sure if that is possible. I am leaning towards CB SSB or VHF. I would prefer VHF because of the waterproof/floating HT options but am concerned about it ability to cover 3 miles of hill/valley terrain. I think CB SSB might be better for the terrain coverage but of course I can't find a waterproof HT.

So I know I will have LOS issues. It is definitely not a clear LOS. The question is what option would have the best chance to work reliably up to 2.5-3 miles given the hills and valley I know we have. I can't get a feel for if one freq or another would have a better chance of bouncing off the steep 70' lake shore and going down the lake, or if nothing will work given the LOS issues. I am not going to be able to get the antenna at the cabin any higher. We will be limited to HTs on the kayaks. I had hoped to use HTs on teh boat to, but I suppose I could look at an external antenna setup.

So bottom line, Given a challenging LOS (hills/valley) with a max 80' vertical elevation differential what option would be most likely to work? I had hoped for a single solution for the longer range boat as well as the shorter range kayak (waterproof HT), but if that is not possible, I might consider two setups.

In the end I know I will just have to "try it out". but given the cost and work to put up an antenna, I am trying to increase the odds of getting a working solution the first time.

Thanks

 

[mikewazowski]

Thread moved since this the OP has said amateur radio isn't an option.

 

[robertmac]

In general as you say who knows? That is the fact with RF, just to many different variables. Stay away from crappy band as it is the most unreliable, especially during the daylight hours. Oh, might be better in a few years [and as you have read up on this you know why]. That leaves you with MURS, GMRS as best options. GMRS repeaters can be used in the US so look at that as probably your best bet. Talk with local radio stores as they may have a repeater in your area where you can rent radios when you need them. Or rent them and try them out and that will be the best.

 

[zz0468]

I'd stick with GMRS, and put a repeater at the house. That way, so long as an ht can communicate with the house, a pair of ht's could communicate together, even if they couldn't communicate directly. A single license will cover the entire family, and high quality radios can be purchased inexpensively. The difference between VHF and UHF would probably not be a factor. GMRS will allow you to run enough power that your 3 mile range requirement would be easy to achieve.

 

[popnokick]

Before you decide anything you'll benefit from a predictive RF plot based upon the terrain at the exact spot where your tower is located. You can get this done professionally but it is likely to be expensive. You might be able to find someone here on RR to do it for the fun of it. Or, you can do it yourself using Radio Mobile Deluxe (steep learning curve) or the W5GFE Splat Page:
W5GFE Splat Page
Both use Shuttle Radar Topography for terrain data. You'll need to put in details about your exact tower location, height, frequency(s) of planned usage, power output levels, and antenna gain as accurately as possible (garbage in, garbage out is the rule here). But in return you'll get at worst an idea of whether or not your planned radio scheme will work or not, and at best may be able to have enough data to select the best option and a fairly accurate coverage plot.
Having written all of the above, GMRS is your best bet. You can start without a repeater, and just put a good omni gain antenna on the tower, high quality low-loss coaxial cable, and a good GMRS base radio running full legal power. If that works for what you need, then you're done. If you want to expand and can easily reach all of your HT's where they are around the lake... and want to add HT to HT capability.... change out your base radio for a repeater and duplexer (more expensive than a simple base radio).

 

[Darth_vader]

I'd say go with CB or MURS if range over hilly terrain is a concern. Or both. A GMRS repeater may be doable, but probably more of a hassle than it's worth, especially if you only go there maybe a couple times a year (and GMRS is expensive in general. If you can, hold out on that until the FCC make their move regarding service revision/deregulation. That $85, from what I gather, is not refundable.)

27 and 151/154 MHz are more tolerant of ruggedness and obstructions than 462/467 MHz, anyways. Across a lake (ship to shore), you *might* be able to get away with using FRS if you have a relatively clean line of sight to the boat (i.e. standing on the dock, if there is one) and they hang relatively close to the shore, but don't rely on it.

"Stay away from crappy band as it is the most unreliable, especially during the daylight hours."

Stop calling it "crappy band", robertmac. It's getting trite and it shows your HAM arrogance. The name is "Citizens' Band".

 

[mirayge]

The option depends on what other lake users have already set up. Are they using marine radios? Does somebody have a GMRS repeater? You may be able to help/rescue eachother if on the same bands. I am not sure if these are repeater capable, but you may try out these Cobra radios. Cobra Marine MR-HH425LI-VP Two Way Radio
They are available all over the internet, Amazon, ebay, etc. I don't usually think its smart to mix bands on a radio, but for this specific instance it may be usefull.

 

[robertmac]

Oh sorry Darth it is the chicken band. But it is crappy to think it is suitable in an emergency. That is why I tried to lead him away from that as I wouldn't even want my enemies to rely on 27 MHz in an emergency. As a 4th or 5th back up maybe, but certainly not primary as a "reliable" means of communications as the OP has requested. Thus my initial response as MURS or GMRS. Having grown up in the chicken band era, I think it is far from arrogance to lead a person away from this [_______] fill in the blanks band.

 

[LakeMan2]

Oh sorry Darth it is the chicken band. But it is crappy to think it is suitable in an emergency. That is why I tried to lead him away from that as I wouldn't even want my enemies to rely on 27 MHz in an emergency. As a 4th or 5th back up maybe, but certainly not primary as a "reliable" means of communications as the OP has requested. Thus my initial response as MURS or GMRS. Having grown up in the chicken band era, I think it is far from arrogance to lead a person away from this [_______] fill in the blanks band.

I am curious as to what makes you say that CB is unreliable. I am not doubting you, but want to understand that comment so I can determine how much it might apply to my situation. From what I have read, I see "unreliability" mentioned as related to illegal high power CB stations and skip conditions etc. Is this what you are referring to, or is there more to it?

My initial thought is that we are sort of out in the middle of no where (although I suppose that is quite relative). We are 8 miles (straight line) from the nearest 4 lane road, and ~40 miles (again straight line) from the nearest interstate. I am not sure how much CB use there is out here. Then, if I specifically were to use SSB, would that not cut down on the possible interference etc?

 

[Darth_vader]

He's just being a typical arrogant HAM troll, LakeMan2. Just ignore him. He likes to hate on CB for no other reason than the sake of doing so. It's an ego/peer pressure thing. About the only agreeable thing he's posted about it yet is on its reliability in an emergency. That's what 9-1-1 is for, or marine band.

About the only real technical reliability issues of CB are skip and electronic noise, the latter especially being prevalent in urban areas (including channels 17 and 19 in general). You can sort of escape that using SSB. Although out at a lake house, which (I assume) is some miles away from a major city, you should be alright using it. CB is perfectly useful out there point-to-point comms amongst yourselves, but forget about trying to use it in an emergency.

 

[popnokick]

There's another reason I didn't recommend CB besides the long-range skip that can play hob with your intended communications: Antennas.
Top of your 40 foot tower: No problem. You can put a large CB ground plane up there.
Vehicles such as large cars/trucks, large boats: You need long antennas for best performance. Everything else is a compromise. So if you're OK with 102-inch whips you can use them on the vehicles.
Canoes, handheld radios, etc: Fuhgedaboutit. The antennas on walkie-talkies are extremely poor performers at the low frequency range of CB. And you don't want to deal with a long telescoping whip on a handheld radio.
MURS has some advantages in the fact that it uses VHF frequencies, but a MURS disadvantage is RF power output which is limited to 2 watts. And no repeaters (even if you think you won't start out with one, you won't be able to add one later).
GMRS offers higher power and repeater-capability. The UHF frequencies may actually experience some reflections that will get you out of the cove and around the bends in the lake. But you won't know that until you try. Is your tower strong enough to climb to the top with a GMRS, MURS, and CB handheld and run some tests?
And run the coverage models using the software tools suggested in my previous post.

 

[LakeMan2]

I ran the coverage models using the W5GFE Splat Page. I ran it using 27Mz, 156Mhz, and 462Mhz and imported them into Google Earth.

For the Line of Sight Coverage plots, I did not see any difference between the three. All three only cover about 40% of the area I am interested in. No big surprise there given the hills.

I ran the Longley-Rice Path Loss Analysis too, but am uncertain how to interpret that. There is no legend for the colors so I am not sure what they mean. I have not had time yet to do any research on Longley-Rice Path Loss Analysis to see if I can figure it out.

I am leaning towards trying dual band MURS/Marine and GMRS. I can get mobile + base antenna and various HTs without breaking the bank. I can get waterproof/floating HT with decent antennas and also and go higher power with a smaller, more reasonable antenna on the boat. I can try both the VHF and UHF and see which works better.

CB SSA might look better on paper, but I would probably have to up the power (on both base and boat) which is not legal, plus as previously mentioned by others, I will have antenna issues on the HT and boat. A 102" CB antenna on the boat won't have a high WAF. I can probably get a smaller VHF/UHF antenna accepted better.

And again, it looks like I can get the equipment to at least try it for a reasonable cost. If it doesn't work, I can decide if I want to try CB.

 

[scanmanmi]

Is there someone else around there who will setup a simplex repeater? There may be others who would be interested but uninformed as to possibilities. Now, don't laugh but I am planning a canoe trip and I did have the thought of taking a kite and some skinny coax.

 

[scannermanner1]

I personally would put up a UHF repeater I would run 50 Watts minimum power with a high gain antenna on top the tower !

 

[scannermanner1]

And get some commercial UHF HTs