Antenna recommendation for a firefighter using VHF analog

[DR04]

I'm a volunteer firefighter emt and have been battling reception issues in my area for years now.

I live in a pretty hilly, fairly rural and heavily wooded area known as the driftless area. I mounted a Diamond BC103 just below my roofline (not wanting to upset my HOA) and have LMR600 going into the house (LMR400 inside) being fed to an Icom R8600 through a Stridsberg Engineering multicoupler (also connects to another scanner and weather radio) which monitors 1) paging broadcasts (repeaters), 2) 2-way dispatch traffic (repeaters) and 3) simplex fireground traffic ALL within a 150mhz to 160 mhz range.

The antenna and Icom receiver are light years better than what my motorola pager picks up in my basement office. The Icom has proven great for listening to and recording fireground traffic after the fact - it's great to review incidents and see what can be improved.

But I'm still surprised reception isn't better. I understand VHF needs line of sight. My house is surrounded by lots of giant trees. I know things aren't perfect but I'm looking to upgrade the performance a little bit. I've opted to put up a separate yagi on its own radio to monitor and recording paging traffic due to some other issues I won't cover here. But I'm looking to improve performance from the repeater for 2-way dispatch traffic and simplex fireground traffic. Since I don't know where fires are going to be I figured omnidirectional is best. That being said I know they'll usually be in one general 180 degree direction from my location based on fire district borders.

Had a few questions though, and open to feedback.
1) In hilly, heavily wooded areas what antenna should I be searching for? Is a 1/4 wave a better performer than my BC103 at my frequencies considering it will be impossible for me to get above the trees?
2) Is height better or gain better (or something else) when trying to maximize reception from repeaters? Again, I won't be able to get taller than the trees here and I'm in a hilly area.
3) Any other potential improvements you could see with the setup I've laid out?

 

[mmckenna]

Had a few questions though, and open to feedback.
1) In hilly, heavily wooded areas what antenna should I be searching for? Is a 1/4 wave a better performer than my BC103 at my frequencies considering it will be impossible for me to get above the trees?

Higher gain can perform better.
The issue you are probably thinking of is the radiation pattern. In a mountainous area, lower gain antennas can work better when the stations are at much higher or much lower altitudes from each other. To me, "hills" doesn't necessarily mean you need a lower gain antenna.
But I wouldn't go overboard on the gain. If there's a signal there, the antenna you have is probably going to pick it up.

2) Is height better or gain better (or something else) when trying to maximize reception from repeaters? Again, I won't be able to get taller than the trees here and I'm in a hilly area.

Height is better. With rolling hills around you, you want the antenna up as high as you can safely get it. That lets it see the transmitter antenna better. Since VHF tends to be ~mostly~ line of sight, altitude is your friend.

Don't get hung up on the trees. Yes, foliage will have some impact on performance, but if trees were a big issue, wildland fire fighters would use something else. VHF works pretty well in those applications.

3) Any other potential improvements you could see with the setup I've laid out?

Get your antenna up as high as you safely can without getting the HOA on your case. Putting it down below the roof line may be causing some shielding, especially if your home has any metal siding, foil backed insulation, metal roof, etc.
Make sure you properly waterproof your outdoor connections.
Use one continuous length of coax to get from the entrance to the house (where you should have a lightning suppressor) to your radios. Don't have unnecessary transitions, connectors, etc.
Try running your radio -without- the multicoupler. That multicoupler, unless it has an amplifier, is splitting what signal you are getting, and each time it's split, you are losing some of it. Try connecting directly to the radio and see if performance improves. If it does, consider adding a good low noise/reasonable gain amplifier ahead of it.

You could try taking one of your radios up on the roof and connecting directly to the antenna to see if performance improves. Don't rule out failed coax connections, corroded connectors, damaged cable, etc.

 

[JoshuaHufford]

Have you checked to see if your HOA would make an exception since you are a firefighter and probably need your radios to work?

Might be someone in your HOA that needs you someday.

 

[jaspence]

People in my HOA accept my vertica antenna because they know what my mission is and I choose a very simple vertical on a plain flagpole. If you can't get above the tops of the trees, it will be difficult to really get a lot of improvement as has been suggested.

 

[MDScanFan]

I agree with the earlier post that height is key. Can you take advantage of those tall trees and mount an omni antenna higher than the roofline?

 

[pb_lonny]

You need to get it as high as possible...

 

[DR04]

Have you checked to see if your HOA would make an exception since you are a firefighter and probably need your radios to work?

Might be someone in your HOA that needs you someday.

People in my HOA accept my vertica antenna because they know what my mission is and I choose a very simple vertical on a plain flagpole. If you can't get above the tops of the trees, it will be difficult to really get a lot of improvement as has been suggested.

I did call them a few years back and they were accommodating and gave me a verbal okay to put up what I did. Up to this point I've hesitated putting up something crazy high or obnoxious just to stay away from any potential drama. If push came to shove I suspect I wouldn't have an issue - I'm one of the few emts in an area with a big first responder shortage after all. But trying to stay away from the drama road as much as possible. Nevertheless I have voiced that reception at my desk in my basement - where I always am during the day - is useless with a pager on my hip- either won't activate or inaudible.

I agree with the earlier post that height is key. Can you take advantage of those tall trees and mount an omni antenna higher than the roofline?

I guess I could mount one right to the tops of the trees, although that would take some intense climbing. If I put the antenna higher up on my roof line and more towards the middle of the house (using a ladder) it will be further from the trees (horizontally) but still a bit below the tree line.

Higher gain can perform better.
The issue you are probably thinking of is the radiation pattern. In a mountainous area, lower gain antennas can work better when the stations are at much higher or much lower altitudes from each other. To me, "hills" doesn't necessarily mean you need a lower gain antenna.
But I wouldn't go overboard on the gain. If there's a signal there, the antenna you have is probably going to pick it up.

Height is better. With rolling hills around you, you want the antenna up as high as you can safely get it. That lets it see the transmitter antenna better. Since VHF tends to be ~mostly~ line of sight, altitude is your friend.

Don't get hung up on the trees. Yes, foliage will have some impact on performance, but if trees were a big issue, wildland fire fighters would use something else. VHF works pretty well in those applications.

Get your antenna up as high as you safely can without getting the HOA on your case. Putting it down below the roof line may be causing some shielding, especially if your home has any metal siding, foil backed insulation, metal roof, etc.
Make sure you properly waterproof your outdoor connections.
Use one continuous length of coax to get from the entrance to the house (where you should have a lightning suppressor) to your radios. Don't have unnecessary transitions, connectors, etc.
Try running your radio -without- the multicoupler. That multicoupler, unless it has an amplifier, is splitting what signal you are getting, and each time it's split, you are losing some of it. Try connecting directly to the radio and see if performance improves. If it does, consider adding a good low noise/reasonable gain amplifier ahead of it.

You could try taking one of your radios up on the roof and connecting directly to the antenna to see if performance improves. Don't rule out failed coax connections, corroded connectors, damaged cable, etc.

Okay this is really helpful - and the comments recommending to get as high as possible. Time to test my firefighter ground ladder skills and get mounting as high as I can!

You also mentioned checking outdoor connections. That just occurred to me as a potential concern. The Diamond uses an UHF connector which I don't really like (prefer N for more watertight connections). It runs to a PL259 inside a underground pull box that can get damp where it connects to a ground rod - ground rod is bonded to house EGC. I'm wondering if there is a connector that is failing somewhere, maybe even on the antenna itself - reception seems to be notably worse from when I put it in. I've been worried the weight of the LMR600 has been to much for the UHF connector on the bottom of the antenna. It's zip tied multiple places but that cord is still heavy...

THe multicoupler is supposed to amplify (I'm not an expert maybe wrong word) so that there is 0 loss on all outputs. But I realize this still won't be as clean as connector directly going to the 1 radio.

I guess I'll explore getting it higher and getting some longer cables. I'll also check the connections before I start going nuts moving everything around. Would be nice if there was a decent high gain VHF antenna (~150 mhz range) that had an n connector on it.

 

[APX8000]

Height is always better than gain. And once you have the height, you can always add gain. There comes a point where where too much gain can inject intermod in the amplifier. Is your multicoupler passive or active ? The Strisbergs active multicouplers have a built in amplifier with just enough gain to balance out the loss from the split, making it basically plus or minus 1 dB depending on the frequency range. They are also a bit noisy. How long are your coax runs? Between your coax and the multicoupler and connections between the 600 and 400, you could be suffering a bit of loss. Are you getting hammered from other unwanted frequencies ? You seems to want to be pretty band specific on VHF so adding a filter might help knock that out. A lot of variables. First test I would do is hook up your receiver at the end of the first run of coax and take readings. Then raise your antenna and take readings. Then add a low noise amplifier as close to the antenna as possible, not at the receiver or you are not reaping its benefits. Once you get some of that dialed in, then add your second run of coax and recheck at the receiver. Etc etc.

 

[DR04]

Height is always better than gain. And once you have the height, you can always add gain. There comes a point where where too much gain can inject intermod in the amplifier. Is your multicoupler passive or active ? The Strisbergs active multicouplers have a built in amplifier with just enough gain to balance out the loss from the split, making it basically plus or minus 1 dB depending on the frequency range. They are also a bit noisy. How long are your coax runs? Between your coax and the multicoupler and connections between the 600 and 400, you could be suffering a bit of loss. Are you getting hammered from other unwanted frequencies ? You seems to want to be pretty band specific on VHF so adding a filter might help knock that out. A lot of variables. First test I would do is hook up your receiver at the end of the first run of coax and take readings. Then raise your antenna and take readings. Then add a low noise amplifier as close to the antenna as possible, not at the receiver or you are not reaping its benefits. Once you get some of that dialed in, then add your second run of coax and recheck at the receiver. Etc etc.

Okay this is good info thank you. I'm using an active multicoupler - MCA204M. Coax runs - antenna to lightning protector is LMR600 ~25 feet. Lightning protector to MCA204M ~ 15 feet LMR600. MCA204M to desk is about ~30 feet with LMR400 and one wall connector inbetween, about 7 feet from radio (maybe I should run direct to the radio so there is no bnc connector in the wall that I'm using).

 

[mmckenna]

Okay this is really helpful - and the comments recommending to get as high as possible. Time to test my firefighter ground ladder skills and get mounting as high as I can!

Yeah, don't worry about the trees. I run a couple of VHF channels for Fire and PD and we have antennas that are below tree level. Trying to get antennas above 2000 year old Redwoods isn't a reality.

You also mentioned checking outdoor connections. That just occurred to me as a potential concern. The Diamond uses an UHF connector which I don't really like (prefer N for more watertight connections). It runs to a PL259 inside a underground pull box that can get damp where it connects to a ground rod - ground rod is bonded to house EGC. I'm wondering if there is a connector that is failing somewhere, maybe even on the antenna itself - reception seems to be notably worse from when I put it in.

OK, couple of things...

A UHF connector isn't ideal, but they'll work on VHF. Sure, the N's have a bit less loss, but it's so negligible that it's not going to cause the issue you are having. If you were going to replace everything across the board, sure, change it all to N, but don't rip and replace….

UHF connectors are not waterproof. N connectors have some water resistance, but should not be installed without proper waterproofing. If you did not waterproof your outdoor connections, there's a "stop and fix" right there. It's possible moisture collected inside the connection and corroded things out. You mentioned that "reception seems to be notably worse" which is a good indicator.

Standard LMR-600 and LMR-400 only has water intrusion protection from the jacket. It's not a direct bury rated cable and should not be used under ground, even in a conduit. If there is a connection point in that pull box, suspect that as another failure point. Again, those PL259 UHF connectors are not waterproof and if it's been below grade, consider the idea that water has entered the cable and probably destroyed it.

I'd recommend replacing all your coaxial cable unless you can 100% prove there is zero corrosion or water damage.
If running it in a conduit below grade is your -only- option, then you need to have a direct bury rated cable. You should (ideally) have no connections below grade. You may have to rethink your grounding system to make that work. Ideally, you need to have a suitable lightning suppressor installed before the coax enters your home.

I've been worried the weight of the LMR600 has been to much for the UHF connector on the bottom of the antenna. It's zip tied multiple places but that cord is still heavy...

I'm using LMR-600 on my home antenna. Done right, it should be OK if you have it secured. It is heavy cable, but a few ty wraps near the antenna base will take the strain off the connection.

THe multicoupler is supposed to amplify (I'm not an expert maybe wrong word) so that there is 0 loss on all outputs. But I realize this still won't be as clean as connector directly going to the 1 radio.

OK, good. But just to be sure that it's not a failed multi-coupler, try bypassing it.

I guess I'll explore getting it higher and getting some longer cables. I'll also check the connections before I start going nuts moving everything around. Would be nice if there was a decent high gain VHF antenna (~150 mhz range) that had an n connector on it.

You didn't say how long the coaxial cable run is. Unless it's over 100 feet or more, LMR-600 should be just fine. If it has to run below grade, make sure you get the direct bury rated. I think it's LMR-600-DB.

Getting the antenna up higher would be a good idea, but you should check everything else first. A bad connection or wet cable could be most of your issue. You'd need to look at your local topology to see what that would do for you. If you have hills around you, trying to get above those may not be a reality. Line of sight is good if you can get it, but going up 10 feet if there isn't a line of site may not be a good payoff.

If budget isn't an issue, there are lots of good antennas that will have N connectors on them. But again, I'd not swap out your antenna just to get that little bit of improvement.

 

[mmckenna]

Okay this is good info thank you. I'm using an active multicoupler - MCA204M. Coax runs - antenna to lightning protector is LMR600 ~25 feet. Lightning protector to MCA204M ~ 15 feet LMR600. MCA204M to desk is about ~30 feet with LMR400 and one wall connector inbetween, about 7 feet from radio (maybe I should run direct to the radio so there is no bnc connector in the wall that I'm using).

OK, that's useful. Glad you have a lightning protector in line. Often hobbyists skip those.
I'd probably move the multicoupler closer to the radio and keep on the LMR-600 as far as you can. If all your radios are in the same place, mount the multicoupler there and use some short runs of RG-58 with correct matching connectors for the radios. Running LMR-400 direct to your radios can put a lot of strain on the antenna jack.

 

[JDrisc3480]

This is just a thought but you said that you are surrounded by giant trees, what about putting up a stealth antenna in those trees if possible. It would let you get it up higher as well as hide that it is there from your HOA.

 

[popnokick]

Agree with mmckenna. "It runs to a PL259 inside a underground pull box that can get damp...." and you also wrote "reception seems to be notably worse from when I put it in." VERY likely you have water in the connector, coax, junction box... individually, or in all of them. Rip and replace everything with new.

 

[DR04]

This is just a thought but you said that you are surrounded by giant trees, what about putting up a stealth antenna in those trees if possible. It would let you get it up higher as well as hide that it is there from your HOA.

I'll use the trees as a potential backup. My land/lot is a bit odd. The road is up higher than the ground level of the house and the lot slopes down from the road. I could put an antenna on a tree higher up by the road but that'd be a pretty long coax run and prove challenging to climb. Also there are many trees around here, all of the same size. So I may keep this option in my back pocket. If I mount to the top on the house then I'll have more open air and clearance from the trees and still be just about that high.

I've seen those "flagpole" antennas used for ham radio guys for HF frequencies and the like. I wish they had something like that I could use for VHF. I could mount that up by the road for great reception. The long coax run may be worth it for something permanent like that. I've been meaning to put up a normal flagpole anyway. But I haven't seen any of those flagpole antennas that can be used for VHF.

OK, that's useful. Glad you have a lightning protector in line. Often hobbyists skip those.
I'd probably move the multicoupler closer to the radio and keep on the LMR-600 as far as you can. If all your radios are in the same place, mount the multicoupler there and use some short runs of RG-58 with correct matching connectors for the radios. Running LMR-400 direct to your radios can put a lot of strain on the antenna jack.

Agree with mmckenna. "It runs to a PL259 inside a underground pull box that can get damp...." and you also wrote "reception seems to be notably worse from when I put it in." VERY likely you have water in the connector, coax, junction box... individually, or in all of them. Rip and replace everything with new.

I think you may be right. My experience with the pull box is this - I actually put it in to keep the connectors away from rain hitting them directly and protected from damage by kids, landscaping work etc. The box sits in rock that's extremely well drained. But some condensation can build in the box. So while there's less water on the connectors, when it does form it persists for a longer period of time. The LMR-600 only goes through ~4 inches of small, drained rock before entering the side of the box. I used to put weather sealing tape over those connectors, but that came off and never came back on when I moved some wires around (my fault for not putting it back on).

I'm thinking this:
- I'll redo the wiring with new LMR600 in case something has corroded. I'll look at direct burial options from the antenna connector to the point it comes to the lightning protection.
- I'll switch to N connectors at a minimum at the connection to the lightning protector and add seal those connections. I also have 2 AWG copper connected to the mast and coming down to the grounding rod in addition to an alpha delta surge protector for the coax itself that's bonded directly to the rod. I did recently replace that alpha delta connector to ensure it wasn't causing the problem.
- Whether or not I keep the Diamond antenna or pick a new one, I'll remount that at the highest point on the house, above the roof line - may need something higher than my 24 foot ladder!
- I'll play with the multicoupler set up; either try removing it to setup a direct run and do a smaller antenna for other devices or try moving it closer to the radios. If I do keep the multicoupler I'll remove the excess BNC connector in line from the multicoupler to radio - I have that there for a "fancy" looking wall connection. I'm worried that may be adding unnecessary loss or noise too.

Open to any additional ideas but this is giving me a lot of direction thank you.

 

[mmckenna]

I've seen those "flagpole" antennas used for ham radio guys for HF frequencies and the like. I wish they had something like that I could use for VHF. I could mount that up by the road for great reception. The long coax run may be worth it for something permanent like that. I've been meaning to put up a normal flagpole anyway. But I haven't seen any of those flagpole antennas that can be used for VHF.

You'd have to fabricate your own. Probably wouldn't be hard to just mount a VHF antenna at the top and run the coax down the inside. But running really long coax is going to be an issue.

I'm thinking this:
- I'll redo the wiring with new LMR600 in case something has corroded. I'll look at direct burial options from the antenna connector to the point it comes to the lightning protection.

You really want the entire run to be LMR-600-DB. The DB rated cable has a gel filling that blocks water intrusion. It's messy and will get everywhere, but it works.
The condensation inside the pull box is going to really like the cold metal connectors. Once those get wet, capillary action is going to take it right up the threads into the connector. I'd avoid any connection below grade. Put your lightning protector near the bottom of the mast, but not below grade in the pull box.

- I'll switch to N connectors at a minimum at the connection to the lightning protector and add seal those connections. I also have 2 AWG copper connected to the mast and coming down to the grounding rod in addition to an alpha delta surge protector for the coax itself that's bonded directly to the rod. I did recently replace that alpha delta connector to ensure it wasn't causing the problem.

Good idea. I'd still suggest getting the lightning suppressor out of the box. Bonding directly to the ground rod isn't necessary. Keep it up on the mast and just run some wire down to the ground rod.

- Whether or not I keep the Diamond antenna or pick a new one, I'll remount that at the highest point on the house, above the roof line - may need something higher than my 24 foot ladder!

While it's expensive, a rental cherry picker can be a good solution. They make some trailer mounted units that will reach up about 35 feet. I've used those on a couple of jobs. Maybe $300 for the day, but cheaper than an ambulance ride. Plus, you can give your kids rides in it.

Open to any additional ideas but this is giving me a lot of direction thank you.

Sounds like you have a really nice and well thought out system. I think addressing the coax issues will prove to be the solution.
Good luck.

 

[N0ZQR]

Have you thought about a amplified charge for your pager? That's what I use with it connected to a outside antenna, the pager is better (for me) than even a "real" radio. I am also able to have a external speaker so that I can have a speaker in another part of the house.

Ron

 

[DR04]

Have you thought about a amplified charge for your pager? That's what I use with it connected to a outside antenna, the pager is better (for me) than even a "real" radio. I am also able to have a external speaker so that I can have a speaker in another part of the house.

Ron

I do have one of these. And it's attached to a yagi pointed at one of the paging repeaters. But that yagi won't help with the other types of traffic I'm trying to get (2-way dispatch and fireground) - my Icom receiver downloads that audio even if I'm not at my place.