Using different antennas with my HT?

[bobthetj03]

I can access 2 repeaters from my front deck using my GM-30, but was wondering if I can increase my range if I mounted an external antenna on the roof and hook it up to my HT? There is one repeater I can't quite get to, but can hear conversations from there. As an experiment, I took the small antenna that came with my MXT-275 and set it on a 2'x3' sheet of steel, then set it on the roof. I was able to have a short conversation with a guy 15 miles away via a local repeater, but not sure if I gained anything or not. 

[SkylinesSuck]

It's situation dependant, but it's very likely it would help considerably.

[mbrun]

I can access 2 repeaters from my front deck using my GM-30, but was wondering if I can increase my range if I mounted an external antenna on the roof and hook it up to my HT? There is one repeater I can't quite get to, but can hear conversations from there. As an experiment, I took the small antenna that came with my MXT-275 and set it on a 2'x3' sheet of steel, then set it on the roof. I was able to have a short conversation with a guy 15 miles away via a local repeater, but not sure if I gained anything or not. 

Nearly anything you do to get the antenna higher in elevation is going to have a positive impact on your range. An HT hooked up to antenna at 20, 40, 60 feet and more is going to result in noticeable increase in range over an HT at 5 feet. Even in a mobile situation, putting an external antenna on the vehicle may add 4 feet of elevation increase. Here you win twice because the antenna is higher, plus the antenna is outside of the box that serves as a signal obstruction.


Michael
WRHS965
KE8PLM

[bobthetj03]

It was amazing how much it helped. Using a mag mount and 16 feet of RG58 coax, I mounted a 5db gain antenna on the roof. I can reach 3 repeaters in my area from my front deck. There is a 4th repeater 30 miles away that I cannot reach. Well, last night I was able to reach it, and had a nice conversation with a fellow. My HT was only pushing 2 watts, so it was amazing how much range I was able to gain just from antenna choice and placement. 

 

[bobthetj03]

The swamp cooler on top of my roof would make a great ground plane, and be even higher up, but I would have to run another 25' of coax to reach it. The mag mount I have now is 16' of RG58 coax. If I extend that cable another 25' will I be exceeding a length requirement or start loosing signal strength to bleed off?

 

[BoxCar]

All coax injects loss. The amount of power lost in the coax can be determined by looking up the specification from the manufacturer and applying it.

[OldRadioGuy]

You could use some heavier, lower loss coax for the middle section of the run where flexibility is not an issue.

Keep the thinner more flexible coax for a few feet at the ends where you need it more flexible.

This will keep your overall loss lower without make it unwieldy.

I would try to limit coax loss to around 3db if you can.   Lower is of course better.

Vince

[bobthetj03]

My experiment continues tonight. Received my 110/12volt DC converter, 10A. 25' of low loss RG8x coax(hoping it's long enough), a couple of coax unions, and a Midland accessory plug. The plan, move my 5db gain antenna to the very top of the roof on top of my swamp cooler, route my cable to the front deck where I normally hang out, remove my Midland MXT-275 from my Jeep and plug it in as a base unit. Having the extra Midland power plug will make it super easy to unplug the unit from my jeep and just plug in to the 12 volt converter. I'll be effectively running 41' of coax, so I'm hoping I won't lose much line loss. The repeater I'll be trying for is 45 miles across the lake on the southern mountain range as seen from my front deck. I was able to reach it ok with my HT with the antenna just on my front porch awning, so with the extra power of the MXT-275 and the antenna another 8ft higher, it should have no problem. 

 

[AdmiralCochrane]

Yes, it should work well.