pete, what's your TVFool report show?

Surprised that 13 can be that difficult. From Montreal, it has an ERP of 21. That should be pretty ideal (I put a height of 30feet in the report I did).

I think you mean TVFool Noise Margin, not ERP.

The ERP in the direction on Montreal is around 1 kW or so.

You might think that a 21 dB NM is good enough for LOS signal on VHF Hi, but there are several mitigating factors here:

1. adjacent channel NTSC on channel 12, about 50 dB higher in level
2. Several high power FM stations in the 105 to 108 MHz range , whose second harmonic can interfere with reception of channel 13.
3. co-channel NTSC station in Trois Rivieres can afect some people.

Hi Folks, long time lurker here.

Has anyone seen any weakness on WPTZ over the last few days? I'm not seeing drop outs on the tv but it's coming in a little weaker than WFFF for me and my hdhomerun can't seem to get much quality from the signal.

BTW, around 01:30 this morning, 6, 46 and 12 were all very weak (just snow). So I scanned and got WVNY on a reflectorless M4 + CM7778. It was nice to finally see it :)

Hi, I just build a GH10 and a bowtie antenna. I live near Montreal Canada and get those channel:

With the GH10 at N-E (45 degree):

2 CBFT
5 WPTZ
6 CBMT
17 CIVM
22 WVNY
35 CFJP
57 WCFE

With the bowtie S-E (135 degree):

3 WCAX
33 VPT
44 WFFF
57 WCFE

Then I Combined both antennas with a backward splitter, everything went fine without phasing problem but unfortunatly I lost channel 3 and 44. So after all the reading, I guest I need a preamp !!!

So this is my question:

I think I need to install the preamp after the splitter but in the preamplifier chart, the input and output ohms gets me confused. I believe I need a preamp with a 75 ohms input and 75 ohms output because the matching transformer transform 300 ohms to 75 ohms. Am I right ???

I want to buy the channel master 7778, is it a good choice for my problem ??

Thanks

Post your TVFool image. I think you must have very strong signals for that combination to work. A strong preamp most likely will make the situation worse.

I believe I need a preamp with a 75 ohms input and 75 ohms output because the matching transformer transform 300 ohms to 75 ohms. Am I right ???
Yes, the output of the balun is 75 ohms, so you need 75 ohms in and out on the preamp.

Running 2 RG6s and using a 75 ohm coax switch would be cheaper and will work better.

This my TvFool image link :



http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dda323fd6ae41e1

Yeah, a preamp will cause you problems. Like ScaryBob said, run two coax downleads (one from each antenna) into an A-B switch at the TV. I would point the GH10 at the more distant stations.

300ohms, where would you point the GH10 ??? Using my compass, I did a scan every 45 degrees and right now at 45 degrees ( north-est), it's the best position, I think for the GH10!!

Am I missing something ??? I'm not a pro !!!

The CFJP-DT (35) channel sometime comes and go, it's the only channel I'm missing right now.


UPDATE I just turn the bowtie about 15 degrees (now at 150 degrees) almost south and the 3 and 44 came back. Yeah !!! If only 35 would be steady...

UPDATE I just turn the bowtie about 15 degrees (now at 150 degrees) almost south and the 3 and 44 came back. Yeah !!! If only 35 would be steady...
I would reverse the position of the bowtie and GH10, as the GH10 has higher gain. 35.1 is a strong station, maybe too strong for the GH10.
If using a compass, use the magnetic degrees from TVFool.

Thanks a lot, gonna try your set up tomorrow !!! I will give you the result.

I tried your suggestion 300ohms, but not better than my first set-up, so gonna live with the fact that 35.1 come and go.

Guizmo,
Is it possible that Mount Royal is blocking your reception of V on channel 42 ? Their transmitter is at the corner of Sherbrooke and Parc Lafontaine.
Yagi

His TV Fool report suggests he has LOS to CFJP-DT.

Sometimes TV Fool is not perfectly accurate and maybe CFJP is not perfectly LOS. That could explain the intermettent nature of his reception.

And of course, there could be man-made obstructions, too, which are not accounted for on TV Fool. Looking at the vectors on his TV Fool report, I can imagine the entire Montreal downtown core blocking CFJP-DT's signal …

Hi, HWP you say there are other things you can try for the sound problem on 35.1 !

What are they beside atenuator.

This my set-up:

DIY GH10 and a bowtie combine together, the GH10 at 40 degrees and the bowtie at 156 degress on my compass. No preamp or booster, just a splitter backward to combine the two antennas. With this set-up I get:

2 CBFT-D
3 WCAX-HD
5 WPTZ-HD
6 CBMT-DT
17 CIVM-HD
22 WVNY-HD
33 VPT-HD
35 CFJP-TR
44 WFFF-HD
57 WCFE-HD

and all they're sub channel.

Interesting situation over the weekend. Like most, I get everything (gound floor, antenna inside) except for WVNY. This weekend, on a 2x6 24 inches long, I put together a crude bowtie (8 wiskers 14 inches long/7 inches apart) and laid it flat on its back on top of the fence outside (15 ft RG6, no amp or preamp). Nothing came in except for CBC and WVNY (83%). Happy..yes! Puzzled.. even more.

I'm going to continue to montinor over the week, then find a way to combine the feed if it holds up

Cheers, K!

Did you build it following mclapp's M4 plans:

Bow Tie TV Antenna Designs (mclapp's M4 featured) (http://www.digitalhome.ca/forum/showthread.php?t=100137)

And why did you lie it flat on its back?

Hi Stamperder... I built it using mclapp's by memory (only 4 whiskers per side). It was just too d*** cold to mount/set it up properly so I layed it on top of the fence (wood fence 7 feet high) and ran back in (-24 at the time).

Cheers, K!

Been having trouble with reception of WPTZ 5.1 this past month or so. The problem comes and goes and manifests itself only on the tuner of my Tivo Series 4 tuner. No reception problems at all on the tuner of my Sharp LCD TV.

Tonight, I just witnessed a very strange event. During the local Plattsburgh evening news, the signal is very strong but as soon as it switched to the national NBC feed for the evening show Jeopardy, the signal became heavily pixelated.

I just don't get it... All the other channels WCAX, WFFF and even ABC come in strong no problem. I'm on the south shore close to Candiac and my CM4228/Custom Yagi VHF13 antennea combo are mounted in the attic.

WPTZ is normally one of the stations with the strongest signal, why is it giving me so many problems when even the weak ones like ABC work just fine?

And no, it's not snow on the roof.. I checked, there isn't any. Tried to reset the Tivo... that's not it either. I don't know what to think anymore.