Tram 1481 - Suitable for GMRS?

[COBrien]

I know, I know. The Tram 1481 is a dual-band amateur radio antenna. I'm fully aware. But has anyone used one with any success on GMRS frequencies?

A little background:

I currently operate a repeater out of my backyard outbuilding, using a Tram 1486 (trimmed to a 1.2:1 SWR on 462.600) mounted to a telescoping flag pole which is hard-mounted to the building, and it gives me decent range. I'm working on securing a better site for my repeater, where I can mount one of the two DB420-B antennas I have stumbled upon.

In the meantime, though, I'd like to eek out whatever range I can from my current setup/location, even if that means spending another $129 on a larger antenna. My flag pole won't support a DB420, and I'm not in a position right now to be erecting a tower in my yard.

I see some Amazon reviews (which I'm coming to trust less and less...) suggesting the 1481 *can be* suitable for GMRS, but I'd like to hear some real input from the hive mind here.

[Socalgmrs]

5 minutes ago, COBrien said:

I know, I know. The Tram 1481 is a dual-band amateur radio antenna. I'm fully aware. But has anyone used one with any success on GMRS frequencies?

A little background:

I currently operate a repeater out of my backyard outbuilding, using a Tram 1486 (trimmed to a 1.2:1 SWR on 462.600) mounted to a telescoping flag pole which is hard-mounted to the building, and it gives me decent range. I'm working on securing a better site for my repeater, where I can mount one of the two DB420-B antennas I have stumbled upon.

In the meantime, though, I'd like to eek out whatever range I can from my current setup/location, even if that means spending another $129 on a larger antenna. My flag pole won't support a DB420, and I'm not in a position right now to be erecting a tower in my yard.

I see some Amazon reviews (which I'm coming to trust less and less...) suggesting the 1481 *can be* suitable for GMRS, but I'd like to hear some real input from the hive mind here.

Looks like it’s 12mhz off or there about.  How about a comet 712efc.  Pre tuned for gmrs    Every small home repeater In my area uses them and they work perfectly fine on gmrs and repeaters.  I have a comet 712efc, a 6nc and a 9nc on the house.  We have big winds here most months and never a problem.  We also have freezing rain and snow  and 120deg heat.  They have all been up there for years.  

[COBrien]

1 hour ago, Socalgmrs said:

Looks like it’s 12mhz off or there about.  How about a comet 712efc.  Pre tuned for gmrs    Every small home repeater In my area uses them and they work perfectly fine on gmrs and repeaters.  I have a comet 712efc, a 6nc and a 9nc on the house.  We have big winds here most months and never a problem.  We also have freezing rain and snow  and 120deg heat.  They have all been up there for years.  

I was looking at the 712EFC, and I like that it comes with an N connector (which all of my repeater coax uses). Honestly, I'd prefer to buy the Tram because they're an Oklahoma-based business (and the 1481 is about half the price of the 712EFC...), but if the antenna won't work, it doesn't do me any good.

EDIT: Wait, the 712EFC is about the same price as the 1481. I must've mis-remembered that. Also, the advertised gain of the 712EFC is comparable to the advertised gain of my 1486. I'm going for 11+ dBd, if possible.

[COBrien]

@Socalgmrs I looked at the Comet GP-9NC, which is most comparable to the Tram 1481, yesterday. That's what I was thinking of.

I may try out the 1481 and see what my NanoVNA shows. If it looks like it won't be suitable, the GP-9NC will be my next purchase.

[WRYZ926]

The Comet CA-712EFC is listed as 9 dBi which is 6.8 dBd. 
 

most antenna manufacturers list gain in dBi. Subtract 2.14 from the dBi value to get the dBd value. 

[COBrien]

15 minutes ago, WRYZ926 said:

The Comet CA-712EFC is listed as 9 dBi which is 6.8 dBd. 
 

most antenna manufacturers list gain in dBi. Subtract 2.14 from the dBi value to get the dBd value. 

Right. And my current Tram 1486 has an advertised gain of 6.5 dBd, which is 8.65 dBi. Comparable to the 712EFC.

The Tram 1481 has an advertised gain of 11.7 dBd, or 13.85 dBi. Comparable to the GP-9NC.

[WRXB215]

@COBrien keep in mind that super high gain isn't always the best. In general, the higher the gain, the flatter the lobe and the lower the gain the fatter the lobe. In some cases, a high gain antenna can "over shoot the target" so to speak. Just make sure the radiation pattern matches your particular use case.

[COBrien]

11 minutes ago, WRXB215 said:

@COBrien keep in mind that super high gain isn't always the best. In general, the higher the gain, the flatter the lobe and the lower the gain the fatter the lobe. In some cases, a high gain antenna can "over shoot the target" so to speak. Just make sure the radiation pattern matches your particular use case.

Heard and understood. I'm in Oklahoma, where the topography is quite flat. Having said that, there are some "hills" that my repeater will never get over unless I'm 120'+ AGL, which isn't going to happen in my back yard (hence the search for a better/higher repeater site). I've got my eye on a water tank/standpipe about 15 miles SW of me that's located on a hill that's about 200' above my elevation, but monthly board meetings mean the time between making a presentation, answering questions, and ultimately getting permission and/or a lease can be unbelievably long.

I've been using Radio Mobile to give rough estimations of coverage area, and higher-gain antennas are still beneficial, even taking the topography into account.