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[Rawkee1]

I am ready to try a new commercial antenna. I'm looking at the Laird/Antenx
FG1560 156-162 Mhz with 2.15 db gain. Anybody have any thoughts? Also I'm running LMR 200 coax cable for about 70' I have a Diamond discone now. Do you think it's worth the changeover. I listen for the most part high band & trains.

 

[mmckenna]

The antenna is low gain, but should be a good antenna. I think I've used those on UHF before.

I'd use a better coax at 70 feet. You need to get that signal to your radio. LMR-400 or LMR-600 would be a good choice.

 

[Rawkee1]

I’m figuring it’s got to be better than the Diamond discone more concentrating on VHF high.

 

[mmckenna]

Not really. It's 0dB gain compared to a 1/4 wave, or the same gain as a discone. You likely won't see much improvement. Might have a bit of a better radiation pattern.

You either need to upgrade your coax, or get a higher gain antenna.

 

[Rawkee1]

What is a high gain antenna that is a good one to purchase?

 

[mmckenna]

What is a high gain antenna that is a good one to purchase?

Depends on your budget. I could easily spend $2K on one at work.
If the Laird looked good to you, just pick one with more gain.

 

[Rawkee1]

Depends on your budget. I could easily spend $2K on one at work.
If the Laird looked good to you, just pick one with more gain.

I would definitely buy one of the Laird's, but I want to be sure it will improve what I have now. I guess there is no generic for Laird.

 

[mmckenna]

Laird is a good company.
You need to use one of the online coax calculator tools to figure out what your coax losses will be.
Figure in antenna gain.
Do the same thing for your existing discone. The discone will be 0dB gain, and maybe less on some frequencies.

 

[Rawkee1]

Laird is a good company.
You need to use one of the online coax calculator tools to figure out what your coax losses will be.
Figure in antenna gain.
Do the same thing for your existing discone. The discone will be 0dB gain, and maybe less on some frequencies.

Do you have any good suggestions on a base antenna for 156-162 Mhz with decent gain? I have the height. I am running LMR240 for about 65'

 

[mmckenna]

Do you have any good suggestions on a base antenna for 156-162 Mhz with decent gain? I have the height. I am running LMR240 for about 65'

70 feet of LMR-240 has 2.15dB of loss at 155MHz. That's not bad, but consider whatever antenna you use should overcome that.
LMR-400 will have 1dB of loss.
LMR-600 will have 0.7dB of loss.

I'd consider replacing both the coax and your antenna at the same time. Reuse the LMR-240 to put your discone back up in another location.

As for antennas, if you like the Laird, just get a higher gain version of it. Here's a Laird with 3dB of gain, that'll overcome your feedline losses:

Laird TE Connectivity FG1523 - 108-260 MHz VHF Omnidirectional Base Antennas

Manufacturer: TE Connectivity; Model #: FG1523; Fiberglass Enclosed Copper Element; Economical fiberglass omnidirectional. Gold anodized support pipe;

theantennafarm.com

 

[Ubbe]

Do you have any good suggestions on a base antenna for 156-162 Mhz with decent gain? I have the height. I am running LMR240 for about 65'

How well did your 7dB gain Diamond F23 antenna work? Was it too long and you now need a shorter antenna?

/Ubbe

 

[Rawkee1]

How well did your 7dB gain Diamond F23 antenna work? Was it too long and you now need a shorter antenna?

/Ubbe

I feel that the Diamond F23 didn't perform like a 7db antenna should have. I was disappointed actually.

 

[majoco]

Gain doesn't mean anything if the reception polar diagram is not pointing at the horizon at the frequencies you want it for. All sorts of things will modify the diagram, ground plane for one, nearby metalwork for another. A good manufacturer will provide the diagram(s) but like most things - you pays your money, you makes your choice.

Although the Laird looks like a very nice antenna, it's bandwidth is only 4MHz in the VHF marine band with a "gain" of only 3dB - 3dB relative to what - a bit of wet string? It should say relative to dBi or dBd . 105" long will make about 5 quarter waves - I would expect better than 3dB for stacked dipoles.

Like a lot of antennas, you have to trade off gain versus bandwidth which is why the discone has wide bandwith versus zero gain - to get more signal get more height and shorten the feeder!

 

[Ubbe]

I feel that the Diamond F23 didn't perform like a 7db antenna should have. I was disappointed actually.

I have compared a 1/4 GP and a 5/8 GP and the F23 and the 5/8 improved signal to the double and the F23 an additional doubling, as expected. If you have a scanner or PC program that show signal strength in dBm you will see that increasing 7dB isn't really a huge difference when listening but will let a -107dBm signal buried in noise to be heard at -100dBm. Keep in mind that going out 3-4MHz from the tuned frequency will no longer give that 7dB gain and a discone might work better when monitoring a wider frequency range.

/Ubbe

 

[Rawkee1]

There is definitely more to just throwing up an antenna and start listening. Between baling, diplexers, coax, ect.

 

[Rawkee1]

Gain doesn't mean anything if the reception polar diagram is not pointing at the horizon at the frequencies you want it for. All sorts of things will modify the diagram, ground plane for one, nearby metalwork for another. A good manufacturer will provide the diagram(s) but like most things - you pays your money, you makes your choice.

Although the Laird looks like a very nice antenna, it's bandwidth is only 4MHz in the VHF marine band with a "gain" of only 3dB - 3dB relative to what - a bit of wet string? It should say relative to dBi or dBd . 105" long will make about 5 quarter waves - I would expect better than 3dB for stacked dipoles.

Like a lot of antennas, you have to trade off gain versus bandwidth which is why the discone has wide bandwith versus zero gain - to get more signal get more height and shorten the feeder!

yes, in the perfect world. I know a guy that raves about his 1/2” copper tubing J pole. He swears by it. I would love to have the knowledge to build a full wave 160 mhz antenna.

 

[Rawkee1]

I was wondering if the Laird Connectivity B1360WS that needs no tuning if it would as or better than the traintenna or the Tram 1490

 

[Rawkee1]

I was wondering if the Laird Connectivity B1360WS that needs no tuning if it would as or better than the traintenna or the Tram 1490

With all thing being equall mounted on a mast on the roof. I hear a lot about the Laird mounted outside. Also to you engineers out there, is it better to go with the 5/8 or 7/8 wave antenna? I was also wondering why the 5/8 wave is 14’ 10” and the 7/8 wave is 10.6’. Why is the 7/8 wave shorter?

 

[mmckenna]

I was wondering if the Laird Connectivity B1360WS that needs no tuning if it would as or better than the traintenna or the Tram 1490

The B1360WS would work fine as a base VHF antenna. It's a 1/2 wave, so it doesn't require a ground plane, but you'll get more gain/better pattern with one. You could add a ground plane under it. Easiest way is to use one of these:

Mobile Antenna To Base Convertor Kits | Antenna Farm

Are you looking for the best mobile antenna to base kits for sale? Shop all the best mobile antenna converters for sale today at the Antenna Farm.

theantennafarm.com

If you are adding a ground plane, you might as well step up to a 5/8 wave antenna, that'll give you a bit more gain for the same price:

Laird TE Connectivity B1323 VHF 132-174 MHz Tunable 3dB Gain 5/8 Wave Mobile Antenna - NMO

Laird TE Connectivity B1323 VHF 132-174 MHz Tunable 3dB Gain 5/8 Wave Mobile Antenna - NMO

theantennafarm.com

The Traintenna is just a 5/8th's wave VHF antenna tuned for 160MHz. No magic, just a regular antenna with a fancy name. You can save money by going with the Laird. You'll get a known good name brand antenna with the same performance.

Tram 1490 is a higher gain base antenna. It'll have more gain, so may work better. It'll need a heavier mount to support. More money. On the other hand, Tram/Browning are just Chinese made antennas. Consider them low quality antennas. You won't see Tram/Browning used in legit commercial applications.

 

[mmckenna]

is it better to go with the 5/8 or 7/8 wave antenna?

Define "better". Theoretically, a 7/8 wave antenna would have a bit more gain. That would mean a tiny bit more signal making it to your radio. I wouldn't get hung up on 5/8 vs. 7/8 though. I'd look more at the quality of the antenna. Putting an antenna up and doing it right takes a lot of work. Don't put all that work into putting up a junky antenna that you'll have to replace sooner.

I was also wondering why the 5/8 wave is 14’ 10” and the 7/8 wave is 10.6’. Why is the 7/8 wave shorter?

You'd need to tell me exactly which one you are looking at.
A true 5/8'ths wave antenna would be about 50 inches or so tall. A 7/8'ths wave antenna would be around 60-70" tall. If you are looking at the Tram 1490, that's a cophased antenna, so 7/8 over 7/8, so about 10-12 feet tall.