VHF/UHF Base Antenna Recommendations for Newbie

[RoyinVA]

Hi, I am a new ham operator who is working from home since the pandemic. I live in a mountainous area of western Virginia and am surround by mountains on most sides. The closest active repeater for 2m is about 20 miles away. My roof is too steep and high for me to climb so I'm looking at mounting a Comet GP-9 on a 10 or 20 foot top rail pole (for chain-link fencing) and attaching it to a corner support 4x4 of my deck with conduit clamps and running about 12 feet of LMR-400 or similar low-loss coax to my shack in the finished basement via a MFJ panel pass through in the window. My deck is about 15 ft high.

Does this sound like a workable and safe set up that will enable me to hit a repeater at least 20 miles away? Right now I just have a Baofeng BF-F8HP HT up and running but am planning on purchasing a power supply for my Kenwood TM281 and using it as a base since I'm not commuting anymore (plus I bought a new 2021 Subaru Crosstrek and don't want to mar it with a magnetic mount antenna.

All comments/suggestions gratefully appreciated.

Thanks,
Roy

 

[sunbulls]

I’m thinking that Comet GP-9 would be sufficient to reach that closest 2 meter repeater, but it’s also a dual band antenna. Reaching any UHF repeaters over the hills might be questionable. VHF is better suited. Since your Kenwood TM281 is VHF only anyway, I would go with a beam such as the Diamond A144S10 at half the cost with more gain. You could also make your own. In any case the higher the better. Another option that many others are doing in your situation is to setup an Allstar or Echolink node.

 

[BJ radionut]

Roy: I am guessing your deck is off second floor type balcony. This deck is supported by 4 x 4 posts from ground level. (?)
Roy, that is a good antenna. However it would seem greater height could be achieved.
I have a homebrew 1/2 wave 10 meter ground plane. (aprox 16 ft. long) This antenna is mounted on a short 20 ft. tower with bracket off the side on my small barn.
The ground plane is at 33 ft. I have aprox 12-14 ft. of double wall fence rail that is extended above the last support.
Yes that antenna moves with the Indiana wind, wobbles in storms etc. BUT it's been there for going on like 10+ years now.
Where this is going Roy, is I think the base of your VHF/UHF ground plane could easily be 10 feet above the top rail of your deck, thus base of antenna at 25+ feet.
Height is always your friend at VHF/UHF frequencies, and feedline length and quality are equally or more important than gain.
I am thinking your feedline length of 12 feet (?)must be a typo. I am using aprox 75 feet of tri-shield RG8 (LMR400MAX equivalent) This is the bare minimum quality and loss.
This spring, I will be changing my VHF Diamond antenna(@48ft.) over to 1/2 inch Heliax style to reduce the loss going to that antenna. I will gain near 2 dB on 2 meters and even more if using 440 band.
So just a thought. I lived in a apartment building where I had a 2 meter antenna up about 30 ft above my deck flooring on third floor.
I mounted a threaded base on the deck floor and a make shift steel pipe bracket off the top rail to secure the mast.
I then ran a push-up pole and had my 2 meter Ringo mounted on that.
I then used a 10 meter Dipole near the top of the pole to act as guyed wires to hold the mast secure using top of the hand rail.
When I was not at home, I simply loosened the push-up clamps and slid the pole together.
How about some pictures ? Might help with some ideas.
Many here to help Roy
GL 73
Gary/W9FNB