15Watts? Good for mobile?

[vefrancis]

Might be a stupid question, but what is your opinion on a 15Watt mobile? adequate? Thanks for your time

[WRUE915]

I use a 20 watt mobile right now for GMRS. The Radioddity DB-20G. It works great! I can get into repeaters 20-30 miles away depending on terrain.

My base is the same radio with an antenna on the roof at 20 feet. Base to mobile I can talk 20 miles reliably.

So 15 watts should be fine.

I've also experimented base to base with a friend at 5 watts that was about 10 miles.

Antenna setup is far more important than wattage fpr line of sight comms. Antenna height specifically.

[kidphc]

Personally, depending on location. Ie mountains and repeater availability.

Usually, 20 watts or so are nice and adequate. Most will let you trim the power back some even enough to get on the frs interants and still be close to inbounds according to some rules. Plus most are economical compared to a 50 watt model.

Most 40/50 watt radios can't turn the power down enough to play with the entire allocation. Hence some channels are blocked etc. But it is always nice to bump up the power when at the fringes of a repeater or in the woods.

With uhf and vhf. Gmrs is uhf. Focus on the antenna setup more then the radio. 15w with a properly setup 5/8 antenna gets you out further and cleaner then a 50w with unity gain antenna with no groundplane and crap coax.




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[SteveShannon]

21 minutes ago, vefrancis said:

Might be a stupid question, but what is your opinion on a 15Watt mobile? adequate? Thanks for your time

As the others said, that’s definitely adequate for most uses.

[WRUE915]

Something to think about what discussing line of sight coms... not to be rude, but it's line of sight. I've heard of folks hitting repeaters or other users from mountain tops out to 100 miles on a 5 watt handheld.

In that scenario, generally the difference between 5 watts and 50 watts would be the volume of your voice coming through on the other end. Power (wattage) equals volume. Power can help with clarity too when there are some obstructions or obstacles the signal pushes through or around.

But not amount of power can get through certain obstacles.

On the ham side, many people have 50-80 watt mobiles. But most of them will tell you they usually don't use more than 10-20 watts most of the time.

[marcspaz]

My primary radio makes 18w at the output.  It works fantastic in my area. We have about 300 feet of elevation variation for about 100 miles in any direction. I get 25 to 35 miles from any given repeater with 80%+ reliability. Once I stretch past 35 miles, going to 48 watts is very helpful in many cases, but doesn't even come close to punching through "every time" I drop out with the 18w.  

 

Long story short, I think 15w is great for many applications. 

[vefrancis]

What type/make/length of antennas do you all use for gmrs mobile?

[kidphc]

Personally, I am all over the place. From ¹/4, 1/2, 3/4, 5/8 over 5/8. Also using a ham base antenna in the attic.

I'll be using a diy yagi made by a local named Roland next.

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[SpeedSpeak2Me]

On my truck I have a Laird BB4503 (NMO) on a mag mount.  It is a 5/8λ ground plane required.  Each time I use it I am impressed with its quality and performance.  It does need to be cut for proper tuning, and they provide the center frequency and length, so you're not guessing.  I'm only running 14-18w into it, and for repeaters with a 250-300' AGL receive antenna I can hold the repeater, and talk out to 50 miles or so, as long as I have a good line-of-sight.

For the car I am considering getting the Laird BB4502 (1/2λ) which is a no-ground plane required, since I don't have a good mounting location.  It won't perform as well as the BB4503, but should be pretty close, and probably not enough of a difference for me to notice.

Only difference between the "B" and the "BB" models is that the base is black, instead of stainless.

[WRUE915]

On mobile ove had great success with the Midland MXTA 26. 5/8 over 5/8. Works much better than the Nagoya 72G I used to use. Although the Nagoya isn't bad. But noticeable difference.

[nokones]

1 hour ago, WRUE915 said:

On mobile ove had great success with the Midland MXTA 26. 5/8 over 5/8. Works much better than the Nagoya 72G I used to use. Although the Nagoya isn't bad. But noticeable difference.
 

The Midland MXTA 26 Phantom Antenna is surprisingly "Not Too Shabby" in performance.  Also, the Midland Mag-Mount NMO Base is not-too-shabby either except for the PL259 which is a "POS".  Just replace it and it will be a great mag-mount base. 

Mr. Randy NotaRubicon did a You Tube review comparing the performance between the   Midland MXTA 26 Phantom Antenna and another antenna which, I can't remember now, and the Phantom Antenna was equally to a Tad better in the "Farz" category.

 

I use the Phantom Antenna while I am in the Greater Phoenix Area but, when I venture out I'll either use the Laird B4502N 2.5 dB 1/2 wave no springs antenna in the foothills and when I am in the mountains I'll throw on the B4505CN 5 dB no spring center load 1/2 wave antenna.

[WRUE915]

I was talking about the MXTA 26, the 6db gain antenna. The MXTA 25 is the ghost or phantom antenna you may be taking about. I've never used it. But some like it. I would only recommend if you can't accommodate the MXTA 26 or equivalent.

[kidphc]

On my truck I have a Laird BB4503 (NMO) on a mag mount.  It is a 5/8λ ground plane required.  Each time I use it I am impressed with its quality and performance.  It does need to be cut for proper tuning, and they provide the center frequency and length, so you're not guessing.  I'm only running 14-18w into it, and for repeaters with a 250-300' AGL receive antenna I can hold the repeater, and talk out to 50 miles or so, as long as I have a good line-of-sight.
For the car I am considering getting the Laird BB4502 (1/2λ) which is a no-ground plane required, since I don't have a good mounting location.  It won't perform as well as the BB4503, but should be pretty close, and probably not enough of a difference for me to notice.
Only difference between the "B" and the "BB" models is that the base is black, instead of stainless.

Try the 4505. The 5/8 over 5/8, other then the size it is a very, very impressive antenna. Did I say impressive.

I am running a 4503 right now. It's not bad, just a bit more deaf than the 4505.

Crap i might be selling mine. Even uncut it was about 1.2 to 1.3 in gmrs repeater frequencies. Still have not cut the 4505 or the 4503 just really no need to.

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[nokones]

51 minutes ago, WRUE915 said:

I was talking about the MXTA 26, the 6db gain antenna. The MXTA 25 is the ghost or phantom antenna you may be taking about. I've never used it. But some like it. I would only recommend if you can't accommodate the MXTA 26 or equivalent.

Oops sorry, my mistake.

[WRWE456]

6 hours ago, WRUE915 said:

generally the difference between 5 watts and 50 watts would be the volume of your voice coming through on the other end. Power (wattage) equals volume.

This is actually not true. More power can make the signal received clearer but it will NOT make the volume of the received signal louder. That is not how it works. Speaking volume into the mic and mic gain will affect volume but not transmit power.

[Over2U]

Another advantage of a 15 watt mobile is ease of installation: such a radio can often be powered directly from a “Power Point” (cigarette lighter outlet).

[SpeedSpeak2Me]

On 4/20/2023 at 5:57 PM, kidphc said:

Try the 4505. The 5/8 over 5/8, other then the size it is a very, very impressive antenna. Did I say impressive.

I am running a 4503 right now. It's not bad, just a bit more deaf than the 4505.

Crap i might be selling mine. Even uncut it was about 1.2 to 1.3 in gmrs repeater frequencies. Still have not cut the 4505 or the 4503 just really no need to.

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I’m height-restricted, so can’t go with something that tall. But have considered it, just to have it in the stable. My BB4503 came from the factory tuned at 452.900-453.000. I set it to about 463.500, and it’s still less than 1.5:1 all the way down to 440 MHz (70cm). I could use it for both bands, but would re-check where its impedance is closest to 50 Ohms, to be safe. 
 

Like others have mentioned, the Midland MXTA26 is an excellent performer, so is the Browning BR-450 (which might require trimming).

[WRUE915]

This is actually not true. More power can make the signal received clearer but it will NOT make the volume of the received signal louder. That is not how it works. Speaking volume into the mic and mic gain will affect volume but not transmit power.

Over distance, this can be true... from my experience

[SpeedSpeak2Me]

On 4/20/2023 at 5:57 PM, kidphc said:

Try the 4505. The 5/8 over 5/8, other then the size it is a very, very impressive antenna. Did I say impressive.

I am running a 4503 right now. It's not bad, just a bit more deaf than the 4505.

Crap i might be selling mine. Even uncut it was about 1.2 to 1.3 in gmrs repeater frequencies. Still have not cut the 4505 or the 4503 just really no need to.

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So, since the thread was bumped, wanted to give an update.  I did get the BB4505C, and used it on two road trips, and also while many farz from a few repeaters.  This antenna is pure excellence in a 32" package.  Got it tuned pretty much damn near flat across the GMRS band, using a Laird mag mount.  Best continued contact I had was just about 100 miles into a repeater.  I was also able to do about 70 miles into a repeater whose receive antenna is about 300' AGL, using about 4.25w.  Those were not just "was able to key", but carried on a conversation.  Granted communications were primarily late evening or at night.  Even day time I can do 40-50 miles, sustained.

Simplex/Repeater outputs (avg to 462.6000 MHz) is 1.13:1.  Repeater inputs (avg to 467.6000 MHz) is 1.17:1.
It has an SWR of 1.5:1 or less from 456.7000 MHz to 477.5000 Mhz.  Staying at 2:1 or less it goes from 437.0000 MHz to 481.2000 MHz.

 

The black horizontal line denotes 1.5:1

 

I also picked up the BB4502N for use on a car where I don't have enough flat surface area for a ground plane to use the BB4503 or BB4505C without being really directional.  The BB4502N is a no-ground plane 1/2λ 10" antenna.  It obviously doesn't have the performance of the BB4503, but it really punches above its weight.  If I am talking into repeaters at 300' AGL, I can easily hit 30-40 miles.

Simplex/Repeater outputs it's 1.24:1.  Repeater inputs it's almost the same, 1.22:1.

I actually went a bit short on this one, but its usable bandwidth is still outstanding.
SWR is 1.5:1 or less from 436.4000 MHz to 486.0000 MHz, that's not a typo.  SWRs of 2:1 or less is 450.000 MHz to 501.4000 MHz.

[bd348]

My mobile is 15W and it does fine.  For comparison, using a handheld with a base antenna in a second story window, I can get 30 miles to the repeater and back with a half watt, which is the low power setting on the otherwise 5W handheld.  In most cases, it really is more about the antenna.

[WRUE915]

My mobile is 15W and it does fine.  For comparison, using a handheld with a base antenna in a second story window, I can get 30 miles to the repeater and back with a half watt, which is the low power setting on the otherwise 5W handheld.  In most cases, it really is more about the antenna.

Agreed... take away to bd348's point is, don't go cheap on the antenna. Budget a good antenna, and then buy the radio that suits your needs/budget.