Another antenna db question 😬

[lobo777]

I have been immersed in research on a proper "base station" antenna, to be located in the roof of my two story home in the mountains of New Mexico. I've been so obsessed with researching this particular piece of equipment, and rightfully so in my mind, that my wife is becoming increasingly annoyed with my preoccupation.

That being said, after all of the posts, reviews, and opinions that I've read, I'm still confused, and I apologize in advance for the repetitive question.

I live at almost 6,500 ft, surrounded by some hilly and even some mountainous areas, with the trails and roads being surrounded by various trees like pinon, juniper, and even some ponderosa pine in the higher areas. The house sits in a valley of sorts, with increasing elevation to the north, a large mountain to the west, rolling hills to the east, and a descending 15 mile LOS to the mountain range to the south.

My rooftop mount will clear anything within a 300-yard radius, so I'm not concerned about the area around me, but I have several handhelds that will be used on trails going up north, east, and south of the home. 

I've that lower decibels on antennas in this type of area seem to be better for mobile units, but my question is about the base station. Should I get a 3 decibel or 6 decibel antenna for this situation? There is a repeater about 10 miles south, with a decent line of site, but I'm not too concerned with that - more wanting to reach our mobile units and handhelds (once I install mobiles) when they're out in various areas. Feel free to give me any antenna suggestions as well (under $200)! I was considering the Browning 6143 (3db).

Thanks for any advice in advance!

[BoxCar]

The piece of data needed in your quest will be the radiation pattern of the two antennas you are looking at. The primary lobes will be similar but look at the secondary lobes as well. Does one antenna's lobes give better coverage close to the antenna in the areas you need?

[WSAM454]

If these are both  vertical antennas, how do you orient it so the stronger lobes are in the "right" place?  Do you mean the antenna's take off angle?  If so, that is not usually given in the specs.

 

[tcp2525]

It's really nice to see someone paying great detail to their environment and taking the needed time consider all aspects of deploying a GMRS system that will perform. In my opinion, since you seem to be budget oriented, which is great, I will make a suggestion of buying it right the first time and doing it right. For the money, you are not going to beat the price and performance of the Comet CA-712EFC. Next is your feedline, keep it as short as possible and buy the best as possible within your budget. Unfortunately, this is where most people skimp. I always lean towards 1/2" Heliax or LMR-600 as a minimum for short runs on UHF, but others will chime in and give you good advice for your requirements. As for all the technical mumbo-jumbo, it's great for a learning experience, but you're most likely not going to gain anything more than a headache. Keep it simple by using gear that has built a good reputation.

https://www.dxengineering.com/parts/cma-ca-712efc

Another choice if shorter length is a requirement is the Tram 1418, but that will need tuning. If you don't want to go through the tuning procedure, get the Comet CA-712EFC.

https://www.buytwowayradios.com/tram-1486.html

[WRUE951]

Like Boxcar said, study the radiation patterns for each of the antennas your looking at..  Don't go with the first one someone recommends as the best.   It may be the best for them but crap for you..  My home is setting about 2800 feet overlooking a huge desert valley with long range mountains in every direction.  I'm setting about 300 feet above the city i live in.  I recently got a Laird 4607 7DB Base antenna and found out it lacked the range i had with my prior Hustler G6-450-3. I never looked at the radiation patterns for the antenna before buying.  The Laird antenna has a sharp low narrow elevation pattern.. So i was not getting the range out of it.  The antenna is meant to be setting on a high mountain top where a downward slope pleases its targets  Setting 40' above my house worked good for short range.  Long story short, ended up ordering another Hustler, which is 6 weeks backordered now.   Gigaparts is a good source to get the antenna pattern information if they sell the specific antenna you are looking at.  They are also a good source for information and have reasonable pricing DX Antennas is another good source based on what i hear..   Do your homework,  Antenna's are expensive..    Don't be 'that guy' (me) making costly mistakes.    

[SvenMarbles]

I wish I could be standing in the area that you're trying to set up, because every terrain circumstance has it's own unique optimal scenario.

If you have general line of sight, but varied elevations of desired contact, and are trying to remain in solid contact of simplex hikers around the trails around you,  I'd stay at about a 6db antenna for your base. Think of gain in terms of 0 gain being an apple shape, 3db a bit more squashed than an apple, 6db being about a donut, and increments ascending resulting in a frisbee shape. Roughly.. This isn't exactly scientific, but just a sort of way to conceptualize what you're doing with gain.

So with that being said, if you're doing a lot of local communicating but at sharply variable elevations, you might want the lower gain options to have the more vertical take off angles.

 

[SteveShannon]

22 minutes ago, WSAM454 said:

If these are both  vertical antennas, how do you orient it so the stronger lobes are in the "right" place?  Do you mean the antenna's take off angle?  If so, that is not usually given in the specs.

 

You can’t really tilt a vertical antenna to manipulate the lobes.  You get an antenna with a different propagation pattern. However, raising an antenna above the ground can change the lobes.  You have only two ways to visualize the propagation pattern.  One is by viewing the charts some of the better manufacturers provide.  The other is to “build” the antenna in one of the simulation programs.

Nor do you necessarily need LMR600 or hardline.  But you must figure out how long your feedline will be and then select the type of feedline that has the losses that you can afford. And loss in a feedline is important, but it’s also unavoidable.  You can go broke chasing perfect or you can live comfortably while settling for good enough. Most of us find that for base station runs of up to 50 feet, LMR 400 is just fine.  For 100 feet and 465 MHz, the difference in loss between LMR400 and LMR600 is 1 db. (2.735 for LMR400, 1.75 for LMR600). https://kv5r.com/ham-radio/coax-loss-calculator/

The Comet CA-GMRS might be a “good enough” choice for you.  Because it has less gain it’s less directional and may be able to flood a hilly annd wooded area better.  The Comet CA-712efc is a great higher gain antenna if you have wide open spaces and wish to have a strong signal within 10° above or below horizontal, but with less concern about higher or lower elevations.

I live in a very mountainous area in Montana.  I use the ham radio equivalent of the CA-GMRS and I use 36 feet of LMR400 for 70 cm.  It works fine for my purposes.

[tcp2525]

3 minutes ago, SvenMarbles said:

So with that being said, if you're doing a lot of local communicating but at sharply variable elevations, you might want the lower gain options to have the more vertical take off angles.

 

Good suggestion. He might want to try a homemade 1/4 wave groundplane feed with high quality feedline prior to buying any antenna. Keep in mind he did say the antenna price range is $200.

[SvenMarbles]

58 minutes ago, WSAM454 said:

If these are both  vertical antennas, how do you orient it so the stronger lobes are in the "right" place?  Do you mean the antenna's take off angle?  If so, that is not usually given in the specs.

 

When you're looking at a radiation pattern diagram, it's usually represented as a sliced side-view. Everything that you're seeing as a lobe is actually meant to be conceptualized as a 360 degree pattern. What it's showing is precisely the take off angles. Usually there's come little packing slip in most good antennas like Comet or Diamond with an illustration of some kind of the radiation pattern. 

[WRYZ926]

Another thing to take into consideration is how manufacturers advertise the gain of their antennas. Most will state the gain in dBi which is always higher than dBd.dBI is the gain measured in free space while dBd is more realistic to what you will see in reality.

Don't worry, it is easy to convert dBi to dBd. Just take the dBi and subtract 2.14 from it to get dBd. We will use the Comet CA-712EFC and Tram 1486 as examples. The Comet is listed as 9 dBi which equals 6.8 dBd. Buy Two Way Radio lists the Tram 1486's gain in dBd at 6.5. Comet antennas generally do not need to be tuned while Tram antennas do need to be tuned.

Another choice if you need a shorter antenna with lower gain is the Comet CA-GMRS. It is listed at 5.5dBi which equals 3.36 dBd and it is only 42" tall.

https://theantennafarm.com/shop-by-categories/antennas-mounts/base-antennas/gmrs-base-antennas/gmrs-omni-directional-base-antennas/comet-ca-gmrs-base-antenna-detail

Now onto coax. First hear is a good online coax loss calculator that I use.  https://kv5r.com/ham-radio/coax-loss-calculator/

Most people will use LMR400 for lengths of 100 feet or less. It will also be cheaper than LMR600 and Heliax. LMR400 Ultra flex will also be easier to work with since it is more flexible. Again get the best quality coax that you can afford. I can recommend DX Engineering 400MAX. Don't skimp on the coax with the el cheapo stuff from Amazon. It will not have a good shield and will have higher losses.

What ever you do, do not use RG8, RG8X, RG58, or any other coax meant for HF. It will have a lot of loss with GMRS frequencies.

Heliax, sometimes called hardline, usually requires special tools to install connectors. Where one can install connectors on LMR400/600 with regular tools.

Another thing to consider is that Comet GMRS antennas have a N type connector while the radio has a SO-239 connector. So you will need to order a cable with a Male N type on one end and PL-259 on the other, change on PL-259 to a N Type or use a SO-239 to male N type adapter.

[SvenMarbles]

12 minutes ago, WRYZ926 said:

Another thing to take into consideration is how manufacturers advertise the gain of their antennas. Most will state the gain in dBi which is always higher than dBd.dBI is the gain measured in free space while dBd is more realistic to what you will see in reality.

Don't worry, it is easy to convert dBi to dBd. Just take the dBi and subtract 2.14 from it to get dBd. We will use the Comet CA-712EFC and Tram 1486 as examples. The Comet is listed as 9 dBi which equals 6.8 dBd. Buy Two Way Radio lists the Tram 1486's gain in dBd at 6.5. Comet antennas generally do not need to be tuned while Tram antennas do need to be tuned.

Another choice if you need a shorter antenna with lower gain is the Comet CA-GMRS. It is listed at 5.5dBi which equals 3.36 dBd and it is only 42" tall.

https://theantennafarm.com/shop-by-categories/antennas-mounts/base-antennas/gmrs-base-antennas/gmrs-omni-directional-base-antennas/comet-ca-gmrs-base-antenna-detail

Now onto coax. First hear is a good online coax loss calculator that I use.  https://kv5r.com/ham-radio/coax-loss-calculator/

Most people will use LMR400 for lengths of 100 feet or less. It will also be cheaper than LMR600 and Heliax. LMR400 Ultra flex will also be easier to work with since it is more flexible. Again get the best quality coax that you can afford. I can recommend DX Engineering 400MAX. Don't skimp on the coax with the el cheapo stuff from Amazon. It will not have a good shield and will have higher losses.

What ever you do, do not use RG8, RG8X, RG58, or any other coax meant for HF. It will have a lot of loss with GMRS frequencies.

Heliax, sometimes called hardline, usually requires special tools to install connectors. Where one can install connectors on LMR400/600 with regular tools.

Another thing to consider is that Comet GMRS antennas have a N type connector while the radio has a SO-239 connector. So you will need to order a cable with a Male N type on one end and PL-259 on the other, change on PL-259 to a N Type or use a SO-239 to male N type adapter.

It's where 90% of people go wrong. The coax type is no trivial thing at UHF frequencies. The losses are alarming. Most people don't understand that MOST of the power is lost through a 50ft run of RG58 type coax. All of these people buying 50 watt radios just to warm up some coax lol...

[tcp2525]

12 minutes ago, SvenMarbles said:

It's where 90% of people go wrong. The coax type is no trivial thing at UHF frequencies. The losses are alarming. Most people don't understand that MOST of the power is lost through a 50ft run of RG58 type coax. All of these people buying 50 watt radios just to warm up some coax lol...

Very true! Not only do you have a really nice space heater when transmitting into that crappy feedline, you have the very best set of ear plugs. The loss for receiving is one of the most important aspects most people never consider.

[WRYZ926]

My coax run going to my GMRS antenna is only 30 feet. Now if the coax length was 100 feet or more, then I would definitely consider LMR600 or Heliax if I could afford it. I would say that LMR400 (and equivalent) coax is a must for runs under 100 feet for GMRS and 70cm.

Using the wrong type of coax effects 2m frequencies too. I had to say something to a friend that lives close by when I found out he got his coax cables mixed up and had RG58 hooked up to his 2m radio and 2m antenna. He was wondering why his receive and transmit was horrible. He put a 160 watt amp in line which overloaded my radio really bad. We are only 325 yards apart.  I found out he had the RG58 hooked up to his 2m rig when I called him to ask that he stopped using the amp.

[lobo777]

2 hours ago, WRUE951 said:

Like Boxcar said, study the radiation patterns for each of the antennas your looking at..  Don't go with the first one someone recommends as the best.   It may be the best for them but crap for you..  My home is setting about 2800 feet overlooking a huge desert valley with long range mountains in every direction.  I'm setting about 300 feet above the city i live in.  I recently got a Laird 4607 7DB Base antenna and found out it lacked the range i had with my prior Hustler G6-450-3. I never looked at the radiation patterns for the antenna before buying.  The Laird antenna has a sharp low narrow elevation pattern.. So i was not getting the range out of it.  The antenna is meant to be setting on a high mountain top where a downward slope pleases its targets  Setting 40' above my house worked good for short range.  Long story short, ended up ordering another Hustler, which is 6 weeks backordered now.   Gigaparts is a good source to get the antenna pattern information if they sell the specific antenna you are looking at.  They are also a good source for information and have reasonable pricing DX Antennas is another good source based on what i hear..   Do your homework,  Antenna's are expensive..    Don't be 'that guy' (me) making costly mistakes.    

I can't find any specs associated with the radiation patterns on this Browning, unfortunately.

[lobo777]

2 hours ago, tcp2525 said:

It's really nice to see someone paying great detail to their environment and taking the needed time consider all aspects of deploying a GMRS system that will perform. In my opinion, since you seem to be budget oriented, which is great, I will make a suggestion of buying it right the first time and doing it right. For the money, you are not going to beat the price and performance of the Comet CA-712EFC. Next is your feedline, keep it as short as possible and buy the best as possible within your budget. Unfortunately, this is where most people skimp. I always lean towards 1/2" Heliax or LMR-600 as a minimum for short runs on UHF, but others will chime in and give you good advice for your requirements. As for all the technical mumbo-jumbo, it's great for a learning experience, but you're most likely not going to gain anything more than a headache. Keep it simple by using gear that has built a good reputation.

https://www.dxengineering.com/parts/cma-ca-712efc

Another choice if shorter length is a requirement is the Tram 1418, but that will need tuning. If you don't want to go through the tuning procedure, get the Comet CA-712EFC.

https://www.buytwowayradios.com/tram-1486.html

I have an 80' run (unavoidable, unfortunately) of LMR400. Thanks for the advice on the antennas!

[WRYZ926]

13 minutes ago, lobo777 said:

I have an 80' run (unavoidable, unfortunately) of LMR400. Thanks for the advice on the antennas!

You should be fine with that as long as it is good quality LMR400.

Using the loss calculator that I linked earlier, you will still get an ERP (effective radiating power) of 117 watts out when using 80 feet of LMR400 and an antenna with 6 dBd of gain.

EDIT to add: the ERP is when using a 50 watt radio on high power.

[WRUE951]

13 minutes ago, lobo777 said:

I can't find any specs associated with the radiation patterns on this Browning, unfortunately.

what is the model on your Browning?

[lobo777]

3 minutes ago, WRUE951 said:

why is the model on your Browning?

It's the Browning br-6143

[lobo777]

2 hours ago, WRYZ926 said:

Another thing to take into consideration is how manufacturers advertise the gain of their antennas. Most will state the gain in dBi which is always higher than dBd.dBI is the gain measured in free space while dBd is more realistic to what you will see in reality.

Don't worry, it is easy to convert dBi to dBd. Just take the dBi and subtract 2.14 from it to get dBd. We will use the Comet CA-712EFC and Tram 1486 as examples. The Comet is listed as 9 dBi which equals 6.8 dBd. Buy Two Way Radio lists the Tram 1486's gain in dBd at 6.5. Comet antennas generally do not need to be tuned while Tram antennas do need to be tuned.

Another choice if you need a shorter antenna with lower gain is the Comet CA-GMRS. It is listed at 5.5dBi which equals 3.36 dBd and it is only 42" tall.

https://theantennafarm.com/shop-by-categories/antennas-mounts/base-antennas/gmrs-base-antennas/gmrs-omni-directional-base-antennas/comet-ca-gmrs-base-antenna-detail

Now onto coax. First hear is a good online coax loss calculator that I use.  https://kv5r.com/ham-radio/coax-loss-calculator/

Most people will use LMR400 for lengths of 100 feet or less. It will also be cheaper than LMR600 and Heliax. LMR400 Ultra flex will also be easier to work with since it is more flexible. Again get the best quality coax that you can afford. I can recommend DX Engineering 400MAX. Don't skimp on the coax with the el cheapo stuff from Amazon. It will not have a good shield and will have higher losses.

What ever you do, do not use RG8, RG8X, RG58, or any other coax meant for HF. It will have a lot of loss with GMRS frequencies.

Heliax, sometimes called hardline, usually requires special tools to install connectors. Where one can install connectors on LMR400/600 with regular tools.

Another thing to consider is that Comet GMRS antennas have a N type connector while the radio has a SO-239 connector. So you will need to order a cable with a Male N type on one end and PL-259 on the other, change on PL-259 to a N Type or use a SO-239 to male N type adapter.

All great info, and I appreciate you taking the time to reply. I have the first 40' run as N male to PL259 to my lightning arrestor, which is Po239 on both sides. The interior 40' run is PL259 (From arrestor) to PL259 to a base unit, which I haven't purchased yet - haven't decided on what I want... I am considering the Retevis RA87, but their site didn't state that it could receive the NOAA frequencies, and that would be a deal breaker for me. Looked at the quad, fairly inexpensive BTECH 50v2, but not sure on its quality, and it doesn't have a Roger beep (not necessarily a deal breaker and I know some people HATE the Roger beep, which is why I want it haha. Just kidding of course). I will look into the Comet CA-GMRS

[lobo777]

2 hours ago, WRYZ926 said:

Another thing to take into consideration is how manufacturers advertise the gain of their antennas. Most will state the gain in dBi which is always higher than dBd.dBI is the gain measured in free space while dBd is more realistic to what you will see in reality.

Don't worry, it is easy to convert dBi to dBd. Just take the dBi and subtract 2.14 from it to get dBd. We will use the Comet CA-712EFC and Tram 1486 as examples. The Comet is listed as 9 dBi which equals 6.8 dBd. Buy Two Way Radio lists the Tram 1486's gain in dBd at 6.5. Comet antennas generally do not need to be tuned while Tram antennas do need to be tuned.

Another choice if you need a shorter antenna with lower gain is the Comet CA-GMRS. It is listed at 5.5dBi which equals 3.36 dBd and it is only 42" tall.

https://theantennafarm.com/shop-by-categories/antennas-mounts/base-antennas/gmrs-base-antennas/gmrs-omni-directional-base-antennas/comet-ca-gmrs-base-antenna-detail

Now onto coax. First hear is a good online coax loss calculator that I use.  https://kv5r.com/ham-radio/coax-loss-calculator/

Most people will use LMR400 for lengths of 100 feet or less. It will also be cheaper than LMR600 and Heliax. LMR400 Ultra flex will also be easier to work with since it is more flexible. Again get the best quality coax that you can afford. I can recommend DX Engineering 400MAX. Don't skimp on the coax with the el cheapo stuff from Amazon. It will not have a good shield and will have higher losses.

What ever you do, do not use RG8, RG8X, RG58, or any other coax meant for HF. It will have a lot of loss with GMRS frequencies.

Heliax, sometimes called hardline, usually requires special tools to install connectors. Where one can install connectors on LMR400/600 with regular tools.

Another thing to consider is that Comet GMRS antennas have a N type connector while the radio has a SO-239 connector. So you will need to order a cable with a Male N type on one end and PL-259 on the other, change on PL-259 to a N Type or use a SO-239 to male N type adapter.

Does the Comet CA-GMRS require tuning? I can't find that info in any of the sites selling this model. Also, noticed the CA-GMRS appears to have the So239 connector, rather than the N type, so I'll need to change that out from my current cable setup, unfortunately, but not a huge deal. 

[SteveShannon]

24 minutes ago, lobo777 said:

Does the Comet CA-GMRS require tuning? I can't find that info in any of the sites selling this model. Also, noticed the CA-GMRS appears to have the So239 connector, rather than the N type, so I'll need to change that out from my current cable setup, unfortunately, but not a huge deal. 

No tuning required for either the CA-GMRS or the CA-712EFC. 

The CA-GMRS has an SO-239 (UHF female connector), but you can use a UHF female to N male adapter. Get a good one, not one of the inexpensive ones on Amazon. 

[SvenMarbles]

2 hours ago, lobo777 said:

It's the Browning br-6143

Info for that antenna shows it being a little bit out of spec for GMRS. 450-460.

[SvenMarbles]

I'd have a look at the Comet CA-GMRS

Comet is a reputable brand, not terribly expensive, and not super high gain.

 

 

[lobo777]

24 minutes ago, SvenMarbles said:

Info for that antenna shows it being a little bit out of spec for GMRS. 450-460.

That's odd! The Antenna Farm shows this:

(MHz)450-470 MHz

[lobo777]

23 minutes ago, SvenMarbles said:

I'd have a look at the Comet CA-GMRS

Comet is a reputable brand, not terribly expensive, and not super high gain.

 

 

You're the second or third to suggest this one, so I'm seriously looking at giving it a shot now.

[WRYZ926]

I have a Comet GP9 dual band and a CA-712EFC. Neither needed tuning so I would say that the CA-GMRS does not either.

26 minutes ago, lobo777 said:

That's odd! The Antenna Farm shows this:

(MHz)450-470 MHz

Even though it says that, you best double check it with an antenna analyzer. I know the Tram 1174 I have stated it was good for GMRS, I did in fact have to cut/tune it for GMRS. It was tuned more for 70cm even though it was labeled as a GMRS antenna.

You really can't go wrong with one of the GMRS antennas from Comet. Even some of their 2m/70 dual band antennas will work pretty good for GMRS, again always double check the SWR first.