Railroad Forums 

  • Can anyone recommend a nice chimney mounted antenna?

  • Discussion related to railroad radio frequencies, railroad communication practices, equipment, and more.
Discussion related to railroad radio frequencies, railroad communication practices, equipment, and more.

Moderator: Aa3rt

 #825011  by CarterB
 
Trainman101. Everything depends on where your house is, and what direction/s and miles away the railroad/s are that you want to monitor. If all is within 5-10 miles on relatively flat ground, then an "Omni" antenna of any sort tuned to the 160-161MHz frequency range will do nicely. If however, there's a lot of terrain differential, and distance/s involved you will need a directional antenna similar to the one you posted. But...directional is exactly that....Number of degrees of angle beam width, pointed in a specific direction. http://www.firestik.com/Catalog/RR-4.htm very good omni /unity antenna. If you need more distance, then the directional antenna with or without a rotor to "aim" it. I am a Motorola and I-Com dealer...so work with this kinda stuff on a daily basis.b WHATEVER you decide on make sure you run the antenna coax to a well grounded lightning arrestor (polyphaser) before it enters your house!
 #825611  by Trainman101
 
Thanks carter. I am basically looking for the best 360 degress of coverage i can get, not really looking to "aim" toward one certain area.

I like that ground antenna you gave me in the link. It looks like i would need to attach a a PL-259 connector to the end of the cable, is that easy enough for the average joe to figure out?

My plans are to run about 40' of cable from the antenna on the roof to a ground and use about 10 more feet of cable from the ground into my house to the scanner.
 #825640  by CarterB
 
For the 360 usage, the one I linked you to should be fine. You should use RG8 /RG213 cable and the PL259 is fine...just be careful how you strip and solder. Not sure what you mean by running cable to 'a ground' then into house. If you actually ground the antenna line you will lose RF, better to use a lightning arrestor or polyphaser and then ground that.
Last edited by CarterB on Thu Jul 08, 2010 11:48 am, edited 1 time in total.
 #825673  by CarterB
 
That AlphaDelta is fine, I tend to use PolyPhaser Mfg Part #: IS-B50HN-C1 with #6 (or larger) copper wire to a grounding rod. When you purchase the lightning arrestor make sure to ask the manufacturer for their recommended grounding wire and rod specs for your type of usage. You can buy direct from Tessco https://www.tessco.com.
 #825750  by Ken W2KB
 
CarterB's advice is good. Also note that the AlphaDelta you linked uses type N connectors which are slightly superior (less loss) to PL-259 connectors (named "UHF" when 50MHz was UHF :wink: ) at railroad frequencies. Your local building code, electric, will likely have grounding requirements. Also, it is extremely important to weatherproof the PL259 / UHF connectors, once water gets in the coax losses will skyrocket. Some N connectors are purportedly waterproof when properly installed but I would err on the side of caution and waterproof them as well. Also bend the coax down in a "U" shape (not too tight a U or coax can be damaged) just before it enters the building to form a "drip loop" so water does not easily run along to coax to into the building.

Some of these articles are more info than you need, but some may help: http://www.arrl.org/lightning-protection
 #845619  by Trainman101
 
Update!!! I bought the firestik antenna carter recommend. I didnt install it on the chimney instead i went with an eve mount, its about 4 ft above my house ridge line on a 1" dia steel tube. It works great! It covers most if not all the dispatchers for good 30+mile radius. Radio from the train is about a 5 mile radius.

This is how i grounded it. Feel free to criticize. I bought #6 grounding wire which i attached to the bottom of the 1" tube steel tube on the eve mount (the tube is 7' long). Drove an 8' grounding rod( i was able to get it in the ground 7.5 ft) and ran the grounding wire to rod. I also bought the a lighting arrester and attatched it to the grounding rod before the coax enters the house.