Is it possible to combine indoor antennas?

Covert

DTVUSA Jr. Member
#1
This idea may seem silly, but if this is plausible, I'd like to combine two indoor antennas on separate sides of my apartment. Would this help? Broadcast towers are located in two separate areas, each directly to the West and East of me.
 

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#2
Hello Covert, welcome to the forum.

You cant really combine antennas in the fashion that you are proposing, but you can run 2 antennas to the same tuner and put them on an A/B switch.

This is a less than satisfying proposition for DVR use though.

Post your TVfool and folks here will help you contemplate your situation and some good solutions for you.
 

Covert

DTVUSA Jr. Member
#3
Hello Covert, welcome to the forum.

You cant really combine antennas in the fashion that you are proposing, but you can run 2 antennas to the same tuner and put them on an A/B switch.

This is a less than satisfying proposition for DVR use though.

Post your TVfool and folks here will help you contemplate your situation and some good solutions for you.
I never even thought of that but that's not a bad idea at all. Just makes for a little more work to have to get up and switch the A/B box back and forth. I've tested my rabbit ears on both sides of the room, and I get different results with each time I scan for channels. Reception also varies, 3/4 of the channels work on one side of the apartment, and 1/4 work on the other side.

I have to take off for now, will try to do a TVFool tonight.
 

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#4
I think there are some remotely controlled A/B switches available as well....but you may have to hunt for them.

Can you manually add channels to your TV or Converter box?
 

Piggie

Super Moderator
#5
I think there are some remotely controlled A/B switches available as well....but you may have to hunt for them.

Can you manually add channels to your TV or Converter box?
Couple of ideas.

It is possible to combine two antenna like the original idea. There are a bunch of traps to fall into. First make the 2 coaxes from each antenna the same length to the combiner. Then you are going to have to fiddle a LOT with them as where the 2 make most stations come in better, you will likely find another station that orientation mess up. You can also place them about 8 inches apart in the same location and turn them different directions. There is a piece written on it.

Silver Sensor

==========

Second there is a remote controlled AB Switch a "The Shack"
Remote Control A-B Switch - RadioShack.com
 

Tim58hsv

DTVUSA Member
#6
This idea may seem silly, but if this is plausible, I'd like to combine two indoor antennas on separate sides of my apartment. Would this help? Broadcast towers are located in two separate areas, each directly to the West and East of me.
It'll work.

Just run both cables into a combiner and connect the combiner to your tv. If by chance you lose some signal from either antenna, add a cheap 10 or 12db distribution amp between the antenna and combiner.

Give it a try and let us know what happens.
 

Covert

DTVUSA Jr. Member
#8
Couple of ideas.

It is possible to combine two antenna like the original idea. There are a bunch of traps to fall into. First make the 2 coaxes from each antenna the same length to the combiner. Then you are going to have to fiddle a LOT with them as where the 2 make most stations come in better, you will likely find another station that orientation mess up. You can also place them about 8 inches apart in the same location and turn them different directions. There is a piece written on it.

Silver Sensor

==========

Second there is a remote controlled AB Switch a "The Shack"
Remote Control A-B Switch - RadioShack.com
It'll work.

Just run both cables into a combiner and connect the combiner to your tv. If by chance you lose some signal from either antenna, add a cheap 10 or 12db distribution amp between the antenna and combiner.

Give it a try and let us know what happens.
I think I'm going to try it. Do either of you know if I have to use the same exact antenna? I know the coax needs to be the same exact length. Thank you for all of the help.
 

Piggie

Super Moderator
#9
Well here is the skinny hopefully simple.

To do the Two Antenna Trick in the link above, they have to be the same antenna, just like stacking two antennas outside.

What happens with different antennas is the result becomes unpredictable to present as a graph or picture, like in the linked article.

So if you use two different antennas on the same band (both VHF or both UHF or both combos) it will become totally a trial and error situation. Which indoors is not that bad of a fate, as indoor antenna placement is 20% predictable and 80% luck anyway.

One thing not mentioned here is if one of your antennas is for UHF stations and the other VHF stations, then instead of a common combiner/splitter use a UVSJ instead.
 

Tim58hsv

DTVUSA Member
#10
The two antenna trick from the link above is for combining two antennas for the same station or stations from the same direction.

I don't see why there would be a problem using two different antennas pointed in totaly different directions. It works for me with my combined 2-bay and 4-bay antennas in the attic.
 

Piggie

Super Moderator
#11
Any two antenna can be just combined, it's the fact that the result can't easily be predicted in modeling software or on paper. Once you combine unlike antennas you are totally into a trial and error situation. It's done all the time.

If you go to the link at the bottom of the Indoor Antenna Trick Stacking multiple antennas you will see you can also make more than one lobe over about a 50 to 60 degree range.

What you might have missed in the understanding. If you simply combine tow antennas in separate directions you loose 3.5 db from each antenna. They essentially reduces the size of each antenna by better than half.

But with the combining trick you don't suffer more than about 0.5 to 1 db loss using Ken's combining graph. So say you have two 4 bay antennas (two of any identical antennas that are on one band only). If you simply point each at two stations 50 degrees apart, run them in phase you loose 3.5 db. But if you follow his idea of running two of them side by side (pointed between both stations) you create two main lobes, one pointing at each station. Then the effect is nearly the same as an AB switch with an antenna pointed at each station, thus reducing the loss down to as low as 0.5 db.

That is the point most people don't get as it does take understanding antenna patterns to the next level.
 

Covert

DTVUSA Jr. Member
#12
Any two antenna can be just combined, it's the fact that the result can't easily be predicted in modeling software or on paper. Once you combine unlike antennas you are totally into a trial and error situation. It's done all the time.

If you go to the link at the bottom of the Indoor Antenna Trick Stacking multiple antennas you will see you can also make more than one lobe over about a 50 to 60 degree range.

What you might have missed in the understanding. If you simply combine tow antennas in separate directions you loose 3.5 db from each antenna. They essentially reduces the size of each antenna by better than half.

But with the combining trick you don't suffer more than about 0.5 to 1 db loss using Ken's combining graph. So say you have two 4 bay antennas (two of any identical antennas that are on one band only). If you simply point each at two stations 50 degrees apart, run them in phase you loose 3.5 db. But if you follow his idea of running two of them side by side (pointed between both stations) you create two main lobes, one pointing at each station. Then the effect is nearly the same as an AB switch with an antenna pointed at each station, thus reducing the loss down to as low as 0.5 db.

That is the point most people don't get as it does take understanding antenna patterns to the next level.
Would two Terk HDTVa's be fine or do I strictly need UHF antennas? I'm hoping to use two UHF/VHF because I do have stations on both frequencies. This is turning out to be more of an experiment than anything because I haven't seen anyone really try this yet with the same conditions. :)
 

Piggie

Super Moderator
#13
Would two Terk HDTVa's be fine or do I strictly need UHF antennas? I'm hoping to use two UHF/VHF because I do have stations on both frequencies. This is turning out to be more of an experiment than anything because I haven't seen anyone really try this yet with the same conditions. :)
We have never seen your TVFool.com plot so suggesting an amplified antenna would be foolish at least on my part.

Another thing we need to know including the TVFool plot are which channels come in on which side of the room.

There maybe an obvious pattern from seeing this and there may be a better way to combine two antennas than to just hook them up, hope for the best, or buy an amplified antenna to find it's worse.


In other words in all the people I have helped with antenna reception, I can waste a lot of time with them suggesting antennas to me to ask me if they would work without knowing their TVFool plot and what they have learned on what comes in where in the room, roof, etc. etc.
 
G

garyb014

Guest
#14
You know what I did... I taped the end of my 2nd one to where the other one goes into the little amplifier box which goes to the tv. It worked! The 3 channels which come and go now came in fine! Hurray! Now if I could find a connection to use that would be great, any ideas?
 

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