300 ohm twin lead

Tim58hsv

DTVUSA Member
#1
Can I use equal lengths of twin lead cable tied together and thru a single balun to connect three antennas together? That 4-way coax combiner I bought is a real signal killer.

Here's what happenened...

I tried hooking up 3 antennas thru a 4-way combiner and it all but killed the reception. The Cincinnati stations 45 miles away were mostly gone and even the Dayton channels were having sound dropouts and a bit of pixelation. Dayton channels are only 7 miles away so that's real bad. The Chillicothe station (53) was still coming in pretty good and it's the furthermost out (54.7 miles) but then again I was using two 4-bay antennas for that one and a single 2-bay for Cincinnati and Dayton.
Seems that the combiner eats up the signal from the 2-bay antenna.

BTW, both 4-bays have pre-cut three foot coax cables and those antennas are pointed to the east. The 2-bay has a longer cable and is pointed to the south. And just to add, there's a channel master 7777 preamp in between the combiner and splitter that feeds the tv's.

Thanks.
 
#2
the twin lead will be even worse the pre amp needs to be before the combiner as it kills the power to the pre amp from the injector. use a 4 way distribution amp 4 in one out instead of the 4 why combiner.
 

Tim58hsv

DTVUSA Member
#3
the twin lead will be even worse the pre amp needs to be before the combiner as it kills the power to the pre amp from the injector. use a 4 way distribution amp 4 in one out instead of the 4 way combiner.
Thanks again, Cowboy! You're always a tremendous help on this forum.

One more question if you don't mind. Can you recommend an amplified combiner? I've searched the web today for one and have came up empty. I did see a RCA bi-directional splitter at a Meijer store tonight. Would that work?

OK. Guess that was two questions.
:)
 
#4
ok this is how you will need to do it put the channels master on the antenna that needs amplifing, attach the power supply then from the power supply run to the combiner. then out to the tvs put a distribution amp between the combiner and the tvs one antenna in then however many tvs you need two out or etc. wouldn't a rotator have been cheaper
 
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DantheMan

DTVUSA Jr. Member
#7
Tim, you're going all out!! Are you trying to receive channels cross state? Is this sort of an antenna stacking setup? Interested to see the results, though I hate to think of how much you've spent so far.
 

Tim58hsv

DTVUSA Member
#8
Tim, you're going all out!! Are you trying to receive channels cross state? Is this sort of an antenna stacking setup? Interested to see the results, though I hate to think of how much you've spent so far.
Sorry it took so long to get back with ya, Dan. Somehow I missed your post.

I'm just trying to pull in as many channels as feasibly possible and so far that's 34 channels from Dayton, Cincinnati, and Chillicothe, Ohio. It would be nice to add Columbus channels to the line up but so far no luck.

The Insignia box does show a couple of weak signals coming from that direction which appear to be channels 10 and 28 from Columbus but I'm not sure since the signals aren't strong enough to produce an actual picture on the screen. Same deal with a Cincinnati station which is probably 25, a low powered station. It's like their almost there but not quite.

The cost hasn't been that much with each 4-bay running about $43.00, the CM7777 pre amp around $65.00, and the 2-way and 4-way combiners about $28.00 for both. The 2-bay and coax I already had.

At this point it doesn't look like there's much hope of picking up anymore channels but who knows? Maybe after the analog shut off some more channels will come in.
 
#9
if any of your stations are running their digital at lower power and reduced coverage for "for the moment" then that could be why

on the FCC website look up some stations in your area and look at the log records, should say if their gonna increase power etc.
 

Tim58hsv

DTVUSA Member
#10
if any of your stations are running their digital at lower power and reduced coverage for "for the moment" then that could be why

on the FCC website look up some stations in your area and look at the log records, should say if their gonna increase power etc.
The FCC post transition coverage maps for Columbus show both channels 10 & 28 increasing their power to just outside of this area so that should be a plus.

Yesterday I tried something that in theory shouldn't work but did, at least a little. I stripped the insulation off one end of a three foot piece of coax and connected the center pin to one side of a 4-bay and the ground of the coax to the other side of the antenna and then connected it to the pre-amp, thus eliminating the balun (and combiner since I was only using one antenna).

I know if a balun isn't used half of the antennas signal is going straight to the ground connection and not being used, but I swear, for a few seconds there was a picture and sound from channel 10 in Columbus. Also channel 4 from Columbus was showing a very weak intermittent signal (but no sound or picture) for the very first time. How could it be that half an antenna could pick up a better signal than a whole antenna???

Afterwards I hooked everything back up as normal but plan to do some more experimenting with it soon. :)
 
#11
The attic is like a crawlspace so a rotator would never fit. Both 4-bays are mounted with the top of each antenna touching the ceiling and the bottoms touching the floor and that's what's holding them up.

Thanks once more for your help.
must be four ft between antennas that is your problem they are canceling each other out, interfering with each other. separate them and see if it does not improve.:)
 

Tim58hsv

DTVUSA Member
#13
must be four ft between antennas that is your problem they are cancelling each other out, interfering with each other. separate them and see if it does not improve.:)
Just got home from work, read this, and measured the distance between the antennas which was 3' 2" from reflector element tip to reflector element tip. Didn't separate them further tonight because I'm tired and didn't wanna dig out another mountain of attic insulation in order to make the antennas fit. :)

Come thursday I'm off work (God willing and the creek don't rise) and will do it. I'll let ya know how it goes.
 
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Tim58hsv

DTVUSA Member
#16
is it impossible to move the antennas outside this would boost your reception 50%
I'm a renter of a townhouse without a balcony so I can't think of any practical way to get an antenna up high enough for good reception. Not sure if a tower would be allowed since that would require digging a hole in the ground and filling it with cement to support the tower.

Looks like I'm stuck with working with what I've got, but really, that ain't too bad either.
 

Tim58hsv

DTVUSA Member
#17
Got the antennas separated by 5'+ now but they're still interfering with each other when pointed in the same direction. That causes the tv's to lose channels instead of gaining them. As long as they're pointed in different directions (one south, one east) they work the same as before which is pretty darn good. I even tried removing the preamp, thinking it might be overloading the signals, but that just made it worse.

I hate my attic. :)
 

Tim58hsv

DTVUSA Member
#19
point one antenna each direction and see if the signal strength increases.
It does and that's how they're set up now.

Gotta add some good news.
Got up this morning and scanned for new channels like I do most mornings and both channels 28 from Columbus and 25 from Cincinnati were coming in intermittently. There both mostly gone now but hopefully will be back tonight.
Either way that's show an improvement with the reception.

28 has only the one channel but 25 has four and one of those is called WKRP in Cincinnati. Is that even legal? :)

Here's a screen cap from the Clear Springs channel on 25.4



Also channel 9 from Cincinnati is coming in now.
I don't think that has anything to do with moving the antennas since even people in Cincinnati were complaining about not being able to pick up the station. Guess the folks at wcpo 9 finally got their act together because that stations coming in great now.
 
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