Question: Pairing coax without signal loss

Polonium9

DTVUSA Jr. Member
#1
Howdy!

So, the gist:
Bought a thrift shop amplifier and got twice as many channels. Big deal, considering I paid $1.75 for it.

I really liked it, and got channels I shouldn't have gotten, according to TVFool, or was too far away. Pretty cool, at least to me.

Problem (there's always one): I needed NBC and ABC, which are local, and it didn't pick them up due to signal loss.

I am using two antennas: a Clearstream 2 and a homemade "gray-hoverman antenna". Yeah, I'm that guy with a weird thing in the window.

I lose channels, due to signal loss as I combine 2 antennas for maximum channels using a Antronix 2to1 splitter a friend gave me, in reverse format.

My question, and I'm sorry for being so long winded, but is there a way to combine the two coax wires without losing much signal, preferably none?

Thanks, in advance.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#2
... My question, and I'm sorry for being so long winded, but is there a way to combine the two coax wires without losing much signal, preferably none?
Thanks, in advance.
:welcome: back, Polonium9

It is generally considered impossible to successfully combine two or more antennas unless they are identical. If they are identical and pointed in the same direction, there will be signal strength gain: if the same identical antennas are aimed in different directions there will be an approximate 50% signal loss. Combining different type antennas will result is even greater signal loss so no, you cannot combine your two antennas. You can use an A-B switch a choose one antenna at a time on separate coaxial feedlines. One exception: you can combine two antennas from different bands such as UHF and VHF using a UVSJ (UHF-VHF-signal-joiner) with very little signal loss.

Please keep in mind, signal strength has little to do with digital TV reception compared to signal quality and that's what the on-screen meter on your TV indicates. A weak but clean data-stream always beats a strong dirty (confused, broken) signal, which confuses TV tuners.

Jim
 
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Polonium9

DTVUSA Jr. Member
#3
I have seen signal loss, and it's a big let down. I use he gray-hoverman for the locals and have the clearstream for way farther away channels (international).
When I just amplified the Clearstream 2, I was picking up channels from Washington DC, which is impressive for my location.
But, when I combine it with the homemade gray-hoverman with the splitter, it removes some from farther away, while bringing in the locals that the clearstream doesn't.
I kinda like the local METv, CBS, ABC, PBS and all that, watching M*A*S*H is something I enjoy, and mom likes Jeopardy (as do I).

I did some more research, thanks to this forum, and have found the Linear 2512 2-way splitter/combiner. It seems to be exactly what I need, but I was curious if anyone on the forum had one, and can tell me about it.
Does it work with minimal loss?
Is there a difference between it and the Antronix 2-way splitter?

Thanks again, and sorry for all the questions. I'm not as knowledgeable as most of the people here, but I am ready and willing to learn.

If you want a TVFool report, I can provide it.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#4
... I did some more research, thanks to this forum, and have found the Linear 2512 2-way splitter/combiner. It seems to be exactly what I need, but I was curious if anyone on the forum had one, and can tell me about it.

If you want a TVFool report, I can provide it.
That splitter will work the same as others and if you try to combine mismatched antennas you will lose 50% signal strength and probably closer to 80%, plus you will introduce confusing secondary signals per my post above. Give up the idea of combining your antennas.

We would appreciate seeing the result of your survey URL.

Jim
 

Polonium9

DTVUSA Jr. Member
#5
I guess some clarification:
Both antennas are pointed towards the same area, but the DIY one is more passive, so it just lets all the locals come in.
The Clearstream 2 is pointed towards the area of international channels (30-1 to 30-12)

Here's the link: TV Fool

As a reference, I get WTTG, but not MPT.

Thank you.
 
#6
The results you've ran into in combining antennas are not unusual. There are no magic antenna combining devices that will make it work. Here are a couple of good pages you can read on the subject.
Merging feedlines
Stacking multiple antennas
While I'm not saying what you are trying to do can't, or hasn't been done using amplifiers, and spliters. By far the simplest most trouble free way to do it is to build a switched, or dual tuner system. Ir remote coax switches are available, but walk across the room ones are cheaper. A learning remote can be programmed to control the TV, the ir switch, or second tuner.
While I know that no one likes this two tuner, or antenna switch solution it is the one that will work.
Steve
 
#8
Using a HBD8X is likely to yield the same or worse results as it simply combines two four bay antennas pointed different directions. A switched antenna system correctly built will work.
 

n2rj

Moderator
Staff member
#9
If you want to combine different antennas for different channels where one antenna is used for one channel or set of channels and the other is used for others, it is doable. There is a company called Tin Lee Electronics that sells filters and combiners to do just that.

But for a simple indoor antenna system it seems like such a waste.

The only time I really see it making sense is if you have multiple channels in multiple directions and do not want to use a rotor.
 

Polonium9

DTVUSA Jr. Member
#11
@RF Steve
after posting the original post, I looked around the forum and found that merging feedlines site and that's what really interested me and made me decide to order the combiner I mentioned previously. If it doesn't work, no loss. I can get a refund.
And, as much as I like to fiddle with stuff, it seems like a lot of work for the two tuner thing.

@n2rj
Heh, the site has some interesting diagrams and useful info, thanks! Didn't want to see the prices after what Fringe said. I'm a college student and am fascinated by antenna tv, but college student budget.

Heck, I got the clearstream 2 for 42 in a store, previously used once.
My Balun was 25 cents from a box of wires. Made in Japan, as well.
I think you get how much my budget is.
 
#12
Low cost coax switches are not difficult to find, and will do the job, but in most situations they require getting out of the chair to change channels.
http://www.amazon.com/RCA-VH71-Slid...bxgy_23_3?ie=UTF8&refRID=1H2QRJ0ZJXFFTKTW6QZF
http://www.amazon.com/RCA-VH74-Delu..._UL160_SR160,160_&refRID=1N135P7A7JF47AZX5KZN
Remote coax switches are available but have gotten a bit more difficult to find in the last year. The current price of one is about the same as a low cost tuner. It would be a choice of which one best suits your needs.
https://www.antennasdirect.com/store/A/B_control_switch.html
http://www.amazon.com/3500STBII-Multi-Function-Converter-Recording-Playback/dp/B00GOILYB6
Most common splitters will all work about the same. Of course it's always possible to get a bad one. In some locations signal conditions are such that what you are trying to do can work, but in many locations it will not.
All of the antenna work I've done in the last three years has been on a junk box, thrift store budget. I am aware of the products from Tin Lee Electronics they are not low budget items.
The links in this thread are not an endorsement of any of the products. They are the simple kind solutions I would try. I probably have a couple coax switches in my box of treasures (junk box).
Steve
 
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