AVS › AVS Forum › HDTV › HDTV Technical › RF Signal Booster
New Posts  All Forums:Forum Nav:

RF Signal Booster

post #1 of 19
3/29/12 at 6:00am
Thread Starter 
Does anybody know of a good one I can use for both radio and TV reception? I'd like to hook up my radio to my TV antenna with an A/B switch/splitter, but the last time I ran a splitter off of my antenna it weakened the signal to TV to the point where it started freezing up/cutting out.

I saw a couple models online but they seem to be designed primarly for HDTV, not sure if they cover the radio frequencies as well? Also what amount of gain is acceptable? All the models I've seen have a fixed gain of around 12dB, should I be looking for one that is adjustable? How much gain is too much?
Reply
Reply

AVS Top Picks

post #2 of 19
3/29/12 at 8:37am
Which "radio"? AM or FM? Amplifiers seldom improve FM reception, AM even less so.

However, most pre-amps that cover TV bands also amplify FM unless the specifications indicate otherwise by the presence of an FM filter or trap.

Sometimes, it's a bad idea to amplify and distribute FM signals with your TV signals, other times it doesn't matter. It all depends on the mix of frequencies and their relative powers at your location as to whether amplification should (or should not) be done or if it will likely to be helpful or detrimental.
Reply
Reply
post #3 of 19
3/29/12 at 10:49am
Thread Starter 
Would be dedicated to FM. What you're describing sounds rather complicated though. Does a comination of FM and TV singals matter if you are only using one tuner at any given moment? Or does the amplification just cause the signals to interfere with each other regardless?
Reply
Reply
post #4 of 19
3/29/12 at 11:58am
FM signals are carried between channels 6 and 7. So, any signal booster should work assuming you have a VHF antenna pointed in the right direction for FM reception. And... also assuming the FM xmitters are in the same (approx.) direction of the TV xmitters.

A simple 2-way splitter is fine. Boosters designated as HDTV are BS. RF is RF.
Get a splitter and booster with no "FM Trap".

Also... it would be helpful to know what type of antenna you are using (indoor, outdoor, make, model).
Reply
Reply
post #5 of 19
3/29/12 at 12:04pm
Quote:
Originally Posted by Mark_1042 View Post

Would be dedicated to FM. What you're describing sounds rather complicated though. Does a comination of FM and TV singals matter if you are only using one tuner at any given moment? Or does the amplification just cause the signals to interfere with each other regardless?

what i did was use a quick disconnect. if i wanted tv the trap was in, if i wanted fm the trap was out.
Reply
Reply
post #6 of 19
3/29/12 at 1:09pm
Thread Starter 
Quote:
Originally Posted by Ratman View Post

FM signals are carried between channels 6 and 7. So, any signal booster should work assuming you have a VHF antenna pointed in the right direction for FM reception. And... also assuming the FM xmitters are in the same (approx.) direction of the TV xmitters.

A simple 2-way splitter is fine. Boosters designated as HDTV are BS. RF is RF.
Get a splitter and booster with no "FM Trap".

Also... it would be helpful to know what type of antenna you are using (indoor, outdoor, make, model).

The antenna is acutally a homemade indoor antenna (I can't have an aerial in my current place due to restrictions, but will be moving later this year).

Its sort of a fractal / bow tie "hybrid" design, basically 2 small bow ties with some triangular patterns in them. Small enough to hang in a window and gets better reception than any store bought antenna I've seen. The cable run is not long either, about 14 feet to the TV.

FM radio reception is decent, but not great with just a small wire antenna. I'm also not getting 1 channel on the TV due to a weak signal, so I figured if I could hook up both radio and TV to the better antenna and amplify the signal I might be able to kill 2 birds with one stone.
Reply
Reply
post #7 of 19
3/29/12 at 2:52pm
Well, good luck.

As I stated, FM is located between VHF TV channels 6 and 7. Sounds like you have a homemade UHF only antenna, which won't work well (or not at all) for FM. Is that one problematic channel a VHF channel?

I personally don't think you will be able to kill two birds with one stone and wouldn't go to any expense. Wait till you move and do it right in your new location.
Reply
Reply
post #8 of 19
3/29/12 at 6:02pm
Thread Starter 
Quote:
Originally Posted by Ratman View Post

Well, good luck.

As I stated, FM is located between VHF TV channels 6 and 7. Sounds like you have a homemade UHF only antenna, which won't work well (or not at all) for FM. Is that one problematic channel a VHF channel?

I personally don't think you will be able to kill two birds with one stone and wouldn't go to any expense. Wait till you move and do it right in your new location.

Probably good advice there.

The homemade TV antenna does do well for FM though. I'm not sure if the TV station I'm having trouble with (the CW) is VHF or UHF. Ever since they went digital I can't really keep them straight, since the channel number tags on the TV no longer mach the RF channel designations. I have a printout somewhere of the true channel numbers but haven't looked at it for a while.

The antenna I built looks something like this, except its smaller and much more asthetically pleasing Different casing/framework on mine but the conductors look the same.

Reply
Reply
post #9 of 19
3/29/12 at 9:19pm
Quote:
Originally Posted by Mark_1042 View Post

Does anybody know of a good one I can use for both radio and TV reception? I'd like to hook up my radio to my TV antenna with an A/B switch/splitter, but the last time I ran a splitter off of my antenna it weakened the signal to TV to the point where it started freezing up/cutting out.

I saw a couple models online but they seem to be designed primarly for HDTV, not sure if they cover the radio frequencies as well? Also what amount of gain is acceptable? All the models I've seen have a fixed gain of around 12dB, should I be looking for one that is adjustable? How much gain is too much?

how about using a tap instead of a splitter?
milt
Reply
Reply
post #10 of 19
3/30/12 at 5:46am
Quote:
Originally Posted by Mark_1042 View Post

...The homemade TV antenna does do well for FM though. I'm not sure if the TV station I'm having trouble with (the CW) is VHF or UHF...

What are the call letters of the problem station?
Reply
Reply
post #11 of 19
3/30/12 at 7:56am
Quote:
Originally Posted by milt9 View Post

how about using a tap instead of a splitter?
milt

Taps have a different purpose. A diplexer (or similar) is used to separate or combine specific frequency bands with minimal loss.
Reply
Reply
post #12 of 19
3/30/12 at 8:22pm
Thread Starter 
Quote:
Originally Posted by arxaw View Post

What are the call letters of the problem station?

It's WCWF, digital channel 21 (displayed as channel 14.1 on the TV).
Reply
Reply
post #13 of 19
3/30/12 at 8:49pm
Use an FM/TV splitter to separate them. The insertion loss is minimal. Just do a search for Cabletronix FM/TV Splitter.
Reply
Reply
post #14 of 19
3/31/12 at 4:19am
Quote:
Originally Posted by Mark_1042 View Post

It's WCWF, digital channel 21 (displayed as channel 14.1 on the TV).

Channel 21 is UHF. FM shouldn't be an interference problem with that channel. But a lot of other things can interfere with reception, including electronics in your home. Try turning off everything else in your house, to rule out something in your house or apt. that's interfering with reception. It could also be something in a nearby apartment. If you live near a hospital, some of their equipment may be interfering with ch 21. Or you may just have bad multipath problems.

Re FM; longer elements are needed for the frequencies FM broadcasts on. A simple dipole antenna (rabbit ears) would likely work better for FM. Extend the dipole rods roughly 57". If they don't extend that long, try ~ 28½" each. Lay them as flat as possible and perpendicular to the FM transmitter tower(s). Amplifying FM usually doesn't help.
Reply
Reply
post #15 of 19
3/31/12 at 5:11am
Quote:
Originally Posted by Mark_1042 View Post


That looks like it belongs in the museum of modern art.
Reply
Reply
post #16 of 19
3/31/12 at 6:07am
Quote:
Originally Posted by egnlsn View Post

Use an FM/TV splitter to separate them. The insertion loss is minimal. Just do a search for Cabletronix FM/TV Splitter.

Model FMTVS available here:
http://www.cencom94.com/subpage19.html
Reply
Reply
post #17 of 19
4/1/12 at 1:39pm
Thread Starter 
Quote:
Originally Posted by Ratman View Post

Model FMTVS available here:
http://www.cencom94.com/subpage19.html

Right on. Thanks!
Reply
Reply
post #18 of 19
4/1/12 at 1:49pm
Thread Starter 
Quote:
Originally Posted by mikepier View Post

That looks like it belongs in the museum of modern art.



Pretty much. The one I built is quite a bit smaller and I have it attached to a suction cup so I can stick it too my window. That little antenna is a champ. Great reception and you don't even know it's there.
Reply
Reply
post #19 of 19
4/1/12 at 2:00pm
Thread Starter 
Quote:
Originally Posted by arxaw View Post

Channel 21 is UHF. FM shouldn't be an interference problem with that channel. But a lot of other things can interfere with reception, including electronics in your home. Try turning off everything else in your house, to rule out something in your house or apt. that's interfering with reception. It could also be something in a nearby apartment. If you live near a hospital, some of their equipment may be interfering with ch 21. Or you may just have bad multipath problems.

Re FM; longer elements are needed for the frequencies FM broadcasts on. A simple dipole antenna (rabbit ears) would likely work better for FM. Extend the dipole rods roughly 57". If they don't extend that long, try ~ 28½" each. Lay them as flat as possible and perpendicular to the FM transmitter tower(s). Amplifying FM usually doesn't help.

I'll give it a shot. I think the channel is just a weak signal though, everybody seems to have trouble getting it. My old place was closer to the station and I still needed an aerial to get it. I think living in a brick building might be part of the problem, too.

Not a big issue though, I'll just be missing out on the latest episodes of Smallville and Gossip Girl.

(w/ the FM antenna, already have the cable ran through the wall / hidden behind the baseboard for the other antenna. So you know, just being lazy )
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: HDTV Technical

AVS Top Picks

AVS › AVS Forum › HDTV › HDTV Technical › RF Signal Booster