: ON - Ottawa, Vanier, Gloucester, Orleans - OTA
2011-08-09, 10:58 AM
Thanks for the insight flavoie and GerryB.
I'm not sure I can accurately measure the signal loss but there's about 5 feet each of 2 coax cables leading to a splitter/combiner from the antennas, then about 5 more feet to an automatic switch (between antenna and video game/blue ray player), then a further 5 feet to the tuner/flat screen TV. There's no amplification of the signal along the way. I'm losing 4 dB maybe? After the DTV switchover I may be able to eliminate the rabbit ears stacked on top of the UHF 4 bay and the first 5 feet of cable run. This is just being used to make analogue channel 11 viewable, and improves analogue 6 and 13. I imagine without that the loss would be reduced to 2 dB.
2011-08-09, 01:29 PM
towerDB8 try the tools in Post #1 of the following thread:
Signal Amplifiers (Amps, Preamps, Distro Amps) - See Chart in Post #1 (http://www.digitalhome.ca/forum/showthread.php?t=42426)
2011-08-09, 10:15 PM
Thanks stampeder, it looks like there's more signal loss involved with my set-up than I thought. And looking at other comments here, I'd probably benefit from the use of a pre amp without much risk of overload.
2011-08-10, 07:31 PM
Towerdb8, worse case you tweak with a variable attenuator or extra splitter if you think the tuner is overloading while monitoring the signal level. Worked for me for one of my tuner which at some point was directly connected to the preamp with no splits. I saw signal increase as I was turning the attenuator dial. A 4-way splitter did the same job...
2011-08-10, 10:02 PM
Good point flavoie. That means I could probably start with the more powerfull cm 7777 and work from there, rather than the cm 7778.
2011-08-12, 11:13 AM
I'd suggest you just put your current one antenna on top of your garage if possible. I think what you're suggesting is known as "ganging" two UHF antennas pointed in different directions and that's beyond my realm to discuss but I think I've seen some threads in this forum that deal with that.
The pre-amps that I've been looking at combine a VHF and a UHF antenna with two seperate inputs, and don't seem to be intended for use with two UHF antennas.
2011-08-12, 12:01 PM
Ganging, stacking, and combining of antennas is in Post #16 in the OTA FAQ ;)
2011-08-13, 10:52 PM
towerDB8, you would do better selecting whichever preamp is closest in gain to what you need, as long as the models you're looking for have similar noise figures. Have a look at the gain difference of VHF and UHF, as well as the FM trap option which I think is a must in Ottawa. Dual inputs for VHF and UHF is also very useful when you're using a UHF antenna and wish to have the option to just add a VHF antenna to your setup later or right now.
2011-08-15, 12:07 AM
Has anyone noticed over the weekend, around 3:00am that both CBC stations and SUNTV had no signal at all?
2011-08-15, 07:39 AM
flavoie, looking at what suits my needs would direct me to the CM 7778 and I'm also looking at Wineguard, both are low noise manufacturers. As I'm only able to set up indoors, I'm using the rabbit ears as my VHF antenna so the dual inputs are usefull for me even at this time. And with Global staying on channel 6, even after they switch to digital, I also see quite a bit of value in an included FM trap.
2011-08-15, 10:05 AM
i am in orleans at bottom of the hill in a valley
i followed the advice given and roof mounted a brand new 91xg
i am using a cm7777
i am pointed at HC and CF booms in off the side
the omni's now come in no problem
the issue now is that cbc is now too strong and overpowers my hauppauge 2250 tuner
for some reason the tuner in my rca tv and my lg tv is able to attenuate the signal on its own
when i tune in it shows 100% with nothing on the screen
then it slowly drops to about 75+% and starts working
what can i do to make it work on my hauppauge 2250
how can i attenuate cbc 4.1/25.1 only
this is my main distribution for TV
2011-08-15, 10:22 AM
get omni now but cbc overpowering tuner
Since the LG and the RCA sets can handle the signal, I would suggest that you add a coaxial attenuator the the input of your Hauppauge 2250.
The RS use to sell 6 and 10 dB attenuators with F59 type connectors.
They are usefull and were reasonably inexpensive.
2011-08-15, 10:39 AM
i tried using splitters as attenuators and it didnt help
all it did was remove the omni's
the splitters had a 7db loss per output
i started with one
then 2 daisychained
then 3 daisychained
for a total of 21 db loss
this still didnt help for CBC
once all 3 were on
the omni's were gone but cbc french still comes in at 100%
someone mentioned a notch filter for 25.1 only attenuation
where can i get this?
I have heard a lot of these types of complaints with the Hauppauge tuners.
Before spending $$ in solutions, consider the cost of a new HDHomeRun as an alternate tuner. You might like it a lot.
2011-08-15, 10:58 AM
is the hdhomerun capable of attenuating a signal on its own
i was already thinking about getting one
but someone said the tunner was too sensitive
id really like to get one but dont want top waste 150$ and end up with same problem
The latest model of the HDHomeRun came out just a couple of months ago. I read that the new HDHomeRun included the most modern chipset, etc.
I have the older HDHomeRun dual (the white one). I am happy with it but I can confirm it will drop weak channels before my TVs do. But it's pretty good.
I haven't tried the 2250 so I can't compare. But I like the HDHomeRun and if/when I need to add/replace network tuners, I'll buy one of the new dual HDHomeRuns.
2011-08-15, 11:35 AM
will your hdhomerun attenuate a channel that is too strong though?
in order to be able to view it
That kind of technology is built-in to all ATSC tuners, as I understand it. It's a matter of how well a given tuner is able to handle errors, weak signal, overload, multipath, etc. etc.
I have read that the Hauppauge 2250 is not as capable as other ATSC tuners --- only anecdotal comments from forum posters. But when I was making my decision between HDHomeRun and Hauppauge 2250 last year, it was those comments that I had read that steered me toward the HDHomeRun -- a decision I don't regret.
I am not an authority on this matter as I have no way to do a comparison between the two, but I can tell you I'm happy with my HDHomeRun and that I have read other people before with the same complaint that you're experiencing.
And before you go spending money on attenuators, splitters, etc. I just wanted to point out that a simpler (although more expensive) solution might be to replace the real cause of the problem -- a tuner that does not seem to handle variable signal strengths well.
2011-08-15, 12:12 PM
I'm in Old Ottawa South (Bank and the canal) and I am getting Global on 6.1 at about 45% signal strength. CBOT-DT and CBOTF-DT are stilling coming in fine on 4.1 and 9.1 at about 75%. Sorry I can't give you the actual channel numbers, my TV doesn't report it.
Edited to add: I have an 8 bay antenna from they-who-cannot-be-named (sorry, I was ignorant when I bought it), pointed at HC.
2011-08-15, 03:25 PM
charettepa, could you post your tvfool report please ? You have a very directional antenna, maybe it is multipath handling. Determining the angles between CF and HC vs your current orientation, the signal levels, plus looking at the XG91 charts may help.
I have the Hauppauge 2250 and used a variable attenuator (0-20dB). I could see what extra attenuation did in real-time when I tuned to my weakest channel, WNYF. The locals also went stronger after attenuation.
My best PC tuner is the Hauppauge 950Q. I also had the 1600 and 1800 and none of them had any problem with overloading when I used the cm7777 with a single tuner on the input. The 2250 is more sensitive to overloading.
Lastly, do you have just the AD XG91 & cm7777 on the roof, then power inserter, then splitter(s) to your 2250 ?