? antenna combiner

Tim58hsv

DTVUSA Member
#1
I'm going to purchase a db4 antenna and would like to combine it with my db2 (or possibly my old RS yaqi). One antenna will be pointed south and the other east. Can I feed the combiners output into my cm7777 pre-amp and if so what type of combiner is recommended? I know next to nothing about combiners.

Thanks.
 
#3
I'm going to purchase a db4 antenna and would like to combine it with my db2 (or possibly my old RS yaqi). One antenna will be pointed south and the other east. Can I feed the combiners output into my cm7777 pre-amp and if so what type of combiner is recommended? I know next to nothing about combiners.

Thanks.
Ok if you use the radio shack antenna you would attach it to the UHf input on the 7777 and attach the DB4 to the UHf side this will combine the signal of those two antennas if you combine a DB2 and DB4 you can get a signal combiner from radio shack, combine the two antennas and then attach to the UHF side of the 7777 but the combiner must be on the antenna side of the pre amp. so if you wanted to you could combine all three antennas buy putting a cross bar on a mast and mounting the two UHF antennas side by side which is called ganging.be aware that if you stack two UHF antennas, they must be 6ft apart if you use a UHF and VHF then you stack them 4ft apart Two VHFs stack 7-8 ft apart, if you gang the two UHF then they need to be 4-5 ft apart. be sure when you combine two antenna with a combiner that the coax lengths are equal.
 
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Tim58hsv

DTVUSA Member
#5
Ok if you use the radio shack antenna you would attach it to the UHf input on the 7777 and attach the DB4 to the UHf side this will combine the signal of those two antennas if you combine a DB2 and DB4 you can get a signal combiner from radio shack, combine the two antennas and then attach to the UHF side of the 7777 but the combiner must be on the antenna side of the pre amp. so if you wanted to you could combine all three antennas buy putting a cross bar on a mast and mounting the two UHF antennas side by side which is called ganging.be aware that if you stack two UHF antennas, they must be 6ft apart if you use a UHF and VHF then you stack them 4ft apart Two VHFs stack 7-8 ft apart, if you gang the two UHF then they need to be 4-5 ft apart. be sure when you combine two antenna with a combiner that the coax lengths are equal.
Do you mean I could use the 7777's vhs input port for the RS yaqi antenna? That would be awesome if that is the case.
 

Tim58hsv

DTVUSA Member
#8
Tim, you decide what you're going to do yet?
No, not yet.

I ordered the db4 last thursday from Summit Source so it should be here today or tomorrow. Went to radio shack yesterday and bought a bidirectional 2-way splitter but I decided to take it back today and exchange it for an actual combiner.

When the db4 gets here I'm going to try in out in an upstairs closet first since there's not enough room in the attic to put it up. The antenna is over 30" tall and the attic clearance is like 28". If it goes into the attic it'll be hung sideways.

Hoping it works well in the upstairs closet because if it does I'll be replacing it with a db8 in the very near future and oh won't the wife love seeing that monstrosity hanging there! :)

I'll let ya' all know how it goes.
 

Tim58hsv

DTVUSA Member
#9
Got 'er done.

Spent a good part of the day experimenting with the set up and am very happy with the results.

First off, compared to the db2 in the attic, the new db4 didn't work as well in the upstairs closet and it was worse when turned on its side. It had to go in the attic.

Turns out there's about 12 inches of insulation on the attic floor so once I cleared out a chunk of that there was room for the db4 to stand upright. It was aimed toward the east to pick up channel 53 WWHO out of Chillicothe, Ohio and it did. That's pretty impressive for such a small antenna to pick up a tv station that's 53 miles away with almost no (as of yet and cross my fingers) pixilation, freeze up's, or drop outs.

After that I put the combiner and db2 on the line and noticed no difference in the signal strength meters reading.

Based on the Zenith converter boxes signal meter I'd guesstimate the db4 has around 20% gain for that channel over the db2 antenna when pointed in the same direction.

Next up, I'm gonna get another db4 antenna to replace the db2 so we can pick up those Cincinnati stations even better.
 

Tim58hsv

DTVUSA Member
#10
Checking the manual tuning on the Zenith 901 box shows a weak signal coming in on channel 21. No picture as of yet, just a weak signal reading. It never showed before adding the db4 and pointing it east toward Chillicothe so channel 21 my actually be channel 10 out of Columbus, Ohio since that's the frequency they use.

When I get the other db4 antenna I'll point it in the same direction to see if that helps pull in any of those elusive Columbus stations 65 miles away.
 

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