Mad Scientist antenna farm 101 <G>

[rgreenpc]

Since our local WB is prooving to be slow to add HD gear I am determined to pull it in from Orlando ( clermont )

That being said here is my soultion.

1. Channel Master 3018 pointed at Riverview.
1. CM 4248 pointed at Holiday for CBS ( gets a locked 97% in bad wx )
1. CM 4248 pointed twoards 17 in Clermont.

I figure if I use 2 join-tennas with the pass thru for 24 and 17 respectivly - combine them with a good CM preamp I should get everything in.

Any of you closet engineers have any thoughts?

[Floyd]

I guess it depends on how well the ch17/Clermont signal comes in alone. If you can't get it a la carte, then combining other antenas probably will only make it worse. The preamp might help if the signals are coming in above threshold, -5 to 0 db. Many times, if a signal is way below threshold(perfect picture), amplification will just make it worse, at least in the analog world.
I don't have a lot of experience with using those join-tennas in outdoor situations, so I don't know if that will work, or if you can just use regular splitter/combiners that have a 4db loss.

[Bschneider]

My first suggestion is to point ONE stand-alone antenna toward Orlando and see what you get and then go from there. If you can't get anything then there is no point in doing your proposed setup.

[OccamMD]

I would go with the 4228 multi-bay for Clermont. Get it as high as you can. Do you have a multi-path problem around your house, the multi-bay should help if it has a screen.

Try running the coax seperately all the way to the rxver, even use a switch instead of combining them if you can into your coax in. After that works you can try to combine them one at a time.

Use good shielded coax (RG-6? I forget the number at the moment) and amplify the 4228 up at the antenna if you can. This can help your Signal-to-noise by the time the signal gets to the rxcver.

Should work, but I would have to check out your location to make a better estimate.

[rgreenpc]

I bought a 4248 for Clermont today I will try both antennas and see where I get.

I have great performace with the 4228 twords CBS and it can barley pull the WB from Orlando - if even a hint of rain its gone.

[OccamMD]

That's odd since the gain is so high, but the narrow beamwidth would probably require you put a rotator up to really get focused.

The 48 will have a wider beamwidth so if the gain is high enough for you then maybe it will go. Do you have your feeds running independently or do you combine them?

[rgreenpc]

They are combined right now - I really want to get away from having 3 runs into the house.

what I am going to do is do 2 phased runs to a combiner for the local stuff, then a run into a 2nd combiner for the Clermont antenna.

I will try it before and after I do a combiner to check loss, and I will do the alignment and lockdown before I try to combine.

I am running a CM7775 amp at the reciever right now. I may try it out by the antenna after all is done to test the signal level differnces.

[OccamMD]

How do you have your antennas stacked, on 1 pole?

Good idea to go in steps. You may have to amp the clermont stuff at the antenna. If you do then make sure you try that before you start combining everything.

The problem with combining is that unless you have filtered out all but the channels you want for a specific antenna then there is out of phase signal (has to do with the distance between antennas) for some of the same channels as they get combined, this can cause you trouble.

Are you going to run a combiner with DC pass-thru to power the amp at the antenna?

[rgreenpc]

I am probably going to mount the Clermont Yagi on its own pole - as I dont have a wavelength of space on my present mast.

I never thought of DC pass thru on the combiner -

I have a couple of Asai ones from DOW - but I am unsure if they have DC Pass Thru.

As far as phasing of the signals... the Clermont Yagi and the Holiday 8-bay have extremely high front to back speration.

I havent evben tried mouting them with the join-tennas as of yet, as I have been told there is enough seperation that it shouldnt be an issue.

[teampozer]

Clarification...
Although licensed to Clermont, WKCF broadcasts from the towers in Bithlo. That's the area east of Orlando off State Road 50. Of course, from this far away, that shouldn't really change your antenna position.

[rgreenpc]

well. - I assembeled the new antenna today - stuck it up and nada -

I think it needs to be higher

I was able to get a LOCKED 100% on CBS when I turned it to Holiday and 100% when it went to Riverview

So it is a great antenna - thats for sure.... now if fox and NBC would go UHF......

[OccamMD]

Did you pre-amp? Got a rotator?

[rgreenpc]

i have a CM 7775 preamp - I don't want to do a rotor if at all possible.

[rgreenpc]

Well - so the antenna farm is complete....

Only Problem is it would appear the CM7777 preamp doesn't like having combined inputs

here is the current setup.

1 CM 8 bay pointed at Clermont
1 CM Quantam Yagi pointed at Holiday
1 CM 3020 pointed at Riverview

The 8bay is sent to a splitter/combiner that is combined with the yagi/3020 then sent to the 7777.

If I don't connect the 8 bay I get near 100% signal... the second I connect the 8 bay I loose 75% singal power.... not sure what else to do.

Oh, and for Jaymer with the 8 bay on an eave mount 8 feet above my roof line I have a 85%+ signal to Clermont.

[rgreenpc]

Only other thing I can think is run a 2nd line and then combine at the source... thoughts?

[jaymer]

richard,
so there are 2 changes from when we had the 8-bay getting 60%...
height and the pre-amp.

is it possible for you to try the 8-bay to orlando with and without the CM Amp? then I can compare the same thing over here.
i also wish you could try the Quantum Yagi at Orlando with the Amp.
I wonder which one would be better for me to get.
if you get 85%, then I should still be able to get a reasonable signal from over here... an aditional 10-15 miles.

jaymer...

[rgreenpc]

I tried the yagi with and without - Yagi would pull 75% with amp 45 without.

8bay without was 55 with the amp you know.

I am thinking of using the 7777 I bought and trying to add yours - one amp on the clermont and 1 amp on the riverview set then comboine them.

Thoughts?

[OccamMD]

How is the 8-bay working without an amp, i.e. directly into the rcver, what is your power then?
It sounds like the holiday antenna is picking up some of the clermont signal. I doubt the 8-bay is doing the same thing if it has a screen on it.
The holiday antenna shouldn't need an amp I wouldn't think.
If you need to amp the 8-bay then amp it at the antenna and combine it at the rcver (but you know my feelings on combining, I prefer a terminated/isolated switch, but I understand the nuisance factor).

Another thing you can try is to place the clermont antenna on the other side of the holiday antenna, or vice-versa, on the same mast. Aren't the antenna positions near 180 degrees apart, not positive? If you do that you may be able to use the screen on the clermont to block the signal from clermont reaching the holiday antenna.

Another thing to do is use an 8-bay for both clermont and holiday since they are so directional and reject multi-path.

I'm glad you got the eaves mount working and got up above your roofline.

Sounds like progress, good luck.

[OccamMD]

Sorry I ddin't see page 2 before posting.

Jaymer,
You should go with the 8-bay if possible, additional 10-15 miles is a lot for the YAGI.

[rgreenpc]

OccamMD- give me a call you have my number still I think.

As far as the antennas, it wasn't JUST CBS ( holiday being lost ) everything went away.

What I will try to do today is this -

1. Attach a seperate 7777 amp to each mast - send each antenna into the attic and combine them before a distribution amp and then see what signal I get.

I will try with and without the distrbution amp.