The UVSJ is a prime candidate as the point of failure.

Question: do your VHF channels really require the RC pre-amp? If not, then put the RC preamp on the UHF antenna side of the UVSJ (assuming it can pass DC power through to the pre-amp).

Also, your location shows as Montreal, which is the one and only area I know of where people actually experience overload for real.

-ml

I bought the RC pre-amp to increase reception for WVNY on channel 13. It's a bit of a hard-to-get station in Montreal.

I'll try using the RC pre-amp with the VHF antenna alone and if reception is worse than with the CM 7777 I'll know that it's a pre-amp issue.

Yes, lots of megawatt UHF stations in Montreal. But they don't upset my CM 7777, so I don't think they should upset the RC 9254 either...

STL

I have some questions maybe someone can clarify this. In this post #210 (http://www.digitalhome.ca/forum/showpost.php?p=642349&postcount=210) two parameters for the amplifiers are mentioned: input and output levels. I am thinking between a pre-amplifier and a drop amplifier. For drop amplifiers I got some parameters from the manufacturer datasheet.

My situation: I receive about 19 digital channels and some of them are quite strong signals. The antenna is connected to the TV with a 100 feet RG6 cable. For the moment my GE amplifier helps me getting FOX, but the noise level is high and I would like to improve this.

What would be recommended in my case pre-amplifier or drop amplifier?

Running a CM 7778 and 4228HD.

CN Tower is about 35 miles from me- north.

It seems, that when I aim the antenna away from Toronto- to the west, reception is better- is this a sign of overload?

goforit, given the weather in your location and huge tropo activity lately the lake might be affecting things, so in the autumn it will be interesting to see if you still have that offset.

Also given the enjoyment you are getting with tweaking your OTA gear and exploring the issues here in our threads, you might want to invest in one of these if you haven't already since they can be very revealing to analyze odd effects: Signal Analyzers and Meters for OTA (http://www.digitalhome.ca/forum/showthread.php?t=96705). Some are super expensive, but there are much cheaper ones that can also help to "see" your reception in better ways.

xebbmw, regarding the amps in Post #210 all but the Winegard are relatively expensive, so check the pricing to see if they fit your budget.The antenna is connected to the TV with a 100 feet RG6 cableDo you actually use/need all of that length? Just that length alone is costing you about 6dB of signal, so is there any way you can cut it down to minimal with a tiny bit of flex room near any joining points? I would say do that first and test the results, then we can talk about amplification if problems endure.

goforit, given the weather in your location and huge tropo activity lately the lake might be affecting things, so in the autumn it will be interesting to see if you still have that offset.

Also given the enjoyment you are getting with tweaking your OTA gear and exploring the issues here in our threads, you might want to invest in one of these if you haven't already since they can be very revealing to analyze odd effects: Signal Analyzers and Meters for OTA (http://www.digitalhome.ca/forum/showthread.php?t=96705). Some are super expensive, but there are much cheaper ones that can also help to "see" your reception in better ways.
Hi Stampeder:

I doubt the lake thing will win my wife over- again the signal was inconsistent last night and she was not happy.

Yah, I might get the meter, if it's not too $$$. I keep tweaking my set-up, b/c (I guess) I'm not satisfied yet, and it doesn't help I want OTA for two TVs. Anyways, I'll consider the meter, but this weekend- I have some major tweaking going on. I'm gonna stack two 4221HDs that have been hacked and see whappens for Buffalo, and maybe add another 4221HD for Toronto.

Thanks and cheers!

G.

stampeder / 300ohm,

FYI, apparently the CM0264 is now DISCONTINUED according to the major OTA gear retailer here in Montreal...

That is true, balm, but the major On Line OTA Gear vendors (http://www.digitalhome.ca/forum/showthread.php?t=78265) in the U.S. have plenty of them. :)

xebbmw, regarding the amps in Post #210 all but the Winegard are relatively expensive, so check the pricing to see if they fit your budget.

Originally Posted by xebbmw
The antenna is connected to the TV with a 100 feet RG6 cable


Do you actually use/need all of that length? Just that length alone is costing you about 6dB of signal, so is there any way you can cut it down to minimal with a tiny bit of flex room near any joining points? I would say do that first and test the results, then we can talk about amplification if problems endure.

stampeder: Maybe my question was not clear, I was not referring exactly to the pre-amplifiers that are mentioned in Post #210. What are the parameters that need to be considered when comparing a pre-amplifier with a drop amplifier beside gain and noise factor. Drop amplifier have mentioned in datasheet the maximum output levels.

I might be able to cut some cable and make it shorter. Would be good to have it below 50 feet, but I am not really sure.

If your cable run to the first distribution point is over 50' and you intended to split the signal a preamp is all you need. You will be able to split the signal 4 to 5 times with no signal loss so no further dist amp is needed.

If your cable run to the first point is less than 50' and the reception is good then all you need is the drop amp.

Good luck.

With the Channel Master and Winegard preamps I've used over the years the output signal was only available as long as the power injector was operating. This meant that in a power outage a battery powered TV could not benefit from using a big preamped rooftop antenna. I always found this to be an irritating shortcoming and an undesirable reality of such preamps, especially for emergency situations in which OTA TV can and should shine.

Most professional CATV/MATV gear allows signal passthrough separate of power injection, and on the high price consumer side Televes preamps from Spain do not have this power outage limitation. I don't know of other consumer preamps that do have continuous signal passthrough, actually. Do the KitzTech and RC preamps allow signal passthrough if the power goes out?

Just a complaint I'd like to see addressed by preamp manufacturers! :mad:

A Home Fix For 24/7Preamp Power Uptime

A consumer who is comfortable with simple electronics can easily create a solution in which the power injector is wired in a parallel circuit to 1 or 2 suitable batteries before feeding the preamp. Note that the battery circuit MUST provide the same voltage as the power injector (typically 18VDC) and beware that the power injector might not be able to simultaneously power the preamp while charging the batteries, possibly leading to burnout, so test, test, test! It might even be necessary to use an automated or manual A-B switch between the power injector and the batteries, which are continually charged by their own AC adapter. Also it will be necessary to shield any exposed soldered joints. Do nor use an unregulated DC power supply (such as a cheap car battery charger) with preamps or else their electronic components could burn out.

In these simple designs, when the injector fails the battery circuit continues feeding the preamp:*** BEFORE ***
(No power outage protection)


DC POS ----> Coax centre conductor to Preamp
/
AC power <---> Power Injector
\
DC NEG ---> Coax outer shield to Preamp



*** AFTER ***
(Power Injector Also Recharging Battery Circuit)


DC POS ----> Battery POS --->
/ \
/ Coax centre conductor to Preamp
AC power <---> Power Injector
\ Coax outer shield to Preamp
\ /
DC NEG ---> Battery NEG --->



*** AFTER ***
(Separate Power Injector & Battery Chargers)


DC POS ----------->
/ Battery POS ---> ] A-B Switch POS lead \
/ ^ |
/ | v
/ + | Coax centre conductor to Preamp
AC power <---> Power Injector AC adapter
\ - | Coax outer shield to Preamp
\ | ^
\ v |
\ Battery NEG ---> ] NEG leads joined ---/
DC NEG ---------->

With the Channel Master and Winegard preamps I've used over the years the output signal was only available as long as the power injector was operating.
Same here, and on the Radio Shack ones as well. No power, severe signal loss.

RVs are in the same situation....A Solar Cell with Battery Charger is the solution:
http://www.batterystuff.com/solar-chargers/

For daytime use, there are also Solar Cells not equipped with a Battery Charger:
http://www.ccrane.com/more-categories/alternative-power/index.aspx
Buy a Solar Cell with a rating at least twice what you "need" for overcast days.

A battery provides operation long after sunset and stabilizes the output voltage.
As I recall, Preamps take about 100-200 mA at 18 VDC (W-G) or 15 VDC (C-M).
That's about 2-4 Watts. Typical, fully charged battery should be 14+ volts and
Preamps are designed for significant voltage drop up the coax....

===========================================
Or get enough Car Batteries on trickle chargers to last a few days.....

The 1dB NF KitzTech amp (admittedly not a pre-amp, but usable as such with some fuss) operates at about 0.5W of power (80mA @ 6VDC).

Or get enough Car Batteries on trickle chargers to last a few days...But make sure it is a regulated DC trickle charger (many of them are not!) to safeguard the delicate electronics of the preamp. :)

mlord, does the KitzTech still passthrough any signal without the power connected?

mlord, does the KitzTech still passthrough any signal without the power connected?
Dunno -- it's out on loan to another forum member for the weekend.

Mmm.. the MythTV box just powered itself up a few minutes ago to record the FIFA C.C. Final game, so I might now be able to check on what the RC preamp does without power.

It'll take a bit of fuss/time, though, as none of the channels currently programmed for that pathway can be received without full amplification. So I'll switch it into another path and then test it.

-ml

I might now be able to check on what the RC preamp does without power.
Okay, it doesn't *block* reception, but things don't look so good with it powered off.

The stations that the RC-amplified antenna are pointed at are generally weak for reception, and are actually about 20 degrees off from where the antenna is pointed (it is pointed at WNPI-DT, which is impossible sans pre-amp). With the RC preamp powered on, they all come in strong and mostly clear, including the analog UHF stations.

With the RC amp powered off, the weaker analog stations vanished, others had poor picture but good audio, and some others looked like I remember them looking before installing the pre-amp. I didn't even try for the two digital stations in that general direction (the very weak Omni's).

Despite being pointed quite wrongly, and having the pre-amp powered off, the array did still manage to pick up the football (soccer) championship on CBC (about 10 degrees off axis from the rear of the dual PR8800 array), though with heavy pixelation.

Dunno what that all shows, but I've plugged it back in again now. :)

So the RC passes the test as I described in Post #1011: in a power outage it would still be possible to use one's RC-preamped antenna with a battery powered TV even if there is no power to the preamp.

Add one more benefit to the RC's list. :)