View Full Version : What kind of splitter to use for FM and HDTV OFF THE AIR?

02-09-17, 02:56 PM
I have a HDTV antenna in my attic and have good reception of the HDTV channels in my area (Minneapolis, St, Paul).

I am using the coax down feed from the antenna to feed my HDTV (pretty standard) and an FM radio feed for my Pioneer AV receiver. In doing some reading on your site I notice that the Mhz rating of the splitter will make a lot of difference when one is talking about good HDTV reception. So what kind of splitter should I get if I'm trying to feed both a HDTV and a good stereo receiver thirsty for a good strong FM signal.

NOTE PLEASE, I am not talking about cable signal, but a signal that is OVER THE AIR and coming through the air, to the antenna in my attic and down via cable to the splitter where the TV and FM hungrily await a feed.

02-09-17, 06:54 PM
Yes, you can split it theoretically, if you have a strong signal.

A VHF/UHF antenna should also cover the FM band:
VHF (channels 2-13) = 30-300 MHz <-- this also covers the FM band, 88-108 MHz
UHF (channels 14-83) = 470-890 MHz (even though the entire UHF band is 300-3GHz)

Some newer antennas have a separate output for FM... If not, you should be able to use any splitter that is labeled to cover the correct frequencies. Most splitters I have around cover 5-2000MHz, some older ones were only designed to cover 5-1000MHz, but they'd also work. Keep in mind that a 2-way splitter will reduce the signal by 3.5dB on each out leg (50-60%), so it will only work if you have good enough signal.

If your TV signal is sketchy and you lose OTA HDTV channels when you introduce the splitter, it may be easier to use a separate dedicated FM antenna. I hope this helps.

Here are some other notes:
- higher frequencies will have bigger loss when split (i.e. UHF channels)
- a tap can be used instead of a splitter (it reduces signal by 1db on the OUT leg, and ~6db on the TAP leg). This can be used to incur the negligible loss on the TV side, and the higher loss on the FM side. See: http://www.speedguide.net/faq/what-is-the-difference-between-a-splitter-and-a-425

02-09-17, 10:44 PM
Thank you . That is precisely the type of information I needed. So the HDTV broadcast signal is still <1000 MHZ? Where would one find a "tap?" I know what a splitter is and how to get one. Is it just called a "tap?"

02-10-17, 07:03 AM
No, they are different. I would start with a splitter, only consider a tap (or a separate FM antenna) if you are losing TV channels.
A splitter divides the signal, i.e. 2-way splitter incurs 50/60% loss on each leg (3.5dB). A tap divides the signal differently, i.e. incurs almost no loss on one output leg, and all the loss on the other. They are a bit less common, often used to keep a clean signal to cable modems.

02-10-17, 12:29 PM
But a splitter that will handle up to 1000 MHz will handle digital TV signal over the air? I've ordered a splitter (before I got the full answers from you yesterday) that's rated as 5-2500 MHz. I assume that will be (more than) adequate.

02-10-17, 01:42 PM
Yes, a splitter with up to 1000MHz will handle all the OTA HDTV channels just fine. A splitter that is rated 5-2500MHz may be better, or, most likely you won't see a difference. It only matters how well it is made, i.e. good RFI shielding and separation (120+dB?), waterproof, etc.

For reference, the HDTV UHF channels range from 470MHz to 890MHz max (even though the entire UHF band is wider, 300MHz to 3Ghz).