GMRS antenna question

[lonestarbandit]

Gents a question. If I was to mount this on the boom of my VQUAD beam....
Would the antenna survive? I mean I understand one would not have the GMRS radio on while dumping 1KW 10m radio waves through the beam but in that scenario would the little GMRS antenna be unhurt when I was to use it later (not concurrently) w 10m.

 

[sp5it]

Antenna could survive, but radio input will be fried for sure.

 

[lonestarbandit]

Oops. This is a very good point. My genius plan was perhaps not so stellar.
Now back to looking at actual base antennas with more poles. My wife will never let me use mine again if this antenna farm keeps sprouting. Fortunantly there are worse addictions than radio.

 

[brandon7861]

Antenna could survive, but radio input will be fried for sure.

What if he added a diplexer to the GMRS feed line to shunt HF to ground?

I think those readily available UHF/VHF diplexers are just a low pass/high pass thing, not a bandpass thing, so the VHF port may be able to shunt the HF to a dummy load.

But adding coax in the presence of the beam may mess up the beam pattern.

 

[SuperLid]

First, I would not use an antenna like that, sold by that company, unless you don't mind replacing it or servicing it often.

If you mount the UHF antenna on the same support as the beam, the vertical separation would be sufficient. t is not uncommon for amateurs to mount a VHF/UHF vertical above or below an HF beam antenna. So add a mast in the center above, or a sidearm off the mast below.

73,

SuperLid

 

[lonestarbandit]

First, I would not use an antenna like that, sold by that company, unless you don't mind replacing it or servicing it often.

If you mount the UHF antenna on the same support as the beam, the vertical separation would be sufficient. t is not uncommon for amateurs to mount a VHF/UHF vertical above or below an HF beam antenna. So add a mast in the center above, or a sidearm off the mast below.

73,

SuperLid

In my case it's a VQUAD so the original plan had been to mount this little stubby thing to the beam boom itself but given the delta loop design versus the traditional beam Im not sure if thats possible.... however I suppose I could mount it on the mast just below the beam if that would make a difference. I dont think I have enough mast extending above the boom to install above. I can appreciate your feelings on this GMRS antenna given my experimentation w the beam I deliberately purchased something cheap enough to be sacrificial if needed.
I would eventually probably get a midland ghost if the location proves "safe".
I am brand new to this GMRS thing just trying to get something set up before the winter cold hits.

 

[Blackcat630]

If your not dead set on mounting an omnidirectional vertical on a separate mast or stand off on your current tower you could consider a beam. A rear of boom mount yagi mounted to your mast below your Vquad could be an option. This would also give you the advantages of directivity and superior gain.

 

[lonestarbandit]

I hadnt thought of that. That is a very fine idea. I am not dead set on anything this is all new to me this GMRS business. Totally open to all ideas. I'd have to cut a new mast piece to accommodate it as due to having snapped a chinesium rotor once already I have it almost resting on the rotor but that could be very doable thing in future.
Would already be on a rotor just 180 out of what rotor box says.

 

[SuperLid]

I would suggest the sidearm below the beam approach. I would use a quarter wave ground plane, before trying to use a Tram low profile antenna.

 

[lonestarbandit]

I would suggest the sidearm below the beam approach. I would use a quarter wave ground plane, before trying to use a Tram low profile antenna.

Something like this on a sidearm you mean?

 

[SuperLid]

You were looking at a low profile mobile antenna, which is a loaded quarter wave antenna in a plastic radome. I am suggesting a quarter wave ground plane, not a gain antenna. The quarter wave is a simple antenna, not much to go wrong if you weatherproof it correctly. If you want a tall gain antenna, then go for it. I would be wary of the longevity of the fiberglass antenna though. I was thinking something like in the links.

https://www.amazon.com/Nagoya-GPK-01-Radials-Ground-Connector/dp/B0744Q3RDM/?tag=worradfor-20

Amazon.com

 

[lonestarbandit]

Ah yes I see. I am completely open to all manner of suggestions. So the mobile antenna I posted plus this groundplane kit @ near as makes no difference to 20 feet up clear of roof and obstructions would perform adequately then in your opinion?

 

[SuperLid]

Ah yes I see. I am completely open to all manner of suggestions. So the mobile antenna I posted plus this groundplane kit @ near as makes no difference to 20 feet up clear of roof and obstructions would perform adequately then in your opinion?

It depends on what coverage you are looking for. A quarter wave, has more of an umbrella type pattern, good for local coverage. Less RF at the horizon, as a gain antenna would have.

 

[lonestarbandit]

Ok. Gotcha. Yes good point. I AM hoping to make 20 miles to my mother's place (once I see what works for me and duplicate at her house) so more on the horizon would be better I can just save the ghost type antenna for the truck.