Moving beyond homebrew antenna

[tss1355]

I live in Saint Joseph, Michigan, and listen to the railroad and marine radio traffic. There is a railroad swing bridge over a navigable river, so it is quite interesting.

Current setup is a home-brew dipole antenna (Homebrewed Off-Center Fed Dipole - The RadioReference Wiki) mounted on my eaves, feeding through RG-6 into a desktop scanner. The audio goes into a Mac Mini, where it is recorded, the silence is cut out, and it is transferred to my iTunes account. Then I use my iPhone to listen to this summary of the day's traffic on my car stereo on my commute.

Initial installation included about 60' of coax and performance was adequate. But I had to move the computer to a different part of the house, and now have 100' of cable in play and performance is much poorer.

I now want to get a better antenna (what kind?) and upgrade to better coax with a shorter run. Does anyone have advice on the best antenna for my application?

I'm located near the corner of Pearl and Wayne streets, St. Joseph, Michigan. I am in a single story house with a 2-story house immediately to the west, which does not help. Can't afford a giant mast/tower, so rooftop, eave, or attic mount are my only options right now.

 

[prcguy]

If your handy with tools you can build this, which is about as good as it gets for VHF. The plans are several posts down in the thread. https://forums.radioreference.com/build-your-own-antenna/109144-4-bay-vhf-dipole-array-project.html
prcguy

I live in Saint Joseph, Michigan, and listen to the railroad and marine radio traffic. There is a railroad swing bridge over a navigable river, so it is quite interesting.

Current setup is a home-brew dipole antenna (Homebrewed Off-Center Fed Dipole - The RadioReference Wiki) mounted on my eaves, feeding through RG-6 into a desktop scanner. The audio goes into a Mac Mini, where it is recorded, the silence is cut out, and it is transferred to my iTunes account. Then I use my iPhone to listen to this summary of the day's traffic on my car stereo on my commute.

Initial installation included about 60' of coax and performance was adequate. But I had to move the computer to a different part of the house, and now have 100' of cable in play and performance is much poorer.

I now want to get a better antenna (what kind?) and upgrade to better coax with a shorter run. Does anyone have advice on the best antenna for my application?

I'm located near the corner of Pearl and Wayne streets, St. Joseph, Michigan. I am in a single story house with a 2-story house immediately to the west, which does not help. Can't afford a giant mast/tower, so rooftop, eave, or attic mount are my only options right now.

 

[mmckenna]

Another option is to pick up an old marine VHF antenna.
They'll work well on marine VHF (obviously) but also on the railroad VHF channels.
They usually come with a length of coaxial cable with a UHF type connector on the end.
They don't require a ground plane, so they are pretty easy to mount off the side of the eaves or on an existing TV antenna mast.

The bigger issue you have isn't necessarily your antenna, it's the long coaxial cable run from where your antenna is to where you radio/computer is. 100 feet is kind of long for RG-6.

Wether you keep your existing antenna or purchase another, you'll either need to move your radio and antenna closer, or you'll need to get to some higher grade coaxial cable. Better coaxial cable can get expensive, so try to move the radio and antenna closer together.
Antenna height is going to be your friend here. VHF can be pretty forgiving, so even if there is a house in the way, it'll still work.

 

[tss1355]

Thanks for the advice. Shortening the cable run is definitely priority one. Will have to explore the antenna options. I was thinking of a discone, but I like the idea of the marine VHF antenna.

 

[popnokick]

Could you mount a TV antenna on an eave mount mast at the end of the house nearest the radio, allowing a shorter coax run? If so, be certain to use a TV antenna that covers the VHF channels, and orient it on the mast vertically. TV antennas are pretty effective scanner antennas. You may also want to try a TV antenna amplifier, but install it at the antenna end of the coax. Try it first with the Off-Center Dipole to see if it improves things or adds more interference / noise. Finally - Is your OCFD mounted vertically from the eave? If not, you could boost reception considerably by orienting it vertically. Just checking....

 

[KE5MC]

Thanks for the advice. Shortening the cable run is definitely priority one. Will have to explore the antenna options. I was thinking of a discone, but I like the idea of the marine VHF antenna.

Discone while it spec'd for a wide bandwidth for reception gives up any gain and may fall in the minus numbers, at best '0'.

The marine VHF antenna is a good recommendation.

Mike

 

[mmckenna]

Thanks for the advice. Shortening the cable run is definitely priority one. Will have to explore the antenna options. I was thinking of a discone, but I like the idea of the marine VHF antenna.

Right, discones provide zero gain. The only benefit to a discone is that they are extremely wide band. If you only plan on listening to VHF marine and railroad, a dedicated VHF antenna will -easily- outperform a discone. Getting an antenna with some gain will improve your reception. Most VHF marine antennas designed for boat use have zero gain, so that may not be your best choice, unless you have a short coax run and use better coax.

Getting one of the amateur radio single or dual band antennas will work, too. Pretty easy to get a <$100 amateur grade base antenna that will not only give you some gain on VHF, but will work well on UHF, too. Just in case you decide to explore the UHF band in your area.
Plus, if you ever decide to get your amateur radio license, you'll already have a suitable antenna.