AVS Forum banner

Status
Not open for further replies.
1 - 4 of 4 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter #1
I currently have the Channel Master 4228 8-Bay antenna with the Channel Master 7777 Titan2 VHF/UHF Preamplifier with Power Supply installed and have been real happy with it for about a year now. I highly recommend this combination to anyone that cares. Anyway, I'm trying to get prepared for the HD Tivo and would like to add 2 or 3 Channel Master 4221A 4-Bay Bowtie UHF Antennas and combine everything together (this is an attic installation). My local towers are in different directions and I have to frequently use the rotator to lock in on a specific signal.


#1) Can I do this?


#2) What do I need (specifically) to combine the 3 or 4 antenna signals?


#3) I have read the antennas have to be spaced apart somewhat. Is this true?


#4) If I can combine them all, can I run the 1 combined wire into the preamplifier?


I'm assuming you can't use a splitter since I am wanting to combine signals. This is primarily for digital channel reception, but I may splice it to other TV's that don't have digital set top boxes.


Thanks in advance for any help.
 

·
Registered
Joined
·
331 Posts
Quote:
Originally posted by HDinIllinois
I currently have the Channel Master 4228 8-Bay antenna with the Channel Master 7777 Titan2 VHF/UHF Preamplifier with Power Supply installed and have been real happy with it for about a year now. I highly recommend this combination to anyone that cares. Anyway, I'm trying to get prepared for the HD Tivo and would like to add 2 or 3 Channel Master 4221A 4-Bay Bowtie UHF Antennas and combine everything together (this is an attic installation). My local towers are in different directions and I have to frequently use the rotator to lock in on a specific signal.
#1) Can I do this?


The answer is 'probably'. It would be very useful if you could post the UHF channels that you want to combine into a single feed.


The situation where you might run into trouble is if any of the UHF channels you're trying to get with separate antennas are within 5 channels of any of the others. The filters on the Join-Tenna combiners aren't very selective for UHF channels, unlike the much steeper filters on their VHF Join-Tennas. It's an RF electrical engineering thing. :)

#2) What do I need (specifically) to combine the 3 or 4 antenna signals?


You will need a set of Channel Master Join-Tenna devices appropriate to the channels you're trying to combine.


Assuming you don't have any channel-adjacency issues, then you attach a Join-Tenna to each of your 4221A's and connect them together starting at the main antenna and working your way down.

#3) I have read the antennas have to be spaced apart somewhat. Is this true?


I'm no expert in this area, but it's my understanding that some separation is desirable.


It does seem to me that you should consider using directional Yagi antennas such as the 4308 instead of the 4221A, if only to reduce the size of the mast required and to more tightly confine the acceptance angle for each antenna. A Yagi design, from what I understand, also reduces the interaction between two antennas sharing a mast but pointing in different directions.

#4) If I can combine them all, can I run the 1 combined wire into the preamplifier?


Yes, but if some of the stations are markedly stronger than the others you run the risk of signal overload at the preamp's input. If this happens, you may end up using individual preamps on only the antennas which require it. It doesn't seem like this is the case for you, but you never know.


It'd be useful if you could post the info from antennaweb.org for the DTV stations you're interested in receiving without a rotor.


BTW, I'm also keeping myself occupied with OTA antenna tweaking while waiting for my HD Tivo to arrive. :)


-T.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #3
These are the channel numbers that the antennas will be picking up at some degree or another.


Digital: 18, 22, 28, 30, 39, 40, 44, 46, 57


Analog: 17, 19, 20, 23, 25, 31, 41, 43, 47, 51, 55, 59


I don't want all of these channels but the antenna will pick them up. Distance from the towers range from 5 to 55 miles.


This is an attic install so, I can move the individual antennas to different parts of the attic. They aren't all installed on one mast, but all of the antennas, including the one on the rotator will hopefully be going into the same preamp.


Thanks for the response.
 

·
Registered
Joined
·
331 Posts
Sorry, should have asked for you to group the stations by transmitter location. If you PM me your zip code I could look it up that way.


In any case, post if you have questions after taking a look at the Join-Tenna product info. CM should be glad to answer any questions regarding that product, including helping you put together the right solution for you.


-T.
 
1 - 4 of 4 Posts
Status
Not open for further replies.
Top