combining antennas

pmr

DTVUSA Member
#1
Hi. I have a general question that maybe you can answer independent of location. I'll post my tvfool a bit later when I have more time. Also when I can I'll go back and re-read hdprimer and other places that discuss joining antennas.

I have a 42xg, 4221hd, 4228hd and a cm7777. Under the right conditions I can get vhf 9, 11, and 13 on each of these. In one location (at 6' above grade right in front of the house) I can get pretty much everything I'm after with the 4228 but the location is unacceptable to the wife. My second best location, at least in terms of convenience (at ~28 feet on existing rooftop mast and easy access to 5 cables installed in walls when the house was built), I have several gaps (no usable signal) on both vhf and uhf: Multiple multipath factors present.

Again I'll post location and more details in a bit but in general is it a) possible and b) desirable to stack a combination of these antennas? Is gain cumulative or will they interfere with each other? Is it worth a try to see what happens? Can two uhf antennas be run through the cm7777 or do I need a joiner?

Thanks.
 

Don_M

DTVUSA Member
#3
Again I'll post location and more details in a bit but in general is it possible and desirable to stack a combination of these antennas?
Possible? Anything's possible. Desirable? It almost assuredly won't be. Combining dissimilar antennas is far more likely to create reception problems than it is to solve them.

Is gain cumulative or will they interfere with each other? Is it worth a try to see what happens?
Not necessarily, most probably yes, and most probably not.

Can two uhf antennas be run through the cm7777 or do I need a joiner?
Not directly. One of the 7777's inputs is for VHF signals, the other for UHF signals. Any antenna connected to the VHF port will be forced to act as a VHF-only antenna. Two UHF antennas would need to be combined ahead of the UHF connector -- not that I'm recommending this, of course. :cheesy:

Look, it's hard enough as it is to find a good antenna for your location, then identify the best spot to mount the thing. Frankly, you're asking for way too many headaches trying to figure out how to conceal the antennas, while getting every desired station reliably, while keeping the wife happy -- all when you've already found an antenna that can do the job, and a location that seems to be optimal. So I hope you'll forgive me if the following sounds extremely blunt, but I'd propose opening the following negotiation with the spouse: Either she swallows hard and learns to accept an antenna and location she dislikes, or she ponies up for the monthly cable or satellite bill. You've already purchased three antennas and spent hour after hour testing mounting locations -- ample proof of your willingness to work hard at keeping her happy. It's not asking too much that she be willing to meet you halfway on this.
 

pmr

DTVUSA Member
#4
:behindsofa: Shhh. She might hear you!

I agree of course but in the interest of maintaining the peace around here I really can't put the antenna in the middle of the front porch. So I'm scouting other options. Now I know combining dissimilar antennas is not an option.

What about identical antennas? For example, it looks like the 4228 is two ganged 4221's. Is there any advantage over the 4228 to stacking a couple 4221's? or a couple 4228's for that matter?

Meanwhile, I'm trying to understand what makes the porch location better than any other place I've tried so far. Besides the obvious (location), the one big difference is the house wall maybe 6 feet behind the antenna (that sits on a pole that's temporarily bungied to the deck railing). There's also a roof over the deck.

Does the wall act like a reflector or does it cause multipath?
 
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