Stacking, Ganging, Combining TV Antennas

[300ohm]

300ohm, when you say that they should point out to the back of the reflector, do you mean like this:

Not exactly. I mean mount the preamp and mixer like I have my preamp mounted so that its behind the reflectors.

[zenno]

Oh i see. So the entire preamp must be behind the reflectors.

Thank you.

My next task will be to find an old cm4228 like mine to finally begin assembling everything. It won't be that hard, i already think of a few peoples who might help. ;-)

[ppauper]

zenno, you might want to take a look at the last few posts in the thread
http://www.digitalhome.ca/forum/show...=112565&page=7
about stacking "hacked" 4228s (and 4228HDs) wherein folks cut the phase lines and used separate baluns on each side of each 4228, and then stacked 2 such "hacked" 4228s

[Lineloss]

Rain...rain...rain....

[zenno]

Ok, a few days later, i'm finish connecting everything.

Thank you to everyone with tips.

I'm happy to see an increase in signal strength of about 10-15% which is above what i expected.

But i did not only add a good uhf/uhf mixer (the 4041 from Televes), i also changed all cables and connections to top notch snap-n-seal and RG6U 95% braid shield. So i guess all this explain the increase.

HOWEVER: I discovered (with horror) that my new mixer seems to completely cut out vhf channels, i was not expecting that. So my only vhf ota digital channel, WVNY-22 (on channel 13) in burlington went from 45% to 0%. Grrrr.....

There is an extra spot on the mixer for a vhf antenna connection, so i was a little surprise about the cutout. Maybe i will later try to switch one of the antenna from the uhf to the vhf input of the mixer, we'll see.

Regards.

[stampeder]

Originally Posted by zenno

There is an extra spot on the mixer for a vhf antenna connection,

A solution is to run the antenna that gets channel 13 into a UVSJ and then run the UHF and VHF outputs into your Televes 4041. I know that it adds complexity and will probably cost some signal but it is probably the only clean solution.

It looks like the Televes mixer was not designed for combo antennas, just 2 separate UHF antennas and 1 separate VHF band antenna.

[zenno]

Funny thing is, without knowing it, before buying that uhf mixer, i use an inverted UVSJ to feed my preamp.

So, now that i know it's suppose to separate the 2 bands, i understand what you are telling me. This might work. Requires that i cut and redo a few cables but what the heck....

Thank you again Mr Stampeder, that's a great idea. I will get back to you probably tomorrow with the results.

Cheers.

p.s. By the way, the UVSJ model i have is the 25-UVSJ from JVI, i hope it's good enough.

[stampeder]

There is of course another option for getting Channel 13 near Montreal:

Ch 13 Yagi for Montreal area - Design Help Needed

Making/using custom channel-cut yagis for UHF/VHF TV

[zenno]

He he he....I will try the uvsj first....Remember, i'm the guy who's not very good building these things.

However, this Yagi calculator is very interesting.

[zenno]

Sorry, couldn't wait until tomorrow. I'm just back from the roof.

Well, Channel 13 is back but not better than before, i still get a lot of mosaics.

As for the lost for the other channels, i will not consider locals because i get them with second antenna.

For the u.s. channels, here are the results, before and after i put the UVSJ :

WCAX-3 (CBS) 86% to 85%
WPTZ-5 (NBC) 82% to 78%
WVNY-22 (ABC) 0% to 55%
WETK-33 (PBS) 84% to 81%
WFFF-44 (FOX) 79% to 73%
WCFE-57 (PBS) 54% to 52%

Maybe i will try a better UVSJ.

[zenno]

Hello,

Since i'm never completely happy with my reception results, can i use on the same line the KT-100VG (that i did not buy yet) and my already installed CM7777 ?

The problem is that i have mosaics on one channel and the other are all at about 75-80% strength.

Also, my setup include a second antenna for local stations in opposite direction. Is it dangerous to overload since these local channels arrives at approx 80-90% signal strength ?

My actual setup is the following:

- 4228+another smaller uhf antenna
- The 4228 goes into a band separator and then into the vhf and uhf entry of an antenna mixer
- The other smaller antenna feeds directly into the second coax uhf input of the antenna mixer
- The output of the antenna mixer is going into the 7777 and then in the house.

Thank you.

[300ohm]

Since i'm never completely happy with my reception results, can i use on the same line the KT-100VG (that i did not buy yet) and my already installed CM7777 ?

Whew, youre liable to overload. The CM7777 has quite a bit of gain. How long is your cable run and hows it split ? Preamps only take care of signal losses after the antenna terminals.

[zenno]

3 feet from the 4228 to the band separator (not a pico macom), then 2 cables about 6 inches goes to the 2 inputs (vhf/uhf) of the mixer (televes 4041)
3 feet from the other cheaper and smaller uhf antenna directly to the other uhf input of 4041.
The output of the 4041 feed directly into the preamp 7777 using a 3 inches cable. And that's it, the rest is a 25 feet cable that feed inside the home.

All cables are RG6U.

[balm]

nwusa:

your terminology may actually be correct, and mine incorrect, but my explanation remains - you can check the FAQ about the terminology.

I edited my post #62 terminology in this thread: http://www.digitalhome.ca/forum/showthread.php?t=111398, sorry about that

[jdemaris]

Originally Posted by balm

nwusa:

your terminology may actually be correct, and mine incorrect, but my explanation remains - you can check the FAQ about the terminology.

I edited my post #62 terminology, sorry about that

There aren't any set-in-stone rules for the word or phrase meanings that I know of. You need context to be sure. Here are few common definitions . . . and there are others.

"Ganging" is the combining of 2 or more antennas' outputs together. Side-by-side ganging is just one of the ways of ganging antennas

"Stacking" is the specific combining of 2 identical antennas faced in the exact same direction for long distance, deepest fringe reception. The goal of stacking is not to make 2 antennas into 1, but rather to get both of the antennas working as a team.

“Quad stacking” can be four antennas both vertical and horizontal.

“Phase-nulling” horizontal stacking by varying the distance between horizontally mounted antennas.

“Vertical stagger stacking” with two verically stacked antennas facing opposite directions. Upper gets mount relocated and moved more forward from the mast. Usually done to opimize only specific channels.