Hi Stampeder. Let me see if I got this right.:confused: I’m installing VHF-HI Bandpass Filter on my Delhi effectively knocking out VHF –LO and UHF , then I combine VHF-HI from Delhi with CM 4228HD through reversed splitter , than preamp , FM trap, ATSC tuner and TV. I was kind –of thinking (with my extremely limited knowledge) that by doing this VHF-HI from Delhi will compete against VHF-Hi from CM4228HD. Am I wrong? Also do I‘ve to worry about NF?
PS. I would probably have to istall balun on Delhi to match Bandpass filter?

Hi Stampeder. Let me see if I got this right.:confused: I’m installing VHF-HI Bandpass Filter on my Delhi effectively knocking out VHF –LO and UHF , then I combine VHF-HI from Delhi with CM 4228HD through reversed splitter , than preamp , FM trap, ATSC tuner and TV. I was kind –of thinking (with my extremely limited knowledge) that by doing this VHF-HI from Delhi will compete against VHF-Hi from CM4228HD. Am I wrong? Also do I‘ve to worry about NF?
PS. I would probably have to istall balun on Delhi to match Bandpass filter?

Your Delhi will be tuned for VHF 2-13 and the CM4228 is already tuned for UHF 14-69 only.

mooseIII, actually I'm thinking you would be best to use a UVSJ (see Post #16 in the OTA FAQ for an explanation).

Tanks Stampeder. Would this sketch represent the set-up?


Delhi VU 936SR VHF/UHF/FM CM4228HD UHF
| |
| |
#1 Pico Macom |
UVSJ |
| |
| |
VHF UHF
| |
| |
\ /
\ /
#2 Pico Macom
UVSJ
|
VHF/UHF
|
V
CM7777
|
V
ATSC tuner

mooseIII, these three methods of combining only the VHF-HI signals from your Delhi combo with a dedicated UHF antenna will each have much the same result, but I personally favour the second one as it is a very tidy solution if you can find some shielded foam core 300Ω twin-lead somewhere! :eek: :)

1. With a UVSJ you would run the Delhi into the VHF-IN, and the UHF antenna into the UHF-IN, then run that into your preamp. It would look like this:Delhi VU-936SR VHF/FM/UHF antenna
\
Pico Macom UVSJ ---> CM7777 Preamp ---> ATSC Tuner
/
UHF Antenna ---------------------2. If you haven't already bought a CM7777 there is another option that eliminates the need for any filters or combiners: a Channel Master Spartan 0264 preamp takes separate VHF-only and VHF/FM/UHF 300Ω twin-lead inputs (and has an FM Trap if needed) and gives one 75Ω coax output:Delhi VU-936SR VHF/FM/UHF antenna
\
CM0264 Preamp ---> ATSC Tuner
/
UHF Antenna ---------------------3. As I mentioned previously, a VHF-HI Bandpass Filter is another option:
Delhi VU-936SR VHF/FM/UHF antenna --- > VHF-HI Bandpass Filter
\
Reversed Splitter ---> ATSC Tuner
/
UHF Antenna(s) -----------------------------------------------

Stapeder I agree that option 2 looks best. As for 300Ω twin-lead I found a company in California that have it and they ship to Canada (I don’t know if can post address of this site), it is about $.50 US per foot. I didn’t buy anything for now. As I stated in my previous posts I’m looking at basically overhauling the whole set-up, and are looking at solid starting set-up before I dismantle the tower for servicing. Another question I’ve got is (providing that I can get 300Ω twin-lead) can I use it to mod CM4228HD instead of baluns?

Yes, the beauty of the CM0264 solution is that you don't need any baluns because the preamp does that internally.

As for the cable source you found, make sure it is shielded foam core 300Ω twin-lead. If it is shielded, please post that info in here:

http://www.digitalhome.ca/forum/showthread.php?t=78265

I just e-mailed the company to confirm if it is shielded. Will post as soon as I get reply.
PS they have picture of it on their site. If you PM me I will send you the link.

I got the e-mail back unfortunately:( they do not stock it anymore:(. Sorry for misleading you. Here is their reply
"
Thanks for the inquiry. While we used to stock 300 ohm shielded twin lead,
we only have unshielded 300 ohm twin lead antenna wire left in stock. This
wire can be ordered online by typing the part number (300B) into our part
number search engine found near the upper right hand corner of our website
(just below the word search box) and then clicking on "search". Next, you
can click onto the camera icon to see a picture of the wire (located near
the cost for these parts), or if ready to order, simply click onto the
shopping cart icon for each part number and follow the prompts to complete
your order. Our website will even generate your shipping cost depending on
your location and how fast you desire the shipment to reach you. Hope to
hear from you soon......Mark"

I'm not surprised at all, others have had the same trouble finding some. Keep searching, but you'll probably have to go with one of the other solutions.

try wintronic computers and also neutron electronics they might still have some in stock. let me know how moding a CM 4228HD to accept 300ohm goes instead of the balun.

Hello all,

Ok I am new at OTA and just wonder if my setup is currently good or if I should makes changes.

I live in Stoney Creek area in an apartment building on the 14th floor.

I am facing towards Hamilton mountain so I have a view of Buffalo to my left and downtown Hamilton to my right and Toronto is basically behind me so I don't have a clear view of the CN TOWER.

I have a Channel Master 4221HD pointed towards mainly buffalo, I have a splitter off the antenna that goes to two tv's the cables are RG6 and are about 15 to 20 feet each to tv's.

My question is with this setup do I need to add anything like a PREAMP?

I get about 20+ DTV channels at the moment, most are between 40 to 60% signal range?

Is there anything I can do to my setup to make it better?

Any advice would be great.

Mavrick

Welcome Mavr1ck!

Being in the creek, you are close to the CHCH tower, so using an amplifier could easily cause overload. If anything, you might want to add an attenuator or use another splitter (as an attenuator) and see if signal strength jumps for your BUF/TO stations. Post what stations you are actually getting and the signal strength- this will help in seeing how well you are doing. :cool:

P.S. There has been much tropo activity over the last little while, which may have given better results than normal- try doing your testing in the middle of the day, and/or before 8PM.

Hi Goforit,

Thanks for the reply...little curious what a attenuator is? where would I get that? also if I add anothet spitter where would I add that? wouldn't that cause even more db lose?

Anyways I will try your advice...just don't how to go by doing it?

I currently getTING the following:

2 - NBC - 40%
4 - CBS - 80%
5 - CBLT - 45%
7 - ABC - 95%
9 - CFTO - 40%
11 - CHCH - 95%
15 - SUN TV - 45%
17 - WQLN - 40%
23 - CW - 45%
29 - FOX - 45%
49 - WNYO - 40%

Those are great results!

An attenuator cools down specific transmissions- e.g., CHCH, so they don't interfere with getting other signals. Sometimes, very strong signals will overpower weaker signals to the point that it seems that you can't get them, but in reality they are being silenced by the stronger signals.

Read the amplifier thread for more on this. Also read this thread to see what others are getting in the Hamilton area.

Attenutors can be had from TIN LEE (from TO), but they are very expensive, therefore, I think you should try splitters as a start. Take the the coax off the antenna, add splitter, single coax out, then second splitter and single coax out to one TV. Try it first w/o and then with the one splitter, then two, and test it on a station that is not 100%, probably FOX 29 or WNYO.


Also, try doing a TVFool analysis for your address (google TVFool), but remember your exact location can hinder or help in getting signals- such as your line of sight (LOS) to the transmission towers> if you are high up, hills, buildings in the way, etc.

Hi Goforit,

Thanks for the reply...little curious what a attenuator is? where would I get that? also if I add anothet spitter where would I add that? wouldn't that cause even more db lose?

Anyways I will try your advice...just don't how to go by doing it?

I currently getTING the following:

2 - NBC - 40%
4 - CBS - 80%
5 - CBLT - 45%
7 - ABC - 95%
9 - CFTO - 40%
11 - CHCH - 95%
15 - SUN TV - 45%
17 - WQLN - 40%
23 - CW - 45%
29 - FOX - 45%
49 - WNYO - 40%
Don't do the pre-amp. Your cabling lengths are too short to need a preamp. A preamp is only if your using long cable runs from an antenna.

Try the CM4221 hacks to widen the antennas beamwidth and focus on aiming at over Lake Ontaio/Buffalo, specifically aim to find the best results for channel 29.1 or 49.1 and the rest will likely come in.

Thanks guys I will try your advice and see what results I get.

Mavr1ck, coax attenuators are cheap at The Source. See Post #14 in the OTA FAQ before you buy one.

Are the attenuators from the Source channel specific? Or would that be a notch filter ($$$)? Maybe I was thinking of the notch filter which would be very precise in knocking down the strong station, and allow the weaker ones to pass?

Are the attenuators from the Source channel specific? Or would that be a notch filter ($$$)? Maybe I was thinking of the notch filter which would be very precise in knocking down the strong station, and allow the weaker ones to pass?

If they're the same as I bought years ago, they'd be 16dB attenuation across a wide swath of spectrum. At least that's what mine is. There's an "F" female at one and "F" male connector at the other end, and is very small, roughly the size of a double female "F" barrel connector, usually used to join and extend cable runs. (adding connection points causes loss... a straight line with fewest connection points is always preferred.)

Cameron