[Todd Willhoit]

While our home is in a metropolitan area we in the fringe coverage zone for some FM stations.  I have a receiver in my garage that really struggles with the basic supplied antenna.  I have been looking at some DIY designs and thought I would ask the collective wisdom here before buying parts.  I will likely mount the antenna in the attic (about 7' clear height) but may consider a bracket attached to the soffit if the design is unobtrusive.

I appreciate any suggestions.  Thanks in advance.

Todd

[I.Greyhound Fan]

Here are some sites that may help you=

http://home.computer.net/~pritch/betterfm.htm

http://www.fmtunerinfo.com/index.html#antennas

[richidoo]

If you put the antenna outside up on the roof, you have building code grounding requirements that you need to understand and follow to reduce damage if lightning strikes.

In short, the roof antenna needs to have it's own grounding wire, separate from the coax signal wire. The ground wire stays outside the building and connects to the house's earth rod near the utility meter with a bronze ground wire clamp. That's the extent of the code requirements, but to protect your equipment from lightning damage use a true, glass cartridge, coax lightning arrestor where the signal enters the house. The arrestor should be grounded to the separate exterior ground wire (preferably without cutting the grounding wire.)  I use ones from Diamond Antenna on my FM and DirecTV antenna feeds but it's not made with F connectors for FM antennas anymore. This one looks very similar. There are also cheaper, resettable coax surge protectors intended to block cable TV power surges from distant lightning strikes, but they are not intended for direct lightning strike. Good antenna grounding should prevent the antenna from attracting lightning by grounding any "feeders," but lightning can still hit it by chance so arrestor is a good idea.

The differing impedances between the antenna's separate exterior ground, the signal coax shield and tuner circuit ground (house neutral/earth) usually will create a strong ground loop hum. Cure that with the capacitor based Jensen isomaxx filter VRD-1FF. It is more expensive than the "transformer" based ones from Parts express, but it is more reliable.

If you use interior type antenna in the attic you don't need any of the grounding stuff, and no ground loop hum from antenna. That's the way to go if it can pull in your desired stations.

[FullRangeMan]

You will find various antennas in this site:
https://www.rfparts.com/catalogsearch/result/?q=fm+antenna
You may email them to suggestions.

[Wayner]

On the other hand, a couple of antenna installers that I have known thru the years recommend not to ground the roof-top antenna as it could become like a lighting rod (which we all know too well) that actually encourages lighting strikes.

'ner

[dB Cooper]

The last time I had a rooftop antenna, it was required by the local building code, as richidoo mentions. Connected to a copper rod driven about 3 feet into the ground. As I understand it, the antenna has potential to draw a strike regardless; it's just a question of whether you want the path to be through the ground or destroy your tuner.

[Todd Willhoit]

Thanks guys for the detailed information.  From the looks of things, it will be far more cost effective, with lower risk, to keep it in the attic.

FM Fool list the towers as follows.  Station 1 & 2 are the ones that suffer both in signal strength as well as adjacent channel interference.
Primary tower locations are at 124 degrees, 18 miles.
Station 1 tower at 16 degrees, 54 miles, 100 kW
Station 2 tower at 72 degrees, 77 miles, 100 kW

Some of the design references I have been looking at on line are here:
http://wiki.radioreference.com/index.php/Homebrewed_Off-Center_Fed_Dipole
http://home.earthlink.net/~schultdw/antenna/PlainWireFancyReception.html
http://www.wryr.org/Antenna_instructions.pdf

It seems clear to me that I either need some type of high gain omnidirectional antenna or a directional antenna facing 1&2 that hopefully would still gather sufficient signal off-axis from the primary tower location, or stacked antennas to gather signals from both general directions.

Does anyone have any experience with these types of DIY antennas in this situation?

Todd

[Todd Willhoit]

I am still curious to know if anyone has experience with the DIY antenna builds.  Thanks in advance.

Todd

[Mortsnets]

I built this modified cubial quad design and it worked pretty well.
http://www.wryr.org/Antenna_instructions.pdf

If you can adjust the orientation a small yagi might be the best.

Another good site:
http://ham-radio.com/k6sti/index.html

[merdy]

Hi i don't know where you are located but if you are somewhere upstate new york ,near new paltz you are welcome to have one of my crazy antennas for free

its about a 6ft long ,10 inch diameter,round mesh tube, with a small amp/power supply filter ,and about 75 ft of the best coax cable in existence i will go to the attic this weekend and check the brand ,i have to clean my diy room as my mother in law is moving in (she is 85)   and this is not  something that would sell as shipping would be nuts

so its yours or any radio guys that want a amazing antenna

i used to pull some stations over 100 miles and the s/n ratio and sound quality was better than spinning vinyl
uncompressed radio was spectacular
once again its free
you can pm me of e mail me at paynehertz at gmail dot com

[richidoo]

I am still curious to know if anyone has experience with the DIY antenna builds.  Thanks in advance.

Todd

No experience with DIY antennas. I bought my yagi, mast, and soffet mounting kit from Radio Shack back in 2005 when they still sold things people want.

I remember seeing an antenna design being commercially produced a few years ago, built around a cardboard tube that supposedly had good reception, but I can't find the link to it. Maybe similar to Merdy's tube antenna?

Here is a list of some antennas with links. Some of them are out of business, but you can follow the links and see what you find out. The "Home Depot Yagi" on the list is DIY, maybe others too?
http://ham-radio.com/k6sti/

[merdy]

hi the company that made the antennas was ramsey electronics ,they dont sell that any more  but you can some parts on e bay
yes the cardboard tube works great the model number is fmba1c
somebody please take it away from me before i make it a sub woofer sonutube antenna

[Todd Willhoit]

The Ramsey fmba1c is an RF amplifier for their broadcast antennas.  I tried to find some link to information about the antenna you mentioned but came up dry.

@richidoo
"...Radio Shack back in 2005 when they still sold things people want."  Now that is funny.   And accurate.

I have a small VHF/UHF antenna purchased at RS around 2000.  Still pulling in great quality HDTV signals.

I have sent inquires regarding the topic to a few HAM sites with no success.  I may just build a J-pole around 100 MHz and see what happens.

[Phil A]

Try one of these?  http://audiokarma.org/forums/index.php?threads/made-a-rhombic-antenna.213882/

[Phil A]

Here's some more info - https://en.wikipedia.org/wiki/Rhombic_antenna