[john5050]

Hi there and thanks for your help.

I just changed from this:

To this:

And immediately lost 15 channels. The Antenna has a preamplifier at the mast.

What am I missing, what am I doing wrong?

Thanks again.

 

[majortom]

The first device is NOT an amplifier. Rather it's a power supply FOR the amplifier that is presumably still up top at your antenna. The 2nd device IS an amplifier, and requires it's own power supply to operate.

I am guessing you just left the old preamp up top, and currently it's not having any DC power so it is dead, like an open circuit to RF.
Either:
1.) Go up top and remove the old Amplifier, and keep it with the Old Power Supply that goes with it.
Then follow the instructions that came with the new Amplifier for installing the new one.
Or
2.) Set the new amplifier aside, and put the old Power Supply back in that goes with the amp up top.
Don't waste your time trying to use both at the same time.

 

[john5050]

Thanks for the reply majortom,

I went ahead and removed the old amplifier and the power supply and hooked the antenna directly into the new powered amplifier and ported the signal out to 2 tvs and still lost 5 important channels that I got with old setup.

 

[majortom]

I have only once used the 1 in 4 out CM3414, but it seemed to work OK.
One thing you have to keep in mind is it's really designed for CABLE TV service, in that it has zero filtering from strong local FM radio. Which can interfere with Local VHF Hi TV stations. At my sister's house I had to add some external FM filtering to keep the VHF Hi TV noise floor under control. And that was with the 3414, so was a net 8 dB Gain on each port I think.

 

[ExDilbert]

Wineguard preamp will work better because it is on the mast, before any line losses. It probably has more than +11dB gain as well.

I assume the CM-3412 was purchased to split the signal. When using a mast mounted preamp, a simple splitter might work better because the extra +11dB gain could cause overload. Try both and see which works best.

 

[majortom]

I would agree with that. Here at my house, I use Winegard AP-8700 up top (it's been up there since 2009), and then spilt 8 ways where the downlead enters the basement. I then feed up to 8 TVs/Computer based TV tuners from that point throughout the house, and they all pretty much receive the same stations...
If your downlead isn't extremely long, you can use the CM412, but I would prefer the Winegard up top.
My sister's house was only like 25 to 30 ft from antenna to CM3414, so we went with that.

 

[john5050]

I was hoping for a better outcome with the new powered amplifier. I naively thought that it would solve my reception problems. It did not.Thanks for your help.

 

[rabbit73]

I was hoping for a better outcome with the new powered amplifier. I naively thought that it would solve my reception problems. It did not.Thanks for your help.

You never told us what the reception problem was that you were trying to solve, you only told us what you did.

Are there some channels that you want but are not getting? If so, we would need to know about your antenna and see a signal report to be able to help you.

 

[john5050]

I've had a love/hate relationship with OTA for the last 5 years. My 8 bay Digiwave Antenna is outside on a chimney, 30 feet up. My cable run is about 50 feet. As of yesterday, I would get 30 channels in my postal code (H4N 1P5 Montreal island). Using a 5 years old "smart" Sony tv. My local channels are not an issue. US channels come in but weaker CBS NBC are weak, Fox is very weak and PBS are excellent. According to some people who have seen my exterior setup, The 6 lane Highway behind my place or the power line 10 feet in front of the antenna is to blame. I thought the Channel master amplifier would outperform the ancient power supply I have been using. It turns out that assumption is invalid. Then again what would I know!

 

[rabbit73]

Thank you for the details about your setup, John.

I've had a love/hate relationship with OTA for the last 5 years.

Yes, I see that. Your earliest posts were in 2013, and your previous post was in 2016:

Airplane interference.
I have a new Digiwave ANT7286 Ultra Clear Digital Outdoor Antenna, mounted on the roof of my duplex in St Laurent, connected to a signal amp. and A-B splitter going to 2 tvs. I tuned the antenna to the best possible setting. I get basically all the channels I should, except ABC. I noticed severe signal loss when ever planes approach for landing. I am right under their landing next to cote vertu and highway 15.

You also said that you didn't have a preamp at the antenna just the power supply down below:

Here I am thinking that this is actually a preamp and it turns out to be just a power supply. I myself have nothing up by the Antenna. I only put up the Antenna as I bought it without adding anything to it. Does this mean I have to buy an amplifier? If so, will it really help in strengthening my signal on the weak channels. If so,Any recommendation for a good pre amp?

At this point, we are not sure if you have a preamp at the antenna or not.

This is another one of your previous threads:
Split signal at Antenna. How?
Split signal at Antenna. How?

I did a signal report for your location:
RabbitEars.Info

The problem is that the weak US channels at 148.5 degrees probably need a preamp, but your strong local channels at 113.4 degrees are most likely to overload a preamp and your tuner. If you aim your antenna at 148.5 degrees to make those channels as strong as possible, then the local channels will be weaker.

There is a great difference in strength between the US channels and the local channels. You would need a very directional antenna to favor the US channels and make the local channels even weaker.

 

[john5050]

Hey rabbit73,

Thanks for the reply. My antenna is and has always been tweaked for the 148.5 signals (NFL centric) but still always had problems getting a strong enough signal. Winegard pre amplifier on the mast. Attached pics to see power lines mentioned as possible reason for weak signals.

Thanks again!

 

[majortom]

As a test...if you can find a way to temporarily reverse the polarity of the balun connections on one of the two 4 Bays, so one antenna is 180 degrees out of phase with the other heading in to the combiner, that will place a deep Null in the boresight of the antenna, and create two major lobes roughly 20 to 30 degrees left and right of the boresight.
Then if you aimed the antenna directly at your locals, they'd actually be in the deep null, while the distant channels would hopefully be in the right hand major lobe.

If that didn't work out, you could always restore your balun connection to original,
to restore the original coverage pattern.

I currently use that trick on my db8e to place some local TV stations in a null here.
I use one lobe for Toronto, and the other for Hamilton, while the null in between is
Downtown Buffalo. Is easy for me to make adjustments from the comfort of my couch with the rotor.

 

[rabbit73]

Hey rabbit73,

Thanks for the reply. My antenna is and has always been tweaked for the 148.5 signals (NFL centric) but still always had problems getting a strong enough signal. Winegard pre amplifier on the mast. Attached pics to see power lines mentioned as possible reason for weak signals.

Thank you for the excellent photos. You DO have a Winegard preamp at the antenna, but we don't know what model. So, when you replaced the Winegard power supply with the CM3412, the preamp wasn't getting any power.

The power lines could affect the reception of the US signals, and so could the trees.

What majortom suggested is called the Two-Antenna Trick (outdoor version) by hdtvprimer.com
Stacking multiple antennas

148 - 113 = 35 degrees
The difference between the two directions is 35 degrees, so you would need a difference of 35 degrees between the null and a peak. The center-to-center spacing of the two 4-bay antennas determines the angle between the null and a peak.

Using CM4221HD's, (without modifications), the Reflector Rods limit how close the 4-Bays can be mounted. With modifications, the Null-to-Beam Angle could be increased a bit more.

Forum member holl_ands had a lot of examples on his ImageEvent, but they are gone because he hasn't paid his renewal fee there. He is an expert computer modeler of antennas, but we haven't heard from him lately; just like 300ohm who was also an expert modeler.

ImageEvent- Share your events

Horiz-Stck 2xCM4221HD Hacked - NULL BEAM

 

[john5050]

Hey guys,

So I tried the Two-Antenna Trick but no luck. I tweaked the signal as much as possible. I'm sure it will weaken when cloudy. I took a pic of my preamplifier:

Winegard HDP-269

Your help is appreciated.

 

[majortom]

That model should be more resistant to overloading, than the model I have, since it has lower gain.
Personally I would try to keep it in play until it flat out dies.
Check out the Preamp Chart in post#1 of the Preamp Thread. Dated but has specs for a comparison of yours vs mine.

Signal Amplifiers (Amps, Preamps, Distro Amps)

This Preamplifier Comparison Chart was modified by holl_ands from an original chart at Solid Signal to show Max Input for two Strong Signals. It was reformatted into PDF form by stampeder with permission of holl_ands for the digitalhome.ca OTA Forum. If you have any questions about the data in...

www.digitalhome.ca

Place a 2 way passive splitter on the downstream TV side of your Winegard power insertor, and that would essentially be like having the Channel Master out at the antenna, instead of inside the house. Then you just should address the lack of FM band filtering (would help clean up the VHF hi noise floor). I don't think any of the stations your missing are VHF however. You MIGHT benefit from a 600 MHz LTE Filter also which might reduce your UHF Noise floor if you live close by to Cellsites. Though I don't know if any Canadian wireless operators are even using the recently cleared 600 MHz spectrum yet such that it could even be a problem. But they would definitely be using 700 MHz.

When you were testing the trick, were you able to find the two distinct lobes and confirm there was a null in the middle?