Homemade FM Antenna

Hello, just thought Id share an antenna I made, that you guys might could use
if you dont have room/the ability to put up a yagi like me.

My main hometheater kenwood has a dipole just good enough to get a few stations, but my Fisher 170 sits on a shelf next to my computer, and I wanted it to be my DX'er.

Cost ranges between $5-10 depending on what you have, or brand you buy.

Its a 2 wavelength (using the top of the band 108mhz 984/108=9.1x2 for gain, you can tweek it to any mhz on the band) Helical Loop, I got a solid pine peice of wood from homedepot, and cut it to 10in wide and 2 and a half foot tall, and half an inch in depth. Since mine is outside most of the time, I used some woodstain/water sealant, this is optional.

And well the picture explains most of it I hope, Im not a graphic artist so sorry for the crappy drawing. Took 18.2ft of 22ga wire and Wraped it in a Helical around the wood, and came back down, used a Coax TV spliter and Soldered one end of the wire inside one Side, and screwed down the other end of the wire to the grounding screw, then I hot glued some parts for the wire so it would hold.

Now Im using 25ft of Coax, with a 300ohm to 75ohm Transformer on the back of my Fisher, things may vary depending on your radio, but it will work if your radio has a Typical F connector.

SO FAR it has been great, I can pick up every local station and have been able to DX 4 stations, one being 206miles away, in Dallas Texas 106.1 Kiss Fm from here in OKC, that was really mostly E skip, but never the less, this is a killer antenna.

Interesting..I think I understand the sketch.

Wonder how it compares to other designs, such as a full wavelength square loop? I may have to try this out, using 20 feet length for the lower FM frequencies.

A question and an observation:

Do you make two wraps, one going up and one coming down, or do you wrap the wire up and send a lead straight down?

It sounds like you use a balun on the back of your Fisher to convert the 75ohm for use with the 300ohm terminals. If this is the case, there is also a balun inside the tuner, converting it back to 75 ohm. You are getting balun loss. If you can install an "F" jack on the rear panel, and bypass both baluns, you'll get even better reception than before.

jhoyt said:

A question and an observation:

Do you make two wraps, one going up and one coming down, or do you wrap the wire up and send a lead straight down?

It sounds like you use a balun on the back of your Fisher to convert the 75ohm for use with the 300ohm terminals. If this is the case, there is also a balun inside the tuner, converting it back to 75 ohm. You are getting balun loss. If you can install an "F" jack on the rear panel, and bypass both baluns, you'll get even better reception than before.

Click to expand...

No its one wire, on the top of the board, on one side I came across over the top edge, and back down in the same helical motion only the other way.

And you know what, I have actully been inside my Fisher and there isnt a balun, all the rest of my rcvr's have on build inside. Both antenna leads come stright off a capacitor??? Any help? should I build one, and install a F jack? In a way I kinda dont wanna mess with it because Im getting great reception, but thank you for the help. Wonder where a schamatic can be found for my radio:scratch2:

radiation8 said:

No its one wire, on the top of the board, on one side I came across over the top edge, and back down in the same helical motion only the other way.

And you know what, I have actully been inside my Fisher and there isnt a balun, all the rest of my rcvr's have on build inside. Both antenna leads come stright off a capacitor??? Any help? should I build one, and install a F jack? In a way I kinda dont wanna mess with it because Im getting great reception, but thank you for the help. Wonder where a schamatic can be found for my radio:scratch2:

Click to expand...

So, the wire actually makes a crosshatch pattern on the wood? Just tryin' to learn a little!

Sometimes older gear will have a funky 75 ohm terminal on the back, a straight coax connection, or screw terminals. Have you tried bypassing the external balun entirely?

An antenna is a wave trap. The bigger the better. You can make a dipole that is tuned for a specific station or the whole FM band. If you listen to a favorite station you can tune to it and rotate the dipole for best reception.

The formulas are out there. It might work better for you.

Is The 22g Wire Stranded Or Solid? Michael

I used solid wire, stranded might be more flexable, if you can find it.

Yes jhoyt, It is kinda like a crosshatch, and I have used the antenna by bypassing the balun, but the Fisher seems to have a little bleed over that way. In a bit I will start a new thred about a new radio I got that handels very nicly:thmbsp:

please can put some real photos of the front and rear of the antenna already built. Thank you very much.

I'd also appreciate pix, i'm very interested in trying this one.

OK, ill get it down from my pole I should have pics by tonite, or tomarrow morning at the latest.

I liked this antenna so much I went and made one for my home theater, a smaller version(1ft tall and 6in wide), but very idenical to the one on my outside pole.

Crapy Pics but its all i can get

Radiation8,

Sorry to be so demanding but a single pic of the back would probably clear up a lot of questions.

Thanks for sharing this cool project.

11 wraps at approx. 2 ft. per wrap says it all (22 ft.). Wrap to top and come straight down on back side. Not enough wire for anything else.

I'm thinking that if you were to fold the wire roughly in half with one side 1' or so longer than the other that you should be able to wrap that without any crossovers.
Both sides of the doubled wire would parallel each other in a spiral up ( or down) the board with the fold spanning the top.

Is this correct Radiation8?

Thanks, Steve

Can you post the sketch again? For some reason it's no longer on this thread.

Thanks.